[PATCH 5.10 8/9] perf unwind: Set userdata for all __report_module() paths

Greg Kroah-Hartman
2021-05-27T15:14:03Z

From: Dave Rigby <d.rigby@me.com>

commit 4e1481445407b86a483616c4542ffdc810efb680 upstream.

When locating the DWARF module for a given address, __find_debuginfo()
requires a 'struct dso' passed via the userdata argument.

However, this field is only set in __report_module() if the module is
found in via dwfl_addrmodule(), not if it is found later via
dwfl_report_elf().

Set userdata irrespective of how the DWARF module was found, as long as
we found a module.

Fixes: bf53fc6b5f41 ("perf unwind: Fix separate debug info files when using elfutils' libdw's unwinder")
Signed-off-by: Dave Rigby <d.rigby@me.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211801
Acked-by: Jan Kratochvil <jan.kratochvil@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/linux-perf-users/20210218165654.36604-1-d.rigby@me.com/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "Tommi Rantala" <tommi.t.rantala@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/perf/util/unwind-libdw.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

--- a/tools/perf/util/unwind-libdw.c
+++ b/tools/perf/util/unwind-libdw.c
@@ -60,10 +60,8 @@ static int __report_module(struct addr_l
mod = dwfl_addrmodule(ui->dwfl, ip);
if (mod) {
Dwarf_Addr s;
- void **userdatap;

- dwfl_module_info(mod, &userdatap, &s, NULL, NULL, NULL, NULL, NULL);
- *userdatap = dso;
+ dwfl_module_info(mod, NULL, &s, NULL, NULL, NULL, NULL, NULL);
if (s != al->map->start - al->map->pgoff)
mod = 0;
}
@@ -79,6 +77,13 @@ static int __report_module(struct addr_l
al->map->start - al->map->pgoff, false);
}

+ if (mod) {
+ void **userdatap;
+
+ dwfl_module_info(mod, &userdatap, NULL, NULL, NULL, NULL, NULL, NULL);
+ *userdatap = dso;
+ }
+
return mod && dwfl_addrmodule(ui->dwfl, ip) == mod ? 0 : -1;
}