[PATCH 5.13 136/151] powerpc/interrupt: Do not call single_step_exception() from other exceptions

Greg Kroah-Hartman
2021-08-16T13:32:30Z

From: Christophe Leroy <christophe.leroy@csgroup.eu>

commit 01fcac8e4dfc112f420dcaeb70056a74e326cacf upstream.

single_step_exception() is called by emulate_single_step() which
is called from (at least) alignment exception() handler and
program_check_exception() handler.

Redefine it as a regular __single_step_exception() which is called
by both single_step_exception() handler and emulate_single_step()
function.

Fixes: 3a96570ffceb ("powerpc: convert interrupt handlers to use wrappers")
Cc: stable@vger.kernel.org # v5.12+
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/aed174f5cbc06f2cf95233c071d8aac948e46043.1628611921.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/kernel/traps.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1103,7 +1103,7 @@ DEFINE_INTERRUPT_HANDLER(RunModeExceptio
_exception(SIGTRAP, regs, TRAP_UNK, 0);
}

-DEFINE_INTERRUPT_HANDLER(single_step_exception)
+static void __single_step_exception(struct pt_regs *regs)
{
clear_single_step(regs);
clear_br_trace(regs);
@@ -1120,6 +1120,11 @@ DEFINE_INTERRUPT_HANDLER(single_step_exc
_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
}

+DEFINE_INTERRUPT_HANDLER(single_step_exception)
+{
+ __single_step_exception(regs);
+}
+
/*
* After we have successfully emulated an instruction, we have to
* check if the instruction was being single-stepped, and if so,
@@ -1129,7 +1134,7 @@ DEFINE_INTERRUPT_HANDLER(single_step_exc
static void emulate_single_step(struct pt_regs *regs)
{
if (single_stepping(regs))
- single_step_exception(regs);
+ __single_step_exception(regs);
}

static inline int __parse_fpscr(unsigned long fpscr)