android_kernel_xiaomi_sm8350/arch/um/include/sysdep-i386/sigcontext.h
Bodo Stroesser c578455a3e [PATCH] uml: S390 preparation, abstract host page fault data
This patch removes the arch-specific fault/trap-infos from thread and
skas-regs.

It adds a new struct faultinfo, that is arch-specific defined in
sysdep/faultinfo.h.

The structure is inserted in thread.arch and thread.regs.skas and
thread.regs.tt

Now, segv and other trap-handlers can copy the contents from regs.X.faultinfo
to thread.arch.faultinfo with one simple assignment.

Also, the number of macros necessary is reduced to

FAULT_ADDRESS(struct faultinfo)
    extracts the faulting address from faultinfo

FAULT_WRITE(struct faultinfo)
    extracts the "is_write" flag

SEGV_IS_FIXABLE(struct faultinfo)
    is true for the fixable segvs, i.e. (TRAP == 14)
    on i386

UPT_FAULTINFO(regs)
    result is (struct faultinfo *) to the faultinfo
    in regs->skas.faultinfo

GET_FAULTINFO_FROM_SC(struct faultinfo, struct sigcontext *)
    copies the relevant parts of the sigcontext to
    struct faultinfo.

On SIGSEGV, call user_signal() instead of handle_segv(), if the architecture
provides the information needed in PTRACE_FAULTINFO, or if PTRACE_FAULTINFO is
missing, because segv-stub will provide the info.

The benefit of the change is, that in case of a non-fixable SIGSEGV, we can
give user processes a SIGSEGV, instead of possibly looping on pagefault
handling.

Since handle_segv() sikked arch_fixup() implicitly by passing ip==0 to segv(),
I changed segv() to call arch_fixup() only, if !is_user.

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05 16:36:36 -07:00

45 lines
1.2 KiB
C

/*
* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#ifndef __SYS_SIGCONTEXT_I386_H
#define __SYS_SIGCONTEXT_I386_H
#include <sysdep/sc.h>
#define IP_RESTART_SYSCALL(ip) ((ip) -= 2)
#define SC_RESTART_SYSCALL(sc) IP_RESTART_SYSCALL(SC_IP(sc))
#define SC_SET_SYSCALL_RETURN(sc, result) SC_EAX(sc) = (result)
#define GET_FAULTINFO_FROM_SC(fi,sc) \
{ \
(fi).cr2 = SC_CR2(sc); \
(fi).error_code = SC_ERR(sc); \
(fi).trap_no = SC_TRAPNO(sc); \
}
/* ptrace expects that, at the start of a system call, %eax contains
* -ENOSYS, so this makes it so.
*/
#define SC_START_SYSCALL(sc) do SC_EAX(sc) = -ENOSYS; while(0)
/* This is Page Fault */
#define SEGV_IS_FIXABLE(fi) ((fi)->trap_no == 14)
extern unsigned long *sc_sigmask(void *sc_ptr);
extern int sc_get_fpregs(unsigned long buf, void *sc_ptr);
#endif
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/