| Message ID | 20210514162420.2911458-1-nathanl@linux.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | powerpc/xmon: make dumping log buffer contents more reliable | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (b68d19e1abdbafef9481c7c0b0bcaff34d7af17d) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 8 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
On Fri, 14 May 2021 11:24:20 -0500, Nathan Lynch wrote: > Log buffer entries that are too long for dump_log_buf()'s small > local buffer are: > > * silently discarded when a single-line entry is too long; > kmsg_dump_get_line() returns true but sets &len to 0. > * silently truncated to the last fitting new line when a multi-line > entry is too long, e.g. register dumps from __show_regs(); this > seems undetectable via the kmsg_dump API. > > [...] Applied to powerpc/next. [1/1] powerpc/xmon: make dumping log buffer contents more reliable https://git.kernel.org/powerpc/c/2cec178e35baf57d307c0982fd2e53055bd1e9bb cheers
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index c8173e92f19d..f73c10869e64 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -2975,7 +2975,7 @@ static void dump_log_buf(void) { struct kmsg_dump_iter iter; - unsigned char buf[128]; + static unsigned char buf[1024]; size_t len; if (setjmp(bus_error_jmp) != 0) {
Log buffer entries that are too long for dump_log_buf()'s small local buffer are: * silently discarded when a single-line entry is too long; kmsg_dump_get_line() returns true but sets &len to 0. * silently truncated to the last fitting new line when a multi-line entry is too long, e.g. register dumps from __show_regs(); this seems undetectable via the kmsg_dump API. xmon_printf()'s internal buffer is already 1KB; enlarge dump_log_buf()'s own buffer to match and make it statically allocated. Verified that this allows complete printing of register dumps on ppc64le with both CONFIG_PRINTK_TIME=y and CONFIG_PRINTK_CALLER=y. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> --- arch/powerpc/xmon/xmon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)