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Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

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Pull perf fixes from Ingo Molnar:
 "x86 PMU driver fixes plus a core code race fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Fix incorrect lbr_sel_mask value
  perf/x86/intel/pt: Don't die on VMXON
  perf/core: Fix perf_event_open() vs. execve() race
  perf/x86/amd: Set the size of event map array to PERF_COUNT_HW_MAX
  perf/core: Make sysctl_perf_cpu_time_max_percent conform to documentation
  perf/x86/intel/rapl: Add missing Haswell model
  perf/x86/intel: Add model number for Skylake Server to perf
This commit is contained in:
Linus Torvalds
2016-04-28 20:19:04 -07:00
parent 2113caed87 cf3beb7c90
commit 814dd9481d
9 changed files with 120 additions and 31 deletions
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55
kernel/events/core.c
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@@ -412,7 +412,8 @@ int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
if (ret || !write)
return ret;
if (sysctl_perf_cpu_time_max_percent == 100) {
if (sysctl_perf_cpu_time_max_percent == 100 ||
sysctl_perf_cpu_time_max_percent == 0) {
printk(KERN_WARNING
"perf: Dynamic interrupt throttling disabled, can hang your system!\n");
WRITE_ONCE(perf_sample_allowed_ns, 0);
@@ -1105,6 +1106,7 @@ static void put_ctx(struct perf_event_context *ctx)
* function.
*
* Lock order:
* cred_guard_mutex
* task_struct::perf_event_mutex
* perf_event_context::mutex
* perf_event::child_mutex;
@@ -3420,7 +3422,6 @@ static struct task_struct *
find_lively_task_by_vpid(pid_t vpid)
{
struct task_struct *task;
int err;
rcu_read_lock();
if (!vpid)
@@ -3434,16 +3435,7 @@ find_lively_task_by_vpid(pid_t vpid)
if (!task)
return ERR_PTR(-ESRCH);
/* Reuse ptrace permission checks for now. */
err = -EACCES;
if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
goto errout;
return task;
errout:
put_task_struct(task);
return ERR_PTR(err);
}
/*
@@ -8413,6 +8405,24 @@ SYSCALL_DEFINE5(perf_event_open,
get_online_cpus();
if (task) {
err = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
if (err)
goto err_cpus;
/*
* Reuse ptrace permission checks for now.
*
* We must hold cred_guard_mutex across this and any potential
* perf_install_in_context() call for this new event to
* serialize against exec() altering our credentials (and the
* perf_event_exit_task() that could imply).
*/
err = -EACCES;
if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
goto err_cred;
}
if (flags & PERF_FLAG_PID_CGROUP)
cgroup_fd = pid;
@@ -8420,7 +8430,7 @@ SYSCALL_DEFINE5(perf_event_open,
NULL, NULL, cgroup_fd);
if (IS_ERR(event)) {
err = PTR_ERR(event);
goto err_cpus;
goto err_cred;
}
if (is_sampling_event(event)) {
@@ -8479,11 +8489,6 @@ SYSCALL_DEFINE5(perf_event_open,
goto err_context;
}
if (task) {
put_task_struct(task);
task = NULL;
}
/*
* Look up the group leader (we will attach this event to it):
*/
@@ -8581,6 +8586,11 @@ SYSCALL_DEFINE5(perf_event_open,
WARN_ON_ONCE(ctx->parent_ctx);
/*
* This is the point on no return; we cannot fail hereafter. This is
* where we start modifying current state.
*/
if (move_group) {
/*
* See perf_event_ctx_lock() for comments on the details
@@ -8652,6 +8662,11 @@ SYSCALL_DEFINE5(perf_event_open,
mutex_unlock(&gctx->mutex);
mutex_unlock(&ctx->mutex);
if (task) {
mutex_unlock(&task->signal->cred_guard_mutex);
put_task_struct(task);
}
put_online_cpus();
mutex_lock(&current->perf_event_mutex);
@@ -8684,6 +8699,9 @@ err_alloc:
*/
if (!event_file)
free_event(event);
err_cred:
if (task)
mutex_unlock(&task->signal->cred_guard_mutex);
err_cpus:
put_online_cpus();
err_task:
@@ -8968,6 +8986,9 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
/*
* When a child task exits, feed back event values to parent events.
*
* Can be called with cred_guard_mutex held when called from
* install_exec_creds().
*/
void perf_event_exit_task(struct task_struct *child)
{