2005-04-16 18:20:36 -04:00
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/*
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* linux/arch/i386/entry.S
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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/*
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* entry.S contains the system-call and fault low-level handling routines.
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* This also contains the timer-interrupt handler, as well as all interrupts
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* and faults that can result in a task-switch.
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*
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* NOTE: This code handles signal-recognition, which happens every time
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* after a timer-interrupt and after each system call.
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*
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* I changed all the .align's to 4 (16 byte alignment), as that's faster
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* on a 486.
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*
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* Stack layout in 'ret_from_system_call':
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* ptrace needs to have all regs on the stack.
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* if the order here is changed, it needs to be
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* updated in fork.c:copy_process, signal.c:do_signal,
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* ptrace.c and ptrace.h
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*
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* 0(%esp) - %ebx
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* 4(%esp) - %ecx
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* 8(%esp) - %edx
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* C(%esp) - %esi
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* 10(%esp) - %edi
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* 14(%esp) - %ebp
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* 18(%esp) - %eax
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* 1C(%esp) - %ds
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* 20(%esp) - %es
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[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
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* 24(%esp) - %gs
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* 28(%esp) - orig_eax
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* 2C(%esp) - %eip
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* 30(%esp) - %cs
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* 34(%esp) - %eflags
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* 38(%esp) - %oldesp
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* 3C(%esp) - %oldss
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2005-04-16 18:20:36 -04:00
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*
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* "current" is in register %ebx during any slow entries.
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*/
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#include <linux/linkage.h>
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#include <asm/thread_info.h>
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2006-07-03 03:24:43 -04:00
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#include <asm/irqflags.h>
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2005-04-16 18:20:36 -04:00
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#include <asm/errno.h>
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#include <asm/segment.h>
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#include <asm/smp.h>
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#include <asm/page.h>
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#include <asm/desc.h>
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2006-12-06 20:14:01 -05:00
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#include <asm/percpu.h>
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2006-06-26 07:57:44 -04:00
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#include <asm/dwarf2.h>
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2005-04-16 18:20:36 -04:00
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#include "irq_vectors.h"
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2006-12-06 20:14:08 -05:00
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/*
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* We use macros for low-level operations which need to be overridden
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* for paravirtualization. The following will never clobber any registers:
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* INTERRUPT_RETURN (aka. "iret")
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* GET_CR0_INTO_EAX (aka. "movl %cr0, %eax")
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* ENABLE_INTERRUPTS_SYSEXIT (aka "sti; sysexit").
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*
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* For DISABLE_INTERRUPTS/ENABLE_INTERRUPTS (aka "cli"/"sti"), you must
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* specify what registers can be overwritten (CLBR_NONE, CLBR_EAX/EDX/ECX/ANY).
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* Allowing a register to be clobbered can shrink the paravirt replacement
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* enough to patch inline, increasing performance.
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*/
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2005-04-16 18:20:36 -04:00
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#define nr_syscalls ((syscall_table_size)/4)
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CF_MASK = 0x00000001
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TF_MASK = 0x00000100
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IF_MASK = 0x00000200
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DF_MASK = 0x00000400
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NT_MASK = 0x00004000
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VM_MASK = 0x00020000
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#ifdef CONFIG_PREEMPT
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2006-12-06 20:14:08 -05:00
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#define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF
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2005-04-16 18:20:36 -04:00
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#else
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2006-12-06 20:14:08 -05:00
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#define preempt_stop(clobbers)
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2005-04-16 18:20:36 -04:00
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#define resume_kernel restore_nocheck
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#endif
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2006-07-03 03:24:43 -04:00
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.macro TRACE_IRQS_IRET
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#ifdef CONFIG_TRACE_IRQFLAGS
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2006-12-06 20:14:02 -05:00
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testl $IF_MASK,PT_EFLAGS(%esp) # interrupts off?
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2006-07-03 03:24:43 -04:00
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jz 1f
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TRACE_IRQS_ON
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1:
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#endif
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.endm
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2006-06-27 05:53:48 -04:00
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#ifdef CONFIG_VM86
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#define resume_userspace_sig check_userspace
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#else
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#define resume_userspace_sig resume_userspace
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#endif
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2005-04-16 18:20:36 -04:00
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#define SAVE_ALL \
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cld; \
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[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
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pushl %gs; \
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CFI_ADJUST_CFA_OFFSET 4;\
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/*CFI_REL_OFFSET gs, 0;*/\
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2005-04-16 18:20:36 -04:00
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pushl %es; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET 4;\
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/*CFI_REL_OFFSET es, 0;*/\
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2005-04-16 18:20:36 -04:00
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pushl %ds; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET 4;\
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/*CFI_REL_OFFSET ds, 0;*/\
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2005-04-16 18:20:36 -04:00
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pushl %eax; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET 4;\
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CFI_REL_OFFSET eax, 0;\
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2005-04-16 18:20:36 -04:00
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pushl %ebp; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET 4;\
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CFI_REL_OFFSET ebp, 0;\
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2005-04-16 18:20:36 -04:00
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pushl %edi; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET 4;\
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CFI_REL_OFFSET edi, 0;\
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2005-04-16 18:20:36 -04:00
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pushl %esi; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET 4;\
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CFI_REL_OFFSET esi, 0;\
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2005-04-16 18:20:36 -04:00
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pushl %edx; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET 4;\
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CFI_REL_OFFSET edx, 0;\
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2005-04-16 18:20:36 -04:00
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pushl %ecx; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET 4;\
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CFI_REL_OFFSET ecx, 0;\
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2005-04-16 18:20:36 -04:00
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pushl %ebx; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET 4;\
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CFI_REL_OFFSET ebx, 0;\
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2005-04-16 18:20:36 -04:00
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movl $(__USER_DS), %edx; \
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movl %edx, %ds; \
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[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
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movl %edx, %es; \
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movl $(__KERNEL_PDA), %edx; \
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movl %edx, %gs
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2005-04-16 18:20:36 -04:00
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#define RESTORE_INT_REGS \
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popl %ebx; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET -4;\
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CFI_RESTORE ebx;\
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2005-04-16 18:20:36 -04:00
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popl %ecx; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET -4;\
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CFI_RESTORE ecx;\
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2005-04-16 18:20:36 -04:00
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popl %edx; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET -4;\
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CFI_RESTORE edx;\
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2005-04-16 18:20:36 -04:00
