linux_dsm_epyc7002/arch/powerpc
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
..
boot powerpc/boot: Update Makefile comment for 64bit wrapper 2020-09-08 22:24:19 +10:00
configs powerpc/configs: Add BLK_DEV_NVME to pseries_defconfig 2020-07-29 23:47:53 +10:00
crypto powerpc: Replace HTTP links with HTTPS ones 2020-07-22 00:01:23 +10:00
include powerpc/pci: unmap legacy INTx interrupts when a PHB is removed 2020-09-15 22:13:39 +10:00
kernel powerpc/pci: unmap legacy INTx interrupts when a PHB is removed 2020-09-15 22:13:39 +10:00
kexec powerpc/kexec_file: Enable early kernel OPAL calls 2020-07-29 23:47:55 +10:00
kvm powerpc/64s: handle ISA v3.1 local copy-paste context switches 2020-09-08 22:57:12 +10:00
lib powerpc/uaccess: Switch __patch_instruction() to __put_user_asm_goto() 2020-09-15 22:13:32 +10:00
math-emu treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
mm powerepc/book3s64/hash: Align start/end address correctly with bolt mapping 2020-09-15 22:13:38 +10:00
net powerpc/ppc-opcode: Consolidate powerpc instructions from bpf_jit.h 2020-07-16 13:12:42 +10:00
oprofile powerpc/oprofile: fix spelling mistake "contex" -> "context" 2020-08-25 01:31:33 +10:00
perf Merge branch 'fixes' into next 2020-09-14 22:57:18 +10:00
platforms powerpc/papr_scm: Fix warning triggered by perf_stats_show() 2020-09-16 22:05:03 +10:00
purgatory powerpc/kexec_file: Enable early kernel OPAL calls 2020-07-29 23:47:55 +10:00
sysdev powerpc/icp-hv: Fix missing of_node_put() in success path 2020-08-25 01:31:31 +10:00
tools powerpc/tools: Remove 90 line limit in checkpatch script 2020-09-08 22:57:11 +10:00
xmon powerpc/watchpoint: Add hw_len wherever missing 2020-09-15 22:13:20 +10:00
Kbuild powerpc/kexec: Move kexec files into a dedicated subdir. 2019-11-21 15:41:34 +11:00
Kconfig powerpc/64/mm: implement page mapping percpu first chunk allocator 2020-09-15 22:13:22 +10:00
Kconfig.debug powerpc: Remove Xilinx PPC405/PPC440 support 2020-05-28 23:24:34 +10:00
Makefile powerpc/4xx: ppc4xx compile flag optimizations 2020-06-22 14:19:12 +10:00
Makefile.postlink powerpc: unrel_branch_check.sh: use nm to find symbol value 2020-09-02 11:00:22 +10:00