Commit 860ec7c6 authored Nov 23, 2017 by Christian Borntraeger Committed by Martin Schwidefsky Nov 24, 2017

s390/debug: use pK for kernel pointers

the s390 debug feature (/sys/kernel/debug/s390dbf/) shows the kernel
pointer of the calling function even for kptr_restrict == 2. Let us
use pK instead of p.

This hides the kernel addresses for kptr_restrict == 2:

root@host $ echo 2 > /proc/sys/kernel/kptr_restrict
root@host $ tail -n1 /sys/kernel/debug/s390dbf/cio_msg/sprintf
00 01511461280:386645 2 - 00 0000000000000000 snsid: device 0.0.3f68: rc=0 3990/e9 3390/0c

root@host $ echo 1 > /proc/sys/kernel/kptr_restrict
root@host $ tail -n1 /sys/kernel/debug/s390dbf/cio_msg/sprintf
00 01511461280:386645 2 - 00 000000000071171c snsid: device 0.0.3f68: rc=0 3990/e9 3390/0c

root@host $ echo 0 > /proc/sys/kernel/kptr_restrict
root@host $ tail -n1 /sys/kernel/debug/s390dbf/cio_msg/sprintf
00 01511461280:386645 2 - 00 000000000071171c snsid: device 0.0.3f68: rc=0 3990/e9 3390/0c

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 53c4ab70

arch/s390/kernel/debug.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1392,7 +1392,7 @@ int debug_dflt_header_fn(debug_info_t id, struct debug_view view,
		else
		except_str = "-";
		caller = (unsigned long) entry->caller;
		rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %p ",
		rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %pK ",
		area, sec, usec, level, except_str,
		entry->id.fields.cpuid, (void *)caller);
		return rc;