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popl %esi; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET -4;\
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CFI_RESTORE esi;\
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2005-04-16 18:20:36 -04:00
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popl %edi; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET -4;\
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CFI_RESTORE edi;\
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2005-04-16 18:20:36 -04:00
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popl %ebp; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET -4;\
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CFI_RESTORE ebp;\
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popl %eax; \
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CFI_ADJUST_CFA_OFFSET -4;\
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CFI_RESTORE eax
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2005-04-16 18:20:36 -04:00
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#define RESTORE_REGS \
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RESTORE_INT_REGS; \
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1: popl %ds; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET -4;\
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/*CFI_RESTORE ds;*/\
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2005-04-16 18:20:36 -04:00
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2: popl %es; \
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2006-06-26 07:57:44 -04:00
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CFI_ADJUST_CFA_OFFSET -4;\
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/*CFI_RESTORE es;*/\
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[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
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3: popl %gs; \
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CFI_ADJUST_CFA_OFFSET -4;\
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/*CFI_RESTORE gs;*/\
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.pushsection .fixup,"ax"; \
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2005-04-16 18:20:36 -04:00
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4: movl $0,(%esp); \
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
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jmp 1b; \
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5: movl $0,(%esp); \
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2005-04-16 18:20:36 -04:00
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jmp 2b; \
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
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6: movl $0,(%esp); \
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jmp 3b; \
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2005-04-16 18:20:36 -04:00
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|
.section __ex_table,"a";\
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.align 4; \
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
|
|
|
.long 1b,4b; \
|
|
|
|
|
.long 2b,5b; \
|
|
|
|
|
.long 3b,6b; \
|
|
|
|
|
.popsection
|
2005-04-16 18:20:36 -04:00
|
|
|
|
2006-06-26 07:57:44 -04:00
|
|
|
#define RING0_INT_FRAME \
|
|
|
|
|
CFI_STARTPROC simple;\
|
2006-09-26 04:52:41 -04:00
|
|
|
CFI_SIGNAL_FRAME;\
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_DEF_CFA esp, 3*4;\
|
|
|
|
|
/*CFI_OFFSET cs, -2*4;*/\
|
|
|
|
|
CFI_OFFSET eip, -3*4
|
|
|
|
|
|
|
|
|
|
#define RING0_EC_FRAME \
|
|
|
|
|
CFI_STARTPROC simple;\
|
2006-09-26 04:52:41 -04:00
|
|
|
CFI_SIGNAL_FRAME;\
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_DEF_CFA esp, 4*4;\
|
|
|
|
|
/*CFI_OFFSET cs, -2*4;*/\
|
|
|
|
|
CFI_OFFSET eip, -3*4
|
|
|
|
|
|
|
|
|
|
#define RING0_PTREGS_FRAME \
|
|
|
|
|
CFI_STARTPROC simple;\
|
2006-09-26 04:52:41 -04:00
|
|
|
CFI_SIGNAL_FRAME;\
|
2006-12-06 20:14:02 -05:00
|
|
|
CFI_DEF_CFA esp, PT_OLDESP-PT_EBX;\
|
|
|
|
|
/*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/\
|
|
|
|
|
CFI_OFFSET eip, PT_EIP-PT_OLDESP;\
|
|
|
|
|
/*CFI_OFFSET es, PT_ES-PT_OLDESP;*/\
|
|
|
|
|
/*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/\
|
|
|
|
|
CFI_OFFSET eax, PT_EAX-PT_OLDESP;\
|
|
|
|
|
CFI_OFFSET ebp, PT_EBP-PT_OLDESP;\
|
|
|
|
|
CFI_OFFSET edi, PT_EDI-PT_OLDESP;\
|
|
|
|
|
CFI_OFFSET esi, PT_ESI-PT_OLDESP;\
|
|
|
|
|
CFI_OFFSET edx, PT_EDX-PT_OLDESP;\
|
|
|
|
|
CFI_OFFSET ecx, PT_ECX-PT_OLDESP;\
|
|
|
|
|
CFI_OFFSET ebx, PT_EBX-PT_OLDESP
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(ret_from_fork)
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_STARTPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %eax
|
2006-07-30 06:04:08 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
call schedule_tail
|
|
|
|
|
GET_THREAD_INFO(%ebp)
|
|
|
|
|
popl %eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET -4
|
2006-09-18 19:20:40 -04:00
|
|
|
pushl $0x0202 # Reset kernel eflags
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
popfl
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET -4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp syscall_exit
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Return to user mode is not as complex as all this looks,
|
|
|
|
|
* but we want the default path for a system call return to
|
|
|
|
|
* go as quickly as possible which is why some of this is
|
|
|
|
|
* less clear than it otherwise should be.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
# userspace resumption stub bypassing syscall exit tracing
|
|
|
|
|
ALIGN
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_PTREGS_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
ret_from_exception:
|
2006-12-06 20:14:08 -05:00
|
|
|
preempt_stop(CLBR_ANY)
|
2005-04-16 18:20:36 -04:00
|
|
|
ret_from_intr:
|
|
|
|
|
GET_THREAD_INFO(%ebp)
|
2006-06-27 05:53:48 -04:00
|
|
|
check_userspace:
|
2006-12-06 20:14:02 -05:00
|
|
|
movl PT_EFLAGS(%esp), %eax # mix EFLAGS and CS
|
|
|
|
|
movb PT_CS(%esp), %al
|
2006-09-26 04:52:39 -04:00
|
|
|
andl $(VM_MASK | SEGMENT_RPL_MASK), %eax
|
|
|
|
|
cmpl $USER_RPL, %eax
|
|
|
|
|
jb resume_kernel # not returning to v8086 or userspace
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
|
|
|
|
2005-04-16 18:20:36 -04:00
|
|
|
ENTRY(resume_userspace)
|
2006-12-06 20:14:08 -05:00
|
|
|
DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
|
2005-04-16 18:20:36 -04:00
|
|
|
# setting need_resched or sigpending
|
|
|
|
|
# between sampling and the iret
|
|
|
|
|
movl TI_flags(%ebp), %ecx
|
|
|
|
|
andl $_TIF_WORK_MASK, %ecx # is there any work to be done on
|
|
|
|
|
# int/exception return?
|
|
|
|
|
jne work_pending
|
|
|
|
|
jmp restore_all
|
|
|
|
|
|
|
|
|
|
#ifdef CONFIG_PREEMPT
|
|
|
|
|
ENTRY(resume_kernel)
|
2006-12-06 20:14:08 -05:00
|
|
|
DISABLE_INTERRUPTS(CLBR_ANY)
|
2005-04-16 18:20:36 -04:00
|
|
|
cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
|
|
|
|
|
jnz restore_nocheck
|
|
|
|
|
need_resched:
|
|
|
|
|
movl TI_flags(%ebp), %ecx # need_resched set ?
|
|
|
|
|
testb $_TIF_NEED_RESCHED, %cl
|
|
|
|
|
jz restore_all
|
2006-12-06 20:14:02 -05:00
|
|
|
testl $IF_MASK,PT_EFLAGS(%esp) # interrupts off (exception path) ?
|
2005-04-16 18:20:36 -04:00
|
|
|
jz restore_all
|
|
|
|
|
call preempt_schedule_irq
|
|
|
|
|
jmp need_resched
|
|
|
|
|
#endif
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
/* SYSENTER_RETURN points to after the "sysenter" instruction in
|
|
|
|
|
the vsyscall page. See vsyscall-sysentry.S, which defines the symbol. */
|
|
|
|
|
|
|
|
|
|
# sysenter call handler stub
|
|
|
|
|
ENTRY(sysenter_entry)
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_STARTPROC simple
|
2006-09-26 04:52:41 -04:00
|
|
|
CFI_SIGNAL_FRAME
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_DEF_CFA esp, 0
|
|
|
|
|
CFI_REGISTER esp, ebp
|
2005-04-16 18:20:36 -04:00
|
|
|
movl TSS_sysenter_esp0(%esp),%esp
|
|
|
|
|
sysenter_past_esp:
|
2006-07-03 03:24:43 -04:00
|
|
|
/*
|
|
|
|
|
* No need to follow this irqs on/off section: the syscall
|
|
|
|
|
* disabled irqs and here we enable it straight after entry:
|
|
|
|
|
*/
|
2006-12-06 20:14:08 -05:00
|
|
|
ENABLE_INTERRUPTS(CLBR_NONE)
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $(__USER_DS)
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
/*CFI_REL_OFFSET ss, 0*/
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %ebp
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
CFI_REL_OFFSET esp, 0
|
2005-04-16 18:20:36 -04:00
|
|
|
pushfl
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $(__USER_CS)
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
/*CFI_REL_OFFSET cs, 0*/
|
[PATCH] vdso: randomize the i386 vDSO by moving it into a vma
Move the i386 VDSO down into a vma and thus randomize it.
Besides the security implications, this feature also helps debuggers, which
can COW a vma-backed VDSO just like a normal DSO and can thus do
single-stepping and other debugging features.
It's good for hypervisors (Xen, VMWare) too, which typically live in the same
high-mapped address space as the VDSO, hence whenever the VDSO is used, they
get lots of guest pagefaults and have to fix such guest accesses up - which
slows things down instead of speeding things up (the primary purpose of the
VDSO).
There's a new CONFIG_COMPAT_VDSO (default=y) option, which provides support
for older glibcs that still rely on a prelinked high-mapped VDSO. Newer
distributions (using glibc 2.3.3 or later) can turn this option off. Turning
it off is also recommended for security reasons: attackers cannot use the
predictable high-mapped VDSO page as syscall trampoline anymore.
There is a new vdso=[0|1] boot option as well, and a runtime
/proc/sys/vm/vdso_enabled sysctl switch, that allows the VDSO to be turned
on/off.
(This version of the VDSO-randomization patch also has working ELF
coredumping, the previous patch crashed in the coredumping code.)
This code is a combined work of the exec-shield VDSO randomization
code and Gerd Hoffmann's hypervisor-centric VDSO patch. Rusty Russell
started this patch and i completed it.
[akpm@osdl.org: cleanups]
[akpm@osdl.org: compile fix]
[akpm@osdl.org: compile fix 2]
[akpm@osdl.org: compile fix 3]
[akpm@osdl.org: revernt MAXMEM change]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Cc: Gerd Hoffmann <kraxel@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 05:53:50 -04:00
|
|
|
/*
|
|
|
|
|
* Push current_thread_info()->sysenter_return to the stack.
|
|
|
|
|
* A tiny bit of offset fixup is necessary - 4*4 means the 4 words
|
|
|
|
|
* pushed above; +8 corresponds to copy_thread's esp0 setting.
|
|
|
|
|
*/
|
|
|
|
|
pushl (TI_sysenter_return-THREAD_SIZE+8+4*4)(%esp)
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
CFI_REL_OFFSET eip, 0
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Load the potential sixth argument from user stack.
|
|
|
|
|
* Careful about security.
|
|
|
|
|
*/
|
|
|
|
|
cmpl $__PAGE_OFFSET-3,%ebp
|
|
|
|
|
jae syscall_fault
|
|
|
|
|
1: movl (%ebp),%ebp
|
|
|
|
|
.section __ex_table,"a"
|
|
|
|
|
.align 4
|
|
|
|
|
.long 1b,syscall_fault
|
|
|
|
|
.previous
|
|
|
|
|
|
|
|
|
|
pushl %eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
SAVE_ALL
|
|
|
|
|
GET_THREAD_INFO(%ebp)
|
|
|
|
|
|
|
|
|
|
/* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
|
[PATCH] UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage
Jeff Dike <jdike@addtoit.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>,
Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL
except that the kernel does not execute the requested syscall; this is useful
to improve performance for virtual environments, like UML, which want to run
the syscall on their own.
In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry
and on exit, and each time you also have two context switches; with SYSEMU you
avoid the 2nd stop and so save two context switches per syscall.
Also, some architectures don't have support in the host for changing the
syscall number via ptrace(), which is currently needed to skip syscall
execution (UML turns any syscall into getpid() to avoid it being executed on
the host). Fixing that is hard, while SYSEMU is easier to implement.
* This version of the patch includes some suggestions of Jeff Dike to avoid
adding any instructions to the syscall fast path, plus some other little
changes, by myself, to make it work even when the syscall is executed with
SYSENTER (but I'm unsure about them). It has been widely tested for quite a
lot of time.
* Various fixed were included to handle the various switches between
various states, i.e. when for instance a syscall entry is traced with one of
PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit.
Basically, this is done by remembering which one of them was used even after
the call to ptrace_notify().
* We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP
to make do_syscall_trace() notice that the current syscall was started with
SYSEMU on entry, so that no notification ought to be done in the exit path;
this is a bit of a hack, so this problem is solved in another way in next
patches.
