kernel/linux.git/arch/powerpc/perf, branch v6.12.80

arch/powerpc/perf: Check the instruction type before creating sample with perf_mem_data_src

2025-05-29T09:02:57+00:00

[ Upstream commit 2ffb26afa64261139e608bf087a0c1fe24d76d4d ] perf mem report aborts as below sometimes (during some corner case) in powerpc: # ./perf mem report 1>out *** stack smashing detected ***: terminated Aborted (core dumped) The backtrace is as below: __pthread_kill_implementation () raise () abort () __libc_message __fortify_fail __stack_chk_fail hist_entry.lvl_snprintf __sort__hpp_entry __hist_entry__snprintf hists.fprintf cmd_report cmd_mem Snippet of code which triggers the issue from tools/perf/util/sort.c static int hist_entry__lvl_snprintf(struct hist_entry *he, char *bf, size_t size, unsigned int width) { char out[64]; perf_mem__lvl_scnprintf(out, sizeof(out), he->mem_info); return repsep_snprintf(bf, size, "%-*s", width, out); } The value of "out" is filled from perf_mem_data_src value. Debugging this further showed that for some corner cases, the value of "data_src" was pointing to wrong value. This resulted in bigger size of string and causing stack check fail. The perf mem data source values are captured in the sample via isa207_get_mem_data_src function. The initial check is to fetch the type of sampled instruction. If the type of instruction is not valid (not a load/store instruction), the function returns. Since 'commit e16fd7f2cb1a ("perf: Use sample_flags for data_src")', data_src field is not initialized by the perf_sample_data_init() function. If the PMU driver doesn't set the data_src value to zero if type is not valid, this will result in uninitailised value for data_src. The uninitailised value of data_src resulted in stack check fail followed by abort for "perf mem report". When requesting for data source information in the sample, the instruction type is expected to be load or store instruction. In ISA v3.0, due to hardware limitation, there are corner cases where the instruction type other than load or store is observed. In ISA v3.0 and before values "0" and "7" are considered reserved. In ISA v3.1, value "7" has been used to indicate "larx/stcx". Drop the sample if instruction type has reserved values for this field with a ISA version check. Initialize data_src to zero in isa207_get_mem_data_src if the instruction type is not load/store. Reported-by: Disha Goel Signed-off-by: Athira Rajeev Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20250121131621.39054-1-atrajeev@linux.vnet.ibm.com Signed-off-by: Sasha Levin

powerpc/perf: Set cpumode flags using sample address

2024-06-17T12:47:16+00:00

Currently in some cases, when the sampled instruction address register latches to a specific address during sampling, the privilege bits captured in the sampled event register are incorrect. For example, a snippet from the perf report on a power10 system is: Overhead Address Command Shared Object Symbol ........ .................. ............ ................. ....................... 2.41% 0x7fff9f94a02c null_syscall [unknown] [k] 0x00007fff9f94a02c 2.20% 0x7fff9f94a02c null_syscall libc.so.6 [.] syscall perf_get_misc_flags() function looks at the privilege bits to return the corresponding flags to be used for the address symbol and these privilege bit details are read from the sampled event register. In the above snippet, address "0x00007fff9f94a02c" is shown as "k" (kernel) due to the incorrect privilege bits captured in the sampled event register. To address this case check whether the sampled address is in the kernel area. Since this is specific to the latest platform, a new pmu flag is added called "PPMU_P10" and is used to contain the proposed fix. PPMU_P10_DD1 marked events are also included under PPMU_P10, hence remove the code specific to PPMU_P10_DD1 marked events. Signed-off-by: Anjali K Reviewed-by: Athira Rajeev > Signed-off-by: Michael Ellerman Link: https://msgid.link/20240528040356.2722275-1-anjalik@linux.ibm.com

driver core: Add device_show_string() helper for sysfs attributes

2024-05-04T15:37:03+00:00

For drivers wishing to expose an unsigned long, int or bool at a static memory location in sysfs, the driver core provides ready-made helpers such as device_show_ulong() to be used as ->show() callback. Some drivers need to expose a string and so far they all provide their own ->show() implementation. arch/powerpc/perf/hv-24x7.c went so far as to create a device_show_string() helper but kept it private. Make it public for reuse by other drivers. The pattern seems to be sufficiently frequent to merit a public helper. Add a DEVICE_STRING_ATTR_RO() macro in line with the existing DEVICE_ULONG_ATTR() and similar macros to ease declaration of string attributes. Signed-off-by: Lukas Wunner Acked-by: Michael Ellerman Link: https://lore.kernel.org/r/2e3eaaf2600bb55c0415c23ba301e809403a7aa2.1713608122.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

powerpc/hv-gpci: Fix the H_GET_PERF_COUNTER_INFO hcall return value checks

2024-03-03T12:05:21+00:00

Running event hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ in one of the system throws below error: ---Logs--- # perf list | grep hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=?/[Kernel PMU event] # perf stat -v -e hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ sleep 2 Using CPUID 00800200 Control descriptor is not initialized Warning: hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ event is not supported by the kernel. failed to read counter hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ Performance counter stats for 'system wide': hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ 2.000700771 seconds time elapsed The above error is because of the hcall failure as required permission "Enable Performance Information Collection" is not set. Based on current code, single_gpci_request function did not check the error type incase hcall fails and by default returns EINVAL. But we can have other reasons for hcall failures like H_AUTHORITY/H_PARAMETER with detail_rc as GEN_BUF_TOO_SMALL, for which we need to act accordingly. Fix this issue by adding new checks in the single_gpci_request and h_gpci_event_init functions. Result after fix patch changes: # perf stat -e hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ sleep 2 Error: No permission to enable hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ event. Fixes: 220a0c609ad1 ("powerpc/perf: Add support for the hv gpci (get performance counter info) interface") Reported-by: Akanksha J N Signed-off-by: Kajol Jain Signed-off-by: Michael Ellerman Link: https://msgid.link/20240229122847.101162-1-kjain@linux.ibm.com

powerpc: Use user_mode() macro when possible

2024-02-22T10:55:33+00:00

There is a nice macro to check user mode. Use it instead of open coding anding with MSR_PR to increase readability and avoid having to comment what that anding is for. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/fbf74887dcf1f1ba9e1680fc3247cbb581b00662.1708078228.git.christophe.leroy@csgroup.eu

powerpc/perf: Power11 Performance Monitoring support

2024-02-21T12:11:00+00:00

Base enablement patch to register performance monitoring hardware support for Power11. Most of fields are copied from power10_pmu struct for power11_pmu struct. Signed-off-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman Link: https://msgid.link/20240221044623.1598642-2-mpe@ellerman.id.au

Merge tag 'perf-core-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2024-01-09T03:37:20+00:00

Pull performance events updates from Ingo Molnar: - Add branch stack counters ABI extension to better capture the growing amount of information the PMU exposes via branch stack sampling. There's matching tooling support. - Fix race when creating the nr_addr_filters sysfs file - Add Intel Sierra Forest and Grand Ridge intel/cstate PMU support - Add Intel Granite Rapids, Sierra Forest and Grand Ridge uncore PMU support - Misc cleanups & fixes * tag 'perf-core-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/uncore: Factor out topology_gidnid_map() perf/x86/intel/uncore: Fix NULL pointer dereference issue in upi_fill_topology() perf/x86/amd: Reject branch stack for IBS events perf/x86/intel/uncore: Support Sierra Forest and Grand Ridge perf/x86/intel/uncore: Support IIO free-running counters on GNR perf/x86/intel/uncore: Support Granite Rapids perf/x86/uncore: Use u64 to replace unsigned for the uncore offsets array perf/x86/intel/uncore: Generic uncore_get_uncores and MMIO format of SPR perf: Fix the nr_addr_filters fix perf/x86/intel/cstate: Add Grand Ridge support perf/x86/intel/cstate: Add Sierra Forest support x86/smp: Export symbol cpu_clustergroup_mask() perf/x86/intel/cstate: Cleanup duplicate attr_groups perf/core: Fix narrow startup race when creating the perf nr_addr_filters sysfs file perf/x86/intel: Support branch counters logging perf/x86/intel: Reorganize attrs and is_visible perf: Add branch_sample_call_stack perf/x86: Add PERF_X86_EVENT_NEEDS_BRANCH_STACK flag perf: Add branch stack counters

powerpc/imc-pmu: Add a null pointer check in update_events_in_group()

2023-12-13T11:19:43+00:00

kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure. Fixes: 885dcd709ba9 ("powerpc/perf: Add nest IMC PMU support") Signed-off-by: Kunwu Chan Signed-off-by: Michael Ellerman Link: https://msgid.link/20231126093719.1440305-1-chentao@kylinos.cn

powerpc/hv-gpci: Add return value check in affinity_domain_via_partition_show function

2023-12-13T10:05:03+00:00

To access hv-gpci kernel interface files data, the "Enable Performance Information Collection" option has to be set in hmc. Incase that option is not set and user try to read the interface files, it should give error message as operation not permitted. Result of accessing added interface files with disabled performance collection option: [command]# cat processor_bus_topology cat: processor_bus_topology: Operation not permitted [command]# cat processor_config cat: processor_config: Operation not permitted [command]# cat affinity_domain_via_domain cat: affinity_domain_via_domain: Operation not permitted [command]# cat affinity_domain_via_virtual_processor cat: affinity_domain_via_virtual_processor: Operation not permitted [command]# cat affinity_domain_via_partition Based on above result there is no error message when reading affinity_domain_via_partition file because of missing check for failed hcall. Fix this issue by adding a check in the start of affinity_domain_via_partition_show function, to return error incase hcall fails, with error type other then H_PARAMETER. Fixes: a15e0d6a6929 ("powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show affinity domain via partition information") Reported-by: Disha Goel Signed-off-by: Kajol Jain Signed-off-by: Michael Ellerman Link: https://msgid.link/20231116122033.160964-1-kjain@linux.ibm.com

Merge branch 'tip/perf/urgent'

2023-11-15T09:15:40+00:00

Avoid conflicts, base on fixes. Signed-off-by: Peter Zijlstra