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uml: stop saving process FP state

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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: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jeff Dike 2007-10-16 01:26:47 -07:00 committed by Linus Torvalds
parent 5c8aaceab8
commit 42daba3165
12 changed files with 74 additions and 215 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/um/include/os.h
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@ -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);

2
arch/um/include/registers.h
View File

@ -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

9
arch/um/include/skas/mode-skas.h
View File

@ -1,18 +1,11 @@
/*
* 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

11
arch/um/include/sysdep-i386/ptrace.h
View File

@ -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:
*/

8
arch/um/include/user.h
View File

@ -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)));

8
arch/um/os-Linux/Makefile
View File

@ -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)

54
arch/um/os-Linux/registers.c Normal file
View File

@ -0,0 +1,54 @@
/*
* 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));
}

2
arch/um/os-Linux/skas/mem.c
View File

@ -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);

8
arch/um/os-Linux/skas/process.c
View File

@ -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;

108
arch/um/os-Linux/sys-i386/registers.c
View File

@ -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){

2
arch/um/os-Linux/sys-x86_64/Makefile
View File

@ -1,5 +1,5 @@
#
# Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
# Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
# Licensed under the GPL
#

75
arch/um/os-Linux/sys-x86_64/registers.c
View File

@ -1,23 +1,15 @@
/*
* 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){