powerpc/ftrace: Fix stack teardown in ftrace_no_trace

commit 4b3338aaa74d7d4ec5b6734dc298f0db94ec83d2 upstream.

Commit 41a506ef71eb ("powerpc/ftrace: Create a dummy stackframe to fix
stack unwind") added use of a new stack frame on ftrace entry to fix
stack unwind. However, the commit missed updating the offset used while
tearing down the ftrace stack when ftrace is disabled. Fix the same.

In addition, the commit missed saving the correct stack pointer in
pt_regs. Update the same.

Fixes: 41a506ef71eb ("powerpc/ftrace: Create a dummy stackframe to fix stack unwind")
Cc: stable@vger.kernel.org # v6.5+
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231130065947.2188860-1-naveen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
index ee66f48770428cf5b3772e8e5a5f21ffee020031..b77949c8e03195fcbb4bc34627884e4aa86a8bbb 100644 (file)
--- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
+++ b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
@@ -54,7 +54,7 @@ _GLOBAL(ftrace_caller)
        SAVE_10GPRS(22, r1)
 
        /* Save previous stack pointer (r1) */
-       addi    r8, r1, SWITCH_FRAME_SIZE
+       addi    r8, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE
        std     r8, GPR1(r1)
 
        /* Load special regs for save below */