From 4b84c69b5f6c08a540e3683f1360a6cdef2806c7 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Mon, 25 Sep 2006 23:33:04 -0700 Subject: [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/os-Linux/sys-x86_64/Makefile | 2 +- arch/um/os-Linux/sys-x86_64/signal.c | 16 ++++++++++++++++ 2 files changed, 17 insertions(+), 1 deletion(-) create mode 100644 arch/um/os-Linux/sys-x86_64/signal.c (limited to 'arch/um/os-Linux/sys-x86_64') diff --git a/arch/um/os-Linux/sys-x86_64/Makefile b/arch/um/os-Linux/sys-x86_64/Makefile index 340ef26f594..f67842a7735 100644 --- a/arch/um/os-Linux/sys-x86_64/Makefile +++ b/arch/um/os-Linux/sys-x86_64/Makefile @@ -3,7 +3,7 @@ # Licensed under the GPL # -obj-$(CONFIG_MODE_SKAS) = registers.o +obj-$(CONFIG_MODE_SKAS) = registers.o signal.o USER_OBJS := $(obj-y) diff --git a/arch/um/os-Linux/sys-x86_64/signal.c b/arch/um/os-Linux/sys-x86_64/signal.c new file mode 100644 index 00000000000..3f369e5f976 --- /dev/null +++ b/arch/um/os-Linux/sys-x86_64/signal.c @@ -0,0 +1,16 @@ +/* + * Copyright (C) 2006 Jeff Dike (jdike@addtoit.com) + * Licensed under the GPL + */ + +#include + +extern void (*handlers[])(int sig, struct sigcontext *sc); + +void hard_handler(int sig) +{ + struct ucontext *uc; + asm("movq %%rdx, %0" : "=r" (uc)); + + (*handlers[sig])(sig, (struct sigcontext *) &uc->uc_mcontext); +} -- cgit v1.2.3