diff options
Diffstat (limited to 'arch/um')
| -rw-r--r-- | arch/um/os-Linux/signal.c | 28 |
1 files changed, 8 insertions, 20 deletions
diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c index 7ff8f57b715..62a66f38a91 100644 --- a/arch/um/os-Linux/signal.c +++ b/arch/um/os-Linux/signal.c @@ -15,6 +15,9 @@ #include "sysdep/sigcontext.h" #include "user.h" +/* Copied from linux/compiler-gcc.h since we can't include it directly */ +#define barrier() __asm__ __volatile__("": : :"memory") + /* * These are the asynchronous signals. SIGPROF is excluded because we want to * be able to profile all of UML, not just the non-critical sections. If @@ -27,13 +30,8 @@ #define SIGVTALRM_BIT 1 #define SIGVTALRM_MASK (1 << SIGVTALRM_BIT) -/* - * These are used by both the signal handlers and - * block/unblock_signals. I don't want modifications cached in a - * register - they must go straight to memory. - */ -static volatile int signals_enabled = 1; -static volatile int pending = 0; +static int signals_enabled; +static unsigned int pending; void sig_handler(int sig, struct sigcontext *sc) { @@ -198,7 +196,7 @@ void block_signals(void) * This might matter if gcc figures out how to inline this and * decides to shuffle this code into the caller. */ - mb(); + barrier(); } void unblock_signals(void) @@ -224,21 +222,11 @@ void unblock_signals(void) * Setting signals_enabled and reading pending must * happen in this order. */ - mb(); + barrier(); save_pending = pending; - if (save_pending == 0) { - /* - * This must return with signals enabled, so - * this barrier ensures that writes are - * flushed out before the return. This might - * matter if gcc figures out how to inline - * this (unlikely, given its size) and decides - * to shuffle this code into the caller. - */ - mb(); + if (save_pending == 0) return; - } pending = 0; |