4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hongchen Zhang <zhanghongchen@xxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
Signed-off-by: Hongchen Zhang <zhanghongchen@xxxxxxxxxxx>
Co-developed-by: Weihao Li <liweihao@xxxxxxxxxxx>
Signed-off-by: Weihao Li <liweihao@xxxxxxxxxxx>
[ rjw: Subject rewrite and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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();
