This is a note to let you know that I've just added the patch titled
powerpc/ftrace: Pass the correct stack pointer for DYNAMIC_FTRACE_WITH_REGS
to the 4.9-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-pass-the-correct-stack-pointer-for-dynamic_ftrace_with_regs.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
rom a4979a7e71eb8da976cbe4a0a1fa50636e76b04f Mon Sep 17 00:00:00 2001
From: "Naveen N. Rao" <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
Date: Thu, 1 Jun 2017 16:18:16 +0530
Subject: powerpc/ftrace: Pass the correct stack pointer for DYNAMIC_FTRACE_WITH_REGS
From: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
commit a4979a7e71eb8da976cbe4a0a1fa50636e76b04f upstream.
For DYNAMIC_FTRACE_WITH_REGS, we should be passing-in the original set
of registers in pt_regs, to capture the state _before_ ftrace_caller.
However, we are instead passing the stack pointer *after* allocating a
stack frame in ftrace_caller. Fix this by saving the proper value of r1
in pt_regs. Also, use SAVE_10GPRS() to simplify the code.
Fixes: 153086644fd1 ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI")
Cc: stable@xxxxxxxxxxxxxxx # v4.6+
Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/entry_64.S | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -1235,10 +1235,14 @@ _GLOBAL(ftrace_caller)
stdu r1,-SWITCH_FRAME_SIZE(r1)
/* Save all gprs to pt_regs */
- SAVE_8GPRS(0,r1)
- SAVE_8GPRS(8,r1)
- SAVE_8GPRS(16,r1)
- SAVE_8GPRS(24,r1)
+ SAVE_GPR(0, r1)
+ SAVE_10GPRS(2, r1)
+ SAVE_10GPRS(12, r1)
+ SAVE_10GPRS(22, r1)
+
+ /* Save previous stack pointer (r1) */
+ addi r8, r1, SWITCH_FRAME_SIZE
+ std r8, GPR1(r1)
/* Load special regs for save below */
mfmsr r8
@@ -1292,10 +1296,10 @@ ftrace_call:
#endif
/* Restore gprs */
- REST_8GPRS(0,r1)
- REST_8GPRS(8,r1)
- REST_8GPRS(16,r1)
- REST_8GPRS(24,r1)
+ REST_GPR(0,r1)
+ REST_10GPRS(2,r1)
+ REST_10GPRS(12,r1)
+ REST_10GPRS(22,r1)
/* Restore callee's TOC */
ld r2, 24(r1)
Patches currently in stable-queue which might be from naveen.n.rao@xxxxxxxxxxxxxxxxxx are
queue-4.9/powerpc-ftrace-pass-the-correct-stack-pointer-for-dynamic_ftrace_with_regs.patch