HWPOISON: Add basic support for poisoned pages in fault handler v3

[safe/jmp/linux-2.6] / kernel / perf_counter.c

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 53abcbe..8cb94a5 100644 (file)
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -46,11 +46,17 @@ static atomic_t nr_task_counters __read_mostly;
 
 /*
  * perf counter paranoia level:
- *  0 - not paranoid
- *  1 - disallow cpu counters to unpriv
- *  2 - disallow kernel profiling to unpriv
+ *  -1 - not paranoid at all
+ *   0 - disallow raw tracepoint access for unpriv
+ *   1 - disallow cpu counters for unpriv
+ *   2 - disallow kernel profiling for unpriv
  */
-int sysctl_perf_counter_paranoid __read_mostly;
+int sysctl_perf_counter_paranoid __read_mostly = 1;
+
+static inline bool perf_paranoid_tracepoint_raw(void)
+{
+       return sysctl_perf_counter_paranoid > -1;
+}
 
 static inline bool perf_paranoid_cpu(void)
 {
@@ -100,16 +106,16 @@ hw_perf_group_sched_in(struct perf_counter *group_leader,
 
 void __weak perf_counter_print_debug(void)     { }
 
-static DEFINE_PER_CPU(int, disable_count);
+static DEFINE_PER_CPU(int, perf_disable_count);
 
 void __perf_disable(void)
 {
-       __get_cpu_var(disable_count)++;
+       __get_cpu_var(perf_disable_count)++;
 }
 
 bool __perf_enable(void)
 {
-       return !--__get_cpu_var(disable_count);
+       return !--__get_cpu_var(perf_disable_count);
 }
 
 void perf_disable(void)
@@ -3971,6 +3977,7 @@ static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
         * have these.
         */
        if ((counter->attr.sample_type & PERF_SAMPLE_RAW) &&
+                       perf_paranoid_tracepoint_raw() &&
                        !capable(CAP_SYS_ADMIN))
                return ERR_PTR(-EPERM);
 
@@ -4103,6 +4110,7 @@ perf_counter_alloc(struct perf_counter_attr *attr,
        hwc->sample_period = attr->sample_period;
        if (attr->freq && attr->sample_freq)
                hwc->sample_period = 1;
+       hwc->last_period = hwc->sample_period;
 
        atomic64_set(&hwc->period_left, hwc->sample_period);
 
@@ -4207,6 +4215,7 @@ static int perf_copy_attr(struct perf_counter_attr __user *uattr,
                        if (val)
                                goto err_size;
                }
+               size = sizeof(*attr);
        }
 
        ret = copy_from_user(attr, uattr, size);
@@ -4308,15 +4317,15 @@ SYSCALL_DEFINE5(perf_counter_open,
        struct file *group_file = NULL;
        int fput_needed = 0;
        int fput_needed2 = 0;
-       int ret;
+       int err;
 
        /* for future expandability... */
        if (flags & ~(PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT))
                return -EINVAL;
 
-       ret = perf_copy_attr(attr_uptr, &attr);
-       if (ret)
-               return ret;
+       err = perf_copy_attr(attr_uptr, &attr);
+       if (err)
+               return err;
 
        if (!attr.exclude_kernel) {
                if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
@@ -4340,7 +4349,7 @@ SYSCALL_DEFINE5(perf_counter_open,
         */
        group_leader = NULL;
        if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) {
-               ret = -EINVAL;
+               err = -EINVAL;
                group_file = fget_light(group_fd, &fput_needed);
                if (!group_file)
                        goto err_put_context;
@@ -4369,22 +4378,22 @@ SYSCALL_DEFINE5(perf_counter_open,
 
        counter = perf_counter_alloc(&attr, cpu, ctx, group_leader,
                                     NULL, GFP_KERNEL);
-       ret = PTR_ERR(counter);
+       err = PTR_ERR(counter);
        if (IS_ERR(counter))
                goto err_put_context;
 
-       ret = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0);
-       if (ret < 0)
+       err = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0);
+       if (err < 0)
                goto err_free_put_context;
 
-       counter_file = fget_light(ret, &fput_needed2);
+       counter_file = fget_light(err, &fput_needed2);
        if (!counter_file)
                goto err_free_put_context;
 
        if (flags & PERF_FLAG_FD_OUTPUT) {
-               ret = perf_counter_set_output(counter, group_fd);
-               if (ret)
-                       goto err_free_put_context;
+               err = perf_counter_set_output(counter, group_fd);
+               if (err)
+                       goto err_fput_free_put_context;
        }
 
        counter->filp = counter_file;
@@ -4400,20 +4409,20 @@ SYSCALL_DEFINE5(perf_counter_open,
        list_add_tail(&counter->owner_entry, &current->perf_counter_list);
        mutex_unlock(&current->perf_counter_mutex);
 
+err_fput_free_put_context:
        fput_light(counter_file, fput_needed2);
 
-out_fput:
-       fput_light(group_file, fput_needed);
-
-       return ret;
-
 err_free_put_context:
-       kfree(counter);
+       if (err < 0)
+               kfree(counter);
 
 err_put_context:
-       put_ctx(ctx);
+       if (err < 0)
+               put_ctx(ctx);
+
+       fput_light(group_file, fput_needed);
 
-       goto out_fput;
+       return err;
 }
 
 /*