perf tools: Fix mode setting in copyfile_mode_ns()

PATCH Applied Adrian Hunter 4 participants 4 messages Oct 7, 2019 – Oct 21, 2019 perf events

Share & tools

Adrian Hunter

author reviewer

2019-10-07 07:03 UTC #0 lore raw

PATCH 1/1 perf tools: Fix mode setting in copyfile_mode_ns()

slow_copyfile() opens the file by name, so "write" permissions must not be removed in copyfile_mode_ns() before calling slow_copyfile().

Example:

Before:

  $ sudo chmod +r /proc/kcore
  $ sudo setcap "cap_sys_admin,cap_sys_ptrace,cap_syslog,cap_sys_rawio=ep" tools/perf/perf
  $ tools/perf/perf buildid-cache -k /proc/kcore
  Couldn't add /proc/kcore

After:

  $ sudo chmod +r /proc/kcore
  $ sudo setcap "cap_sys_admin,cap_sys_ptrace,cap_syslog,cap_sys_rawio=ep" tools/perf/perf
  $ tools/perf/perf buildid-cache -v -k /proc/kcore
  kcore added to build-id cache directory /home/ahunter/.debug/[kernel.kcore]/37e340b1b5a7cf4f57ba8de2bc777359588a957f/2019100709562289

Signed-off-by Adrian Hunter <[email protected]>

---
 tools/perf/util/copyfile.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

tools/perf/util/copyfile.c +5 -3

index 3fa0db136667..47e03de7c235 100644
@@ -101,14 +101,16 @@ static int copyfile_mode_ns(const char *from, const char *to, mode_t mode,
 	if (tofd < 0)
 		goto out;
 
-	if (fchmod(tofd, mode))
-		goto out_close_to;
-
 	if (st.st_size == 0) { /* /proc? do it slowly... */
 		err = slow_copyfile(from, tmp, nsi);
+		if (!err && fchmod(tofd, mode))
+			err = -1;
 		goto out_close_to;
 	}
 
+	if (fchmod(tofd, mode))
+		goto out_close_to;
+
 	nsinfo__mountns_enter(nsi, &nsc);
 	fromfd = open(from, O_RDONLY);
 	nsinfo__mountns_exit(&nsc);

Signature · 1 line

2.17.1

Jiri Olsa

Acked-by on v1 1/1

2019-10-07 10:47 UTC #1 lore raw

Quoted 11 lines · Adrian Hunter

slow_copyfile() opens the file by name, so "write" permissions must not be removed in copyfile_mode_ns() before calling slow_copyfile().
Example:
Before:
  $ sudo chmod +r /proc/kcore
  $ sudo setcap "cap_sys_admin,cap_sys_ptrace,cap_syslog,cap_sys_rawio=ep" tools/perf/perf
  $ tools/perf/perf buildid-cache -k /proc/kcore
  Couldn't add /proc/kcore

Quoted 7 lines

After:

  $ sudo chmod +r /proc/kcore
  $ sudo setcap "cap_sys_admin,cap_sys_ptrace,cap_syslog,cap_sys_rawio=ep" tools/perf/perf
  $ tools/perf/perf buildid-cache -v -k /proc/kcore
  kcore added to build-id cache directory /home/ahunter/.debug/[kernel.kcore]/37e340b1b5a7cf4f57ba8de2bc777359588a957f/2019100709562289

Signed-off-by Adrian Hunter <[email protected]>

Acked-by Jiri Olsa <[email protected]>

thanks,
jirka

Quoted 31 lines

---
 tools/perf/util/copyfile.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

tools/perf/util/copyfile.c +5 -3

index 3fa0db136667..47e03de7c235 100644
@@ -101,14 +101,16 @@ static int copyfile_mode_ns(const char *from, const char *to, mode_t mode,
 	if (tofd < 0)
 		goto out;
 
-	if (fchmod(tofd, mode))
-		goto out_close_to;
-
 	if (st.st_size == 0) { /* /proc? do it slowly... */
 		err = slow_copyfile(from, tmp, nsi);
+		if (!err && fchmod(tofd, mode))
+			err = -1;
 		goto out_close_to;
 	}
 
+	if (fchmod(tofd, mode))
+		goto out_close_to;
+
 	nsinfo__mountns_enter(nsi, &nsc);
 	fromfd = open(from, O_RDONLY);
 	nsinfo__mountns_exit(&nsc);

Signature · 1 line

2.17.1

Arnaldo Carvalho de Melo

Applied

2019-10-15 15:07 UTC #2 lore raw

Em Mon, Oct 07, 2019 at 12:47:47PM +0200, Jiri Olsa escreveu:

Quoted 18 lines · Adrian Hunter

Quoted 17 lines

slow_copyfile() opens the file by name, so "write" permissions must not be removed in copyfile_mode_ns() before calling slow_copyfile().

