[RFC PATCH v0 06/19] perf/x86/intel/ds: Check insn_get_length() retval

Borislav Petkov
2020-11-24T10:20:24Z

intel_pmu_pebs_fixup_ip() needs only the insn length so use the
appropriate helper instead of a full decode. A full decode differs only
in running insn_complete() on the decoded insn but that is not needed
here.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/events/intel/ds.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index fb327d11a04d..56cbcfee0ab1 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1263,14 +1263,14 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
is_64bit = kernel_ip(to) || any_64bit_mode(regs);
#endif
insn_init(&insn, kaddr, size, is_64bit);
- insn_get_length(&insn);
+
/*
* Make sure there was not a problem decoding the
* instruction and getting the length. This is
* doubly important because we have an infinite
* loop if insn.length=0.
*/
- if (!insn.length)
+ if (insn_get_length(&insn) || !insn.length)
break;

to += insn.length;
--
2.21.0