* Also, the effects of the patch:
"Ptrace - i386: fix Syscall Audit interaction with singlestep"
are cancelled; they are restored back in the last patch of this series.
Detailed descriptions of the patches doing this kind of processing follow (but
I've already summed everything up).
* Fix behaviour when changing interception kind #1.
In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag
only after doing the debugger notification; but the debugger might have
changed the status of this flag because he continued execution with
PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag
status before calling ptrace_notify().
* Fix behaviour when changing interception kind #2:
avoid intercepting syscall on return when using SYSCALL again.
A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL
crashes.
The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch
inhibits the syscall-handler to be called, but does not prevent
do_syscall_trace() to be called after this for syscall completion
interception.
The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to
remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since
the flag is unused in the depicted situation.
* Fix behaviour when changing interception kind #3:
avoid intercepting syscall on return when using SINGLESTEP.
When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had
problems with singlestepping on UML in SKAS with SYSEMU. It looped
receiving SIGTRAPs without moving forward. EIP of the traced process was
the same for all SIGTRAPs.
What's missing is to handle switching from PTRACE_SYSCALL_EMU to
PTRACE_SINGLESTEP in a way very similar to what is done for the change from
PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE.
I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is
notified and then wake ups the process; the syscall is executed (or skipped,
when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and
do_syscall_trace() is called again. Since we are on the return path of a
SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL),
we must still avoid notifying the parent of the syscall exit. Now, this
behaviour is extended even to resuming with PTRACE_SINGLESTEP.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-03 18:57:18 -04:00
|
|
|
testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
|
2005-04-16 18:20:36 -04:00
|
|
|
jnz syscall_trace_entry
|
|
|
|
|
cmpl $(nr_syscalls), %eax
|
|
|
|
|
jae syscall_badsys
|
|
|
|
|
call *sys_call_table(,%eax,4)
|
2006-12-06 20:14:02 -05:00
|
|
|
movl %eax,PT_EAX(%esp)
|
2006-12-06 20:14:08 -05:00
|
|
|
DISABLE_INTERRUPTS(CLBR_ECX|CLBR_EDX)
|
2006-07-03 03:24:43 -04:00
|
|
|
TRACE_IRQS_OFF
|
2005-04-16 18:20:36 -04:00
|
|
|
movl TI_flags(%ebp), %ecx
|
|
|
|
|
testw $_TIF_ALLWORK_MASK, %cx
|
|
|
|
|
jne syscall_exit_work
|
|
|
|
|
/* if something modifies registers it must also disable sysexit */
|
2006-12-06 20:14:02 -05:00
|
|
|
movl PT_EIP(%esp), %edx
|
|
|
|
|
movl PT_OLDESP(%esp), %ecx
|
2005-04-16 18:20:36 -04:00
|
|
|
xorl %ebp,%ebp
|
2006-07-03 03:24:43 -04:00
|
|
|
TRACE_IRQS_ON
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
|
|
|
1: mov PT_GS(%esp), %gs
|
2006-09-26 04:52:39 -04:00
|
|
|
ENABLE_INTERRUPTS_SYSEXIT
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
|
|
|
.pushsection .fixup,"ax"
|
|
|
|
|
2: movl $0,PT_GS(%esp)
|
|
|
|
|
jmp 1b
|
|
|
|
|
.section __ex_table,"a"
|
|
|
|
|
.align 4
|
|
|
|
|
.long 1b,2b
|
|
|
|
|
.popsection
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
# system call handler stub
|
|
|
|
|
ENTRY(system_call)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME # can't unwind into user space anyway
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %eax # save orig_eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
SAVE_ALL
|
|
|
|
|
GET_THREAD_INFO(%ebp)
|
2006-12-06 20:14:02 -05:00
|
|
|
testl $TF_MASK,PT_EFLAGS(%esp)
|
[PATCH] i386: fix singlestep through an int80 syscall
Using PTRACE_SINGLESTEP on a child that does an int80 syscall misses the
SIGTRAP that should be delivered upon syscall exit. Fix that by setting
TIF_SINGLESTEP when entering the kernel via int80 with TF set.
/* Test whether singlestep through an int80 syscall works.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <asm/user.h>
static int child, status;
static struct user_regs_struct regs;
static void do_child()
{
ptrace(PTRACE_TRACEME, 0, 0, 0);
kill(getpid(), SIGUSR1);
asm ("int $0x80" : : "a" (20)); /* getpid */
}
static void do_parent()
{
unsigned long eip, expected = 0;
again:
waitpid(child, &status, 0);
if (WIFEXITED(status) || WIFSIGNALED(status))
return;
if (WIFSTOPPED(status)) {
ptrace(PTRACE_GETREGS, child, 0, ®s);
eip = regs.eip;
if (expected)
fprintf(stderr, "child stop @ %08x, expected %08x %s\n",
eip, expected,
eip == expected ? "" : " <== ERROR");
if (*(unsigned short *)eip == 0x80cd) {
fprintf(stderr, "int 0x80 at %08x\n", (unsigned int)eip);
expected = eip + 2;
} else
expected = 0;
ptrace(PTRACE_SINGLESTEP, child, NULL, NULL);
}
goto again;
}
int main(int argc, char * const argv[])
{
child = fork();
if (child)
do_parent();
else
do_child();
return 0;
}
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23 05:59:48 -05:00
|
|
|
jz no_singlestep
|
|
|
|
|
orl $_TIF_SINGLESTEP,TI_flags(%ebp)
|
|
|
|
|
no_singlestep:
|
[PATCH] UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage
Jeff Dike <jdike@addtoit.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>,
Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL
except that the kernel does not execute the requested syscall; this is useful
to improve performance for virtual environments, like UML, which want to run
the syscall on their own.
In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry
and on exit, and each time you also have two context switches; with SYSEMU you
avoid the 2nd stop and so save two context switches per syscall.
Also, some architectures don't have support in the host for changing the
syscall number via ptrace(), which is currently needed to skip syscall
execution (UML turns any syscall into getpid() to avoid it being executed on
the host). Fixing that is hard, while SYSEMU is easier to implement.
* This version of the patch includes some suggestions of Jeff Dike to avoid
adding any instructions to the syscall fast path, plus some other little
changes, by myself, to make it work even when the syscall is executed with
SYSENTER (but I'm unsure about them). It has been widely tested for quite a
lot of time.
* Various fixed were included to handle the various switches between
various states, i.e. when for instance a syscall entry is traced with one of
PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit.
Basically, this is done by remembering which one of them was used even after
the call to ptrace_notify().
* We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP
to make do_syscall_trace() notice that the current syscall was started with
SYSEMU on entry, so that no notification ought to be done in the exit path;
this is a bit of a hack, so this problem is solved in another way in next
patches.
* Also, the effects of the patch:
"Ptrace - i386: fix Syscall Audit interaction with singlestep"
are cancelled; they are restored back in the last patch of this series.
Detailed descriptions of the patches doing this kind of processing follow (but
I've already summed everything up).
* Fix behaviour when changing interception kind #1.
In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag
only after doing the debugger notification; but the debugger might have
changed the status of this flag because he continued execution with
PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag
status before calling ptrace_notify().
* Fix behaviour when changing interception kind #2:
avoid intercepting syscall on return when using SYSCALL again.
A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL
crashes.
The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch
inhibits the syscall-handler to be called, but does not prevent
do_syscall_trace() to be called after this for syscall completion
interception.
The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to
remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since
the flag is unused in the depicted situation.
* Fix behaviour when changing interception kind #3:
avoid intercepting syscall on return when using SINGLESTEP.
When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had
problems with singlestepping on UML in SKAS with SYSEMU. It looped
receiving SIGTRAPs without moving forward. EIP of the traced process was
the same for all SIGTRAPs.
What's missing is to handle switching from PTRACE_SYSCALL_EMU to
PTRACE_SINGLESTEP in a way very similar to what is done for the change from
PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE.
I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is
notified and then wake ups the process; the syscall is executed (or skipped,
when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and
do_syscall_trace() is called again. Since we are on the return path of a
SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL),
we must still avoid notifying the parent of the syscall exit. Now, this
behaviour is extended even to resuming with PTRACE_SINGLESTEP.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-03 18:57:18 -04:00
|
|
|
# system call tracing in operation / emulation
|
2005-04-16 18:20:36 -04:00
|
|
|
/* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
|
[PATCH] UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage
Jeff Dike <jdike@addtoit.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>,
Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL
except that the kernel does not execute the requested syscall; this is useful
to improve performance for virtual environments, like UML, which want to run
the syscall on their own.
In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry
and on exit, and each time you also have two context switches; with SYSEMU you
avoid the 2nd stop and so save two context switches per syscall.
Also, some architectures don't have support in the host for changing the
syscall number via ptrace(), which is currently needed to skip syscall
execution (UML turns any syscall into getpid() to avoid it being executed on
the host). Fixing that is hard, while SYSEMU is easier to implement.
* This version of the patch includes some suggestions of Jeff Dike to avoid
adding any instructions to the syscall fast path, plus some other little
changes, by myself, to make it work even when the syscall is executed with
SYSENTER (but I'm unsure about them). It has been widely tested for quite a
lot of time.
* Various fixed were included to handle the various switches between
various states, i.e. when for instance a syscall entry is traced with one of
PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit.
Basically, this is done by remembering which one of them was used even after
the call to ptrace_notify().
* We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP
to make do_syscall_trace() notice that the current syscall was started with
SYSEMU on entry, so that no notification ought to be done in the exit path;
this is a bit of a hack, so this problem is solved in another way in next
patches.