Example:

Before:

  $ sudo chmod +r /proc/kcore
  $ sudo setcap "cap_sys_admin,cap_sys_ptrace,cap_syslog,cap_sys_rawio=ep" tools/perf/perf
  $ tools/perf/perf buildid-cache -k /proc/kcore
  Couldn't add /proc/kcore

After:

  $ sudo chmod +r /proc/kcore
  $ sudo setcap "cap_sys_admin,cap_sys_ptrace,cap_syslog,cap_sys_rawio=ep" tools/perf/perf
  $ tools/perf/perf buildid-cache -v -k /proc/kcore
  kcore added to build-id cache directory /home/ahunter/.debug/[kernel.kcore]/37e340b1b5a7cf4f57ba8de2bc777359588a957f/2019100709562289

Quoted 3 lines

Quoted 1 line
Signed-off-by Adrian Hunter <[email protected]>
Acked-by Jiri Olsa <[email protected]>

Thanks, applied to perf/urgent.

- Arnaldo

Quoted 34 lines

thanks,
jirka

Quoted 31 lines

---
 tools/perf/util/copyfile.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

tools/perf/util/copyfile.c +5 -3

index 3fa0db136667..47e03de7c235 100644
@@ -101,14 +101,16 @@ static int copyfile_mode_ns(const char *from, const char *to, mode_t mode,
 	if (tofd < 0)
 		goto out;
 
-	if (fchmod(tofd, mode))
-		goto out_close_to;
-
 	if (st.st_size == 0) { /* /proc? do it slowly... */
 		err = slow_copyfile(from, tmp, nsi);
+		if (!err && fchmod(tofd, mode))
+			err = -1;
 		goto out_close_to;
 	}
 
+	if (fchmod(tofd, mode))
+		goto out_close_to;
+
 	nsinfo__mountns_enter(nsi, &nsc);
 	fromfd = open(from, O_RDONLY);
 	nsinfo__mountns_exit(&nsc);

Signature · 1 line

2.17.1

Signature · 1 line

- Arnaldo

tip-bot2 for Adrian Hunter

merge bot Applied

2019-10-21 06:27 UTC #3 lore raw

In reply to Adrian Hunter

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     5a0baf5123236362fda4e9772cc63b7faa16a0df
Gitweb:        https://git.kernel.org/tip/5a0baf5123236362fda4e9772cc63b7faa16a0df
Author:        Adrian Hunter <[email protected]>
AuthorDate:    Mon, 07 Oct 2019 10:02:21 +03:00
Committer:     Arnaldo Carvalho de Melo <[email protected]>
CommitterDate: Tue, 15 Oct 2019 12:05:18 -03:00

perf tools: Fix mode setting in copyfile_mode_ns()

slow_copyfile() opens the file by name, so "write" permissions must not be removed in copyfile_mode_ns() before calling slow_copyfile().

Example:

Before:

  $ sudo chmod +r /proc/kcore
  $ sudo setcap "cap_sys_admin,cap_sys_ptrace,cap_syslog,cap_sys_rawio=ep" tools/perf/perf
  $ tools/perf/perf buildid-cache -k /proc/kcore
  Couldn't add /proc/kcore

After:

  $ sudo chmod +r /proc/kcore
  $ sudo setcap "cap_sys_admin,cap_sys_ptrace,cap_syslog,cap_sys_rawio=ep" tools/perf/perf
  $ tools/perf/perf buildid-cache -v -k /proc/kcore
  kcore added to build-id cache directory /home/ahunter/.debug/[kernel.kcore]/37e340b1b5a7cf4f57ba8de2bc777359588a957f/2019100709562289

Signed-off-by Adrian Hunter <[email protected]>

Acked-by Jiri Olsa <[email protected]>

Tested-by Arnaldo Carvalho de Melo <[email protected]>

Link http://lore.kernel.org/lkml/[email protected] open here

Signed-off-by Arnaldo Carvalho de Melo <[email protected]>

---
 tools/perf/util/copyfile.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

tools/perf/util/copyfile.c +5 -3

index 3fa0db1..47e03de 100644
@@ -101,14 +101,16 @@ static int copyfile_mode_ns(const char *from, const char *to, mode_t mode,
 	if (tofd < 0)
 		goto out;
 
-	if (fchmod(tofd, mode))
-		goto out_close_to;
-
 	if (st.st_size == 0) { /* /proc? do it slowly... */
 		err = slow_copyfile(from, tmp, nsi);
+		if (!err && fchmod(tofd, mode))
+			err = -1;
 		goto out_close_to;
 	}
 
+	if (fchmod(tofd, mode))
+		goto out_close_to;
+
 	nsinfo__mountns_enter(nsi, &nsc);
 	fromfd = open(from, O_RDONLY);
 	nsinfo__mountns_exit(&nsc);