| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Wed, 08 Dec 2010 15:22:37 -0700
From: "David S. Ahern" <daahern@...co.com>
To: Arnaldo Carvalho de Melo <acme@...stprotocols.net>
CC: linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] perf tools: Add symfs option for off-box analysis using
specified tree
On 12/08/10 13:56, Arnaldo Carvalho de Melo wrote:
> Em Tue, Dec 07, 2010 at 07:42:54PM -0700, David Ahern escreveu:
>> The symfs argument allows analysis of perf.data file using a locally
>> accessible filesystem tree with debug symbols - e.g., tree created
>> during image builds, sshfs mount, loop mounted KVM disk images,
>> USB keys, initrds, etc. Anything with an OS tree can be analyzed from
>> anywhere without the need to populate a local data store with
>> build-ids.
>>
>> Signed-off-by: David Ahern <daahern@...co.com>
>> ---
>> tools/perf/builtin-annotate.c | 16 +++++--
>> tools/perf/builtin-diff.c | 2 +
>> tools/perf/builtin-report.c | 2 +
>> tools/perf/builtin-timechart.c | 2 +
>> tools/perf/util/hist.c | 14 +++++-
>> tools/perf/util/symbol.c | 82 +++++++++++++++++++++++++---------------
>> tools/perf/util/symbol.h | 1 +
>> 7 files changed, 80 insertions(+), 39 deletions(-)
>>
>> diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
>> index 569a276..0c47bee 100644
>> --- a/tools/perf/builtin-annotate.c
>> +++ b/tools/perf/builtin-annotate.c
>> @@ -280,7 +280,8 @@ static int hist_entry__tty_annotate(struct hist_entry *he)
>> struct map *map = he->ms.map;
>> struct dso *dso = map->dso;
>> struct symbol *sym = he->ms.sym;
>> - const char *filename = dso->long_name, *d_filename;
>> + const char *filename = dso->long_name;
>> + char d_filename[PATH_MAX];
>> u64 len;
>> LIST_HEAD(head);
>> struct objdump_line *pos, *n;
>> @@ -288,10 +289,13 @@ static int hist_entry__tty_annotate(struct hist_entry *he)
>> if (hist_entry__annotate(he, &head, 0) < 0)
>> return -1;
>>
>> - if (full_paths)
>> - d_filename = filename;
>> - else
>> - d_filename = basename(filename);
>> + if (full_paths) {
>> + snprintf(d_filename, sizeof(d_filename), "%s%s",
>> + symbol_conf.symfs, filename);
>> + } else {
>> + snprintf(d_filename, sizeof(d_filename), "%s/%s",
>> + symbol_conf.symfs, basename(filename));
>> + }
>
> Are you sure about the one above? I guess you don't need to concat here,
> its just informative message, if you're using --symfs, you know
> everything is from there, and in the !full_paths case the resulting
> filename will be bogus, right?
Ok. I removed.
>
>> len = sym->end - sym->start;
>>
>> @@ -437,6 +441,8 @@ static const struct option options[] = {
>> "print matching source lines (may be slow)"),
>> OPT_BOOLEAN('P', "full-paths", &full_paths,
>> "Don't shorten the displayed pathnames"),
>> + OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
>> + "Look for files with symbols relative to this directory"),
>> OPT_END()
>> };
In which case the above is not needed.
>> diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
>> index 2022e87..b24ae53 100644
>> --- a/tools/perf/util/hist.c
>> +++ b/tools/perf/util/hist.c
>> @@ -1092,6 +1092,12 @@ int hist_entry__annotate(struct hist_entry *self, struct list_head *head,
>> FILE *file;
>> int err = 0;
>> u64 len;
>> + char symfs_filename[PATH_MAX];
>> +
>> + if (filename) {
>> + snprintf(symfs_filename, sizeof(symfs_filename), "%s%s",
>> + symbol_conf.symfs, filename);
>
> Above you have tab/space damage
fixed
>
>> + }
>>
>> if (filename == NULL) {
>> if (dso->has_build_id) {
>> @@ -1100,9 +1106,9 @@ int hist_entry__annotate(struct hist_entry *self, struct list_head *head,
>> return -ENOMEM;
>> }
>> goto fallback;
>> - } else if (readlink(filename, command, sizeof(command)) < 0 ||
>> + } else if (readlink(symfs_filename, command, sizeof(command)) < 0 ||
>> strstr(command, "[kernel.kallsyms]") ||
>> - access(filename, R_OK)) {
>> + access(symfs_filename, R_OK)) {
>> free(filename);
>> fallback:
>> /*
>> @@ -1111,6 +1117,8 @@ fallback:
>> * DSO is the same as when 'perf record' ran.
