[PATCH] powerpc/ftrace: Fix dropping weak symbols with older toolchains
From: Naveen N Rao <naveen@kernel.org>
Date: 2023-06-15 13:26:41
Subsystem:
function hooks (ftrace), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Steven Rostedt, Masami Hiramatsu, Madhavan Srinivasan, Linus Torvalds
The minimum level of gcc supported for building the kernel is v5.1.
v5.x releases of gcc emitted a three instruction sequence for
-mprofile-kernel:
mflr r0
std r0, 16(r1)
bl _mcount
It is only with the v6.x releases that gcc started emitting the two
instruction sequence for -mprofile-kernel, omitting the second store
instruction.
With the older three instruction sequence, the actual ftrace location
can be the 5th instruction into a function. Update the allowed offset
for ftrace location from 12 to 16 to accommodate the same.
Cc: stable@vger.kernel.org
Fixes: 7af82ff90a2b06 ("powerpc/ftrace: Ignore weak functions")
Signed-off-by: Naveen N Rao <naveen@kernel.org>
---
arch/powerpc/include/asm/ftrace.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
index 91c049d51d0e10..2edc6269b1a357 100644
--- a/arch/powerpc/include/asm/ftrace.h
+++ b/arch/powerpc/include/asm/ftrace.h@@ -12,7 +12,7 @@ /* Ignore unused weak functions which will have larger offsets */ #ifdef CONFIG_MPROFILE_KERNEL -#define FTRACE_MCOUNT_MAX_OFFSET 12 +#define FTRACE_MCOUNT_MAX_OFFSET 16 #elif defined(CONFIG_PPC32) #define FTRACE_MCOUNT_MAX_OFFSET 8 #endif
base-commit: bd517a8442b6c6646a136421cd4c1b95bf4ce32b -- 2.40.1