[PATCH 5.7 094/112] Drivers: hv: Change flag to write log level in panic msg to false

Greg Kroah-Hartman
2020-07-07T15:27:40Z

From: Joseph Salisbury <joseph.salisbury@microsoft.com>

commit 77b48bea2fee47c15a835f6725dd8df0bc38375a upstream.

When the kernel panics, one page of kmsg data may be collected and sent to
Hyper-V to aid in diagnosing the failure. The collected kmsg data typically
contains 50 to 100 lines, each of which has a log level prefix that isn't
very useful from a diagnostic standpoint. So tell kmsg_dump_get_buffer()
to not include the log level, enabling more information that *is* useful to
fit in the page.

Requesting in stable kernels, since many kernels running in production are
stable releases.

Cc: stable@vger.kernel.org
Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1593210497-114310-1-git-send-email-joseph.salisbury@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/hv/vmbus_drv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1328,7 +1328,7 @@ static void hv_kmsg_dump(struct kmsg_dum
* Write dump contents to the page. No need to synchronize; panic should
* be single-threaded.
*/
- kmsg_dump_get_buffer(dumper, true, hv_panic_page, HV_HYP_PAGE_SIZE,
+ kmsg_dump_get_buffer(dumper, false, hv_panic_page, HV_HYP_PAGE_SIZE,
&bytes_written);
if (bytes_written)
hyperv_report_panic_msg(panic_pa, bytes_written);