On 2017/06/26 08:20AM, gregkh@xxxxxxxxxxxxxxxxxxx wrote: > > The patch below does not apply to the 4.9-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to <stable@xxxxxxxxxxxxxxx>. Michael, Greg, Here is a version that applies on v4.9 and v4.11. These bits have been moved under arch/powerpc/kernel/trace and as such needed adjustment to apply to entry_64.S. I couldn't test this as I get the below error trying to compile v4.9: ld: arch/powerpc/boot/zImage.pseries: Not enough room for program headers, try linking with -N ld: final link failed: Bad value Michael, Can you please help test this? Thanks, Naveen - [PATCH] powerpc/ftrace: Pass the correct stack pointer for DYNAMIC_FTRACE_WITH_REGS 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> --- arch/powerpc/kernel/entry_64.S | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 767ef6d68c9e..caa659671599 100644 --- 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) -- 2.13.1