* Also, the effects of the patch:
"Ptrace - i386: fix Syscall Audit interaction with singlestep"
are cancelled; they are restored back in the last patch of this series.
Detailed descriptions of the patches doing this kind of processing follow (but
I've already summed everything up).
* Fix behaviour when changing interception kind #1.
In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag
only after doing the debugger notification; but the debugger might have
changed the status of this flag because he continued execution with
PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag
status before calling ptrace_notify().
* Fix behaviour when changing interception kind #2:
avoid intercepting syscall on return when using SYSCALL again.
A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL
crashes.
The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch
inhibits the syscall-handler to be called, but does not prevent
do_syscall_trace() to be called after this for syscall completion
interception.
The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to
remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since
the flag is unused in the depicted situation.
* Fix behaviour when changing interception kind #3:
avoid intercepting syscall on return when using SINGLESTEP.
When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had
problems with singlestepping on UML in SKAS with SYSEMU. It looped
receiving SIGTRAPs without moving forward. EIP of the traced process was
the same for all SIGTRAPs.
What's missing is to handle switching from PTRACE_SYSCALL_EMU to
PTRACE_SINGLESTEP in a way very similar to what is done for the change from
PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE.
I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is
notified and then wake ups the process; the syscall is executed (or skipped,
when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and
do_syscall_trace() is called again. Since we are on the return path of a
SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL),
we must still avoid notifying the parent of the syscall exit. Now, this
behaviour is extended even to resuming with PTRACE_SINGLESTEP.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-03 18:57:18 -04:00
|
|
|
testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
|
2005-04-16 18:20:36 -04:00
|
|
|
jnz syscall_trace_entry
|
|
|
|
|
cmpl $(nr_syscalls), %eax
|
|
|
|
|
jae syscall_badsys
|
|
|
|
|
syscall_call:
|
|
|
|
|
call *sys_call_table(,%eax,4)
|
2006-12-06 20:14:02 -05:00
|
|
|
movl %eax,PT_EAX(%esp) # store the return value
|
2005-04-16 18:20:36 -04:00
|
|
|
syscall_exit:
|
2006-12-06 20:14:08 -05:00
|
|
|
DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
|
2005-04-16 18:20:36 -04:00
|
|
|
# setting need_resched or sigpending
|
|
|
|
|
# between sampling and the iret
|
2006-07-03 03:24:43 -04:00
|
|
|
TRACE_IRQS_OFF
|
2005-04-16 18:20:36 -04:00
|
|
|
movl TI_flags(%ebp), %ecx
|
|
|
|
|
testw $_TIF_ALLWORK_MASK, %cx # current->work
|
|
|
|
|
jne syscall_exit_work
|
|
|
|
|
|
|
|
|
|
restore_all:
|
2006-12-06 20:14:02 -05:00
|
|
|
movl PT_EFLAGS(%esp), %eax # mix EFLAGS, SS and CS
|
|
|
|
|
# Warning: PT_OLDSS(%esp) contains the wrong/random values if we
|
2005-04-16 18:24:01 -04:00
|
|
|
# are returning to the kernel.
|
|
|
|
|
# See comments in process.c:copy_thread() for details.
|
2006-12-06 20:14:02 -05:00
|
|
|
movb PT_OLDSS(%esp), %ah
|
|
|
|
|
movb PT_CS(%esp), %al
|
2006-09-26 04:52:39 -04:00
|
|
|
andl $(VM_MASK | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax
|
|
|
|
|
cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_REMEMBER_STATE
|
2005-04-16 18:20:36 -04:00
|
|
|
je ldt_ss # returning to user-space with LDT SS
|
|
|
|
|
restore_nocheck:
|
2006-07-03 03:24:43 -04:00
|
|
|
TRACE_IRQS_IRET
|
|
|
|
|
restore_nocheck_notrace:
|
2005-04-16 18:20:36 -04:00
|
|
|
RESTORE_REGS
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
|
|
|
addl $4, %esp # skip orig_eax/error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET -4
|
2006-09-26 04:52:39 -04:00
|
|
|
1: INTERRUPT_RETURN
|
2005-04-16 18:20:36 -04:00
|
|
|
.section .fixup,"ax"
|
|
|
|
|
iret_exc:
|
2006-07-03 03:24:43 -04:00
|
|
|
TRACE_IRQS_ON
|
2006-12-06 20:14:08 -05:00
|
|
|
ENABLE_INTERRUPTS(CLBR_NONE)
|
2005-04-29 12:38:44 -04:00
|
|
|
pushl $0 # no error code
|
|
|
|
|
pushl $do_iret_error
|
|
|
|
|
jmp error_code
|
2005-04-16 18:20:36 -04:00
|
|
|
.previous
|
|
|
|
|
.section __ex_table,"a"
|
|
|
|
|
.align 4
|
|
|
|
|
.long 1b,iret_exc
|
|
|
|
|
.previous
|
|
|
|
|
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_RESTORE_STATE
|
2005-04-16 18:20:36 -04:00
|
|
|
ldt_ss:
|
2006-12-06 20:14:02 -05:00
|
|
|
larl PT_OLDSS(%esp), %eax
|
2005-04-16 18:20:36 -04:00
|
|
|
jnz restore_nocheck
|
|
|
|
|
testl $0x00400000, %eax # returning to 32bit stack?
|
|
|
|
|
jnz restore_nocheck # allright, normal return
|
2006-12-06 20:14:07 -05:00
|
|
|
|
|
|
|
|
#ifdef CONFIG_PARAVIRT
|
|
|
|
|
/*
|
|
|
|
|
* The kernel can't run on a non-flat stack if paravirt mode
|
|
|
|
|
* is active. Rather than try to fixup the high bits of
|
|
|
|
|
* ESP, bypass this code entirely. This may break DOSemu
|
|
|
|
|
* and/or Wine support in a paravirt VM, although the option
|
|
|
|
|
* is still available to implement the setting of the high
|
|
|
|
|
* 16-bits in the INTERRUPT_RETURN paravirt-op.
|
|
|
|
|
*/
|
|
|
|
|
cmpl $0, paravirt_ops+PARAVIRT_enabled
|
|
|
|
|
jne restore_nocheck
|
|
|
|
|
#endif
|
|
|
|
|
|
2005-04-16 18:20:36 -04:00
|
|
|
/* If returning to userspace with 16bit stack,
|
|
|
|
|
* try to fix the higher word of ESP, as the CPU
|
|
|
|
|
* won't restore it.
|
|
|
|
|
* This is an "official" bug of all the x86-compatible
|
|
|
|
|
* CPUs, which we can try to work around to make
|
|
|
|
|
* dosemu and wine happy. */
|
2006-12-06 20:14:02 -05:00
|
|
|
movl PT_OLDESP(%esp), %eax
|
2006-12-06 20:14:01 -05:00
|
|
|
movl %esp, %edx
|
|
|
|
|
call patch_espfix_desc
|
|
|
|
|
pushl $__ESPFIX_SS
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
pushl %eax
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2006-12-06 20:14:08 -05:00
|
|
|
DISABLE_INTERRUPTS(CLBR_EAX)
|
2006-07-03 03:24:43 -04:00
|
|
|
TRACE_IRQS_OFF
|
2006-12-06 20:14:01 -05:00
|
|
|
lss (%esp), %esp
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
|
|
|
jmp restore_nocheck
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
# perform work that needs to be done immediately before resumption
|
|
|
|
|
ALIGN
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_PTREGS_FRAME # can't unwind into user space anyway
|
2005-04-16 18:20:36 -04:00
|
|
|
work_pending:
|
|
|
|
|
testb $_TIF_NEED_RESCHED, %cl
|
|
|
|
|
jz work_notifysig
|
|
|
|
|
work_resched:
|
|
|
|
|
call schedule
|
2006-12-06 20:14:08 -05:00
|
|
|
DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
|
2005-04-16 18:20:36 -04:00
|
|
|
# setting need_resched or sigpending
|
|
|
|
|
# between sampling and the iret
|
2006-07-03 03:24:43 -04:00
|
|
|
TRACE_IRQS_OFF
|
2005-04-16 18:20:36 -04:00
|
|
|
movl TI_flags(%ebp), %ecx
|
|
|
|
|
andl $_TIF_WORK_MASK, %ecx # is there any work to be done other
|
|
|
|
|
# than syscall tracing?
|
|
|
|
|
jz restore_all
|
|
|
|
|
testb $_TIF_NEED_RESCHED, %cl
|
|
|
|
|
jnz work_resched
|
|
|
|
|
|
|
|
|
|
work_notifysig: # deal with pending signals and
|
|
|
|
|
# notify-resume requests
|
2006-12-06 20:14:04 -05:00
|
|
|
#ifdef CONFIG_VM86
|
2006-12-06 20:14:02 -05:00
|
|
|
testl $VM_MASK, PT_EFLAGS(%esp)
|
2005-04-16 18:20:36 -04:00
|
|
|
movl %esp, %eax
|
|
|
|
|
jne work_notifysig_v86 # returning to kernel-space or
|
|
|
|
|
# vm86-space
|
|
|
|
|
xorl %edx, %edx
|
|
|
|
|
call do_notify_resume
|
2006-06-27 05:53:48 -04:00
|
|
|
jmp resume_userspace_sig
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ALIGN
|
|
|
|
|
work_notifysig_v86:
|
|
|
|
|
pushl %ecx # save ti_flags for do_notify_resume
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
call save_v86_state # %eax contains pt_regs pointer
|
|
|
|
|
popl %ecx
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET -4
|
2005-04-16 18:20:36 -04:00
|
|
|
movl %eax, %esp
|
2006-12-06 20:14:04 -05:00
|
|
|
#else
|
|
|
|
|
movl %esp, %eax
|
|
|
|
|
#endif
|
2005-04-16 18:20:36 -04:00
|
|
|
xorl %edx, %edx
|
|
|
|
|
call do_notify_resume
|
2006-06-27 05:53:48 -04:00
|
|
|
jmp resume_userspace_sig
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
# perform syscall exit tracing
|
|
|
|
|
ALIGN
|
|
|
|
|
syscall_trace_entry:
|
2006-12-06 20:14:02 -05:00
|
|
|
movl $-ENOSYS,PT_EAX(%esp)
|
2005-04-16 18:20:36 -04:00
|
|
|
movl %esp, %eax
|
|
|
|
|
xorl %edx,%edx
|
|
|
|
|
call do_syscall_trace
|
[PATCH] UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage
Jeff Dike <jdike@addtoit.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>,
Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL
except that the kernel does not execute the requested syscall; this is useful
to improve performance for virtual environments, like UML, which want to run
the syscall on their own.
