lkml.org 
[lkml]   [2022]   [Mar]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
SubjectRe: [PATCH v6 10/12] perf tools: Improve IBS error handling
On Mon, Mar 14, 2022 at 11:23 PM Ravi Bangoria <ravi.bangoria@amd.com> wrote:
>
> >> +static bool is_amd(const char *arch, const char *cpuid)
> >> +{
> >> + return arch && !strcmp("x86", arch) && cpuid && strstarts(cpuid, "AuthenticAMD");
> >> +}
> >> +
> >> +static bool is_amd_ibs(struct evsel *evsel)
> >> +{
> >> + return evsel->core.attr.precise_ip || !strncmp(evsel->pmu_name, "ibs", 3);
> >> +}
> >> +
> >> int evsel__open_strerror(struct evsel *evsel, struct target *target,
> >> int err, char *msg, size_t size)
> >> {
> >> + struct perf_env *env = evsel__env(evsel);
> >> + const char *arch = perf_env__arch(env);
> >> + const char *cpuid = perf_env__cpuid(env);
> >
> >
> > This code dies for me on the latest tip.git because env = NULL and
> > perf_env_cpuid() is broken for NULL argument.
> > I don't quite know where this env global variable is set but I hope
> > there is a better way of doing this, maybe using
> > the evsel__env() function in the same util/evsel.c file.
> >
> > Similarly, the is_amd_ibs() suffers from a NULL pointer dereference
> > because evsel->pmu_name maybe NULL:
> >
> > $ perf record -e rc2 .....
> >
> > causes a NULL pmu_name.
>
> This should fix the issue:
>
> @@ -2965,7 +2989,7 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target,
>
> struct perf_env *evsel__env(struct evsel *evsel)
> {
> - if (evsel && evsel->evlist)
> + if (evsel && evsel->evlist && evsel->evlist->env)
> return evsel->evlist->env;
> return &perf_env;
> }
>
I will check with that change. Similarly, the IBS helper needs to have
the following change:
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2854,13 +2854,18 @@ static bool is_amd(const char *arch, const char *cpuid)

static bool is_amd_ibs(struct evsel *evsel)
{
- return evsel->core.attr.precise_ip ||
!strncmp(evsel->pmu_name, "ibs", 3);
+ return evsel->core.attr.precise_ip
+ || (evsel->pmu_name && !strncmp(evsel->pmu_name, "ibs", 3));
}

\
 
 \ /
  Last update: 2022-03-15 08:15    [W:0.047 / U:0.664 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site