android_kernel_xiaomi_sm8350/arch/um/os-Linux/sys-x86_64/registers.c
Jeff Dike 75e29b18d9 [PATCH] uml: stack usage reduction
The KSTK_* macros used an inordinate amount of stack.  In order to overcome
an impedance mismatch between their interface, which just returns a single
register value, and the interface of get_thread_regs, which took a full
pt_regs, the implementation created an on-stack pt_regs, filled it in, and
returned one field.  do_task_stat calls KSTK_* twice, resulting in two
local pt_regs, blowing out the stack.

This patch changes the interface (and name) of get_thread_regs to just
return a single register from a jmp_buf.

The include of archsetjmp.h" in registers.h to get the definition of
jmp_buf exposed a bogus include of <setjmp.h> in start_up.c.  <setjmp.h>
shouldn't be used anywhere any more since UML uses the klibc
setjmp/longjmp.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:49:09 -07:00

92 lines
2.1 KiB
C

/*
* Copyright (C) 2004 PathScale, Inc
* Licensed under the GPL
*/
#include <errno.h>
#include <string.h>
#include "ptrace_user.h"
#include "uml-config.h"
#include "skas_ptregs.h"
#include "registers.h"
#include "longjmp.h"
#include "user.h"
/* These are set once at boot time and not changed thereafter */
static unsigned long exec_regs[HOST_FRAME_SIZE];
static unsigned long exec_fp_regs[HOST_FP_SIZE];
void init_thread_registers(union uml_pt_regs *to)
{
memcpy(to->skas.regs, exec_regs, sizeof(to->skas.regs));
memcpy(to->skas.fp, exec_fp_regs, sizeof(to->skas.fp));
}
static int move_registers(int pid, int int_op, int fp_op,
union uml_pt_regs *regs)
{
if(ptrace(int_op, pid, 0, regs->skas.regs) < 0)
return(-errno);
if(ptrace(fp_op, pid, 0, regs->skas.fp) < 0)
return(-errno);
return(0);
}
void save_registers(int pid, union uml_pt_regs *regs)
{
int err;
err = move_registers(pid, PTRACE_GETREGS, PTRACE_GETFPREGS, regs);
if(err)
panic("save_registers - saving registers failed, errno = %d\n",
-err);
}
void restore_registers(int pid, union uml_pt_regs *regs)
{
int err;
err = move_registers(pid, PTRACE_SETREGS, PTRACE_SETFPREGS, regs);
if(err)
panic("restore_registers - saving registers failed, "
"errno = %d\n", -err);
}
void init_registers(int pid)
{
int err;
err = ptrace(PTRACE_GETREGS, pid, 0, exec_regs);
if(err)
panic("check_ptrace : PTRACE_GETREGS failed, errno = %d",
errno);
err = ptrace(PTRACE_GETFPREGS, pid, 0, exec_fp_regs);
if(err)
panic("check_ptrace : PTRACE_GETFPREGS failed, errno = %d",
errno);
}
void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
{
memcpy(regs, exec_regs, HOST_FRAME_SIZE * sizeof(unsigned long));
if(fp_regs != NULL)
memcpy(fp_regs, exec_fp_regs,
HOST_FP_SIZE * sizeof(unsigned long));
}
unsigned long get_thread_reg(int reg, jmp_buf *buf)
{
switch(reg){
case RIP: return buf[0]->__rip;
case RSP: return buf[0]->__rsp;
case RBP: return buf[0]->__rbp;
default:
printk("get_thread_regs - unknown register %d\n", reg);
return 0;
}
}