In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry
and on exit, and each time you also have two context switches; with SYSEMU you
avoid the 2nd stop and so save two context switches per syscall.
Also, some architectures don't have support in the host for changing the
syscall number via ptrace(), which is currently needed to skip syscall
execution (UML turns any syscall into getpid() to avoid it being executed on
the host). Fixing that is hard, while SYSEMU is easier to implement.
* This version of the patch includes some suggestions of Jeff Dike to avoid
adding any instructions to the syscall fast path, plus some other little
changes, by myself, to make it work even when the syscall is executed with
SYSENTER (but I'm unsure about them). It has been widely tested for quite a
lot of time.
* Various fixed were included to handle the various switches between
various states, i.e. when for instance a syscall entry is traced with one of
PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit.
Basically, this is done by remembering which one of them was used even after
the call to ptrace_notify().
* We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP
to make do_syscall_trace() notice that the current syscall was started with
SYSEMU on entry, so that no notification ought to be done in the exit path;
this is a bit of a hack, so this problem is solved in another way in next
patches.
* Also, the effects of the patch:
"Ptrace - i386: fix Syscall Audit interaction with singlestep"
are cancelled; they are restored back in the last patch of this series.
Detailed descriptions of the patches doing this kind of processing follow (but
I've already summed everything up).
* Fix behaviour when changing interception kind #1.
In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag
only after doing the debugger notification; but the debugger might have
changed the status of this flag because he continued execution with
PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag
status before calling ptrace_notify().
* Fix behaviour when changing interception kind #2:
avoid intercepting syscall on return when using SYSCALL again.
A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL
crashes.
The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch
inhibits the syscall-handler to be called, but does not prevent
do_syscall_trace() to be called after this for syscall completion
interception.
The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to
remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since
the flag is unused in the depicted situation.
* Fix behaviour when changing interception kind #3:
avoid intercepting syscall on return when using SINGLESTEP.
When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had
problems with singlestepping on UML in SKAS with SYSEMU. It looped
receiving SIGTRAPs without moving forward. EIP of the traced process was
the same for all SIGTRAPs.
What's missing is to handle switching from PTRACE_SYSCALL_EMU to
PTRACE_SINGLESTEP in a way very similar to what is done for the change from
PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE.
I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is
notified and then wake ups the process; the syscall is executed (or skipped,
when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and
do_syscall_trace() is called again. Since we are on the return path of a
SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL),
we must still avoid notifying the parent of the syscall exit. Now, this
behaviour is extended even to resuming with PTRACE_SINGLESTEP.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-03 18:57:18 -04:00
|
|
|
cmpl $0, %eax
|
2005-09-03 18:57:22 -04:00
|
|
|
jne resume_userspace # ret != 0 -> running under PTRACE_SYSEMU,
|
[PATCH] UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage
Jeff Dike <jdike@addtoit.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>,
Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL
except that the kernel does not execute the requested syscall; this is useful
to improve performance for virtual environments, like UML, which want to run
the syscall on their own.
In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry
and on exit, and each time you also have two context switches; with SYSEMU you
avoid the 2nd stop and so save two context switches per syscall.
Also, some architectures don't have support in the host for changing the
syscall number via ptrace(), which is currently needed to skip syscall
execution (UML turns any syscall into getpid() to avoid it being executed on
the host). Fixing that is hard, while SYSEMU is easier to implement.
* This version of the patch includes some suggestions of Jeff Dike to avoid
adding any instructions to the syscall fast path, plus some other little
changes, by myself, to make it work even when the syscall is executed with
SYSENTER (but I'm unsure about them). It has been widely tested for quite a
lot of time.
* Various fixed were included to handle the various switches between
various states, i.e. when for instance a syscall entry is traced with one of
PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit.
Basically, this is done by remembering which one of them was used even after
the call to ptrace_notify().
* We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP
to make do_syscall_trace() notice that the current syscall was started with
SYSEMU on entry, so that no notification ought to be done in the exit path;
this is a bit of a hack, so this problem is solved in another way in next
patches.
* Also, the effects of the patch:
"Ptrace - i386: fix Syscall Audit interaction with singlestep"
are cancelled; they are restored back in the last patch of this series.
Detailed descriptions of the patches doing this kind of processing follow (but
I've already summed everything up).
* Fix behaviour when changing interception kind #1.
In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag
only after doing the debugger notification; but the debugger might have
changed the status of this flag because he continued execution with
PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag
status before calling ptrace_notify().
* Fix behaviour when changing interception kind #2:
avoid intercepting syscall on return when using SYSCALL again.
A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL
crashes.
The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch
inhibits the syscall-handler to be called, but does not prevent
do_syscall_trace() to be called after this for syscall completion
interception.
The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to
remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since
the flag is unused in the depicted situation.
* Fix behaviour when changing interception kind #3:
avoid intercepting syscall on return when using SINGLESTEP.
When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had
problems with singlestepping on UML in SKAS with SYSEMU. It looped
receiving SIGTRAPs without moving forward. EIP of the traced process was
the same for all SIGTRAPs.
What's missing is to handle switching from PTRACE_SYSCALL_EMU to
PTRACE_SINGLESTEP in a way very similar to what is done for the change from
PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE.
I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is
notified and then wake ups the process; the syscall is executed (or skipped,
when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and
do_syscall_trace() is called again. Since we are on the return path of a
SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL),
we must still avoid notifying the parent of the syscall exit. Now, this
behaviour is extended even to resuming with PTRACE_SINGLESTEP.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-03 18:57:18 -04:00
|
|
|
# so must skip actual syscall
|
2006-12-06 20:14:02 -05:00
|
|
|
movl PT_ORIG_EAX(%esp), %eax
|
2005-04-16 18:20:36 -04:00
|
|
|
cmpl $(nr_syscalls), %eax
|
|
|
|
|
jnae syscall_call
|
|
|
|
|
jmp syscall_exit
|
|
|
|
|
|
|
|
|
|
# perform syscall exit tracing
|
|
|
|
|
ALIGN
|
|
|
|
|
syscall_exit_work:
|
|
|
|
|
testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl
|
|
|
|
|
jz work_pending
|
2006-07-03 03:24:43 -04:00
|
|
|
TRACE_IRQS_ON
|
2006-12-06 20:14:08 -05:00
|
|
|
ENABLE_INTERRUPTS(CLBR_ANY) # could let do_syscall_trace() call
|
2005-04-16 18:20:36 -04:00
|
|
|
# schedule() instead
|
|
|
|
|
movl %esp, %eax
|
|
|
|
|
movl $1, %edx
|
|
|
|
|
call do_syscall_trace
|
|
|
|
|
jmp resume_userspace
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME # can't unwind into user space anyway
|
2005-04-16 18:20:36 -04:00
|
|
|
syscall_fault:
|
|
|
|
|
pushl %eax # save orig_eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
SAVE_ALL
|
|
|
|
|
GET_THREAD_INFO(%ebp)
|
2006-12-06 20:14:02 -05:00
|
|
|
movl $-EFAULT,PT_EAX(%esp)
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp resume_userspace
|
|
|
|
|
|
|
|
|
|
syscall_badsys:
|
2006-12-06 20:14:02 -05:00
|
|
|
movl $-ENOSYS,PT_EAX(%esp)
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp resume_userspace
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
#define FIXUP_ESPFIX_STACK \
|
2006-12-06 20:14:01 -05:00
|
|
|
/* since we are on a wrong stack, we cant make it a C code :( */ \
|
2006-12-06 20:14:03 -05:00
|
|
|
movl %gs:PDA_cpu, %ebx; \
|
2006-12-06 20:14:01 -05:00
|
|
|
PER_CPU(cpu_gdt_descr, %ebx); \
|
|
|
|
|
movl GDS_address(%ebx), %ebx; \
|
|
|
|
|
GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah); \
|
|
|
|
|
addl %esp, %eax; \
|
|
|
|
|
pushl $__KERNEL_DS; \
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET 4; \
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %eax; \
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4; \
|
2006-12-06 20:14:01 -05:00
|
|
|
lss (%esp), %esp; \
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET -8;
|
|
|
|
|
#define UNWIND_ESPFIX_STACK \
|
2005-04-16 18:20:36 -04:00
|
|
|
movl %ss, %eax; \
|
2006-12-06 20:14:01 -05:00
|
|
|
/* see if on espfix stack */ \
|
2005-04-16 18:20:36 -04:00
|
|
|
cmpw $__ESPFIX_SS, %ax; \
|
2006-12-06 20:14:01 -05:00
|
|
|
jne 27f; \
|
|
|
|
|
movl $__KERNEL_DS, %eax; \
|
2006-06-26 07:57:44 -04:00
|
|
|
movl %eax, %ds; \
|
|
|
|
|
movl %eax, %es; \
|
2006-12-06 20:14:01 -05:00
|
|
|
/* switch to normal stack */ \
|
2006-06-26 07:57:44 -04:00
|
|
|
FIXUP_ESPFIX_STACK; \
|
2006-12-06 20:14:01 -05:00
|
|
|
27:;
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Build the entry stubs and pointer table with
|
|
|
|
|
* some assembler magic.
