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

Vijaya Kumar K committed 12 years ago

Commit d498d4b1 parent 44679a41 file · +1 −1Browse files

Showing the changes to kernel/debug (1 of 1 file). Show all

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kernel/debug/debug_core.c+1−1

@@ -1035,7 +1035,7 @@ int dbg_io_get_char(void) · 1034 unmodified lines
1035	1035	* otherwise as a quick means to stop program execution and "break" into
1036	1036	* the debugger.
1037	1037	*/
1038		−void kgdb_breakpoint(void)
	1038	+noinline void kgdb_breakpoint(void)
1039	1039	{
1040	1040	atomic_inc(&kgdb_setting_breakpoint);
1041	1041	wmb(); /* Sync point before breakpoint */