linux/arch/powerpc/platforms
Vaibhav Jain ca78ef2f08 powerpc/papr_scm: Fix warning triggered by perf_stats_show()
A warning is reported by the kernel in case perf_stats_show() returns
an error code. The warning is of the form below:

 papr_scm ibm,persistent-memory:ibm,pmemory@44100001:
 	  Failed to query performance stats, Err:-10
 dev_attr_show: perf_stats_show+0x0/0x1c0 [papr_scm] returned bad count
 fill_read_buffer: dev_attr_show+0x0/0xb0 returned bad count

On investigation it looks like that the compiler is silently
truncating the return value of drc_pmem_query_stats() from 'long' to
'int', since the variable used to store the return code 'rc' is an
'int'. This truncated value is then returned back as a 'ssize_t' back
from perf_stats_show() to 'dev_attr_show()' which thinks of it as a
large unsigned number and triggers this warning..

To fix this we update the type of variable 'rc' from 'int' to
'ssize_t' that prevents the compiler from truncating the return value
of drc_pmem_query_stats() and returning correct signed value back from
perf_stats_show().

Fixes: 2d02bf835e ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200912081451.66225-1-vaibhav@linux.ibm.com
2020-09-16 22:05:03 +10:00
..
4xx powerpc/4xx: Don't unmap NULL mbase 2020-05-28 23:24:36 +10:00
8xx mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
40x powerpc: Remove IBM405 Erratum #77 2020-05-28 23:24:36 +10:00
44x powerpc: Move flush_instruction_cache() prototype in asm/cacheflush.h 2020-09-02 11:00:21 +10:00
52xx powerpc updates for 5.9 2020-08-07 10:33:50 -07:00
82xx powerpc/82xx: Blacklist pq2_restart() for kprobe 2020-06-02 20:59:09 +10:00
83xx powerpc: Use simple i2c probe function 2020-09-02 11:00:20 +10:00
85xx powerpc/Kconfig: Replace HTTP links with HTTPS ones 2020-07-16 13:12:46 +10:00
86xx mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
512x powerpc/512x: Use dma_request_chan() instead dma_request_slave_channel() 2020-01-06 16:25:29 +11:00
amigaone powerpc/32: drop unused ISA_DMA_THRESHOLD 2020-04-01 14:30:50 +11:00
cell powerpc updates for 5.9 2020-08-07 10:33:50 -07:00
chrp mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
embedded6xx powerpc: Drop _nmask_and_or_msr() 2020-09-02 11:00:20 +10:00
maple mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
pasemi powerpc: use for_each_child_of_node() macro 2020-07-29 22:30:33 +10:00
powermac powerpc/powermac: Fix low_sleep_handler with KUAP and KUEP 2020-09-15 22:13:37 +10:00
powernv powerpc/powernv/idle: add a basic stop 0-3 driver for POWER10 2020-09-15 22:13:38 +10:00
ps3 powerpc/ps3: make two symbols static 2020-09-15 22:13:38 +10:00
pseries powerpc/papr_scm: Fix warning triggered by perf_stats_show() 2020-09-16 22:05:03 +10:00
fsl_uli1575.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
Kconfig powerpc/tau: Disable TAU between measurements 2020-09-15 22:13:30 +10:00
Kconfig.cputype powerpc/64: Make VDSO32 track COMPAT on 64-bit 2020-09-14 23:07:04 +10:00
Makefile powerpc: Add -Werror at arch/powerpc level 2018-10-19 00:56:17 +11:00