|
|
|
|
|
*/
|
|
|
|
|
.data
|
|
|
|
|
ENTRY(interrupt)
|
|
|
|
|
.text
|
|
|
|
|
|
|
|
|
|
vector=0
|
|
|
|
|
ENTRY(irq_entries_start)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
.rept NR_IRQS
|
|
|
|
|
ALIGN
|
2006-06-26 07:57:44 -04:00
|
|
|
.if vector
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
|
|
|
.endif
|
2006-06-27 05:53:44 -04:00
|
|
|
1: pushl $~(vector)
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp common_interrupt
|
|
|
|
|
.data
|
|
|
|
|
.long 1b
|
|
|
|
|
.text
|
|
|
|
|
vector=vector+1
|
|
|
|
|
.endr
|
|
|
|
|
|
2006-07-03 03:24:43 -04:00
|
|
|
/*
|
|
|
|
|
* the CPU automatically disables interrupts when executing an IRQ vector,
|
|
|
|
|
* so IRQ-flags tracing has to follow that:
|
|
|
|
|
*/
|
2005-04-16 18:20:36 -04:00
|
|
|
ALIGN
|
|
|
|
|
common_interrupt:
|
|
|
|
|
SAVE_ALL
|
2006-07-03 03:24:43 -04:00
|
|
|
TRACE_IRQS_OFF
|
2005-04-16 18:20:36 -04:00
|
|
|
movl %esp,%eax
|
|
|
|
|
call do_IRQ
|
|
|
|
|
jmp ret_from_intr
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
#define BUILD_INTERRUPT(name, nr) \
|
|
|
|
|
ENTRY(name) \
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME; \
|
2006-06-27 05:53:44 -04:00
|
|
|
pushl $~(nr); \
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4; \
|
|
|
|
|
SAVE_ALL; \
|
2006-07-03 03:24:43 -04:00
|
|
|
TRACE_IRQS_OFF \
|
2005-04-16 18:20:36 -04:00
|
|
|
movl %esp,%eax; \
|
|
|
|
|
call smp_/**/name; \
|
2006-07-03 03:24:43 -04:00
|
|
|
jmp ret_from_intr; \
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
/* The include is where all of the SMP etc. interrupts come from */
|
|
|
|
|
#include "entry_arch.h"
|
|
|
|
|
|
[PATCH] x86: error_code is not safe for kprobes
This patch moves the entry.S:error_entry to .kprobes.text section,
since code marked unsafe for kprobes jumps directly to entry.S::error_entry,
that must be marked unsafe as well.
This patch also moves all the ".previous.text" asm directives to ".previous"
for kprobes section.
AK: Following a similar i386 patch from Chuck Ebbert
AK: Also merged Jeremy's fix in.
+From: Jeremy Fitzhardinge <jeremy@goop.org>
KPROBE_ENTRY does a .section .kprobes.text, and expects its users to
do a .previous at the end of the function.
Unfortunately, if any code within the function switches sections, for
example .fixup, then the .previous ends up putting all subsequent code
into .fixup. Worse, any subsequent .fixup code gets intermingled with
the code its supposed to be fixing (which is also in .fixup). It's
surprising this didn't cause more havok.
The fix is to use .pushsection/.popsection, so this stuff nests
properly. A further cleanup would be to get rid of all
.section/.previous pairs, since they're inherently fragile.
+From: Chuck Ebbert <76306.1226@compuserve.com>
Because code marked unsafe for kprobes jumps directly to
entry.S::error_code, that must be marked unsafe as well.
The easiest way to do that is to move the page fault entry
point to just before error_code and let it inherit the same
section.
Also moved all the ".previous" asm directives for kprobes
sections to column 1 and removed ".text" from them.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 04:52:34 -04:00
|
|
|
KPROBE_ENTRY(page_fault)
|
|
|
|
|
RING0_EC_FRAME
|
|
|
|
|
pushl $do_page_fault
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
ALIGN
|
|
|
|
|
error_code:
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
|
|
|
/* the function address is in %gs's slot on the stack */
|
|
|
|
|
pushl %es
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
/*CFI_REL_OFFSET es, 0*/
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %ds
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
/*CFI_REL_OFFSET ds, 0*/
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
CFI_REL_OFFSET eax, 0
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %ebp
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
CFI_REL_OFFSET ebp, 0
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %edi
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
CFI_REL_OFFSET edi, 0
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %esi
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
CFI_REL_OFFSET esi, 0
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %edx
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
CFI_REL_OFFSET edx, 0
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %ecx
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
CFI_REL_OFFSET ecx, 0
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %ebx
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
CFI_REL_OFFSET ebx, 0
|
2005-04-16 18:20:36 -04:00
|
|
|
cld
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
|
|
|
pushl %gs
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
|
|
|
/*CFI_REL_OFFSET gs, 0*/
|
|
|
|
|
movl $(__KERNEL_PDA), %ecx
|
|
|
|
|
movl %ecx, %gs
|
2005-04-16 18:20:36 -04:00
|
|
|
UNWIND_ESPFIX_STACK
|
|
|
|
|
popl %ecx
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
|
|
|
/*CFI_REGISTER es, ecx*/
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
|
|
|
movl PT_GS(%esp), %edi # get the function address
|
2006-12-06 20:14:02 -05:00
|
|
|
movl PT_ORIG_EAX(%esp), %edx # get the error code
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
|
|
|
movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart
|
|
|
|
|
mov %ecx, PT_GS(%esp)
|
|
|
|
|
/*CFI_REL_OFFSET gs, ES*/
|
2005-04-16 18:20:36 -04:00
|
|
|
movl $(__USER_DS), %ecx
|
|
|
|
|
movl %ecx, %ds
|
|
|
|
|
movl %ecx, %es
|
|
|
|
|
movl %esp,%eax # pt_regs pointer
|
|
|
|
|
call *%edi
|
|
|
|
|
jmp ret_from_exception
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
[PATCH] x86: error_code is not safe for kprobes
This patch moves the entry.S:error_entry to .kprobes.text section,
since code marked unsafe for kprobes jumps directly to entry.S::error_entry,
that must be marked unsafe as well.
This patch also moves all the ".previous.text" asm directives to ".previous"
for kprobes section.
AK: Following a similar i386 patch from Chuck Ebbert
AK: Also merged Jeremy's fix in.
+From: Jeremy Fitzhardinge <jeremy@goop.org>
KPROBE_ENTRY does a .section .kprobes.text, and expects its users to
do a .previous at the end of the function.
Unfortunately, if any code within the function switches sections, for
example .fixup, then the .previous ends up putting all subsequent code
into .fixup. Worse, any subsequent .fixup code gets intermingled with
the code its supposed to be fixing (which is also in .fixup). It's
surprising this didn't cause more havok.
The fix is to use .pushsection/.popsection, so this stuff nests
properly. A further cleanup would be to get rid of all
.section/.previous pairs, since they're inherently fragile.
+From: Chuck Ebbert <76306.1226@compuserve.com>
Because code marked unsafe for kprobes jumps directly to
entry.S::error_code, that must be marked unsafe as well.
The easiest way to do that is to move the page fault entry
point to just before error_code and let it inherit the same
section.
Also moved all the ".previous" asm directives for kprobes
sections to column 1 and removed ".text" from them.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 04:52:34 -04:00
|
|
|
KPROBE_END(page_fault)
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(coprocessor_error)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $0
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_coprocessor_error
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(simd_coprocessor_error)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $0
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_simd_coprocessor_error
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(device_not_available)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $-1 # mark this as an int
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
SAVE_ALL
|
2006-09-26 04:52:39 -04:00
|
|
|
GET_CR0_INTO_EAX
|
2005-04-16 18:20:36 -04:00
|
|
|
testl $0x4, %eax # EM (math emulation bit)
|
|
|
|
|
jne device_not_available_emulate
|
2006-12-06 20:14:08 -05:00
|
|
|
preempt_stop(CLBR_ANY)
|
2005-04-16 18:20:36 -04:00
|
|
|
call math_state_restore
|
|
|
|
|
jmp ret_from_exception
|
|
|
|
|
device_not_available_emulate:
|
|
|
|
|
pushl $0 # temporary storage for ORIG_EIP
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
call math_emulate
|
|
|
|
|
addl $4, %esp
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET -4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp ret_from_exception
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Debug traps and NMI can happen at the one SYSENTER instruction
|
|
|
|
|
* that sets up the real kernel stack. Check here, since we can't
|
|
|
|
|
* allow the wrong stack to be used.
|
|
|
|
|
*
|
|
|
|
|
* "TSS_sysenter_esp0+12" is because the NMI/debug handler will have
|
|
|
|
|
* already pushed 3 words if it hits on the sysenter instruction:
|
|
|
|
|
* eflags, cs and eip.
