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authorKees Cook <keescook@chromium.org>2012-12-17 16:03:14 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-17 17:15:22 -0800
commit2f4b3bf6b2318cfaa177ec5a802f4d8d6afbd816 (patch)
treed4db7dc0ff5972232e2edbf08004e4ee838823c2
parent834f82e2aa9a8ede94b17b656329f850c1471514 (diff)
/proc/pid/status: add "Seccomp" field
It is currently impossible to examine the state of seccomp for a given process. While attaching with gdb and attempting "call prctl(PR_GET_SECCOMP,...)" will work with some situations, it is not reliable. If the process is in seccomp mode 1, this query will kill the process (prctl not allowed), if the process is in mode 2 with prctl not allowed, it will similarly be killed, and in weird cases, if prctl is filtered to return errno 0, it can look like seccomp is disabled. When reviewing the state of running processes, there should be a way to externally examine the seccomp mode. ("Did this build of Chrome end up using seccomp?" "Did my distro ship ssh with seccomp enabled?") This adds the "Seccomp" line to /proc/$pid/status. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: James Morris <jmorris@namei.org> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--Documentation/filesystems/proc.txt2
-rw-r--r--fs/proc/array.c8
2 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 74cb394e688..12665ee7094 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -181,6 +181,7 @@ read the file /proc/PID/status:
CapPrm: 0000000000000000
CapEff: 0000000000000000
CapBnd: ffffffffffffffff
+ Seccomp: 0
voluntary_ctxt_switches: 0
nonvoluntary_ctxt_switches: 1
@@ -237,6 +238,7 @@ Table 1-2: Contents of the status files (as of 2.6.30-rc7)
CapPrm bitmap of permitted capabilities
CapEff bitmap of effective capabilities
CapBnd bitmap of capabilities bounding set
+ Seccomp seccomp mode, like prctl(PR_GET_SECCOMP, ...)
Cpus_allowed mask of CPUs on which this process may run
Cpus_allowed_list Same as previous, but in "list format"
Mems_allowed mask of memory nodes allowed to this process
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 377a37366dd..077235ffb38 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -336,6 +336,13 @@ static inline void task_cap(struct seq_file *m, struct task_struct *p)
render_cap_t(m, "CapBnd:\t", &cap_bset);
}
+static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
+{
+#ifdef CONFIG_SECCOMP
+ seq_printf(m, "Seccomp:\t%d\n", p->seccomp.mode);
+#endif
+}
+
static inline void task_context_switch_counts(struct seq_file *m,
struct task_struct *p)
{
@@ -369,6 +376,7 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
}
task_sig(m, task);
task_cap(m, task);
+ task_seccomp(m, task);
task_cpus_allowed(m, task);
cpuset_task_status_allowed(m, task);
task_context_switch_counts(m, task);