perf/x86/intel/ds: Check insn_get_length() retval

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>
Link: https://lkml.kernel.org/r/20210304174237.31945-8-bp@alien8.de

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 7ebae18264033c73293d0293504fd3439303c83e..cdd195a3804e3a18ef9495772ce065fe082c47bb 100644 (file)
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1353,14 +1353,13 @@ 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.
+                * Make sure there was not a problem decoding the instruction.
+                * This is doubly important because we have an infinite loop if
+                * insn.length=0.
                 */
-               if (!insn.length)
+               if (insn_get_length(&insn))
                        break;
 
                to += insn.length;