From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jianlin Lv <Jianlin.Lv@arm.com>,
peterz@infradead.org, mingo@redhat.com, mark.rutland@arm.com,
alexander.shishkin@linux.intel.com, jolsa@redhat.com,
namhyung@kernel.org, srikar@linux.vnet.ibm.com,
adrian.hunter@intel.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] perf probe: Added protection to avoid endless loop
Date: Wed, 3 Feb 2021 13:22:58 -0300 [thread overview]
Message-ID: <20210203162258.GF854763@kernel.org> (raw)
In-Reply-To: <20210204000814.7bebaeda0edb54f121159fbd@kernel.org>
Em Thu, Feb 04, 2021 at 12:08:14AM +0900, Masami Hiramatsu escreveu:
> On Wed, 3 Feb 2021 22:57:02 +0800
> Jianlin Lv <Jianlin.Lv@arm.com> wrote:
>
> > if dwarf_offdie() return NULL, the continue statement forces the next
> > iteration of the loop without update variable off. It will cause an
> > endless loop in the process of traversing the compilation unit.
> > So added exception protection for loop CUs.
> >
>
> Thanks for the quick update!
>
> Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Thanks, applied.
- Arnaldo
> Thank you,
>
> > Signed-off-by: Jianlin Lv <Jianlin.Lv@arm.com>
> > ---
> > v2: removed the statement that updates variable in the function argument.
> > ---
> > tools/perf/util/probe-finder.c | 8 ++++++--
> > 1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> > index 76dd349aa48d..1b118c9c86a6 100644
> > --- a/tools/perf/util/probe-finder.c
> > +++ b/tools/perf/util/probe-finder.c
> > @@ -1187,8 +1187,10 @@ static int debuginfo__find_probe_location(struct debuginfo *dbg,
> > while (!dwarf_nextcu(dbg->dbg, off, &noff, &cuhl, NULL, NULL, NULL)) {
> > /* Get the DIE(Debugging Information Entry) of this CU */
> > diep = dwarf_offdie(dbg->dbg, off + cuhl, &pf->cu_die);
> > - if (!diep)
> > + if (!diep) {
> > + off = noff;
> > continue;
> > + }
> >
> > /* Check if target file is included. */
> > if (pp->file)
> > @@ -1949,8 +1951,10 @@ int debuginfo__find_line_range(struct debuginfo *dbg, struct line_range *lr)
> >
> > /* Get the DIE(Debugging Information Entry) of this CU */
> > diep = dwarf_offdie(dbg->dbg, off + cuhl, &lf.cu_die);
> > - if (!diep)
> > + if (!diep) {
> > + off = noff;
> > continue;
> > + }
> >
> > /* Check if target file is included. */
> > if (lr->file)
> > --
> > 2.25.1
> >
>
>
> --
> Masami Hiramatsu <mhiramat@kernel.org>
--
- Arnaldo
prev parent reply other threads:[~2021-02-03 16:23 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-03 14:57 [PATCH v2] perf probe: Added protection to avoid endless loop Jianlin Lv
2021-02-03 15:08 ` Masami Hiramatsu
2021-02-03 16:22 ` Arnaldo Carvalho de Melo [this message]
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