We've seen cases (softice) where DWARF unwinder went
through non executable mmaps, which we need to lookup
in MAP__VARIABLE tree.

Reported-by: Noel Grandin <[email protected]>
Tested-by: Noel Grandin <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Jiri Olsa <[email protected]>
---
 tools/perf/util/unwind-libdw.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c
index db8142ba7cb9..cf5e250bc78e 100644
--- a/tools/perf/util/unwind-libdw.c
+++ b/tools/perf/util/unwind-libdw.c
@@ -96,6 +96,16 @@ static int access_dso_mem(struct unwind_info *ui, Dwarf_Addr 
addr,
        thread__find_addr_map(ui->thread, PERF_RECORD_MISC_USER,
                              MAP__FUNCTION, addr, &al);
        if (!al.map) {
+               /*
+                * We've seen cases (softice) where DWARF unwinder went
+                * through non executable mmaps, which we need to lookup
+                * in MAP__VARIABLE tree.
+                */
+               thread__find_addr_map(ui->thread, PERF_RECORD_MISC_USER,
+                                     MAP__VARIABLE, addr, &al);
+       }
+
+       if (!al.map) {
                pr_debug("unwind: no map for %lx\n", (unsigned long)addr);
                return -1;
        }
-- 
2.4.3

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