pmaports/device/testing/linux-xiaomi-tissot/fix-ramoops-header.patch
Oliver Smith 64035ac463
device/*: move to device/testing/* (!1063)
Prepare for better device categorization by moving everything to testing
subdir first.

[skip-ci]: chicken-egg problem: passing pmaports CI depends on pmbootstrap MR
				depends on this MR

Related: postmarketos#16
2020-03-14 08:35:32 +01:00

88 lines
2.9 KiB
Diff

The ramoops driver prepends a "====timestamp.timestamp-C|D\n"
header to the compressed record before handing it over to pstore
driver which doesn't know about the header. In pstore_decompress(),
the pstore driver reads the first "==" as a zlib header, so the
decompression always fails. For example, this causes the driver
to write /dev/pstore/dmesg-ramoops-0.enc.z instead of
/dev/pstore/dmesg-ramoops-0.
This patch makes the ramoops driver remove the header before
pstore decompression.
Signed-off-by: Ben Zhang <benzh@chromium.org>
---
fs/pstore/ram.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 3b57443..ec881b3 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -135,25 +135,27 @@ ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
return prz;
}
-static void ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
+static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
bool *compressed)
{
char data_type;
+ int header_length = 0;
- if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
- &time->tv_sec, &time->tv_nsec, &data_type) == 3) {
+ if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
+ &time->tv_nsec, &data_type, &header_length) == 3) {
if (data_type == 'C')
*compressed = true;
else
*compressed = false;
- } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
- &time->tv_sec, &time->tv_nsec) == 2) {
+ } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
+ &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
*compressed = false;
} else {
time->tv_sec = 0;
time->tv_nsec = 0;
*compressed = false;
}
+ return header_length;
}
static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
@@ -165,6 +167,7 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
ssize_t ecc_notice_size;
struct ramoops_context *cxt = psi->data;
struct persistent_ram_zone *prz;
+ int header_length;
prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
cxt->max_dump_cnt, id, type,
@@ -178,7 +181,13 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
if (!prz)
return 0;
+ if (!persistent_ram_old(prz))
+ return 0;
+
size = persistent_ram_old_size(prz);
+ header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz), time,
+ compressed);
+ size -= header_length;
/* ECC correction notice */
ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
@@ -187,8 +196,7 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
if (*buf == NULL)
return -ENOMEM;
- memcpy(*buf, persistent_ram_old(prz), size);
- ramoops_read_kmsg_hdr(*buf, time, compressed);
+ memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1);
return size + ecc_notice_size;
--
2.1.0.rc2.206.gedb03e5