提交 42daba31 编写于 作者: J Jeff Dike 提交者: Linus Torvalds

uml: stop saving process FP state

Throw out a lot of code dealing with saving and restoring floating-point
state.  In skas mode, where processes run in a restoring floating-point state
on kernel entry and exit is pointless.

This eliminates most of arch/um/os-Linux/sys-{i386,x86_64}/registers.c.  Most
of what remained is now arch-indpendent, and can be moved up to
arch/um/os-Linux/registers.c.  Both arches need the jmp_buf accessor
get_thread_reg, and i386 needs {save,restore}_fp_regs because it cheats during
sigreturn by getting the fp state using ptrace rather than copying it out of
the process sigcontext.

After this, it turns out that arch/um/include/skas/mode-skas.h is almost
completely unneeded.  The declarations in it are variables which either don't
exist or which don't have global scope.  The one exception is
kill_off_processes_skas.  If that's removed, this header can be deleted.

This uncovered a bug in user.h, which wasn't correctly making sure that a
size_t definition was available to both userspace and kernelspace files.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 5c8aacea
......@@ -307,6 +307,8 @@ extern int protect(struct mm_id * mm_idp, unsigned long addr,
extern int is_skas_winch(int pid, int fd, void *data);
extern int start_userspace(unsigned long stub_stack);
extern int copy_context_skas0(unsigned long stack, int pid);
extern void save_registers(int pid, union uml_pt_regs *regs);
extern void restore_registers(int pid, union uml_pt_regs *regs);
extern void userspace(union uml_pt_regs *regs);
extern void map_stub_pages(int fd, unsigned long code,
unsigned long data, unsigned long stack);
......
......@@ -15,7 +15,7 @@ extern int restore_fp_registers(int pid, unsigned long *fp_regs);
extern void save_registers(int pid, union uml_pt_regs *regs);
extern void restore_registers(int pid, union uml_pt_regs *regs);
extern void init_registers(int pid);
extern void get_safe_registers(unsigned long * regs, unsigned long * fp_regs);
extern void get_safe_registers(unsigned long *regs);
extern unsigned long get_thread_reg(int reg, jmp_buf *buf);
#endif
/*
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
* Licensed under the GPL
*/
#ifndef __MODE_SKAS_H__
#define __MODE_SKAS_H__
#include <sysdep/ptrace.h>
extern unsigned long exec_regs[];
extern unsigned long exec_fp_regs[];
extern unsigned long exec_fpx_regs[];
extern int have_fpx_regs;
extern void kill_off_processes_skas(void);
#endif
......@@ -219,14 +219,3 @@ struct syscall_args {
CHOOSE_MODE((&(r)->tt.faultinfo), (&(r)->skas.faultinfo))
#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:
*/
......@@ -14,10 +14,12 @@
*/
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
/*
* This will provide the size_t definition in both kernel and userspace builds
*/
/* This is to get size_t */
#ifdef __KERNEL__
#include <linux/types.h>
#else
#include <stddef.h>
#endif
extern void panic(const char *fmt, ...)
__attribute__ ((format (printf, 1, 2)));
......
......@@ -4,8 +4,8 @@
#
obj-y = aio.o elf_aux.o execvp.o file.o helper.o irq.o main.o mem.o process.o \
sigio.o signal.o start_up.o time.o trap.o tty.o uaccess.o umid.o tls.o \
user_syms.o util.o drivers/ sys-$(SUBARCH)/
registers.o sigio.o signal.o start_up.o time.o trap.o tty.o uaccess.o \
umid.o tls.o user_syms.o util.o drivers/ sys-$(SUBARCH)/
obj-$(CONFIG_MODE_SKAS) += skas/
......@@ -16,8 +16,8 @@ obj-$(CONFIG_TTY_LOG) += tty_log.o
user-objs-$(CONFIG_TTY_LOG) += tty_log.o
USER_OBJS := $(user-objs-y) aio.o elf_aux.o execvp.o file.o helper.o irq.o \
main.o mem.o process.o sigio.o signal.o start_up.o time.o trap.o tty.o \
tls.o uaccess.o umid.o util.o
main.o mem.o process.o registers.o sigio.o signal.o start_up.o time.o \
trap.o tty.o tls.o uaccess.o umid.o util.o
CFLAGS_user_syms.o += -DSUBARCH_$(SUBARCH)
......
/*
* Copyright (C) 2004 PathScale, Inc
* Licensed under the GPL
*/
#include <errno.h>
#include <string.h>
#include <sys/ptrace.h>
#include "user.h"
#include "sysdep/ptrace.h"
/* This is set once at boot time and not changed thereafter */
static unsigned long exec_regs[MAX_REG_NR];
void init_thread_registers(union uml_pt_regs *to)
{
memcpy(to->skas.regs, exec_regs, sizeof(to->skas.regs));
}
void save_registers(int pid, union uml_pt_regs *regs)
{
int err;
err = ptrace(PTRACE_GETREGS, pid, 0, regs->skas.regs);
if(err < 0)
panic("save_registers - saving registers failed, errno = %d\n",
errno);
}
void restore_registers(int pid, union uml_pt_regs *regs)
{
int err;
err = ptrace(PTRACE_SETREGS, pid, 0, regs->skas.regs);
if(err < 0)
panic("restore_registers - saving registers failed, "
"errno = %d\n", errno);
}
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);
}