|
|
|
|
|
*
|
|
|
|
|
* We just load the right stack, and push the three (known) values
|
|
|
|
|
* by hand onto the new stack - while updating the return eip past
|
|
|
|
|
* the instruction that would have done it for sysenter.
|
|
|
|
|
*/
|
|
|
|
|
#define FIX_STACK(offset, ok, label) \
|
|
|
|
|
cmpw $__KERNEL_CS,4(%esp); \
|
|
|
|
|
jne ok; \
|
|
|
|
|
label: \
|
|
|
|
|
movl TSS_sysenter_esp0+offset(%esp),%esp; \
|
2006-09-26 04:52:37 -04:00
|
|
|
CFI_DEF_CFA esp, 0; \
|
|
|
|
|
CFI_UNDEFINED eip; \
|
2005-04-16 18:20:36 -04:00
|
|
|
pushfl; \
|
2006-09-26 04:52:37 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4; \
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $__KERNEL_CS; \
|
2006-09-26 04:52:37 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4; \
|
|
|
|
|
pushl $sysenter_past_esp; \
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET 4; \
|
|
|
|
|
CFI_REL_OFFSET eip, 0
|
2005-04-16 18:20:36 -04:00
|
|
|
|
2005-09-06 18:19:27 -04:00
|
|
|
KPROBE_ENTRY(debug)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
cmpl $sysenter_entry,(%esp)
|
|
|
|
|
jne debug_stack_correct
|
|
|
|
|
FIX_STACK(12, debug_stack_correct, debug_esp_fix_insn)
|
|
|
|
|
debug_stack_correct:
|
|
|
|
|
pushl $-1 # mark this as an int
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
SAVE_ALL
|
|
|
|
|
xorl %edx,%edx # error code 0
|
|
|
|
|
movl %esp,%eax # pt_regs pointer
|
|
|
|
|
call do_debug
|
|
|
|
|
jmp ret_from_exception
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
[PATCH] x86: error_code is not safe for kprobes
This patch moves the entry.S:error_entry to .kprobes.text section,
since code marked unsafe for kprobes jumps directly to entry.S::error_entry,
that must be marked unsafe as well.
This patch also moves all the ".previous.text" asm directives to ".previous"
for kprobes section.
AK: Following a similar i386 patch from Chuck Ebbert
AK: Also merged Jeremy's fix in.
+From: Jeremy Fitzhardinge <jeremy@goop.org>
KPROBE_ENTRY does a .section .kprobes.text, and expects its users to
do a .previous at the end of the function.
Unfortunately, if any code within the function switches sections, for
example .fixup, then the .previous ends up putting all subsequent code
into .fixup. Worse, any subsequent .fixup code gets intermingled with
the code its supposed to be fixing (which is also in .fixup). It's
surprising this didn't cause more havok.
The fix is to use .pushsection/.popsection, so this stuff nests
properly. A further cleanup would be to get rid of all
.section/.previous pairs, since they're inherently fragile.
+From: Chuck Ebbert <76306.1226@compuserve.com>
Because code marked unsafe for kprobes jumps directly to
entry.S::error_code, that must be marked unsafe as well.
The easiest way to do that is to move the page fault entry
point to just before error_code and let it inherit the same
section.
Also moved all the ".previous" asm directives for kprobes
sections to column 1 and removed ".text" from them.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 04:52:34 -04:00
|
|
|
KPROBE_END(debug)
|
|
|
|
|
|
2005-04-16 18:20:36 -04:00
|
|
|
/*
|
|
|
|
|
* NMI is doubly nasty. It can happen _while_ we're handling
|
|
|
|
|
* a debug fault, and the debug fault hasn't yet been able to
|
|
|
|
|
* clear up the stack. So we first check whether we got an
|
|
|
|
|
* NMI on the sysenter entry path, but after that we need to
|
|
|
|
|
* check whether we got an NMI on the debug path where the debug
|
|
|
|
|
* fault happened on the sysenter path.
|
|
|
|
|
*/
|
2006-09-26 04:52:36 -04:00
|
|
|
KPROBE_ENTRY(nmi)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
movl %ss, %eax
|
|
|
|
|
cmpw $__ESPFIX_SS, %ax
|
|
|
|
|
popl %eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET -4
|
2006-12-06 20:14:01 -05:00
|
|
|
je nmi_espfix_stack
|
2005-04-16 18:20:36 -04:00
|
|
|
cmpl $sysenter_entry,(%esp)
|
|
|
|
|
je nmi_stack_fixup
|
|
|
|
|
pushl %eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
movl %esp,%eax
|
|
|
|
|
/* Do not access memory above the end of our stack page,
|
|
|
|
|
* it might not exist.
|
|
|
|
|
*/
|
|
|
|
|
andl $(THREAD_SIZE-1),%eax
|
|
|
|
|
cmpl $(THREAD_SIZE-20),%eax
|
|
|
|
|
popl %eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET -4
|
2005-04-16 18:20:36 -04:00
|
|
|
jae nmi_stack_correct
|
|
|
|
|
cmpl $sysenter_entry,12(%esp)
|
|
|
|
|
je nmi_debug_stack_check
|
|
|
|
|
nmi_stack_correct:
|
2006-09-26 04:52:37 -04:00
|
|
|
/* We have a RING0_INT_FRAME here */
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
SAVE_ALL
|
|
|
|
|
xorl %edx,%edx # zero error code
|
|
|
|
|
movl %esp,%eax # pt_regs pointer
|
|
|
|
|
call do_nmi
|
2006-07-03 03:24:43 -04:00
|
|
|
jmp restore_nocheck_notrace
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
nmi_stack_fixup:
|
2006-09-26 04:52:37 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
FIX_STACK(12,nmi_stack_correct, 1)
|
|
|
|
|
jmp nmi_stack_correct
|
2006-09-26 04:52:37 -04:00
|
|
|
|
2005-04-16 18:20:36 -04:00
|
|
|
nmi_debug_stack_check:
|
2006-09-26 04:52:37 -04:00
|
|
|
/* We have a RING0_INT_FRAME here */
|
2005-04-16 18:20:36 -04:00
|
|
|
cmpw $__KERNEL_CS,16(%esp)
|
|
|
|
|
jne nmi_stack_correct
|
2005-11-13 19:06:52 -05:00
|
|
|
cmpl $debug,(%esp)
|
|
|
|
|
jb nmi_stack_correct
|
2005-04-16 18:20:36 -04:00
|
|
|
cmpl $debug_esp_fix_insn,(%esp)
|
2005-11-13 19:06:52 -05:00
|
|
|
ja nmi_stack_correct
|
2005-04-16 18:20:36 -04:00
|
|
|
FIX_STACK(24,nmi_stack_correct, 1)
|
|
|
|
|
jmp nmi_stack_correct
|
|
|
|
|
|
2006-12-06 20:14:01 -05:00
|
|
|
nmi_espfix_stack:
|
2006-09-26 04:52:37 -04:00
|
|
|
/* We have a RING0_INT_FRAME here.
|
|
|
|
|
*
|
|
|
|
|
* create the pointer to lss back
|
|
|
|
|
*/
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %ss
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl %esp
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
addw $4, (%esp)
|
|
|
|
|
/* copy the iret frame of 12 bytes */
|
|
|
|
|
.rept 3
|
|
|
|
|
pushl 16(%esp)
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
.endr
|
|
|
|
|
pushl %eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
SAVE_ALL
|
|
|
|
|
FIXUP_ESPFIX_STACK # %eax == %esp
|
|
|
|
|
xorl %edx,%edx # zero error code
|
|
|
|
|
call do_nmi
|
|
|
|
|
RESTORE_REGS
|
2006-12-06 20:14:01 -05:00
|
|
|
lss 12+4(%esp), %esp # back to espfix stack
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET -24
|
2006-09-26 04:52:39 -04:00
|
|
|
1: INTERRUPT_RETURN
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
.section __ex_table,"a"
|
|
|
|
|
.align 4
|
|
|
|
|
.long 1b,iret_exc
|
|
|
|
|
.previous
|
2006-09-26 04:52:36 -04:00
|
|
|
KPROBE_END(nmi)
|
2005-04-16 18:20:36 -04:00
|
|
|
|
2006-12-06 20:14:07 -05:00
|
|
|
#ifdef CONFIG_PARAVIRT
|
|
|
|
|
ENTRY(native_iret)
|
|
|
|
|
1: iret
|
|
|
|
|
.section __ex_table,"a"
|
|
|
|
|
.align 4
|
|
|
|
|
.long 1b,iret_exc
|
|
|
|
|
.previous
|
|
|
|
|
|
|
|
|
|
ENTRY(native_irq_enable_sysexit)
|
|
|
|
|
sti
|
|
|
|
|
sysexit
|
|
|
|
|
#endif
|
|
|
|
|
|
2005-09-06 18:19:27 -04:00
|
|
|
KPROBE_ENTRY(int3)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $-1 # mark this as an int
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
SAVE_ALL
|
|
|
|
|
xorl %edx,%edx # zero error code
|
|
|
|
|
movl %esp,%eax # pt_regs pointer
|
|
|
|
|
call do_int3
|
|
|
|
|
jmp ret_from_exception
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
[PATCH] x86: error_code is not safe for kprobes
This patch moves the entry.S:error_entry to .kprobes.text section,
since code marked unsafe for kprobes jumps directly to entry.S::error_entry,
that must be marked unsafe as well.
This patch also moves all the ".previous.text" asm directives to ".previous"
for kprobes section.
AK: Following a similar i386 patch from Chuck Ebbert
AK: Also merged Jeremy's fix in.
