From f25f9074c24f1451a74942c4bc089bb53e47f462 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 7 Feb 2009 20:22:40 +0000 Subject: [PATCH] powerpc/ftrace: Fix math to calculate offset in TOC Impact: fix dynamic ftrace with large modules in PPC64 The math to calculate the offset into the TOC that is taken from reading the trampoline is incorrect. The bottom half of the offset is a signed extended short. The current code was using an OR to create the offset when it should have been using an addition. Signed-off-by: Steven Rostedt Acked-by: Geoff Levand Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/ftrace.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 5355244c99ff..60c60ccf5e3c 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -195,8 +195,9 @@ __ftrace_make_nop(struct module *mod, return -EINVAL; } - offset = (unsigned)((unsigned short)jmp[0]) << 16 | - (unsigned)((unsigned short)jmp[1]); + /* The bottom half is signed extended */ + offset = ((unsigned)((unsigned short)jmp[0]) << 16) + + (int)((short)jmp[1]); DEBUGP(" %x ", offset); -- 2.20.1