pmaports/device/linux-xiaomi-tissot/fix-ramoops-header.patch
Ion Agorria 797f0d5319
xiaomi-tissot: Add firmware for WiFi and fix ramoops (!189)
Add firmware required to make WiFi work. Patch the kernel so the ramoops
dmesgs can be read properly without having to remove that header every
time.

[skip ci]: already built successfully in CI
2019-02-05 09:25:30 +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