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: 153086644f ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI")
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Naveen N. Rao 2017-06-01 16:18:16 +05:30 committed by Michael Ellerman
parent a9f8553e93
commit a4979a7e71

View File

@ -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)