Skip to content

L
linux
Switch branch/tag
  1. 10 Apr, 2024 1 commit
    • Namhyung Kim's avatar
      perf/x86: Fix out of range data · dec8ced8
      Namhyung Kim authored 
      On x86 each struct cpu_hw_events maintains a table for counter assignment but
it missed to update one for the deleted event in x86_pmu_del().  This
can make perf_clear_dirty_counters() reset used counter if it's called
before event scheduling or enabling.  Then it would return out of range
data which doesn't make sense.

The following code can reproduce the problem.

  $ cat repro.c
  #include <pthread.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <linux/perf_event.h>
  #include <sys/ioctl.h>
  #include <sys/mman.h>
  #include <sys/syscall.h>

  struct perf_event_attr attr = {
  	.type = PERF_TYPE_HARDWARE,
  	.config = PERF_COUNT_HW_CPU_CYCLES,
  	.disabled = 1,
  };

  void *worker(void *arg)
  {
  	int cpu = (long)arg;
  	int fd1 = syscall(SYS_perf_event_open, &attr, -1, cpu, -1, 0);
  	int fd2 = syscall(SYS_perf_event_open, &attr, -1, cpu, -1, 0);
  	void *p;

  	do {
  		ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0);
  		p = mmap(NULL, 4096, PROT_READ, MAP_SHARED, fd1, 0);
  		ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0);

  		ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
  		munmap(p, 4096);
  		ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
  	} while (1);

  	return NULL;
  }

  int main(void)
  {
  	int i;
  	int n = sysconf(_SC_NPROCESSORS_ONLN);
  	pthread_t *th = calloc(n, sizeof(*th));

  	for (i = 0; i < n; i++)
  		pthread_create(&th[i], NULL, worker, (void *)(long)i);
  	for (i = 0; i < n; i++)
  		pthread_join(th[i], NULL);

  	free(th);
  	return 0;
  }

And you can see the out of range data using perf stat like this.
Probably it'd be easier to see on a large machine.

  $ gcc -o repro repro.c -pthread
  $ ./repro &
  $ sudo perf stat -A -I 1000 2>&1 | awk '{ if (length($3) > 15) print }'
       1.001028462 CPU6   196,719,295,683,763      cycles                           # 194290.996 GHz                       (71.54%)
       1.001028462 CPU3   396,077,485,787,730      branch-misses                    # 15804359784.80% of all branches      (71.07%)
       1.001028462 CPU17  197,608,350,727,877      branch-misses                    # 14594186554.56% of all branches      (71.22%)
       2.020064073 CPU4   198,372,472,612,140      cycles                           # 194681.113 GHz                       (70.95%)
       2.020064073 CPU6   199,419,277,896,696      cycles                           # 195720.007 GHz                       (70.57%)
       2.020064073 CPU20  198,147,174,025,639      cycles                           # 194474.654 GHz                       (71.03%)
       2.020064073 CPU20  198,421,240,580,145      stalled-cycles-frontend          #  100.14% frontend cycles idle        (70.93%)
       3.037443155 CPU4   197,382,689,923,416      cycles                           # 194043.065 GHz                       (71.30%)
       3.037443155 CPU20  196,324,797,879,414      cycles                           # 193003.773 GHz                       (71.69%)
       3.037443155 CPU5   197,679,956,608,205      stalled-cycles-backend           # 1315606428.66% backend cycles idle   (71.19%)
       3.037443155 CPU5   198,571,860,474,851      instructions                     # 13215422.58  insn per cycle

It should move the contents in the cpuc->assign as well.

Fixes: 5471eea5 ("perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task")
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarKan Liang <kan.liang@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240306061003.1894224-1-namhyung@kernel.org
      dec8ced8
  3. 09 Apr, 2024 4 commits
  5. 08 Apr, 2024 10 commits
  7. 07 Apr, 2024 4 commits
  9. 06 Apr, 2024 13 commits
  11. 05 Apr, 2024 8 commits
    • Linus Torvalds's avatar
      Merge tag 'io_uring-6.9-20240405' of git://git.kernel.dk/linux · 4f72ed49
      Linus Torvalds authored 
      Pull io_uring fixes from Jens Axboe:

 - Backport of some fixes that came up during development of the 6.10
   io_uring patches. This includes some kbuf cleanups and reference
   fixes.

 - Disable multishot read if we don't have NOWAIT support on the target

 - Fix for a dependency issue with workqueue flushing

* tag 'io_uring-6.9-20240405' of git://git.kernel.dk/linux:
  io_uring/kbuf: hold io_buffer_list reference over mmap
  io_uring/kbuf: protect io_buffer_list teardown with a reference
  io_uring/kbuf: get rid of bl->is_ready
  io_uring/kbuf: get rid of lower BGID lists
  io_uring: use private workqueue for exit work
  io_uring: disable io-wq execution of multishot NOWAIT requests
  io_uring/rw: don't allow multishot reads without NOWAIT support
      4f72ed49
    • Linus Torvalds's avatar
      Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · 4de2ff26
      Linus Torvalds authored 
      Pull SCSI fixes from James Bottomley:
 "The most important is the libsas fix, which is a problem for DMA to a
  kmalloc'd structure too small causing cache line interference. The
  other fixes (all in drivers) are mostly for allocation length fixes,
  error leg unwinding, suspend races and a missing retry"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ufs: core: Fix MCQ mode dev command timeout
  scsi: libsas: Align SMP request allocation to ARCH_DMA_MINALIGN
  scsi: sd: Unregister device if device_add_disk() failed in sd_probe()
  scsi: ufs: core: WLUN suspend dev/link state error recovery
  scsi: mylex: Fix sysfs buffer lengths
      4de2ff26
    • Linus Torvalds's avatar
      Merge tag 'devicetree-fixes-for-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux · 84985eb2
      Linus Torvalds authored 
      Pull devicetree fixes from Rob Herring:

 - Fix NIOS2 boot with external DTB

 - Add missing synchronization needed between fw_devlink and DT overlay
   removals

 - Fix some unit-address regex's to be hex only

 - Drop some 10+ year old "unstable binding" statements

 - Add new SoCs to QCom UFS binding

 - Add TPM bindings to TPM maintainers

* tag 'devicetree-fixes-for-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  nios2: Only use built-in devicetree blob if configured to do so
  dt-bindings: timer: narrow regex for unit address to hex numbers
  dt-bindings: soc: fsl: narrow regex for unit address to hex numbers
  dt-bindings: remoteproc: ti,davinci: remove unstable remark
  dt-bindings: clock: ti: remove unstable remark
  dt-bindings: clock: keystone: remove unstable remark
  of: module: prevent NULL pointer dereference in vsnprintf()
  dt-bindings: ufs: qcom: document SM6125 UFS
  dt-bindings: ufs: qcom: document SC7180 UFS
  dt-bindings: ufs: qcom: document SC8180X UFS
  of: dynamic: Synchronize of_changeset_destroy() with the devlink removals
  driver core: Introduce device_link_wait_removal()
  docs: dt-bindings: add missing address/size-cells to example
  MAINTAINERS: Add TPM DT bindings to TPM maintainers
      84985eb2
    • Linus Torvalds's avatar
      Merge tag 'mm-hotfixes-stable-2024-04-05-11-30' of... · af709adf
      Linus Torvalds authored 
      Merge tag 'mm-hotfixes-stable-2024-04-05-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "8 hotfixes, 3 are cc:stable

  There are a couple of fixups for this cycle's vmalloc changes and one
  for the stackdepot changes. And a fix for a very old x86 PAT issue
  which can cause a warning splat"

* tag 'mm-hotfixes-stable-2024-04-05-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  stackdepot: rename pool_index to pool_index_plus_1
  x86/mm/pat: fix VM_PAT handling in COW mappings
  MAINTAINERS: change vmware.com addresses to broadcom.com
  selftests/mm: include strings.h for ffsl
  mm: vmalloc: fix lockdep warning
  mm: vmalloc: bail out early in find_vmap_area() if vmap is not init
  init: open output files from cpio unpacking with O_LARGEFILE
  mm/secretmem: fix GUP-fast succeeding on secretmem folios
      af709adf
    • Linus Torvalds's avatar
      Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux · c7830236
      Linus Torvalds authored 
      Pull arm64 fix from Catalin Marinas:
 "arm64/ptrace fix to use the correct SVE layout based on the saved
  floating point state rather than the TIF_SVE flag. The latter may be
  left on during syscalls even if the SVE state is discarded"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64/ptrace: Use saved floating point state type to determine SVE layout
      c7830236
    • Linus Torvalds's avatar
      Merge tag 'riscv-for-linus-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux · 261b8e89
      Linus Torvalds authored 
      Pull RISC-V fixes from Palmer Dabbelt:

 - A fix for an __{get,put}_kernel_nofault to avoid an uninitialized
   value causing spurious failures

 - compat_vdso.so.dbg is now installed to the standard install location

 - A fix to avoid initializing PERF_SAMPLE_BRANCH_*-related events, as
   they aren't supported and will just later fail

 - A fix to make AT_VECTOR_SIZE_ARCH correct now that we're providing
   AT_MINSIGSTKSZ

 - pgprot_nx() is now implemented, which fixes vmap W^X protection

 - A fix for the vector save/restore code, which at least manifests as
   corrupted vector state when a signal is taken

 - A fix for a race condition in instruction patching

 - A fix to avoid leaking the kernel-mode GP to userspace, which is a
   kernel pointer leak that can be used to defeat KASLR in various ways

 - A handful of smaller fixes to build warnings, an overzealous printk,
   and some missing tracing annotations

* tag 'riscv-for-linus-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: process: Fix kernel gp leakage
  riscv: Disable preemption when using patch_map()
  riscv: Fix warning by declaring arch_cpu_idle() as noinstr
  riscv: use KERN_INFO in do_trap
  riscv: Fix vector state restore in rt_sigreturn()
  riscv: mm: implement pgprot_nx
  riscv: compat_vdso: align VDSOAS build log
  RISC-V: Update AT_VECTOR_SIZE_ARCH for new AT_MINSIGSTKSZ
  riscv: Mark __se_sys_* functions __used
  drivers/perf: riscv: Disable PERF_SAMPLE_BRANCH_* while not supported
  riscv: compat_vdso: install compat_vdso.so.dbg to /lib/modules/*/vdso/
  riscv: hwprobe: do not produce frtace relocation
  riscv: Fix spurious errors from __get/put_kernel_nofault
  riscv: mm: Fix prototype to avoid discarding const
      261b8e89
    • Linus Torvalds's avatar
      Merge tag 's390-6.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux · 50094473
      Linus Torvalds authored 
      Pull s390 fixes from Alexander Gordeev:

 - Fix missing NULL pointer check when determining guest/host fault

 - Mark all functions in asm/atomic_ops.h, asm/atomic.h and
   asm/preempt.h as __always_inline to avoid unwanted instrumentation

 - Fix removal of a Processor Activity Instrumentation (PAI) sampling
   event in PMU device driver

 - Align system call table on 8 bytes

* tag 's390-6.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/entry: align system call table on 8 bytes
  s390/pai: fix sampling event removal for PMU device driver
  s390/preempt: mark all functions __always_inline
  s390/atomic: mark all functions __always_inline
  s390/mm: fix NULL pointer dereference
      50094473
    • Linus Torvalds's avatar
      Merge tag 'pm-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · 2f9fd9e4
      Linus Torvalds authored 
      Pull power management fix from Rafael Wysocki:
 "Fix a recent Energy Model change that went against a recent scheduler
  change made independently (Vincent Guittot)"

* tag 'pm-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: EM: fix wrong utilization estimation in em_cpu_energy()
      2f9fd9e4
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7