This is a note to let you know that I've just added the patch titled
s390/cpum_sf.c: fix file permission for cpum_sfb_size
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
s390-cpum_sf.c-fix-file-permission-for-cpum_sfb_size.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 78d732e1f326f74f240d416af9484928303d9951 Mon Sep 17 00:00:00 2001
From: Thomas Richter <tmricht@xxxxxxxxxxxxx>
Date: Wed, 11 Nov 2020 16:26:25 +0100
Subject: s390/cpum_sf.c: fix file permission for cpum_sfb_size
From: Thomas Richter <tmricht@xxxxxxxxxxxxx>
commit 78d732e1f326f74f240d416af9484928303d9951 upstream.
This file is installed by the s390 CPU Measurement sampling
facility device driver to export supported minimum and
maximum sample buffer sizes.
This file is read by lscpumf tool to display the details
of the device driver capabilities. The lscpumf tool might
be invoked by a non-root user. In this case it does not
print anything because the file contents can not be read.
Fix this by allowing read access for all users. Reading
the file contents is ok, changing the file contents is
left to the root user only.
For further reference and details see:
[1] https://github.com/ibm-s390-tools/s390-tools/issues/97
Fixes: 69f239ed335a ("s390/cpum_sf: Dynamically extend the sampling buffer if overflows occur")
Cc: <stable@xxxxxxxxxxxxxxx> # 3.14
Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
Acked-by: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/kernel/perf_cpum_sf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -1666,4 +1666,4 @@ out:
return err;
}
arch_initcall(init_cpum_sampling_pmu);
-core_param(cpum_sfb_size, CPUM_SF_MAX_SDB, sfb_size, 0640);
+core_param(cpum_sfb_size, CPUM_SF_MAX_SDB, sfb_size, 0644);
Patches currently in stable-queue which might be from tmricht@xxxxxxxxxxxxx are
queue-4.4/s390-cpum_sf.c-fix-file-permission-for-cpum_sfb_size.patch
