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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-04-09 10:53:45 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-09 11:50:52 +0200 |
| commit | 1ccd15497869f3ed83b5225d410df53a96e52757 (patch) | |
| tree | 67c475136503f53c2b2d9d9ada1c281aef0a162b | |
| parent | 9ee318a7825929bc3734110b83ae8e20e53d9de3 (diff) | |
| download | kernel_samsung_smdk4412-1ccd15497869f3ed83b5225d410df53a96e52757.tar.gz kernel_samsung_smdk4412-1ccd15497869f3ed83b5225d410df53a96e52757.tar.bz2 kernel_samsung_smdk4412-1ccd15497869f3ed83b5225d410df53a96e52757.zip | |
perf_counter: sysctl for system wide perf counters
Impact: add sysctl for paranoid/relaxed perfcounters policy
Allow the use of system wide perf counters to everybody, but provide
a sysctl to disable it for the paranoid security minded.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090409085524.514046352@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/linux/perf_counter.h | 2 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 4 | ||||
| -rw-r--r-- | kernel/sysctl.c | 11 |
3 files changed, 16 insertions, 1 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index c22363a4f74..98143288530 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -568,6 +568,8 @@ struct perf_callchain_entry { extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs); +extern int sysctl_perf_counter_priv; + #else static inline void perf_counter_task_sched_in(struct task_struct *task, int cpu) { } diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 76376ecb23b..7efb7ebaaae 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -42,6 +42,8 @@ static atomic_t nr_mmap_tracking __read_mostly; static atomic_t nr_munmap_tracking __read_mostly; static atomic_t nr_comm_tracking __read_mostly; +int sysctl_perf_counter_priv __read_mostly; /* do we need to be privileged */ + /* * Mutex for (sysadmin-configurable) counter reservations: */ @@ -1132,7 +1134,7 @@ 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 (!capable(CAP_SYS_ADMIN)) + if (sysctl_perf_counter_priv && !capable(CAP_SYS_ADMIN)) return ERR_PTR(-EACCES); if (cpu < 0 || cpu > num_possible_cpus()) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 4286b62b34a..8ba457838d9 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -49,6 +49,7 @@ #include <linux/reboot.h> #include <linux/ftrace.h> #include <linux/slow-work.h> +#include <linux/perf_counter.h> #include <asm/uaccess.h> #include <asm/processor.h> @@ -920,6 +921,16 @@ static struct ctl_table kern_table[] = { .child = slow_work_sysctls, }, #endif +#ifdef CONFIG_PERF_COUNTERS + { + .ctl_name = CTL_UNNUMBERED, + .procname = "perf_counter_privileged", + .data = &sysctl_perf_counter_priv, + .maxlen = sizeof(sysctl_perf_counter_priv), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, +#endif /* * NOTE: do not add new entries to this table unless you have read * Documentation/sysctl/ctl_unnumbered.txt |