Messages in this thread | | | Date | Thu, 29 Sep 2022 12:30:10 +0530 | Subject | Re: [PATCH 1/2] perf/x86/utils: fix uninitialized var in get_branch_type() | From | Sandipan Das <> |
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On 9/29/2022 12:10 AM, Stephane Eranian wrote: > offset is passed as a pointer and on certain call path is not set by the > function. If the caller does not re-initialize offset between calls, value > could be inherited between calls. Prevent this by initializing offset on each > call. > This impacts the code in amd_pmu_lbr_filter() which does > for(i=0; ...) { > ret = get_branch_type_fused(..., &offset); > if (offset) > lbr_entries[i].from += offset; > } > > Signed-off-by: Stephane Eranian <eranian@google.com> > --- > arch/x86/events/utils.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/x86/events/utils.c b/arch/x86/events/utils.c > index 5f5617afde79..76b1f8bb0fd5 100644 > --- a/arch/x86/events/utils.c > +++ b/arch/x86/events/utils.c > @@ -94,6 +94,10 @@ static int get_branch_type(unsigned long from, unsigned long to, int abort, > u8 buf[MAX_INSN_SIZE]; > int is64 = 0; > > + /* make sure we initialize offset */ > + if (offset) > + *offset = 0; > + > to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER; > from_plm = kernel_ip(from) ? X86_BR_KERNEL : X86_BR_USER; >
Reviewed-by: Sandipan Das <sandipan.das@amd.com>
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