This is a note to let you know that I've just added the patch titled
powerpc/ftrace: Fix dropping weak symbols with older toolchains
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-ftrace-fix-dropping-weak-symbols-with-older-toolchains.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f6834c8c59a8e977a6f6e4f96c5d28dfa5db8430 Mon Sep 17 00:00:00 2001
From: Naveen N Rao <naveen@xxxxxxxxxx>
Date: Mon, 19 Jun 2023 15:17:19 +0530
Subject: powerpc/ftrace: Fix dropping weak symbols with older toolchains
From: Naveen N Rao <naveen@xxxxxxxxxx>
commit f6834c8c59a8e977a6f6e4f96c5d28dfa5db8430 upstream.
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@xxxxxxxxxxxxxxx
Fixes: 7af82ff90a2b06 ("powerpc/ftrace: Ignore weak functions")
Signed-off-by: Naveen N Rao <naveen@xxxxxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://msgid.link/7b265908a9461e38fc756ef9b569703860a80621.1687166935.git.naveen@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/ftrace.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- 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
Patches currently in stable-queue which might be from naveen@xxxxxxxxxx are
queue-6.5/powerpc-ftrace-fix-dropping-weak-symbols-with-older-toolchains.patch
