| From 78d732e1f326f74f240d416af9484928303d9951 Mon Sep 17 00:00:00 2001 |
| From: Thomas Richter <tmricht@linux.ibm.com> |
| 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@linux.ibm.com> |
| |
| 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@vger.kernel.org> # 3.14 |
| Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> |
| Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> |
| Signed-off-by: Heiko Carstens <hca@linux.ibm.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| 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 |
| @@ -2097,4 +2097,4 @@ 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); |