When we test S4(suspend to disk) on LoongArch 3A6000 platform, the
test case sometimes fails. The dmesg log shows the following error:
Invalid LZO compressed length
After we dig into the code, we find out that:
When compress/decompress the image, the synchronization operation
between the control thread and the compress/decompress/crc thread
uses 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 get a old cmp_len and write to disk. When cpu resume from S4,
wrong cmp_len is loaded.
To maintain data consistency between two threads, we should use the
acquire/release ordering interface. So we change atomic_read/atomic_set
to atomic_read_acquire/atomic_set_release.
Signed-off-by: Hongchen Zhang <zhanghongchen@xxxxxxxxxxx>
Signed-off-by: Weihao Li <liweihao@xxxxxxxxxxx>
---
kernel/power/swap.c | 38 +++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index a2cb0babb5ec..d44f5937f1e5 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -606,11 +606,11 @@ 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;
}
@@ -619,7 +619,7 @@ 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;
@@ -649,12 +649,12 @@ static int lzo_compress_threadfn(void *data)
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;
}
@@ -663,7 +663,7 @@ static int lzo_compress_threadfn(void *data)
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;
@@ -798,7 +798,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
data[thr].unc_len = off;
- atomic_set(&data[thr].ready, 1);
+ atomic_set_release(&data[thr].ready, 1);
wake_up(&data[thr].go);
}
@@ -806,12 +806,12 @@ static int save_image_lzo(struct swap_map_handle *handle,
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;
@@ -850,7 +850,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
}
}
- wait_event(crc->done, atomic_read(&crc->stop));
+ wait_event(crc->done, atomic_read_acquire(&crc->stop));
atomic_set(&crc->stop, 0);
}
@@ -1132,12 +1132,12 @@ static int lzo_decompress_threadfn(void *data)
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;
}
@@ -1150,7 +1150,7 @@ static int lzo_decompress_threadfn(void *data)
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;
@@ -1335,7 +1335,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
}
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;
}
@@ -1371,7 +1371,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
pg = 0;
}
- atomic_set(&data[thr].ready, 1);
+ atomic_set_release(&data[thr].ready, 1);
wake_up(&data[thr].go);
}
@@ -1390,7 +1390,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
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;
@@ -1421,7 +1421,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
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;
}
@@ -1429,13 +1429,13 @@ static int load_image_lzo(struct swap_map_handle *handle,
}
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();
--
2.33.0
