[PATCH 1/3] perf report: don't try to map ip to invalid map

[Milian Wolff]

Fixes a crash when the report encounters an address that
could not be associated with an mmaped region:

#0  0x00005555557bdc4a in callchain_srcline (ip=<error reading variable: Cannot 
access memory at address 0x38>, sym=0x0, map=0x0) at util/machine.c:2329
#1  unwind_entry (entry=entry@entry=0x7fffffff9180, 
arg=arg@entry=0x7ffff5642498) at util/machine.c:2329
#2  0x00005555558370af in entry (arg=0x7ffff5642498, cb=0x5555557bdb50 
<unwind_entry>, thread=<optimized out>, ip=18446744073709551615) at 
util/unwind-libunwind-local.c:586
#3  get_entries (ui=ui@entry=0x7fffffff9620, cb=0x5555557bdb50 <unwind_entry>, 
arg=0x7ffff5642498, max_stack=<optimized out>) at 
util/unwind-libunwind-local.c:703
#4  0x0000555555837192 in _unwind__get_entries (cb=<optimized out>, 
arg=<optimized out>, thread=<optimized out>, data=<optimized out>, 
max_stack=<optimized out>) at util/unwind-libunwind-local.c:725
#5  0x00005555557c310f in thread__resolve_callchain_unwind (max_stack=127, 
sample=0x7fffffff9830, evsel=0x555555c7b3b0, cursor=0x7ffff5642498, 
thread=0x555555c7f6f0) at util/machine.c:2351
#6  thread__resolve_callchain (thread=0x555555c7f6f0, cursor=0x7ffff5642498, 
evsel=0x555555c7b3b0, sample=0x7fffffff9830, parent=0x7fffffff97b8, 
root_al=0x7fffffff9750, max_stack=127) at util/machine.c:2378
#7  0x00005555557ba4ee in sample__resolve_callchain (sample=<optimized out>, 
cursor=<optimized out>, parent=parent@entry=0x7fffffff97b8, evsel=<optimized 
out>, al=al@entry=0x7fffffff9750,
    max_stack=<optimized out>) at util/callchain.c:1085

Signed-off-by: Milian Wolff <milian.wo...@kdab.com>
Cc: Sandipan Das <sandi...@linux.ibm.com>
Cc: Arnaldo Carvalho de Melo <a...@kernel.org>
---
 tools/perf/util/machine.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index c4acd2001db0..0cb4f8bf3ca7 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2312,7 +2312,7 @@ static int unwind_entry(struct unwind_entry *entry, void 
*arg)
 {
        struct callchain_cursor *cursor = arg;
        const char *srcline = NULL;
-       u64 addr;
+       u64 addr = entry->ip;
 
        if (symbol_conf.hide_unresolved && entry->sym == NULL)
                return 0;
@@ -2324,7 +2324,8 @@ static int unwind_entry(struct unwind_entry *entry, void 
*arg)
         * Convert entry->ip from a virtual address to an offset in
         * its corresponding binary.
         */
-       addr = map__map_ip(entry->map, entry->ip);
+       if (entry->map)
+               addr = map__map_ip(entry->map, entry->ip);
 
        srcline = callchain_srcline(entry->map, entry->sym, addr);
        return callchain_cursor_append(cursor, entry->ip,
-- 
2.19.0