Re: [PATCH] perf top: fix crash on annotate request

[David Ahern <dsahern@gmail.com>]

Getting another crash with the default sym sorting -- the addr is much
less than the start of the sym so the offset goes negative:

(gdb) bt
#0  0x0000000000429de3 in symbol__inc_addr_samples (sym=0x8f0f90,
map=0x8aae00, evidx=0,
    addr=329985) at util/annotate.c:73
#1  0x000000000041b073 in record_precise_ip (he=0x8a2a10, counter=0,
ip=329985)
    at builtin-top.c:221
#2  0x000000000041c821 in perf_event__process_sample (event=0x7fffefbc74c8,
    sample=0x7fffffffe1b0, session=0x89a140) at builtin-top.c:801
#3  0x000000000041c8d4 in perf_session__mmap_read_idx (self=0x89a140,
idx=12)
    at builtin-top.c:821
#4  0x000000000041c95b in perf_session__mmap_read (self=0x89a140) at
builtin-top.c:832
#5  0x000000000041cdf1 in __cmd_top () at builtin-top.c:960
#6  0x000000000041d585 in cmd_top (argc=0, argv=0x7fffffffe590, prefix=0x0)
    at builtin-top.c:1252
#7  0x00000000004077b9 in run_builtin (p=0x75fb68, argc=2,
argv=0x7fffffffe590) at perf.c:286
#8  0x00000000004079bb in handle_internal_command (argc=2,
argv=0x7fffffffe590) at perf.c:358
#9  0x0000000000407b07 in run_argv (argcp=0x7fffffffe47c,
argv=0x7fffffffe470) at perf.c:402
#10 0x0000000000407dee in main (argc=2, argv=0x7fffffffe590) at perf.c:512


The following fixes the crash. If it seems reasonable I'll add to the
other one:

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index bc8f477..f1f20b5 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -63,6 +63,8 @@ int symbol__inc_addr_samples(struct symbol *sym,
struct map *map,
        return -ENOMEM;

    pr_debug3("%s: addr=%#" PRIx64 "\n", __func__, map->unmap_ip(map,
addr));
+   if (addr < sym->start)
+       return 0;

    if (addr >= sym->end)
        return 0;


I'll combine