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author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-04-27 21:21:09 -0300 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-05-02 18:23:04 -0300 |
commit | b843f62ad942f3879c2d7acd27b44f931c609685 (patch) | |
tree | 5367408cae8262e00b559250bbfc6f8f222f5c38 /tools/perf/builtin-buildid-cache.c | |
parent | 96395cbbc7e94cbbe4f76cf64cf122fabc19123d (diff) | |
download | op-kernel-dev-b843f62ad942f3879c2d7acd27b44f931c609685.zip op-kernel-dev-b843f62ad942f3879c2d7acd27b44f931c609685.tar.gz |
perf symbols: Accept symbols starting at address 0
That is the case of _text on s390, and we have some functions that return an
address, using address zero to report problems, oops.
This would lead the symbol loading routines to not use "_text" as the reference
relocation symbol, or the first symbol for the kernel, but use instead
"_stext", that is at the same address on x86_64 and others, but not on s390:
[acme@localhost perf-4.11.0-rc6]$ head -15 /proc/kallsyms
0000000000000000 T _text
0000000000000418 t iplstart
0000000000000800 T start
000000000000080a t .base
000000000000082e t .sk8x8
0000000000000834 t .gotr
0000000000000842 t .cmd
0000000000000846 t .parm
000000000000084a t .lowcase
0000000000010000 T startup
0000000000010010 T startup_kdump
0000000000010214 t startup_kdump_relocated
0000000000011000 T startup_continue
00000000000112a0 T _ehead
0000000000100000 T _stext
[acme@localhost perf-4.11.0-rc6]$
Which in turn would make 'perf test vmlinux' to fail because it wouldn't find
the symbols before "_stext" in kallsyms.
Fix it by using the return value only for errors and storing the
address, when the symbol is successfully found, in a provided pointer
arg.
Before this patch:
After:
[acme@localhost perf-4.11.0-rc6]$ tools/perf/perf test -v 1
1: vmlinux symtab matches kallsyms :
--- start ---
test child forked, pid 40693
Looking at the vmlinux_path (8 entries long)
Using /usr/lib/debug/lib/modules/3.10.0-654.el7.s390x/vmlinux for symbols
ERR : 0: _text not on kallsyms
ERR : 0x418: iplstart not on kallsyms
ERR : 0x800: start not on kallsyms
ERR : 0x80a: .base not on kallsyms
ERR : 0x82e: .sk8x8 not on kallsyms
ERR : 0x834: .gotr not on kallsyms
ERR : 0x842: .cmd not on kallsyms
ERR : 0x846: .parm not on kallsyms
ERR : 0x84a: .lowcase not on kallsyms
ERR : 0x10000: startup not on kallsyms
ERR : 0x10010: startup_kdump not on kallsyms
ERR : 0x10214: startup_kdump_relocated not on kallsyms
ERR : 0x11000: startup_continue not on kallsyms
ERR : 0x112a0: _ehead not on kallsyms
<SNIP warnings>
test child finished with -1
---- end ----
vmlinux symtab matches kallsyms: FAILED!
[acme@localhost perf-4.11.0-rc6]$
After:
[acme@localhost perf-4.11.0-rc6]$ tools/perf/perf test -v 1
1: vmlinux symtab matches kallsyms :
--- start ---
test child forked, pid 47160
<SNIP warnings>
test child finished with 0
---- end ----
vmlinux symtab matches kallsyms: Ok
[acme@localhost perf-4.11.0-rc6]$
Reported-by: Michael Petlan <mpetlan@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-9x9bwgd3btwdk1u51xie93fz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/builtin-buildid-cache.c')
-rw-r--r-- | tools/perf/builtin-buildid-cache.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c index 64b44e8..9eba7f1 100644 --- a/tools/perf/builtin-buildid-cache.c +++ b/tools/perf/builtin-buildid-cache.c @@ -49,19 +49,22 @@ static bool same_kallsyms_reloc(const char *from_dir, char *to_dir) char to[PATH_MAX]; const char *name; u64 addr1 = 0, addr2 = 0; - int i; + int i, err = -1; scnprintf(from, sizeof(from), "%s/kallsyms", from_dir); scnprintf(to, sizeof(to), "%s/kallsyms", to_dir); for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) { - addr1 = kallsyms__get_function_start(from, name); - if (addr1) + err = kallsyms__get_function_start(from, name, &addr1); + if (!err) break; } - if (name) - addr2 = kallsyms__get_function_start(to, name); + if (err) + return false; + + if (kallsyms__get_function_start(to, name, &addr2)) + return false; return addr1 == addr2; } |