[PATCH] uml: Move signal handlers to arch code
Have most signals go through an arch-provided handler which recovers the
sigcontext and then calls a generic handler. This replaces the
ARCH_GET_SIGCONTEXT macro, which was somewhat fragile. On x86_64, recovering
%rdx (which holds the sigcontext pointer) must be the first thing that
happens. sig_handler duly invokes that first, but there is no guarantee that
I can see that instructions won't be reordered such that %rdx is used before
that. Having the arch provide the handler seems much more robust.
Some signals in some parts of UML require their own handlers - these places
don't call set_handler any more. They call sigaction or signal themselves.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index 3afde92..ff20362 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -246,7 +246,17 @@
set_sigstack(sig_stack, pages * page_size());
flags = SA_ONSTACK;
}
- if(usr1_handler) set_handler(SIGUSR1, usr1_handler, flags, -1);
+ if(usr1_handler){
+ struct sigaction sa;
+
+ sa.sa_handler = usr1_handler;
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = flags;
+ sa.sa_restorer = NULL;
+ if(sigaction(SIGUSR1, &sa, NULL) < 0)
+ panic("init_new_thread_stack - sigaction failed - "
+ "errno = %d\n", errno);
+ }
}
void init_new_thread_signals(void)