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-rw-r--r--kernel/perf_counter.c25
1 files changed, 23 insertions, 2 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 8b89b40bd0f0..63f1987c1c1c 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -43,7 +43,23 @@ static atomic_t nr_counters __read_mostly;
43static atomic_t nr_mmap_counters __read_mostly; 43static atomic_t nr_mmap_counters __read_mostly;
44static atomic_t nr_comm_counters __read_mostly; 44static atomic_t nr_comm_counters __read_mostly;
45 45
46int sysctl_perf_counter_priv __read_mostly; /* do we need to be privileged */ 46/*
47 * 0 - not paranoid
48 * 1 - disallow cpu counters to unpriv
49 * 2 - disallow kernel profiling to unpriv
50 */
51int sysctl_perf_counter_paranoid __read_mostly; /* do we need to be privileged */
52
53static inline bool perf_paranoid_cpu(void)
54{
55 return sysctl_perf_counter_paranoid > 0;
56}
57
58static inline bool perf_paranoid_kernel(void)
59{
60 return sysctl_perf_counter_paranoid > 1;
61}
62
47int sysctl_perf_counter_mlock __read_mostly = 512; /* 'free' kb per user */ 63int sysctl_perf_counter_mlock __read_mostly = 512; /* 'free' kb per user */
48int sysctl_perf_counter_limit __read_mostly = 100000; /* max NMIs per second */ 64int sysctl_perf_counter_limit __read_mostly = 100000; /* max NMIs per second */
49 65
@@ -1385,7 +1401,7 @@ static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
1385 */ 1401 */
1386 if (cpu != -1) { 1402 if (cpu != -1) {
1387 /* Must be root to operate on a CPU counter: */ 1403 /* Must be root to operate on a CPU counter: */
1388 if (sysctl_perf_counter_priv && !capable(CAP_SYS_ADMIN)) 1404 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
1389 return ERR_PTR(-EACCES); 1405 return ERR_PTR(-EACCES);
1390 1406
1391 if (cpu < 0 || cpu > num_possible_cpus()) 1407 if (cpu < 0 || cpu > num_possible_cpus())
@@ -3618,6 +3634,11 @@ SYSCALL_DEFINE5(perf_counter_open,
3618 if (copy_from_user(&attr, attr_uptr, sizeof(attr)) != 0) 3634 if (copy_from_user(&attr, attr_uptr, sizeof(attr)) != 0)
3619 return -EFAULT; 3635 return -EFAULT;
3620 3636
3637 if (!attr.exclude_kernel) {
3638 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
3639 return -EACCES;
3640 }
3641
3621 /* 3642 /*
3622 * Get the target context (task or percpu): 3643 * Get the target context (task or percpu):
3623 */ 3644 */