path: root/arch/um/sys-i386
diff options
authorJeff Dike <jdike@addtoit.com>2008-02-04 22:30:56 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-05 09:44:28 -0800
commitee3d9bd4de1ed93d2a7ee41c331ed30a1c7b8acd (patch)
treef49369c9f941066bdb8bbb2b4fd9d40bf2fda292 /arch/um/sys-i386
parentca77b555c0aafa3070fbb67592abaaa1b8d31913 (diff)
uml: simplify SIGSEGV handling
Simplify the page fault stub by not masking signals while it is running. This allows it to signal that it is done by executing an instruction which will generate a SIGTRAP (int3 on x86) rather than running sigreturn by hand after queueing a blocked SIGUSR1. userspace_tramp now no longer puts anything in the SIGSEGV sa_mask, but it does add SA_NODEFER to sa_flags so that SIGSEGV is still enabled after the signal handler fails to run sigreturn. SIGWINCH is just blocked so that we don't have to deal with it and the signal masks used by wait_stub_done are updated to reflect the smaller number of signals that it has to worry about. 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>
Diffstat (limited to 'arch/um/sys-i386')
1 files changed, 2 insertions, 17 deletions
diff --git a/arch/um/sys-i386/stub_segv.c b/arch/um/sys-i386/stub_segv.c
index b3999cb76bfd..28ccf737a79f 100644
--- a/arch/um/sys-i386/stub_segv.c
+++ b/arch/um/sys-i386/stub_segv.c
@@ -1,32 +1,17 @@
- * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
+ * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
-#include <signal.h>
-#include <sys/select.h> /* The only way I can see to get sigset_t */
-#include <asm/unistd.h>
-#include "as-layout.h"
-#include "uml-config.h"
#include "sysdep/stub.h"
#include "sysdep/sigcontext.h"
-#include "sysdep/faultinfo.h"
void __attribute__ ((__section__ (".__syscall_stub")))
stub_segv_handler(int sig)
struct sigcontext *sc = (struct sigcontext *) (&sig + 1);
- int pid;
GET_FAULTINFO_FROM_SC(*((struct faultinfo *) STUB_DATA), sc);
- pid = stub_syscall0(__NR_getpid);
- stub_syscall2(__NR_kill, pid, SIGUSR1);
- /* Load pointer to sigcontext into esp, since we need to leave
- * the stack in its original form when we do the sigreturn here, by
- * hand.
- */
- __asm__ __volatile__("mov %0,%%esp ; movl %1, %%eax ; "
- "int $0x80" : : "a" (sc), "g" (__NR_sigreturn));
+ trap_myself();

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