void get_safe_registers(unsigned long *regs)
{
memcpy(regs, exec_regs, sizeof(exec_regs));
}
......@@ -44,7 +44,7 @@ static unsigned long syscall_regs[MAX_REG_NR];
static int __init init_syscall_regs(void)
{
get_safe_registers(syscall_regs, NULL);
get_safe_registers(syscall_regs);
syscall_regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
((unsigned long) &batch_syscall_stub -
(unsigned long) &__syscall_stub_start);
......
......@@ -357,11 +357,10 @@ void userspace(union uml_pt_regs *regs)
}
static unsigned long thread_regs[MAX_REG_NR];
static unsigned long thread_fp_regs[HOST_FP_SIZE];
static int __init init_thread_regs(void)
{
get_safe_registers(thread_regs, thread_fp_regs);
get_safe_registers(thread_regs);
/* Set parent's instruction pointer to start of clone-stub */
thread_regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
(unsigned long) stub_clone_handler -
......@@ -398,11 +397,6 @@ int copy_context_skas0(unsigned long new_stack, int pid)
panic("copy_context_skas0 : PTRACE_SETREGS failed, "
"pid = %d, errno = %d\n", pid, -err);
err = ptrace_setfpregs(pid, thread_fp_regs);
if(err < 0)
panic("copy_context_skas0 : PTRACE_SETFPREGS failed, "
"pid = %d, errno = %d\n", pid, -err);
/* set a well known return code for detection of child write failure */
child_data->err = 12345678;
......
......@@ -4,30 +4,10 @@
*/
#include <errno.h>
#include <string.h>
#include "sysdep/ptrace_user.h"
#include "sysdep/ptrace.h"
#include "uml-config.h"
#include "skas_ptregs.h"
#include "registers.h"
#include <sysdep/ptrace_user.h>
#include "longjmp.h"
#include "user.h"
/* These are set once at boot time and not changed thereafter */
static unsigned long exec_regs[MAX_REG_NR];
static unsigned long exec_fp_regs[HOST_FP_SIZE];
static unsigned long exec_fpx_regs[HOST_XFP_SIZE];
static int have_fpx_regs = 1;
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));
if(have_fpx_regs)
memcpy(to->skas.xfp, exec_fpx_regs, sizeof(to->skas.xfp));
}
/* XXX These need to use [GS]ETFPXREGS and copy_sc_{to,from}_user_skas needs
* to pass in a sufficiently large buffer
*/
......@@ -45,92 +25,6 @@ int restore_fp_registers(int pid, unsigned long *fp_regs)
return 0;
}
static int move_registers(int pid, int int_op, union uml_pt_regs *regs,
int fp_op, unsigned long *fp_regs)
{
if(ptrace(int_op, pid, 0, regs->skas.regs) < 0)
return -errno;
if(ptrace(fp_op, pid, 0, fp_regs) < 0)
return -errno;
return 0;
}
void save_registers(int pid, union uml_pt_regs *regs)
{
unsigned long *fp_regs;
int err, fp_op;
if(have_fpx_regs){
fp_op = PTRACE_GETFPXREGS;
fp_regs = regs->skas.xfp;
}
else {
fp_op = PTRACE_GETFPREGS;
fp_regs = regs->skas.fp;
}
err = move_registers(pid, PTRACE_GETREGS, regs, fp_op, fp_regs);
if(err)
panic("save_registers - saving registers failed, errno = %d\n",
-err);
}
void restore_registers(int pid, union uml_pt_regs *regs)
{
unsigned long *fp_regs;
int err, fp_op;
if(have_fpx_regs){
fp_op = PTRACE_SETFPXREGS;
fp_regs = regs->skas.xfp;
}
else {
fp_op = PTRACE_SETFPREGS;
fp_regs = regs->skas.fp;
}
err = move_registers(pid, PTRACE_SETREGS, regs, fp_op, fp_regs);
if(err)
panic("restore_registers - saving registers failed, "
"errno = %d\n", -err);
}
void init_registers(int pid)
{
int err;
memset(exec_regs, 0, sizeof(exec_regs));
err = ptrace(PTRACE_GETREGS, pid, 0, exec_regs);
if(err)
panic("check_ptrace : PTRACE_GETREGS failed, errno = %d",
errno);
errno = 0;
err = ptrace(PTRACE_GETFPXREGS, pid, 0, exec_fpx_regs);
if(!err)
return;
if(errno != EIO)
panic("check_ptrace : PTRACE_GETFPXREGS failed, errno = %d",
errno);
have_fpx_regs = 0;
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, sizeof(exec_regs));
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){
......
#
# Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
# Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
# Licensed under the GPL
#
......
/*
* Copyright (C) 2004 PathScale, Inc
* Copyright (C) 2006-2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <errno.h>
#include <sys/ptrace.h>
#include <string.h>
#include "ptrace_user.h"
#include "uml-config.h"
#include "skas_ptregs.h"
#include "registers.h"
#define __FRAME_OFFSETS
#include <asm/ptrace.h>
#include "longjmp.h"
#include "user.h"
/* These are set once at boot time and not changed thereafter */
static unsigned long exec_regs[MAX_REG_NR];
static unsigned long exec_fp_regs[HOST_FP_SIZE];
int save_fp_registers(int pid, unsigned long *fp_regs)
{
if(ptrace(PTRACE_GETFPREGS, pid, 0, fp_regs) < 0)
......@@ -32,67 +24,6 @@ int restore_fp_registers(int pid, unsigned long *fp_regs)
return 0;
}
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, sizeof(exec_regs));
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){
......
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