Commit-ID: 87aaff2ae09036cf699fde20dfd52ce7d3c8eabe Gitweb: http://git.kernel.org/tip/87aaff2ae09036cf699fde20dfd52ce7d3c8eabe Author: Josh Poimboeuf <[email protected]> AuthorDate: Sun, 28 Feb 2016 22:22:40 -0600 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 29 Feb 2016 08:35:12 +0100
x86/kprobes: Mark kretprobe_trampoline() stack frame as non-standard objtool reports the following warning for kretprobe_trampoline(): arch/x86/kernel/kprobes/core.o: warning: objtool: kretprobe_trampoline()+0x20: call without frame pointer save/setup kretprobes are a special case where the stack is intentionally wrong. The return address isn't known at the beginning of the trampoline, so the stack frame can't be set up properly before it calls trampoline_handler(). Because kretprobe handlers don't sleep, the frame pointer doesn't *have* to be accurate in the trampoline. So it's ok to tell objtool to ignore it. This results in no actual changes to the generated code. Signed-off-by: Josh Poimboeuf <[email protected]> Cc: Ananth N Mavinakayanahalli <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Anil S Keshavamurthy <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Bernd Petrovitsch <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Chris J Arges <[email protected]> Cc: David S. Miller <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Michal Marek <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Pedro Alves <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/7eaf37de52456ff822ffc86b928edb5d48a40ef1.1456719558.git.jpoim...@redhat.com Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/kernel/kprobes/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 48acaac..ae703ac 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -49,6 +49,7 @@ #include <linux/kdebug.h> #include <linux/kallsyms.h> #include <linux/ftrace.h> +#include <linux/frame.h> #include <asm/cacheflush.h> #include <asm/desc.h> @@ -703,6 +704,7 @@ asm( ".size kretprobe_trampoline, .-kretprobe_trampoline\n" ); NOKPROBE_SYMBOL(kretprobe_trampoline); +STACK_FRAME_NON_STANDARD(kretprobe_trampoline); /* * Called from kretprobe_trampoline
