4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hongchen Zhang zhanghongchen@loongson.cn
commit 71cd7e80cfde548959952eac7063aeaea1f2e1c6 upstream.
An S4 (suspend to disk) test on the LoongArch 3A6000 platform sometimes fails with the following error messaged in the dmesg log:
Invalid LZO compressed length
That happens because when compressing/decompressing the image, the synchronization between the control thread and the compress/decompress/crc thread is based on a relaxed ordering interface, which is unreliable, and the following situation may occur:
CPU 0 CPU 1 save_image_lzo lzo_compress_threadfn atomic_set(&d->stop, 1); atomic_read(&data[thr].stop) data[thr].cmp = data[thr].cmp_len; WRITE data[thr].cmp_len
Then CPU0 gets a stale cmp_len and writes it to disk. During resume from S4, wrong cmp_len is loaded.
To maintain data consistency between the two threads, use the acquire/release variants of atomic set and read operations.
Fixes: 081a9d043c98 ("PM / Hibernate: Improve performance of LZO/plain hibernation, checksum image") Cc: All applicable stable@vger.kernel.org Signed-off-by: Hongchen Zhang zhanghongchen@loongson.cn Co-developed-by: Weihao Li liweihao@loongson.cn Signed-off-by: Weihao Li liweihao@loongson.cn [ rjw: Subject rewrite and changelog edits ] Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/power/swap.c | 38 +++++++++++++++++++------------------- 1 file changed, 19 insertions(+), 19 deletions(-)
--- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -596,11 +596,11 @@ static int crc32_threadfn(void *data) unsigned i;
while (1) { - wait_event(d->go, atomic_read(&d->ready) || + wait_event(d->go, atomic_read_acquire(&d->ready) || kthread_should_stop()); if (kthread_should_stop()) { d->thr = NULL; - atomic_set(&d->stop, 1); + atomic_set_release(&d->stop, 1); wake_up(&d->done); break; } @@ -609,7 +609,7 @@ static int crc32_threadfn(void *data) for (i = 0; i < d->run_threads; i++) *d->crc32 = crc32_le(*d->crc32, d->unc[i], *d->unc_len[i]); - atomic_set(&d->stop, 1); + atomic_set_release(&d->stop, 1); wake_up(&d->done); } return 0; @@ -639,12 +639,12 @@ static int lzo_compress_threadfn(void *d struct cmp_data *d = data;
while (1) { - wait_event(d->go, atomic_read(&d->ready) || + wait_event(d->go, atomic_read_acquire(&d->ready) || kthread_should_stop()); if (kthread_should_stop()) { d->thr = NULL; d->ret = -1; - atomic_set(&d->stop, 1); + atomic_set_release(&d->stop, 1); wake_up(&d->done); break; } @@ -653,7 +653,7 @@ static int lzo_compress_threadfn(void *d d->ret = lzo1x_1_compress(d->unc, d->unc_len, d->cmp + LZO_HEADER, &d->cmp_len, d->wrk); - atomic_set(&d->stop, 1); + atomic_set_release(&d->stop, 1); wake_up(&d->done); } return 0; @@ -791,7 +791,7 @@ static int save_image_lzo(struct swap_ma
data[thr].unc_len = off;
- atomic_set(&data[thr].ready, 1); + atomic_set_release(&data[thr].ready, 1); wake_up(&data[thr].go); }
@@ -799,12 +799,12 @@ static int save_image_lzo(struct swap_ma break;
crc->run_threads = thr; - atomic_set(&crc->ready, 1); + atomic_set_release(&crc->ready, 1); wake_up(&crc->go);
for (run_threads = thr, thr = 0; thr < run_threads; thr++) { wait_event(data[thr].done, - atomic_read(&data[thr].stop)); + atomic_read_acquire(&data[thr].stop)); atomic_set(&data[thr].stop, 0);
ret = data[thr].ret; @@ -843,7 +843,7 @@ static int save_image_lzo(struct swap_ma } }
- wait_event(crc->done, atomic_read(&crc->stop)); + wait_event(crc->done, atomic_read_acquire(&crc->stop)); atomic_set(&crc->stop, 0); }
@@ -1124,12 +1124,12 @@ static int lzo_decompress_threadfn(void struct dec_data *d = data;
while (1) { - wait_event(d->go, atomic_read(&d->ready) || + wait_event(d->go, atomic_read_acquire(&d->ready) || kthread_should_stop()); if (kthread_should_stop()) { d->thr = NULL; d->ret = -1; - atomic_set(&d->stop, 1); + atomic_set_release(&d->stop, 1); wake_up(&d->done); break; } @@ -1142,7 +1142,7 @@ static int lzo_decompress_threadfn(void flush_icache_range((unsigned long)d->unc, (unsigned long)d->unc + d->unc_len);
- atomic_set(&d->stop, 1); + atomic_set_release(&d->stop, 1); wake_up(&d->done); } return 0; @@ -1330,7 +1330,7 @@ static int load_image_lzo(struct swap_ma }
if (crc->run_threads) { - wait_event(crc->done, atomic_read(&crc->stop)); + wait_event(crc->done, atomic_read_acquire(&crc->stop)); atomic_set(&crc->stop, 0); crc->run_threads = 0; } @@ -1366,7 +1366,7 @@ static int load_image_lzo(struct swap_ma pg = 0; }
- atomic_set(&data[thr].ready, 1); + atomic_set_release(&data[thr].ready, 1); wake_up(&data[thr].go); }
@@ -1385,7 +1385,7 @@ static int load_image_lzo(struct swap_ma
for (run_threads = thr, thr = 0; thr < run_threads; thr++) { wait_event(data[thr].done, - atomic_read(&data[thr].stop)); + atomic_read_acquire(&data[thr].stop)); atomic_set(&data[thr].stop, 0);
ret = data[thr].ret; @@ -1416,7 +1416,7 @@ static int load_image_lzo(struct swap_ma ret = snapshot_write_next(snapshot); if (ret <= 0) { crc->run_threads = thr + 1; - atomic_set(&crc->ready, 1); + atomic_set_release(&crc->ready, 1); wake_up(&crc->go); goto out_finish; } @@ -1424,13 +1424,13 @@ static int load_image_lzo(struct swap_ma }
crc->run_threads = thr; - atomic_set(&crc->ready, 1); + atomic_set_release(&crc->ready, 1); wake_up(&crc->go); }
out_finish: if (crc->run_threads) { - wait_event(crc->done, atomic_read(&crc->stop)); + wait_event(crc->done, atomic_read_acquire(&crc->stop)); atomic_set(&crc->stop, 0); } stop = ktime_get();