Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'rework/prb-fixes' into for-linus
+17
-14
+15
-12
kernel/printk/printk_ringbuffer.c
+15
-12
kernel/printk/printk_ringbuffer.c
···
14
14
*
15
15
* Data Structure
16
16
* --------------
17
-
* The printk_ringbuffer is made up of 3 internal ringbuffers:
17
+
* The printk_ringbuffer is made up of 2 internal ringbuffers:
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18
*
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* desc_ring
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20
* A ring of descriptors and their meta data (such as sequence number,
···
224
224
*
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* prb_rec_init_rd(&r, &info, &text_buf[0], sizeof(text_buf));
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*
227
-
* prb_for_each_record(0, &test_rb, &seq, &r) {
227
+
* prb_for_each_record(0, &test_rb, seq, &r) {
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* if (info.seq != seq)
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* pr_warn("lost %llu records\n", info.seq - seq);
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*
···
1302
1302
return NULL;
1303
1303
}
1304
1304
1305
-
/* Sanity check. Data-less blocks were handled earlier. */
1306
-
if (WARN_ON_ONCE(!data_check_size(data_ring, *data_size) || !*data_size))
1307
-
return NULL;
1308
-
1309
1305
/* A valid data block will always be aligned to the ID size. */
1310
1306
if (WARN_ON_ONCE(blk_lpos->begin != ALIGN(blk_lpos->begin, sizeof(db->id))) ||
1311
1307
WARN_ON_ONCE(blk_lpos->next != ALIGN(blk_lpos->next, sizeof(db->id)))) {
1312
1308
return NULL;
1313
1309
}
1314
1310
1315
-
/* A valid data block will always have at least an ID. */
1316
-
if (WARN_ON_ONCE(*data_size < sizeof(db->id)))
1311
+
/*
1312
+
* A regular data block will always have an ID and at least
1313
+
* 1 byte of data. Data-less blocks were handled earlier.
1314
+
*/
1315
+
if (WARN_ON_ONCE(*data_size <= sizeof(db->id)))
1317
1316
return NULL;
1318
1317
1319
1318
/* Subtract block ID space from size to reflect data size. */
1320
1319
*data_size -= sizeof(db->id);
1320
+
1321
+
/* Sanity check the max size of the regular data block. */
1322
+
if (WARN_ON_ONCE(!data_check_size(data_ring, *data_size)))
1323
+
return NULL;
1321
1324
1322
1325
return &db->data[0];
1323
1326
}
···
1368
1365
*
1369
1366
* WMB from _prb_commit:A to _prb_commit:B
1370
1367
* matching
1371
-
* MB If desc_reopen_last:A to prb_reserve_in_last:A
1368
+
* MB from desc_reopen_last:A to prb_reserve_in_last:A
1372
1369
*/
1373
1370
if (!atomic_long_try_cmpxchg(&d->state_var, &prev_state_val,
1374
1371
DESC_SV(id, desc_reserved))) { /* LMM(desc_reopen_last:A) */
···
1773
1770
*
1774
1771
* Relies on:
1775
1772
*
1776
-
* MB _prb_commit:B to prb_commit:A
1773
+
* MB from _prb_commit:B to prb_commit:A
1777
1774
* matching
1778
-
* MB desc_reserve:D to desc_make_final:A
1775
+
* MB from desc_reserve:D to desc_make_final:A
1779
1776
*/
1780
1777
if (!atomic_long_try_cmpxchg(&d->state_var, &prev_state_val,
1781
1778
DESC_SV(e->id, state_val))) { /* LMM(_prb_commit:B) */
···
2038
2035
*
2039
2036
* MB from desc_push_tail:B to desc_reserve:F
2040
2037
* matching
2041
-
* RMB prb_first_seq:B to prb_first_seq:A
2038
+
* RMB from prb_first_seq:B to prb_first_seq:A
2042
2039
*/
2043
2040
smp_rmb(); /* LMM(prb_first_seq:C) */
2044
2041
}
+2
-2
kernel/printk/printk_ringbuffer.h
+2
-2
kernel/printk/printk_ringbuffer.h
···
127
127
};
128
128
129
129
#define _DATA_SIZE(sz_bits) (1UL << (sz_bits))
130
-
#define _DESCS_COUNT(ct_bits) (1U << (ct_bits))
130
+
#define _DESCS_COUNT(ct_bits) (1UL << (ct_bits))
131
131
#define DESC_SV_BITS BITS_PER_LONG
132
132
#define DESC_FLAGS_SHIFT (DESC_SV_BITS - 2)
133
133
#define DESC_FLAGS_MASK (3UL << DESC_FLAGS_SHIFT)
···
388
388
*
389
389
* This is a macro for conveniently iterating over a ringbuffer.
390
390
* Note that @s may not be the sequence number of the record on each
391
-
* iteration. For the sequence number, @r->info->seq should be checked.
391
+
* iteration. For the sequence number, @i->seq should be checked.
392
392
*
393
393
* Context: Any context.
394
394
*/