Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'trace-fixes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
"Minor last minute fixes:
- Fix a very tight race between the ring buffer readers and resizing
the ring buffer
- Correct some stale comments in the ring buffer code
- Fix kernel-doc in the rv code
- Add a MODULE_DESCRIPTION to preemptirq_delay_test"
* tag 'trace-fixes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
rv: Update rv_en(dis)able_monitor doc to match kernel-doc
tracing: Add MODULE_DESCRIPTION() to preemptirq_delay_test
ring-buffer: Fix a race between readers and resize checks
ring-buffer: Correct stale comments related to non-consuming readers
+15
-13
+1
kernel/trace/preemptirq_delay_test.c
+1
kernel/trace/preemptirq_delay_test.c
+12
-13
kernel/trace/ring_buffer.c
+12
-13
kernel/trace/ring_buffer.c
···
1460
1460
*
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1461
* As a safety measure we check to make sure the data pages have not
1462
1462
* been corrupted.
1463
+
*
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+
* Callers of this function need to guarantee that the list of pages doesn't get
1465
+
* modified during the check. In particular, if it's possible that the function
1466
+
* is invoked with concurrent readers which can swap in a new reader page then
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+
* the caller should take cpu_buffer->reader_lock.
1463
1468
*/
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static void rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
1465
1470
{
···
2215
2210
*/
2216
2211
synchronize_rcu();
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2212
for_each_buffer_cpu(buffer, cpu) {
2213
+
unsigned long flags;
2214
+
2218
2215
cpu_buffer = buffer->buffers[cpu];
2216
+
raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
2219
2217
rb_check_pages(cpu_buffer);
2218
+
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
2220
2219
}
2221
2220
atomic_dec(&buffer->record_disabled);
2222
2221
}
···
5055
5046
* @flags: gfp flags to use for memory allocation
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*
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* This performs the initial preparations necessary to iterate
5058
-
* through the buffer. Memory is allocated, buffer recording
5049
+
* through the buffer. Memory is allocated, buffer resizing
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* is disabled, and the iterator pointer is returned to the caller.
5060
-
*
5061
-
* Disabling buffer recording prevents the reading from being
5062
-
* corrupted. This is not a consuming read, so a producer is not
5063
-
* expected.
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*
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* After a sequence of ring_buffer_read_prepare calls, the user is
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* expected to make at least one call to ring_buffer_read_prepare_sync.
···
5144
5139
* ring_buffer_read_finish - finish reading the iterator of the buffer
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* @iter: The iterator retrieved by ring_buffer_start
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*
5147
-
* This re-enables the recording to the buffer, and frees the
5148
-
* iterator.
5142
+
* This re-enables resizing of the buffer, and frees the iterator.
5149
5143
*/
5150
5144
void
5151
5145
ring_buffer_read_finish(struct ring_buffer_iter *iter)
···
5152
5148
struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
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5149
unsigned long flags;
5154
5150
5155
-
/*
5156
-
* Ring buffer is disabled from recording, here's a good place
5157
-
* to check the integrity of the ring buffer.
5158
-
* Must prevent readers from trying to read, as the check
5159
-
* clears the HEAD page and readers require it.
5160
-
*/
5151
+
/* Use this opportunity to check the integrity of the ring buffer. */
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raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
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5153
rb_check_pages(cpu_buffer);
5163
5154
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+2
kernel/trace/rv/rv.c
+2
kernel/trace/rv/rv.c
···
245
245
246
246
/**
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247
* rv_disable_monitor - disable a given runtime monitor
248
+
* @mdef: Pointer to the monitor definition structure.
248
249
*
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250
* Returns 0 on success.
250
251
*/
···
257
256
258
257
/**
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* rv_enable_monitor - enable a given runtime monitor
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+
* @mdef: Pointer to the monitor definition structure.
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*
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* Returns 0 on success, error otherwise.
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*/