aboutsummaryrefslogtreecommitdiffstats
path: root/arch/um
diff options
context:
space:
mode:
authorJeff Dike <jdike@addtoit.com>2005-11-22 00:32:09 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2005-11-22 12:13:41 -0500
commit17d469715c6453e4994e6617e8f644bf10f38584 (patch)
tree0bfc17100309b888315c3cae02adfd1783c04774 /arch/um
parente23181deec0d2a8be576faf9d71211abb84d5ccc (diff)
[PATCH] uml: properly invoke x86_64 system calls
This patch makes stub_segv use the stub_syscall macros. This was needed anyway, but the bug that prompted this was the discovery that gcc was storing stuff in RCX, which is trashed across a system call. This is exactly the sort of problem that the new macros fix. There is a stub_syscall0 for getpid. stub_segv was changed to be a libc file, and that caused some include changes. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um')
-rw-r--r--arch/um/include/sysdep-i386/stub.h9
-rw-r--r--arch/um/include/sysdep-x86_64/stub.h12
-rw-r--r--arch/um/sys-i386/Makefile2
-rw-r--r--arch/um/sys-i386/stub_segv.c11
-rw-r--r--arch/um/sys-x86_64/Makefile2
-rw-r--r--arch/um/sys-x86_64/stub_segv.c20
6 files changed, 39 insertions, 17 deletions
diff --git a/arch/um/include/sysdep-i386/stub.h b/arch/um/include/sysdep-i386/stub.h
index a49ceb199ee5..6ba8cbbe0d36 100644
--- a/arch/um/include/sysdep-i386/stub.h
+++ b/arch/um/include/sysdep-i386/stub.h
@@ -16,6 +16,15 @@ extern void stub_clone_handler(void);
16#define STUB_MMAP_NR __NR_mmap2 16#define STUB_MMAP_NR __NR_mmap2
17#define MMAP_OFFSET(o) ((o) >> PAGE_SHIFT) 17#define MMAP_OFFSET(o) ((o) >> PAGE_SHIFT)
18 18
19static inline long stub_syscall0(long syscall)
20{
21 long ret;
22
23 __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall));
24
25 return ret;
26}
27
19static inline long stub_syscall1(long syscall, long arg1) 28static inline long stub_syscall1(long syscall, long arg1)
20{ 29{
21 long ret; 30 long ret;
diff --git a/arch/um/include/sysdep-x86_64/stub.h b/arch/um/include/sysdep-x86_64/stub.h
index 2bd6e7a97286..c41689c13dc9 100644
--- a/arch/um/include/sysdep-x86_64/stub.h
+++ b/arch/um/include/sysdep-x86_64/stub.h
@@ -6,7 +6,6 @@
6#ifndef __SYSDEP_STUB_H 6#ifndef __SYSDEP_STUB_H
7#define __SYSDEP_STUB_H 7#define __SYSDEP_STUB_H
8 8
9#include <asm/ptrace.h>
10#include <asm/unistd.h> 9#include <asm/unistd.h>
11#include <sysdep/ptrace_user.h> 10#include <sysdep/ptrace_user.h>
12 11
@@ -20,6 +19,17 @@ extern void stub_clone_handler(void);
20#define __syscall_clobber "r11","rcx","memory" 19#define __syscall_clobber "r11","rcx","memory"
21#define __syscall "syscall" 20#define __syscall "syscall"
22 21
22static inline long stub_syscall0(long syscall)
23{
24 long ret;
25
26 __asm__ volatile (__syscall
27 : "=a" (ret)
28 : "0" (syscall) : __syscall_clobber );
29
30 return ret;
31}
32
23static inline long stub_syscall2(long syscall, long arg1, long arg2) 33static inline long stub_syscall2(long syscall, long arg1, long arg2)
24{ 34{
25 long ret; 35 long ret;
diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile
index 6dfeb70f6957..150059dbee12 100644
--- a/arch/um/sys-i386/Makefile
+++ b/arch/um/sys-i386/Makefile
@@ -5,7 +5,7 @@ obj-y = bitops.o bugs.o checksum.o delay.o fault.o ksyms.o ldt.o ptrace.o \
5obj-$(CONFIG_HIGHMEM) += highmem.o 5obj-$(CONFIG_HIGHMEM) += highmem.o
6obj-$(CONFIG_MODULES) += module.o 6obj-$(CONFIG_MODULES) += module.o
7 7
8USER_OBJS := bugs.o ptrace_user.o sigcontext.o fault.o 8USER_OBJS := bugs.o ptrace_user.o sigcontext.o fault.o stub_segv.o
9 9
10SYMLINKS = bitops.c semaphore.c highmem.c module.c 10SYMLINKS = bitops.c semaphore.c highmem.c module.c
11 11
diff --git a/arch/um/sys-i386/stub_segv.c b/arch/um/sys-i386/stub_segv.c
index 1e88b275edac..a37f672ec964 100644
--- a/arch/um/sys-i386/stub_segv.c
+++ b/arch/um/sys-i386/stub_segv.c
@@ -3,9 +3,11 @@
3 * Licensed under the GPL 3 * Licensed under the GPL
4 */ 4 */
5 5
6#include <asm/signal.h> 6#include <signal.h>
7#include <sys/select.h> /* The only way I can see to get sigset_t */
7#include <asm/unistd.h> 8#include <asm/unistd.h>
8#include "uml-config.h" 9#include "uml-config.h"
10#include "sysdep/stub.h"
9#include "sysdep/sigcontext.h" 11#include "sysdep/sigcontext.h"
10#include "sysdep/faultinfo.h" 12#include "sysdep/faultinfo.h"
11 13
@@ -13,13 +15,14 @@ void __attribute__ ((__section__ (".__syscall_stub")))
13stub_segv_handler(int sig) 15stub_segv_handler(int sig)
14{ 16{
15 struct sigcontext *sc = (struct sigcontext *) (&sig + 1); 17 struct sigcontext *sc = (struct sigcontext *) (&sig + 1);
18 int pid;
16 19
17 GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA), 20 GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
18 sc); 21 sc);
19 22
20 __asm__("movl %0, %%eax ; int $0x80": : "g" (__NR_getpid)); 23 pid = stub_syscall0(__NR_getpid);
21 __asm__("movl %%eax, %%ebx ; movl %0, %%eax ; movl %1, %%ecx ;" 24 stub_syscall2(__NR_kill, pid, SIGUSR1);
22 "int $0x80": : "g" (__NR_kill), "g" (SIGUSR1)); 25
23 /* Load pointer to sigcontext into esp, since we need to leave 26 /* Load pointer to sigcontext into esp, since we need to leave
24 * the stack in its original form when we do the sigreturn here, by 27 * the stack in its original form when we do the sigreturn here, by
25 * hand. 28 * hand.
diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index ea977df395a1..00b2025427df 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -12,7 +12,7 @@ lib-y = bitops.o bugs.o csum-partial.o delay.o fault.o ldt.o mem.o memcpy.o \
12obj-y := ksyms.o 12obj-y := ksyms.o
13obj-$(CONFIG_MODULES) += module.o um_module.o 13obj-$(CONFIG_MODULES) += module.o um_module.o
14 14
15USER_OBJS := ptrace_user.o sigcontext.o 15USER_OBJS := ptrace_user.o sigcontext.o stub_segv.o
16 16
17SYMLINKS = bitops.c csum-copy.S csum-partial.c csum-wrappers.c ldt.c memcpy.S \ 17SYMLINKS = bitops.c csum-copy.S csum-partial.c csum-wrappers.c ldt.c memcpy.S \
18 thunk.S module.c 18 thunk.S module.c
diff --git a/arch/um/sys-x86_64/stub_segv.c b/arch/um/sys-x86_64/stub_segv.c
index d1e53bdf2e85..a27099533198 100644
--- a/arch/um/sys-x86_64/stub_segv.c
+++ b/arch/um/sys-x86_64/stub_segv.c
@@ -3,14 +3,14 @@
3 * Licensed under the GPL 3 * Licensed under the GPL
4 */ 4 */
5 5
6#include <asm/signal.h> 6#include <stddef.h>
7#include <signal.h>
7#include <linux/compiler.h> 8#include <linux/compiler.h>
8#include <asm/unistd.h> 9#include <asm/unistd.h>
9#include <asm/ucontext.h>
10#include "uml-config.h" 10#include "uml-config.h"
11#include "sysdep/sigcontext.h" 11#include "sysdep/sigcontext.h"
12#include "sysdep/faultinfo.h" 12#include "sysdep/faultinfo.h"
13#include <stddef.h> 13#include "sysdep/stub.h"
14 14
15/* Copied from sys-x86_64/signal.c - Can't find an equivalent definition 15/* Copied from sys-x86_64/signal.c - Can't find an equivalent definition
16 * in the libc headers anywhere. 16 * in the libc headers anywhere.
@@ -31,21 +31,21 @@ void __attribute__ ((__section__ (".__syscall_stub")))
31stub_segv_handler(int sig) 31stub_segv_handler(int sig)
32{ 32{
33 struct ucontext *uc; 33 struct ucontext *uc;
34 int pid;
34 35
35 __asm__("movq %%rdx, %0" : "=g" (uc) :); 36 __asm__("movq %%rdx, %0" : "=g" (uc) :);
36 GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA), 37 GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
37 &uc->uc_mcontext); 38 &uc->uc_mcontext);
38 39
39 __asm__("movq %0, %%rax ; syscall": : "g" (__NR_getpid)); 40 pid = stub_syscall0(__NR_getpid);
40 __asm__("movq %%rax, %%rdi ; movq %0, %%rax ; movq %1, %%rsi ;" 41 stub_syscall2(__NR_kill, pid, SIGUSR1);
41 "syscall": : "g" (__NR_kill), "g" (SIGUSR1) : 42
42 "%rdi", "%rax", "%rsi");
43 /* sys_sigreturn expects that the stack pointer will be 8 bytes into 43 /* sys_sigreturn expects that the stack pointer will be 8 bytes into
44 * the signal frame. So, we use the ucontext pointer, which we know 44 * the signal frame. So, we use the ucontext pointer, which we know
45 * already, to get the signal frame pointer, and add 8 to that. 45 * already, to get the signal frame pointer, and add 8 to that.
46 */ 46 */
47 __asm__("movq %0, %%rsp": : 47 __asm__("movq %0, %%rsp; movq %1, %%rax ; syscall": :
48 "g" ((unsigned long) container_of(uc, struct rt_sigframe, 48 "g" ((unsigned long) container_of(uc, struct rt_sigframe,
49 uc) + 8)); 49 uc) + 8),
50 __asm__("movq %0, %%rax ; syscall" : : "g" (__NR_rt_sigreturn)); 50 "g" (__NR_rt_sigreturn));
51} 51}