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-rw-r--r--kernel/events/core.c78
1 files changed, 43 insertions, 35 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 5636c9c48545..0736508d595b 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -94,11 +94,11 @@ static void remote_function(void *data)
* @info: the function call argument
*
* Calls the function @func when the task is currently running. This might
- * be on the current CPU, which just calls the function directly
+ * be on the current CPU, which just calls the function directly. This will
+ * retry due to any failures in smp_call_function_single(), such as if the
+ * task_cpu() goes offline concurrently.
*
- * returns: @func return value, or
- * -ESRCH - when the process isn't running
- * -EAGAIN - when the process moved away
+ * returns @func return value or -ESRCH or -ENXIO when the process isn't running
*/
static int
task_function_call(struct task_struct *p, remote_function_f func, void *info)
@@ -111,11 +111,17 @@ task_function_call(struct task_struct *p, remote_function_f func, void *info)
};
int ret;
- do {
- ret = smp_call_function_single(task_cpu(p), remote_function, &data, 1);
+ for (;;) {
+ ret = smp_call_function_single(task_cpu(p), remote_function,
+ &data, 1);
if (!ret)
ret = data.ret;
- } while (ret == -EAGAIN);
+
+ if (ret != -EAGAIN)
+ break;
+
+ cond_resched();
+ }
return ret;
}
@@ -3912,7 +3918,9 @@ find_get_context(struct pmu *pmu, struct task_struct *task,
cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
ctx = &cpuctx->ctx;
get_ctx(ctx);
+ raw_spin_lock_irqsave(&ctx->lock, flags);
++ctx->pin_count;
+ raw_spin_unlock_irqrestore(&ctx->lock, flags);
return ctx;
}
@@ -5201,11 +5209,11 @@ static void perf_pmu_output_stop(struct perf_event *event);
static void perf_mmap_close(struct vm_area_struct *vma)
{
struct perf_event *event = vma->vm_file->private_data;
-
struct ring_buffer *rb = ring_buffer_get(event);
struct user_struct *mmap_user = rb->mmap_user;
int mmap_locked = rb->mmap_locked;
unsigned long size = perf_data_size(rb);
+ bool detach_rest = false;
if (event->pmu->event_unmapped)
event->pmu->event_unmapped(event, vma->vm_mm);
@@ -5236,7 +5244,8 @@ static void perf_mmap_close(struct vm_area_struct *vma)
mutex_unlock(&event->mmap_mutex);
}
- atomic_dec(&rb->mmap_count);
+ if (atomic_dec_and_test(&rb->mmap_count))
+ detach_rest = true;
if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
goto out_put;
@@ -5245,7 +5254,7 @@ static void perf_mmap_close(struct vm_area_struct *vma)
mutex_unlock(&event->mmap_mutex);
/* If there's still other mmap()s of this buffer, we're done. */
- if (atomic_read(&rb->mmap_count))
+ if (!detach_rest)
goto out_put;
/*
@@ -6101,7 +6110,6 @@ void perf_output_sample(struct perf_output_handle *handle,
static u64 perf_virt_to_phys(u64 virt)
{
u64 phys_addr = 0;
- struct page *p = NULL;
if (!virt)
return 0;
@@ -6120,14 +6128,15 @@ static u64 perf_virt_to_phys(u64 virt)
* If failed, leave phys_addr as 0.
*/
if (current->mm != NULL) {
+ struct page *p;
+
pagefault_disable();
- if (__get_user_pages_fast(virt, 1, 0, &p) == 1)
+ if (__get_user_pages_fast(virt, 1, 0, &p) == 1) {
phys_addr = page_to_phys(p) + virt % PAGE_SIZE;
+ put_page(p);
+ }
pagefault_enable();
}
-
- if (p)
- put_page(p);
}
return phys_addr;
@@ -6444,7 +6453,7 @@ static void perf_event_addr_filters_exec(struct perf_event *event, void *data)
raw_spin_lock_irqsave(&ifh->lock, flags);
list_for_each_entry(filter, &ifh->list, entry) {
- if (filter->inode) {
+ if (filter->path.dentry) {
event->addr_filters_offs[count] = 0;
restart++;
}
@@ -7118,7 +7127,11 @@ static bool perf_addr_filter_match(struct perf_addr_filter *filter,
struct file *file, unsigned long offset,
unsigned long size)
{
- if (filter->inode != file_inode(file))
+ /* d_inode(NULL) won't be equal to any mapped user-space file */
+ if (!filter->path.dentry)
+ return false;
+
+ if (d_inode(filter->path.dentry) != file_inode(file))
return false;
if (filter->offset > offset + size)
@@ -8339,8 +8352,7 @@ static void free_filters_list(struct list_head *filters)
struct perf_addr_filter *filter, *iter;
list_for_each_entry_safe(filter, iter, filters, entry) {
- if (filter->inode)
- iput(filter->inode);
+ path_put(&filter->path);
list_del(&filter->entry);
kfree(filter);
}
@@ -8423,7 +8435,7 @@ static void perf_event_addr_filters_apply(struct perf_event *event)
if (!ifh->nr_file_filters)
return;
- mm = get_task_mm(event->ctx->task);
+ mm = get_task_mm(task);
if (!mm)
goto restart;
@@ -8437,7 +8449,7 @@ static void perf_event_addr_filters_apply(struct perf_event *event)
* Adjust base offset if the filter is associated to a binary
* that needs to be mapped:
*/
- if (filter->inode)
+ if (filter->path.dentry)
event->addr_filters_offs[count] =
perf_addr_filter_apply(filter, mm);
@@ -8510,7 +8522,6 @@ perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
{
struct perf_addr_filter *filter = NULL;
char *start, *orig, *filename = NULL;
- struct path path;
substring_t args[MAX_OPT_ARGS];
int state = IF_STATE_ACTION, token;
unsigned int kernel = 0;
@@ -8573,6 +8584,7 @@ perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
if (token == IF_SRC_FILE || token == IF_SRC_FILEADDR) {
int fpos = filter->range ? 2 : 1;
+ kfree(filename);
filename = match_strdup(&args[fpos]);
if (!filename) {
ret = -ENOMEM;
@@ -8611,22 +8623,18 @@ perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
*/
ret = -EOPNOTSUPP;
if (!event->ctx->task)
- goto fail_free_name;
+ goto fail;
/* look up the path and grab its inode */
- ret = kern_path(filename, LOOKUP_FOLLOW, &path);
+ ret = kern_path(filename, LOOKUP_FOLLOW,
+ &filter->path);
if (ret)
- goto fail_free_name;
-
- filter->inode = igrab(d_inode(path.dentry));
- path_put(&path);
- kfree(filename);
- filename = NULL;
+ goto fail;
ret = -EINVAL;
- if (!filter->inode ||
- !S_ISREG(filter->inode->i_mode))
- /* free_filters_list() will iput() */
+ if (!filter->path.dentry ||
+ !S_ISREG(d_inode(filter->path.dentry)
+ ->i_mode))
goto fail;
event->addr_filters.nr_file_filters++;
@@ -8641,13 +8649,13 @@ perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
if (state != IF_STATE_ACTION)
goto fail;
+ kfree(filename);
kfree(orig);
return 0;
-fail_free_name:
- kfree(filename);
fail:
+ kfree(filename);
free_filters_list(filters);
kfree(orig);
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-04-30 16:12:15 +0000