Messages in this thread | | | Subject | Re: [BUGFIX PATCH] perf probe: Do not depend on dwfl_module_addrsym() | From | Alexandre Ghiti <> | Date | Thu, 27 Feb 2020 17:20:39 +0100 |
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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
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