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Groups > linux.kernel > #1216369
| From | Andy Shevchenko <andy.shevchenko@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2 1/6] perf: Introduce extended syscall error reporting |
| Date | 2015-08-31 20:50 +0200 |
| Message-ID | <q3Cjv-7HJ-1@gated-at.bofh.it> (permalink) |
| References | <q114K-23E-1@gated-at.bofh.it> <q114K-23E-23@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Mon, Aug 24, 2015 at 5:32 PM, Alexander Shishkin
<alexander.shishkin@linux.intel.com> wrote:
One small comment below.
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -49,6 +49,79 @@
>
> #include <asm/irq_regs.h>
>
> +static bool extended_reporting_enabled(struct perf_event_attr *attr)
> +{
> + if (attr->size >= PERF_ATTR_SIZE_VER6 &&
> + attr->perf_err_size > 0)
> + return true;
> +
> + return false;
> +}
> +
> +/*
> + * Provide a JSON formatted error report to the user if they asked for it.
> + */
> +static void perf_error_report_site(struct perf_event_attr *attr,
> + const struct perf_err_site *site)
> +{
> + unsigned long len;
> + char *buffer;
> +
> + if (!site || !extended_reporting_enabled(attr))
> + return;
> +
> + /* in case of nested perf_err()s, which you shouldn't really do */
> + while (site->code <= -PERF_ERRNO)
> + site = perf_errno_to_site(site->code);
> +
> + buffer = kasprintf(GFP_KERNEL,
> + "{\n"
> + "\t\"code\": %d,\n"
> + "\t\"module\": \"%s\",\n"
> + "\t\"message\": \"%s\"\n"
> + "}\n",
> + site->code, site->owner, site->message
> + );
> + if (!buffer)
> + return;
> +
> + /* trim the buffer to the supplied boundary */
> + len = strlen(buffer);
> + if (len >= attr->perf_err_size) {
> + len = attr->perf_err_size - 1;
> + buffer[len] = 0;
> + }
len = strnlen(buffer, attr->perf_err_size);
buffer[len] = 0;
And perhaps perf_err_size has to be length (perf_err_len) ?
> +
> + if (copy_to_user((void __user *)attr->perf_err, buffer, len + 1)) {
> + /* if we failed to copy once, don't bother later */
> + attr->perf_err_size = 0;
Kaboom next time on buffer[-1] = 0; since len >= 0?
> + }
> +
> + kfree(buffer);
> +}
--
With Best Regards,
Andy Shevchenko
--
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[PATCH v2 0/6] perf: Introduce extended syscall error reporting Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2015-08-24 16:40 +0200
[PATCH v2 5/6] perf/x86/intel/pt: Use extended error reporting in event initialization Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2015-08-24 16:40 +0200
[PATCH v2 6/6] perf/x86/intel/bts: Use extended error reporting in event initialization Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2015-08-24 16:40 +0200
[PATCH v2 1/6] perf: Introduce extended syscall error reporting Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2015-08-24 16:40 +0200
Re: [PATCH v2 1/6] perf: Introduce extended syscall error reporting Andy Shevchenko <andy.shevchenko@gmail.com> - 2015-08-31 20:50 +0200
Re: [PATCH v2 1/6] perf: Introduce extended syscall error reporting Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2015-09-01 08:40 +0200
[PATCH v2 3/6] perf: Annotate some of the error codes with perf_err() Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2015-08-24 16:40 +0200
[PATCH v2 2/6] perf: Add file name and line number to perf extended error reports Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2015-08-24 16:40 +0200
[PATCH v2 4/6] perf/x86: Annotate some of the error codes with perf_err() Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2015-08-24 16:40 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Ingo Molnar <mingo@kernel.org> - 2015-08-25 10:30 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Johannes Berg <johannes@sipsolutions.net> - 2015-08-25 11:00 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Ingo Molnar <mingo@kernel.org> - 2015-08-25 11:10 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Ingo Molnar <mingo@kernel.org> - 2015-08-25 11:20 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Johannes Berg <johannes@sipsolutions.net> - 2015-08-25 11:40 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Ingo Molnar <mingo@kernel.org> - 2015-08-25 12:10 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Johannes Berg <johannes@sipsolutions.net> - 2015-08-25 12:30 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Ingo Molnar <mingo@kernel.org> - 2015-08-26 07:00 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Johannes Berg <johannes@sipsolutions.net> - 2015-08-26 09:10 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Ingo Molnar <mingo@kernel.org> - 2015-08-26 09:30 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2015-08-26 19:00 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-08-26 23:00 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Andrew Morton <akpm@linux-foundation.org> - 2015-08-26 20:50 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Peter Zijlstra <peterz@infradead.org> - 2015-08-26 22:10 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Andrew Morton <akpm@linux-foundation.org> - 2015-08-26 22:30 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Vince Weaver <vince@deater.net> - 2015-08-26 23:00 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Andrew Morton <akpm@linux-foundation.org> - 2015-08-26 23:00 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Vince Weaver <vince@deater.net> - 2015-08-26 23:20 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Ingo Molnar <mingo@kernel.org> - 2015-08-28 12:10 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Arnaldo Carvalho de Melo <acme@infradead.org> - 2015-08-26 23:10 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Ingo Molnar <mingo@kernel.org> - 2015-08-26 09:30 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Johannes Berg <johannes@sipsolutions.net> - 2015-08-26 09:40 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Ingo Molnar <mingo@kernel.org> - 2015-08-26 09:10 +0200
Re: [PATCH v2 0/6] perf: Introduce extended syscall error reporting Alexander Shishkin <alexander.shishkin@linux.intel.com> - 2015-08-26 13:40 +0200
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