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>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 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: [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> diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S index 7c933a99f5d5..fa0921410fa4 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S +++ b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S @@ -45,10 +45,14 @@ _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 @@ -103,10 +107,10 @@ 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 possibly modified LR */ ld r0, _LINK(r1)