From d498d4b47fb3050f2f7840cc49251f87f04d1ca9 Mon Sep 17 00:00:00 2001 From: Vijaya Kumar K Date: Tue, 28 Jan 2014 16:50:20 +0530 Subject: [PATCH] KGDB: make kgdb_breakpoint() as noinline The function kgdb_breakpoint() sets up break point at compile time by calling arch_kgdb_breakpoint(); Though this call is surrounded by wmb() barrier, the compile can still re-order the break point, because this scheduling barrier is not a code motion barrier in gcc. Making kgdb_breakpoint() as noinline solves this problem of code reording around break point instruction and also avoids problem of being called as inline function from other places More details about discussion on this can be found here http://comments.gmane.org/gmane.linux.ports.arm.kernel/269732 Signed-off-by: Vijaya Kumar K Acked-by: Will Deacon Acked-by: Jason Wessel Signed-off-by: Catalin Marinas --- kernel/debug/debug_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 334b3980ffc1..99982a70ddad 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -1035,7 +1035,7 @@ int dbg_io_get_char(void) * otherwise as a quick means to stop program execution and "break" into * the debugger. */ -void kgdb_breakpoint(void) +noinline void kgdb_breakpoint(void) { atomic_inc(&kgdb_setting_breakpoint); wmb(); /* Sync point before breakpoint */