aboutsummaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-06-11 11:18:36 +0200
committerIngo Molnar <mingo@elte.hu>2009-06-11 16:48:38 +0200
commit0764771dab80d7b84b9a271bee7f1b21a04a3f0c (patch)
tree36cb6400e257393208779a95b4868df2f9af6cf6 /kernel
parent106b506c3a8b74daa5751e83ed3e46438fcf9a52 (diff)
downloadlinux-2.6.34-ux500-0764771dab80d7b84b9a271bee7f1b21a04a3f0c.tar.gz
perf_counter: More paranoia settings
Rename the perf_counter_priv knob to perf_counter_paranoia (because priv can be read as private, as opposed to privileged) and provide one more level: 0 - permissive 1 - restrict cpu counters to privilidged contexts 2 - restrict kernel-mode code counting and profiling Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/perf_counter.c25
-rw-r--r--kernel/sysctl.c6
2 files changed, 26 insertions, 5 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 8b89b40bd0f..63f1987c1c1 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -43,7 +43,23 @@ static atomic_t nr_counters __read_mostly;
static atomic_t nr_mmap_counters __read_mostly;
static atomic_t nr_comm_counters __read_mostly;
-int sysctl_perf_counter_priv __read_mostly; /* do we need to be privileged */
+/*
+ * 0 - not paranoid
+ * 1 - disallow cpu counters to unpriv
+ * 2 - disallow kernel profiling to unpriv
+ */
+int sysctl_perf_counter_paranoid __read_mostly; /* do we need to be privileged */
+
+static inline bool perf_paranoid_cpu(void)
+{
+ return sysctl_perf_counter_paranoid > 0;
+}
+
+static inline bool perf_paranoid_kernel(void)
+{
+ return sysctl_perf_counter_paranoid > 1;
+}
+
int sysctl_perf_counter_mlock __read_mostly = 512; /* 'free' kb per user */
int sysctl_perf_counter_limit __read_mostly = 100000; /* max NMIs per second */
@@ -1385,7 +1401,7 @@ static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
*/
if (cpu != -1) {
/* Must be root to operate on a CPU counter: */
- if (sysctl_perf_counter_priv && !capable(CAP_SYS_ADMIN))
+ if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
return ERR_PTR(-EACCES);
if (cpu < 0 || cpu > num_possible_cpus())
@@ -3618,6 +3634,11 @@ SYSCALL_DEFINE5(perf_counter_open,
if (copy_from_user(&attr, attr_uptr, sizeof(attr)) != 0)
return -EFAULT;
+ if (!attr.exclude_kernel) {
+ if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
+ return -EACCES;
+ }
+
/*
* Get the target context (task or percpu):
*/
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 0c4bf863afa..344a65981de 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -916,9 +916,9 @@ static struct ctl_table kern_table[] = {
#ifdef CONFIG_PERF_COUNTERS
{
.ctl_name = CTL_UNNUMBERED,
- .procname = "perf_counter_privileged",
- .data = &sysctl_perf_counter_priv,
- .maxlen = sizeof(sysctl_perf_counter_priv),
+ .procname = "perf_counter_paranoid",
+ .data = &sysctl_perf_counter_paranoid,
+ .maxlen = sizeof(sysctl_perf_counter_paranoid),
.mode = 0644,
.proc_handler = &proc_dointvec,
},