Messages in this thread Patch in this message | | | From | "Naveen N. Rao" <> | Subject | [PATCH] tools/perf probe: Print a hint if adding a probe fails | Date | Thu, 10 Jun 2021 15:14:42 +0530 |
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Adding a probe can fail in a few scenarios. perf already checks for the address in the kprobe blacklist. However, the address could still be a jump label, or have a BUG_ON(). In such cases, it isn't always evident why adding the probe failed. Add a hint so that the user knows how to proceed.
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- tools/perf/builtin-probe.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c index 6b150756677014..ff9f3fdce600dd 100644 --- a/tools/perf/builtin-probe.c +++ b/tools/perf/builtin-probe.c @@ -352,8 +352,11 @@ static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs) } ret = apply_perf_probe_events(pevs, npevs); - if (ret < 0) + if (ret < 0) { + pr_info("Hint: Check dmesg to understand reason for probe failure.\n" + " Consider probing at the next/previous instruction.\n"); goto out_cleanup; + } for (i = k = 0; i < npevs; i++) k += pevs[i].ntevs; base-commit: 0808b3d5b7514dc856178dbc509929329bbf301d -- 2.31.1
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