perf tools: Fix symbol offset computation for some dsos

For some dsos (e.g., libc, libpthread, kernel modules) the symbol offset
is huge. e.g.,

qemu-kvm 17238/17242 [007] 762235.640311:
    ffffffff816288a1 __schedule+0x451 ([kernel.kallsyms])
    ffffffff81629609 schedule+0x29 ([kernel.kallsyms])
    ffffffffa00a6ded kvm_vcpu_block+0xffffffffa00a106d (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
    ffffffffa00bae6b kvm_arch_vcpu_ioctl_run+0xffffffffa00a118b (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
    ffffffffa00a4d7a kvm_vcpu_ioctl+0xffffffffa00a141a (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
    ffffffff811a7bdb do_vfs_ioctl+0x8b ([kernel.kallsyms])
    ffffffff811a80c1 sys_ioctl+0x91 ([kernel.kallsyms])
    ffffffff81633182 system_call+0x72 ([kernel.kallsyms])
        7f882a97af27 __GI___ioctl+0x7f882a891007 (/lib64/libc-2.14.90.so)
           100000002 [unknown] ([unknown])

It seems to be maps with a non-0 start. Taking that into account the
offsets are correct:

qemu-kvm 17238/17242 [007] 762235.640311:
    ffffffff816288a1 __schedule+0x451 ([kernel.kallsyms])
    ffffffff81629609 schedule+0x29 ([kernel.kallsyms])
    ffffffffa00a6ded kvm_vcpu_block+0x6d (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
    ffffffffa00bae6b kvm_arch_vcpu_ioctl_run+0x18b (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
    ffffffffa00a4d7a kvm_vcpu_ioctl+0x41a (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
    ffffffff811a7bdb do_vfs_ioctl+0x8b ([kernel.kallsyms])
    ffffffff811a80c1 sys_ioctl+0x91 ([kernel.kallsyms])
    ffffffff81633182 system_call+0x72 ([kernel.kallsyms])
        7f882a97af27 __GI___ioctl+0x7 (/lib64/libc-2.14.90.so)
           100000002 [unknown] ([unknown])

Signed-off-by: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/1375026512-45826-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 5 insertions, 1 deletions

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 07642a7b9346..1fc0c628683e 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1513,6 +1513,7 @@ void perf_evsel__print_ip(struct perf_evsel *evsel, union perf_event *event,
                                 printf(" ");
                                 if (print_symoffset) {
                                         al.addr = node->ip;
+                                        al.map  = node->map;
                                         symbol__fprintf_symname_offs(node->sym, &al, stdout);
                                 } else
                                         symbol__fprintf_symname(node->sym, stdout);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 77f3b95bb46d..7eb0362f4ffd 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -259,7 +259,10 @@ size_t symbol__fprintf_symname_offs(const struct symbol *sym,
         if (sym && sym->name) {
                 length = fprintf(fp, "%s", sym->name);
                 if (al) {
-                        offset = al->addr - sym->start;
+                        if (al->addr < sym->end)
+                                offset = al->addr - sym->start;
+                        else
+                                offset = al->addr - al->map->start - sym->start;
                         length += fprintf(fp, "+0x%lx", offset);
                 }
                 return length;