>> */
>> filename = dso->long_name;
>> + snprintf(symfs_filename, sizeof(symfs_filename), "%s%s",
>> + symbol_conf.symfs, filename);
>
> Ditto above
fixed
>
>> free_filename = false;
>> }
>>
>> @@ -1137,7 +1145,7 @@ fallback:
>> "objdump --start-address=0x%016Lx --stop-address=0x%016Lx -dS -C %s|grep -v %s|expand",
>> map__rip_2objdump(map, sym->start),
>> map__rip_2objdump(map, sym->end),
>> - filename, filename);
>> + symfs_filename, filename);
>>
>> pr_debug("Executing: %s\n", command);
>>
>> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
>> index a348906..7a0d284 100644
>> --- a/tools/perf/util/symbol.c
>> +++ b/tools/perf/util/symbol.c
>> @@ -41,6 +41,7 @@ struct symbol_conf symbol_conf = {
>> .exclude_other = true,
>> .use_modules = true,
>> .try_vmlinux_path = true,
>> + .symfs = "",
>> };
>>
>> int dso__name_len(const struct dso *self)
>> @@ -833,8 +834,11 @@ static int dso__synthesize_plt_symbols(struct dso *self, struct map *map,
>> char sympltname[1024];
>> Elf *elf;
>> int nr = 0, symidx, fd, err = 0;
>> + char name[PATH_MAX];
>>
>> - fd = open(self->long_name, O_RDONLY);
>> + snprintf(name, sizeof(name), "%s%s",
>> + symbol_conf.symfs, self->long_name);
>> + fd = open(name, O_RDONLY);
>> if (fd < 0)
>> goto out;
>>
>> @@ -1446,16 +1450,19 @@ int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
>> self->origin++) {
>> switch (self->origin) {
>> case DSO__ORIG_BUILD_ID_CACHE:
>> - if (dso__build_id_filename(self, name, size) == NULL)
>> + /* skip the locally configured cache if a symfs is given */
>> + if ((strlen(symbol_conf.symfs) != 0) ||
>
> I suggest you use:
>
> if (symbol_conf.symfs[1] ||
>
> cheaper :)
Changed. I presume you meant: symbol_conf.symfs[0] -- ie., element 0
has something other than '\0' which means strlen > 0
...
>> @@ -1778,17 +1786,20 @@ static int dso__load_vmlinux(struct dso *self, struct map *map,
>> const char *vmlinux, symbol_filter_t filter)
>> {
>> int err = -1, fd;
>> + char symfs_vmlinux[PATH_MAX];
>> - fd = open(vmlinux, O_RDONLY);
>> + snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s/%s",
>> + symbol_conf.symfs, vmlinux);
>
> Its userspace, so stack is plenty, but I guess if using asprintf
> wouldn't be better...
>
> I.e. if we were programming some kernel module, creating a 4K stack
> variable would be considered bad practice, so I think it is here as
> well.
Declaring symfs_vmlinux on the stack is consistent with other PATH_MAX
declarations within perf, and especially within util/symbol.c.
>
>> + fd = open(symfs_vmlinux, O_RDONLY);
>> if (fd < 0)
>> return -1;
>>
>> dso__set_loaded(self, map->type);
>> - err = dso__load_sym(self, map, vmlinux, fd, filter, 0, 0);
>> + err = dso__load_sym(self, map, symfs_vmlinux, fd, filter, 0, 0);
>> close(fd);
>>
>> if (err > 0)
>> - pr_debug("Using %s for symbols\n", vmlinux);
>> + pr_debug("Using %s for symbols\n", symfs_vmlinux);
>>
>> return err;
>> }
>> @@ -1861,6 +1872,10 @@ static int dso__load_kernel_sym(struct dso *self, struct map *map,
>> goto out_fixup;
>> }
>>
>> + /* do not try local files if a symfs was given */
>> + if (strlen(symbol_conf.symfs) != 0)
>> + return -1;
>> +
changed that strlen as well.
>> /*
>> * Say the kernel DSO was created when processing the build-id header table,
>> * we have a build-id, so check if it is the same as the running kernel,
>> @@ -2210,9 +2225,6 @@ static int vmlinux_path__init(void)
>> struct utsname uts;
>> char bf[PATH_MAX];
>>
>> - if (uname(&uts) < 0)
>> - return -1;
>> -
>> vmlinux_path = malloc(sizeof(char *) * 5);
>> if (vmlinux_path == NULL)
>> return -1;
>> @@ -2225,22 +2237,30 @@ static int vmlinux_path__init(void)
>> if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
>> goto out_fail;
>> ++vmlinux_path__nr_entries;
>> - snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
>> - vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
>> - if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
>> - goto out_fail;
>> - ++vmlinux_path__nr_entries;
>> - snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
>> - vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
>> - if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
>> - goto out_fail;
>> - ++vmlinux_path__nr_entries;
>> - snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
>> - uts.release);
>> - vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
>> - if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
>> - goto out_fail;
>> - ++vmlinux_path__nr_entries;
>> +
>> + /* if no symfs has been given try running kernel version too */
>> + if (strlen(symbol_conf.symfs) == 0) {
>
> Do it as:
>
> if (!symbol_conf.symfs[1])
> return 0;
>
> And then the patch can be made smaller.
Done.
I also added the symfs option to the Documentation files. Will send an
updated patch.
David
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists