kernel.git/arch/x86/events, branch linux-5.13.y

perf/x86/amd/ibs: Extend PERF_PMU_CAP_NO_EXCLUDE to IBS Op

2021-09-15T08:00:57Z

commit f11dd0d80555cdc8eaf5cfc9e19c9e198217f9f1 upstream. Commit: 2ff40250691e ("perf/core, arch/x86: Use PERF_PMU_CAP_NO_EXCLUDE for exclusion incapable PMUs") neglected to do so. Fixes: 2ff40250691e ("perf/core, arch/x86: Use PERF_PMU_CAP_NO_EXCLUDE for exclusion incapable PMUs") Signed-off-by: Kim Phillips Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210817221048.88063-2-kim.phillips@amd.com Signed-off-by: Greg Kroah-Hartman

perf/x86/amd/power: Assign pmu.module

2021-09-08T06:50:20Z

[ Upstream commit ccf26483416a339c114409f6e7cd02abdeaf8052 ] Assign pmu.module so the driver can't be unloaded whilst in use. Signed-off-by: Kim Phillips Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210817221048.88063-4-kim.phillips@amd.com Signed-off-by: Sasha Levin

perf/x86/amd/ibs: Work around erratum #1197

2021-09-08T06:50:20Z

[ Upstream commit 26db2e0c51fe83e1dd852c1321407835b481806e ] Erratum #1197 "IBS (Instruction Based Sampling) Register State May be Incorrect After Restore From CC6" is published in a document: "Revision Guide for AMD Family 19h Models 00h-0Fh Processors" 56683 Rev. 1.04 July 2021 https://bugzilla.kernel.org/show_bug.cgi?id=206537 Implement the erratum's suggested workaround and ignore IBS samples if MSRC001_1031 == 0. Signed-off-by: Kim Phillips Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210817221048.88063-3-kim.phillips@amd.com Signed-off-by: Sasha Levin

perf/x86/intel/pt: Fix mask of num_address_ranges

2021-09-08T06:50:20Z

[ Upstream commit c53c6b7409f4cd9e542991b53d597fbe2751d7db ] Per SDM, bit 2:0 of CPUID(0x14,1).EAX[2:0] reports the number of configurable address ranges for filtering, not bit 1:0. Signed-off-by: Xiaoyao Li Signed-off-by: Peter Zijlstra (Intel) Acked-by: Alexander Shishkin Link: https://lkml.kernel.org/r/20210824040622.4081502-1-xiaoyao.li@intel.com Signed-off-by: Sasha Levin

perf/x86/intel/uncore: Fix integer overflow on 23 bit left shift of a u32

2021-09-03T08:22:59Z

[ Upstream commit 0b3a8738b76fe2087f7bc2bd59f4c78504c79180 ] The u32 variable pci_dword is being masked with 0x1fffffff and then left shifted 23 places. The shift is a u32 operation,so a value of 0x200 or more in pci_dword will overflow the u32 and only the bottow 32 bits are assigned to addr. I don't believe this was the original intent. Fix this by casting pci_dword to a resource_size_t to ensure no overflow occurs. Note that the mask and 12 bit left shift operation does not need this because the mask SNR_IMC_MMIO_MEM0_MASK and shift is always a 32 bit value. Fixes: ee49532b38dd ("perf/x86/intel/uncore: Add IMC uncore support for Snow Ridge") Addresses-Coverity: ("Unintentional integer overflow") Signed-off-by: Colin Ian King Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Kan Liang Link: https://lore.kernel.org/r/20210706114553.28249-1-colin.king@canonical.com Signed-off-by: Sasha Levin

perf/x86: Fix out of bound MSR access

2021-08-26T12:35:00Z

[ Upstream commit f4b4b45652578357031fbbef7f7a1b04f6fa2dc3 ] On Wed, Jul 28, 2021 at 12:49:43PM -0400, Vince Weaver wrote: > [32694.087403] unchecked MSR access error: WRMSR to 0x318 (tried to write 0x0000000000000000) at rIP: 0xffffffff8106f854 (native_write_msr+0x4/0x20) > [32694.101374] Call Trace: > [32694.103974] perf_clear_dirty_counters+0x86/0x100 The problem being that it doesn't filter out all fake counters, in specific the above (erroneously) tries to use FIXED_BTS. Limit the fixed counters indexes to the hardware supplied number. Reported-by: Vince Weaver Signed-off-by: Peter Zijlstra (Intel) Tested-by: Vince Weaver Tested-by: Like Xu Link: https://lkml.kernel.org/r/YQJxka3dxgdIdebG@hirez.programming.kicks-ass.net Signed-off-by: Sasha Levin

perf/x86/intel: Apply mid ACK for small core

2021-08-18T07:06:54Z

[ Upstream commit acade6379930dfa7987f4bd9b26d1a701cc1b542 ] A warning as below may be occasionally triggered in an ADL machine when these conditions occur: - Two perf record commands run one by one. Both record a PEBS event. - Both runs on small cores. - They have different adaptive PEBS configuration (PEBS_DATA_CFG). [ ] WARNING: CPU: 4 PID: 9874 at arch/x86/events/intel/ds.c:1743 setup_pebs_adaptive_sample_data+0x55e/0x5b0 [ ] RIP: 0010:setup_pebs_adaptive_sample_data+0x55e/0x5b0 [ ] Call Trace: [ ] [ ] intel_pmu_drain_pebs_icl+0x48b/0x810 [ ] perf_event_nmi_handler+0x41/0x80 [ ] [ ] __perf_event_task_sched_in+0x2c2/0x3a0 Different from the big core, the small core requires the ACK right before re-enabling counters in the NMI handler, otherwise a stale PEBS record may be dumped into the later NMI handler, which trigger the warning. Add a new mid_ack flag to track the case. Add all PMI handler bits in the struct x86_hybrid_pmu to track the bits for different types of PMUs. Apply mid ACK for the small cores on an Alder Lake machine. The existing hybrid() macro has a compile error when taking address of a bit-field variable. Add a new macro hybrid_bit() to get the bit-field value of a given PMU. Fixes: f83d2f91d259 ("perf/x86/intel: Add Alder Lake Hybrid support") Reported-by: Ammy Yi Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Andi Kleen Tested-by: Ammy Yi Link: https://lkml.kernel.org/r/1627997128-57891-1-git-send-email-kan.liang@linux.intel.com Signed-off-by: Sasha Levin

perf/x86/amd: Don't touch the AMD64_EVENTSEL_HOSTONLY bit inside the guest

2021-08-12T11:32:25Z

commit df51fe7ea1c1c2c3bfdb81279712fdd2e4ea6c27 upstream. If we use "perf record" in an AMD Milan guest, dmesg reports a #GP warning from an unchecked MSR access error on MSR_F15H_PERF_CTLx: [] unchecked MSR access error: WRMSR to 0xc0010200 (tried to write 0x0000020000110076) at rIP: 0xffffffff8106ddb4 (native_write_msr+0x4/0x20) [] Call Trace: [] amd_pmu_disable_event+0x22/0x90 [] x86_pmu_stop+0x4c/0xa0 [] x86_pmu_del+0x3a/0x140 The AMD64_EVENTSEL_HOSTONLY bit is defined and used on the host, while the guest perf driver should avoid such use. Fixes: 1018faa6cf23 ("perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabled") Signed-off-by: Like Xu Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Liam Merwick Tested-by: Kim Phillips Tested-by: Liam Merwick Link: https://lkml.kernel.org/r/20210802070850.35295-1-likexu@tencent.com Signed-off-by: Greg Kroah-Hartman

perf/x86/intel/uncore: Clean up error handling path of iio mapping

2021-07-25T12:37:31Z

[ Upstream commit d4ba0b06306a70c99a43f9d452886a86e2d3bd26 ] The error handling path of iio mapping looks fragile. We already fixed one issue caused by it, commit f797f05d917f ("perf/x86/intel/uncore: Fix for iio mapping on Skylake Server"). Clean up the error handling path and make the code robust. Reported-by: gushengxian Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/40e66cf9-398b-20d7-ce4d-433be6e08921@linux.intel.com Signed-off-by: Sasha Levin

perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task

2021-07-14T15:06:27Z

[ Upstream commit 5471eea5d3bf850316f1064a6f57b34c444bce67 ] The counter value of a perf task may leak to another RDPMC task. For example, a perf stat task as below is running on CPU 0. perf stat -e 'branches,cycles' -- taskset -c 0 ./workload In the meantime, an RDPMC task, which is also running on CPU 0, may read the GP counters periodically. (The RDPMC task creates a fixed event, but read four GP counters.) $./rdpmc_read_all_counters index 0x0 value 0x8001e5970f99 index 0x1 value 0x8005d750edb6 index 0x2 value 0x0 index 0x3 value 0x0 index 0x0 value 0x8002358e48a5 index 0x1 value 0x8006bd1e3bc9 index 0x2 value 0x0 index 0x3 value 0x0 It is a potential security issue. Once the attacker knows what the other thread is counting. The PerfMon counter can be used as a side-channel to attack cryptosystems. The counter value of the perf stat task leaks to the RDPMC task because perf never clears the counter when it's stopped. Three methods were considered to address the issue. - Unconditionally reset the counter in x86_pmu_del(). It can bring extra overhead even when there is no RDPMC task running. - Only reset the un-assigned dirty counters when the RDPMC task is scheduled in via sched_task(). It fails for the below case. Thread A Thread B clone(CLONE_THREAD) ---> set_affine(0) set_affine(1) while (!event-enabled) ; event = perf_event_open() mmap(event) ioctl(event, IOC_ENABLE); ---> RDPMC Counters are still leaked to the thread B. - Only reset the un-assigned dirty counters before updating the CR4.PCE bit. The method is implemented here. The dirty counter is a counter, on which the assigned event has been deleted, but the counter is not reset. To track the dirty counters, add a 'dirty' variable in the struct cpu_hw_events. The security issue can only be found with an RDPMC task. To enable the RDMPC, the CR4.PCE bit has to be updated. Add a perf_clear_dirty_counters() right before updating the CR4.PCE bit to clear the existing dirty counters. Only the current un-assigned dirty counters are reset, because the RDPMC assigned dirty counters will be updated soon. After applying the patch, $ ./rdpmc_read_all_counters index 0x0 value 0x0 index 0x1 value 0x0 index 0x2 value 0x0 index 0x3 value 0x0 index 0x0 value 0x0 index 0x1 value 0x0 index 0x2 value 0x0 index 0x3 value 0x0 Performance The performance of a context switch only be impacted when there are two or more perf users and one of the users must be an RDPMC user. In other cases, there is no performance impact. The worst-case occurs when there are two users: the RDPMC user only uses one counter; while the other user uses all available counters. When the RDPMC task is scheduled in, all the counters, other than the RDPMC assigned one, have to be reset. Test results for the worst-case, using a modified lat_ctx as measured on an Ice Lake platform, which has 8 GP and 3 FP counters (ignoring SLOTS). lat_ctx -s 128K -N 1000 processes 2 Without the patch: The context switch time is 4.97 us With the patch: The context switch time is 5.16 us There is ~4% performance drop for the context switching time in the worst-case. Suggested-by: Peter Zijlstra (Intel) Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/1623693582-187370-1-git-send-email-kan.liang@linux.intel.com Signed-off-by: Sasha Levin