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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-06-11 11:18:36 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-06-11 16:48:38 +0200 |
| commit | 0764771dab80d7b84b9a271bee7f1b21a04a3f0c (patch) | |
| tree | 36cb6400e257393208779a95b4868df2f9af6cf6 | |
| parent | 106b506c3a8b74daa5751e83ed3e46438fcf9a52 (diff) | |
| download | op-kernel-dev-0764771dab80d7b84b9a271bee7f1b21a04a3f0c.zip op-kernel-dev-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>
| -rw-r--r-- | include/linux/perf_counter.h | 2 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 25 | ||||
| -rw-r--r-- | kernel/sysctl.c | 6 |
3 files changed, 27 insertions, 6 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 5b96647..386be91 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -648,7 +648,7 @@ struct perf_callchain_entry { extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs); -extern int sysctl_perf_counter_priv; +extern int sysctl_perf_counter_paranoid; extern int sysctl_perf_counter_mlock; extern int sysctl_perf_counter_limit; diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 8b89b40..63f1987 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 0c4bf86..344a659 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, }, |
