* Re: [PATCH v3 1/1] perf tools: Check access permission when reading symbol files
[not found] <1434704253-2632-1-git-send-email-zhlcindy@linux.vnet.ibm.com>
@ 2015-06-26 6:22 ` Li Zhang
2015-06-26 15:36 ` Arnaldo Carvalho de Melo
2015-06-30 4:59 ` [tip:perf/urgent] perf symbols: " tip-bot for Li Zhang
1 sibling, 1 reply; 3+ messages in thread
From: Li Zhang @ 2015-06-26 6:22 UTC (permalink / raw)
To: Li Zhang; +Cc: acme, mingo, sukadev, linux-kernel
ping ?
On 2015年06月19日 16:57, Li Zhang wrote:
> There 2 problems when reading symbols files:
>
> * It doesn't report any errors even if when users specify symbol
> files which don't exist with --kallsyms or --vmlinux. The result
> just shows the address without symbols, which is not what is expected.
> So it's better to report errors and exit the program.
>
> * When using command perf report --kallsyms=/proc/kallsyms with a
> non-root user, symbols are resolved. Then select one symbol and
> annotate it, it reports the error as the following:
> Can't annotate __clear_user: No vmlinux file with build id xxx was
> found.
>
> The problem is caused by reading /proc/kcore without access permission.
> /proc/kcore requires CAP_SYS_RAWIO capability to access, so it needs to
> change access permission to allow a specific user to read /proc/kcore or
> use root to execute the perf command.
>
> This patch is to report errors when symbol files specified by users
> don't exist. And check access permission of /proc/kcore when reading it.
>
> Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
> ---
>
> v3 -> v2:
> * Add checking symbol files when user specify these files.
> * Report an error to users when open fails. Suggested by Sukar
>
> v2 -> v1:
> * Report one useful message to users about the access permision,
> then go back to the tools. Suggested by Arnaldo Carvalho de Melo.
>
> tools/perf/builtin-report.c | 11 +++++++++++
> tools/perf/util/symbol.c | 5 ++++-
> 2 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
> index 476cdf7..1c353b1 100644
> --- a/tools/perf/builtin-report.c
> +++ b/tools/perf/builtin-report.c
> @@ -731,6 +731,17 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
>
> argc = parse_options(argc, argv, options, report_usage, 0);
>
> + if (symbol_conf.vmlinux_name &&
> + access(symbol_conf.vmlinux_name, R_OK)) {
> + pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
> + return -EINVAL;
> + }
> + if (symbol_conf.kallsyms_name &&
> + access(symbol_conf.kallsyms_name, R_OK)) {
> + pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
> + return -EINVAL;
> + }
> +
> if (report.use_stdio)
> use_browser = 0;
> else if (report.use_tui)
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index 201f6c4c..46aa93d 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -1126,8 +1126,11 @@ static int dso__load_kcore(struct dso *dso, struct map *map,
> INIT_LIST_HEAD(&md.maps);
>
> fd = open(kcore_filename, O_RDONLY);
> - if (fd < 0)
> + if (fd < 0) {
> + pr_err("%s requires CAP_SYS_RAWIO capability to access.\n",
> + kcore_filename);
> return -EINVAL;
> + }
>
> /* Read new maps into temporary lists */
> err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
--
Li Zhang
IBM China Linux Technology Centre
^ permalink raw reply [flat|nested] 3+ messages in thread* [tip:perf/urgent] perf symbols: Check access permission when reading symbol files
[not found] <1434704253-2632-1-git-send-email-zhlcindy@linux.vnet.ibm.com>
2015-06-26 6:22 ` [PATCH v3 1/1] perf tools: Check access permission when reading symbol files Li Zhang
@ 2015-06-30 4:59 ` tip-bot for Li Zhang
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot for Li Zhang @ 2015-06-30 4:59 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, acme, tglx, zhlcindy, sukadev
Commit-ID: 36c8bb56a9f718a9a5f35d1834ca9dcec95deb4a
Gitweb: http://git.kernel.org/tip/36c8bb56a9f718a9a5f35d1834ca9dcec95deb4a
Author: Li Zhang <zhlcindy@linux.vnet.ibm.com>
AuthorDate: Fri, 19 Jun 2015 16:57:33 +0800
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Fri, 26 Jun 2015 12:11:53 -0300
perf symbols: Check access permission when reading symbol files
There 2 problems when reading symbols files:
* It doesn't report any errors even if when users specify symbol
files which don't exist with --kallsyms or --vmlinux. The result
just shows the address without symbols, which is not what is expected.
So it's better to report errors and exit the program.
* When using command perf report --kallsyms=/proc/kallsyms with a
non-root user, symbols are resolved. Then select one symbol and
annotate it, it reports the error as the following:
Can't annotate __clear_user: No vmlinux file with build id xxx was
found.
The problem is caused by reading /proc/kcore without access permission.
/proc/kcore requires CAP_SYS_RAWIO capability to access, so it needs to
change access permission to allow a specific user to read /proc/kcore or
use root to execute the perf command.
This patch is to report errors when symbol files specified by users
don't exist. And check access permission of /proc/kcore when reading it.
Signed-off-by: Li Zhang <zhlcindy@linux.vnet.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1434704253-2632-1-git-send-email-zhlcindy@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-report.c | 11 +++++++++++
tools/perf/util/symbol.c | 5 ++++-
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 32626ea..348bed4 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -742,6 +742,17 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
argc = parse_options(argc, argv, options, report_usage, 0);
+ if (symbol_conf.vmlinux_name &&
+ access(symbol_conf.vmlinux_name, R_OK)) {
+ pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
+ return -EINVAL;
+ }
+ if (symbol_conf.kallsyms_name &&
+ access(symbol_conf.kallsyms_name, R_OK)) {
+ pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
+ return -EINVAL;
+ }
+
if (report.use_stdio)
use_browser = 0;
else if (report.use_tui)
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 504f2d7..48b588c 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1132,8 +1132,11 @@ static int dso__load_kcore(struct dso *dso, struct map *map,
INIT_LIST_HEAD(&md.maps);
fd = open(kcore_filename, O_RDONLY);
- if (fd < 0)
+ if (fd < 0) {
+ pr_err("%s requires CAP_SYS_RAWIO capability to access.\n",
+ kcore_filename);
return -EINVAL;
+ }
/* Read new maps into temporary lists */
err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
^ permalink raw reply related [flat|nested] 3+ messages in thread