* Re: [BUGFIX PATCH] perf probe: Do not depend on dwfl_module_addrsym()
[not found] ` <158281812176.476.14164573830975116234.stgit@devnote2>
@ 2020-02-27 16:20 ` Alexandre Ghiti
2020-02-27 23:52 ` Masami Hiramatsu
0 siblings, 1 reply; 3+ messages in thread
From: Alexandre Ghiti @ 2020-02-27 16:20 UTC (permalink / raw)
To: Masami Hiramatsu, Arnaldo Carvalho de Melo
Cc: Peter Zijlstra, Ingo Molnar, Alexander Shishkin, Jiri Olsa,
Namhyung Kim, Sasha Levin, Greg Kroah-Hartman, linux-kernel,
stable
On 2/27/20 4:42 PM, Masami Hiramatsu wrote:
> Do not depend on dwfl_module_addrsym() because it can fail
> on user-space shared libraries.
>
> Actually, same bug was fixed by commit 664fee3dc379 ("perf
> probe: Do not use dwfl_module_addrsym if dwarf_diename finds
> symbol name"), but commit 07d369857808 ("perf probe: Fix
> wrong address verification) reverted to get actual symbol
> address from symtab.
>
> This fixes it again by getting symbol address from DIE,
> and only if the DIE has only address range, it uses
> dwfl_module_addrsym().
>
> Fixes: 07d369857808 ("perf probe: Fix wrong address verification)
> Reported-by: Alexandre Ghiti <alex@ghiti.fr>
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> ---
> tools/perf/util/probe-finder.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> index 1c817add6ca4..e4cff49384f4 100644
> --- a/tools/perf/util/probe-finder.c
> +++ b/tools/perf/util/probe-finder.c
> @@ -637,14 +637,19 @@ static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
> return -EINVAL;
> }
>
> - /* Try to get actual symbol name from symtab */
> - symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
> + if (dwarf_entrypc(sp_die, &eaddr) == 0) {
> + /* If the DIE has entrypc, use it. */
> + symbol = dwarf_diename(sp_die);
> + } else {
> + /* Try to get actual symbol name and address from symtab */
> + symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
> + eaddr = sym.st_value;
> + }
> if (!symbol) {
> pr_warning("Failed to find symbol at 0x%lx\n",
> (unsigned long)paddr);
> return -ENOENT;
> }
> - eaddr = sym.st_value;
>
> tp->offset = (unsigned long)(paddr - eaddr);
> tp->address = (unsigned long)paddr;
>
I have just tested your patch, that fixes the issue, so you can add:
Tested-by: Alexandre Ghiti <alex@ghiti.fr>
I added stable in cc.
Thanks,
Alex
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [BUGFIX PATCH] perf probe: Do not depend on dwfl_module_addrsym()
2020-02-27 16:20 ` [BUGFIX PATCH] perf probe: Do not depend on dwfl_module_addrsym() Alexandre Ghiti
@ 2020-02-27 23:52 ` Masami Hiramatsu
2020-03-09 13:44 ` Arnaldo Carvalho de Melo
0 siblings, 1 reply; 3+ messages in thread
From: Masami Hiramatsu @ 2020-02-27 23:52 UTC (permalink / raw)
To: Alexandre Ghiti
Cc: Arnaldo Carvalho de Melo, Peter Zijlstra, Ingo Molnar,
Alexander Shishkin, Jiri Olsa, Namhyung Kim, Sasha Levin,
Greg Kroah-Hartman, linux-kernel, stable
On Thu, 27 Feb 2020 17:20:39 +0100
Alexandre Ghiti <alex@ghiti.fr> wrote:
> On 2/27/20 4:42 PM, Masami Hiramatsu wrote:
> > Do not depend on dwfl_module_addrsym() because it can fail
> > on user-space shared libraries.
> >
> > Actually, same bug was fixed by commit 664fee3dc379 ("perf
> > probe: Do not use dwfl_module_addrsym if dwarf_diename finds
> > symbol name"), but commit 07d369857808 ("perf probe: Fix
> > wrong address verification) reverted to get actual symbol
> > address from symtab.
> >
> > This fixes it again by getting symbol address from DIE,
> > and only if the DIE has only address range, it uses
> > dwfl_module_addrsym().
> >
> > Fixes: 07d369857808 ("perf probe: Fix wrong address verification)
> > Reported-by: Alexandre Ghiti <alex@ghiti.fr>
> > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> > ---
> > tools/perf/util/probe-finder.c | 11 ++++++++---
> > 1 file changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> > index 1c817add6ca4..e4cff49384f4 100644
> > --- a/tools/perf/util/probe-finder.c
> > +++ b/tools/perf/util/probe-finder.c
> > @@ -637,14 +637,19 @@ static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
> > return -EINVAL;
> > }
> >
> > - /* Try to get actual symbol name from symtab */
> > - symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
> > + if (dwarf_entrypc(sp_die, &eaddr) == 0) {
> > + /* If the DIE has entrypc, use it. */
> > + symbol = dwarf_diename(sp_die);
> > + } else {
> > + /* Try to get actual symbol name and address from symtab */
> > + symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
> > + eaddr = sym.st_value;
> > + }
> > if (!symbol) {
> > pr_warning("Failed to find symbol at 0x%lx\n",
> > (unsigned long)paddr);
> > return -ENOENT;
> > }
> > - eaddr = sym.st_value;
> >
> > tp->offset = (unsigned long)(paddr - eaddr);
> > tp->address = (unsigned long)paddr;
> >
>
> I have just tested your patch, that fixes the issue, so you can add:
>
> Tested-by: Alexandre Ghiti <alex@ghiti.fr>
Thanks Alexandre,
Arnaldo, could you also pick this for fix?
Thank you,
--
Masami Hiramatsu <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [BUGFIX PATCH] perf probe: Do not depend on dwfl_module_addrsym()
2020-02-27 23:52 ` Masami Hiramatsu
@ 2020-03-09 13:44 ` Arnaldo Carvalho de Melo
0 siblings, 0 replies; 3+ messages in thread
From: Arnaldo Carvalho de Melo @ 2020-03-09 13:44 UTC (permalink / raw)
To: Masami Hiramatsu
Cc: Alexandre Ghiti, Peter Zijlstra, Ingo Molnar, Alexander Shishkin,
Jiri Olsa, Namhyung Kim, Sasha Levin, Greg Kroah-Hartman,
linux-kernel, stable
Em Fri, Feb 28, 2020 at 08:52:38AM +0900, Masami Hiramatsu escreveu:
> On Thu, 27 Feb 2020 17:20:39 +0100
> Alexandre Ghiti <alex@ghiti.fr> wrote:
>
> > On 2/27/20 4:42 PM, Masami Hiramatsu wrote:
> > > Do not depend on dwfl_module_addrsym() because it can fail
> > > on user-space shared libraries.
> > >
> > > Actually, same bug was fixed by commit 664fee3dc379 ("perf
> > > probe: Do not use dwfl_module_addrsym if dwarf_diename finds
> > > symbol name"), but commit 07d369857808 ("perf probe: Fix
> > > wrong address verification) reverted to get actual symbol
> > > address from symtab.
> > >
> > > This fixes it again by getting symbol address from DIE,
> > > and only if the DIE has only address range, it uses
> > > dwfl_module_addrsym().
> > >
> > > Fixes: 07d369857808 ("perf probe: Fix wrong address verification)
> > > Reported-by: Alexandre Ghiti <alex@ghiti.fr>
> > > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> > > ---
> > > tools/perf/util/probe-finder.c | 11 ++++++++---
> > > 1 file changed, 8 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> > > index 1c817add6ca4..e4cff49384f4 100644
> > > --- a/tools/perf/util/probe-finder.c
> > > +++ b/tools/perf/util/probe-finder.c
> > > @@ -637,14 +637,19 @@ static int convert_to_trace_point(Dwarf_Die *sp_die, Dwfl_Module *mod,
> > > return -EINVAL;
> > > }
> > >
> > > - /* Try to get actual symbol name from symtab */
> > > - symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
> > > + if (dwarf_entrypc(sp_die, &eaddr) == 0) {
> > > + /* If the DIE has entrypc, use it. */
> > > + symbol = dwarf_diename(sp_die);
> > > + } else {
> > > + /* Try to get actual symbol name and address from symtab */
> > > + symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL);
> > > + eaddr = sym.st_value;
> > > + }
> > > if (!symbol) {
> > > pr_warning("Failed to find symbol at 0x%lx\n",
> > > (unsigned long)paddr);
> > > return -ENOENT;
> > > }
> > > - eaddr = sym.st_value;
> > >
> > > tp->offset = (unsigned long)(paddr - eaddr);
> > > tp->address = (unsigned long)paddr;
> > >
> >
> > I have just tested your patch, that fixes the issue, so you can add:
> >
> > Tested-by: Alexandre Ghiti <alex@ghiti.fr>
>
> Thanks Alexandre,
> Arnaldo, could you also pick this for fix?
Thanks, applied.
- Arnaldo
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-02-27 16:20 ` [BUGFIX PATCH] perf probe: Do not depend on dwfl_module_addrsym() Alexandre Ghiti
2020-02-27 23:52 ` Masami Hiramatsu
2020-03-09 13:44 ` Arnaldo Carvalho de Melo
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