+From: Jeremy Fitzhardinge <jeremy@goop.org>
KPROBE_ENTRY does a .section .kprobes.text, and expects its users to
do a .previous at the end of the function.
Unfortunately, if any code within the function switches sections, for
example .fixup, then the .previous ends up putting all subsequent code
into .fixup. Worse, any subsequent .fixup code gets intermingled with
the code its supposed to be fixing (which is also in .fixup). It's
surprising this didn't cause more havok.
The fix is to use .pushsection/.popsection, so this stuff nests
properly. A further cleanup would be to get rid of all
.section/.previous pairs, since they're inherently fragile.
+From: Chuck Ebbert <76306.1226@compuserve.com>
Because code marked unsafe for kprobes jumps directly to
entry.S::error_code, that must be marked unsafe as well.
The easiest way to do that is to move the page fault entry
point to just before error_code and let it inherit the same
section.
Also moved all the ".previous" asm directives for kprobes
sections to column 1 and removed ".text" from them.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 04:52:34 -04:00
|
|
|
KPROBE_END(int3)
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(overflow)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $0
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_overflow
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(bounds)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $0
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_bounds
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(invalid_op)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $0
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_invalid_op
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(coprocessor_segment_overrun)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $0
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_coprocessor_segment_overrun
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(invalid_TSS)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_EC_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_invalid_TSS
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(segment_not_present)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_EC_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_segment_not_present
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(stack_segment)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_EC_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_stack_segment
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
2005-09-06 18:19:27 -04:00
|
|
|
KPROBE_ENTRY(general_protection)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_EC_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_general_protection
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
[PATCH] x86: error_code is not safe for kprobes
This patch moves the entry.S:error_entry to .kprobes.text section,
since code marked unsafe for kprobes jumps directly to entry.S::error_entry,
that must be marked unsafe as well.
This patch also moves all the ".previous.text" asm directives to ".previous"
for kprobes section.
AK: Following a similar i386 patch from Chuck Ebbert
AK: Also merged Jeremy's fix in.
+From: Jeremy Fitzhardinge <jeremy@goop.org>
KPROBE_ENTRY does a .section .kprobes.text, and expects its users to
do a .previous at the end of the function.
Unfortunately, if any code within the function switches sections, for
example .fixup, then the .previous ends up putting all subsequent code
into .fixup. Worse, any subsequent .fixup code gets intermingled with
the code its supposed to be fixing (which is also in .fixup). It's
surprising this didn't cause more havok.
The fix is to use .pushsection/.popsection, so this stuff nests
properly. A further cleanup would be to get rid of all
.section/.previous pairs, since they're inherently fragile.
+From: Chuck Ebbert <76306.1226@compuserve.com>
Because code marked unsafe for kprobes jumps directly to
entry.S::error_code, that must be marked unsafe as well.
The easiest way to do that is to move the page fault entry
point to just before error_code and let it inherit the same
section.
Also moved all the ".previous" asm directives for kprobes
sections to column 1 and removed ".text" from them.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 04:52:34 -04:00
|
|
|
KPROBE_END(general_protection)
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(alignment_check)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_EC_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_alignment_check
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
[PATCH] x86: error_code is not safe for kprobes
This patch moves the entry.S:error_entry to .kprobes.text section,
since code marked unsafe for kprobes jumps directly to entry.S::error_entry,
that must be marked unsafe as well.
This patch also moves all the ".previous.text" asm directives to ".previous"
for kprobes section.
AK: Following a similar i386 patch from Chuck Ebbert
AK: Also merged Jeremy's fix in.
+From: Jeremy Fitzhardinge <jeremy@goop.org>
KPROBE_ENTRY does a .section .kprobes.text, and expects its users to
do a .previous at the end of the function.
Unfortunately, if any code within the function switches sections, for
example .fixup, then the .previous ends up putting all subsequent code
into .fixup. Worse, any subsequent .fixup code gets intermingled with
the code its supposed to be fixing (which is also in .fixup). It's
surprising this didn't cause more havok.
The fix is to use .pushsection/.popsection, so this stuff nests
properly. A further cleanup would be to get rid of all
.section/.previous pairs, since they're inherently fragile.
+From: Chuck Ebbert <76306.1226@compuserve.com>
Because code marked unsafe for kprobes jumps directly to
entry.S::error_code, that must be marked unsafe as well.
The easiest way to do that is to move the page fault entry
point to just before error_code and let it inherit the same
section.
Also moved all the ".previous" asm directives for kprobes
sections to column 1 and removed ".text" from them.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 04:52:34 -04:00
|
|
|
ENTRY(divide_error)
|
|
|
|
|
RING0_INT_FRAME
|
|
|
|
|
pushl $0 # no error code
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
pushl $do_divide_error
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
#ifdef CONFIG_X86_MCE
|
|
|
|
|
ENTRY(machine_check)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $0
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl machine_check_vector
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
ENTRY(spurious_interrupt_bug)
|
2006-06-26 07:57:44 -04:00
|
|
|
RING0_INT_FRAME
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $0
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_spurious_interrupt_bug
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
2005-04-16 18:20:36 -04:00
|
|
|
jmp error_code
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2005-04-16 18:20:36 -04:00
|
|
|
|
2006-06-26 07:57:41 -04:00
|
|
|
#ifdef CONFIG_STACK_UNWIND
|
|
|
|
|
ENTRY(arch_unwind_init_running)
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_STARTPROC
|
2006-06-26 07:57:41 -04:00
|
|
|
movl 4(%esp), %edx
|
|
|
|
|
movl (%esp), %ecx
|
|
|
|
|
leal 4(%esp), %eax
|
2006-12-06 20:14:02 -05:00
|
|
|
movl %ebx, PT_EBX(%edx)
|
2006-06-26 07:57:41 -04:00
|
|
|
xorl %ebx, %ebx
|
2006-12-06 20:14:02 -05:00
|
|
|
movl %ebx, PT_ECX(%edx)
|
|
|
|
|
movl %ebx, PT_EDX(%edx)
|
|
|
|
|
movl %esi, PT_ESI(%edx)
|
|
|
|
|
movl %edi, PT_EDI(%edx)
|
|
|
|
|
movl %ebp, PT_EBP(%edx)
|
|
|
|
|
movl %ebx, PT_EAX(%edx)
|
|
|
|
|
movl $__USER_DS, PT_DS(%edx)
|
|
|
|
|
movl $__USER_DS, PT_ES(%edx)
|
[PATCH] i386: Use %gs as the PDA base-segment in the kernel
This patch is the meat of the PDA change. This patch makes several related
changes:
1: Most significantly, %gs is now used in the kernel. This means that on
entry, the old value of %gs is saved away, and it is reloaded with
__KERNEL_PDA.
2: entry.S constructs the stack in the shape of struct pt_regs, and this
is passed around the kernel so that the process's saved register
state can be accessed.
Unfortunately struct pt_regs doesn't currently have space for %gs
(or %fs). This patch extends pt_regs to add space for gs (no space
is allocated for %fs, since it won't be used, and it would just
complicate the code in entry.S to work around the space).
3: Because %gs is now saved on the stack like %ds, %es and the integer
registers, there are a number of places where it no longer needs to
be handled specially; namely context switch, and saving/restoring the
register state in a signal context.
4: And since kernel threads run in kernel space and call normal kernel
code, they need to be created with their %gs == __KERNEL_PDA.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-12-06 20:14:02 -05:00
|
|
|
movl $0, PT_GS(%edx)
|
2006-12-06 20:14:02 -05:00
|
|
|
movl %ebx, PT_ORIG_EAX(%edx)
|
|
|
|
|
movl %ecx, PT_EIP(%edx)
|
2006-06-26 07:57:41 -04:00
|
|
|
movl 12(%esp), %ecx
|
2006-12-06 20:14:02 -05:00
|
|
|
movl $__KERNEL_CS, PT_CS(%edx)
|
|
|
|
|
movl %ebx, PT_EFLAGS(%edx)
|
|
|
|
|
movl %eax, PT_OLDESP(%edx)
|
2006-06-26 07:57:41 -04:00
|
|
|
movl 8(%esp), %eax
|
|
|
|
|
movl %ecx, 8(%esp)
|
2006-12-06 20:14:02 -05:00
|
|
|
movl PT_EBX(%edx), %ebx
|
|
|
|
|
movl $__KERNEL_DS, PT_OLDSS(%edx)
|
2006-06-26 07:57:41 -04:00
|
|
|
jmpl *%eax
|
2006-06-26 07:57:44 -04:00
|
|
|
CFI_ENDPROC
|
2006-06-26 07:57:41 -04:00
|
|
|
ENDPROC(arch_unwind_init_running)
|
|
|
|
|
#endif
|
|
|
|
|
|
2006-09-26 04:52:35 -04:00
|
|
|
ENTRY(kernel_thread_helper)
|
|
|
|
|
pushl $0 # fake return address for unwinder
|
|
|
|
|
CFI_STARTPROC
|
|
|
|
|
movl %edx,%eax
|
|
|
|
|
push %edx
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
call *%ebx
|
|
|
|
|
push %eax
|
|
|
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
|
|
|
call do_exit
|
|
|
|
|
CFI_ENDPROC
|
|
|
|
|
ENDPROC(kernel_thread_helper)
|
|
|
|
|
|
2006-01-06 03:12:05 -05:00
|
|
|
.section .rodata,"a"
|
2005-05-01 11:58:55 -04:00
|
|
|
#include "syscall_table.S"
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
syscall_table_size=(.-sys_call_table)
|
