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  1. 27 Jul, 2023 2 commits
    • Linus Torvalds's avatar
      Merge tag 'fixes-2023-07-27' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock · 379e6671
      Linus Torvalds authored 
      Pull memblock fix from Mike Rapoport:
 "A call to memblock_free() or memblock_phys_free() issued after
  memblock data is discarded will result in use after free in
  memblock_isolate_range().

  Avoid those issues by making sure that memblock_discard points
  memblock.reserved.regions back at the static buffer"

* tag 'fixes-2023-07-27' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  mm,memblock: reset memblock.reserved to system init state to prevent UAF
      379e6671
    • Jann Horn's avatar
      mm: lock_vma_under_rcu() must check vma->anon_vma under vma lock · 657b5146
      Jann Horn authored 
      lock_vma_under_rcu() tries to guarantee that __anon_vma_prepare() can't
be called in the VMA-locked page fault path by ensuring that
vma->anon_vma is set.

However, this check happens before the VMA is locked, which means a
concurrent move_vma() can concurrently call unlink_anon_vmas(), which
disassociates the VMA's anon_vma.

This means we can get UAF in the following scenario:

  THREAD 1                   THREAD 2
  ========                   ========
  <page fault>
    lock_vma_under_rcu()
      rcu_read_lock()
      mas_walk()
      check vma->anon_vma

                             mremap() syscall
                               move_vma()
                                vma_start_write()
                                 unlink_anon_vmas()
                             <syscall end>

    handle_mm_fault()
      __handle_mm_fault()
        handle_pte_fault()
          do_pte_missing()
            do_anonymous_page()
              anon_vma_prepare()
                __anon_vma_prepare()
                  find_mergeable_anon_vma()
                    mas_walk() [looks up VMA X]

                             munmap() syscall (deletes VMA X)

                    reusable_anon_vma() [called on freed VMA X]

This is a security bug if you can hit it, although an attacker would
have to win two races at once where the first race window is only a few
instructions wide.

This patch is based on some previous discussion with Linus Torvalds on
the security list.

Cc: stable@vger.kernel.org
Fixes: 5e31275c ("mm: add per-VMA lock and helper functions to control it")
Signed-off-by: default avatarJann Horn <jannh@google.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      657b5146
  3. 26 Jul, 2023 3 commits
    • Linus Torvalds's avatar
      Merge tag 'platform-drivers-x86-v6.5-3' of... · 0a8db05b
      Linus Torvalds authored 
      Merge tag 'platform-drivers-x86-v6.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86

Pull x86 platform driver fixes from Hans de Goede:
 "Misc small fixes and hw-id additions"

* tag 'platform-drivers-x86-v6.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86:
  platform/x86: huawei-wmi: Silence ambient light sensor
  platform/x86: msi-laptop: Fix rfkill out-of-sync on MSI Wind U100
  platform/x86: asus-wmi: Fix setting RGB mode on some TUF laptops
  platform/x86: think-lmi: Use kfree_sensitive instead of kfree
  platform/x86/intel/hid: Add HP Dragonfly G2 to VGBS DMI quirks
  platform/x86: intel: hid: Always call BTNL ACPI method
  platform/x86/amd/pmf: Notify OS power slider update
  platform/x86/amd/pmf: reduce verbosity of apmf_get_system_params
  platform/x86: serial-multi-instantiate: Auto detect IRQ resource for CSC3551
  platform/x86/amd: pmc: Use release_mem_region() to undo request_mem_region_muxed()
  platform/x86: touchscreen_dmi.c: small changes for Archos 101 Cesium Educ tablet
      0a8db05b
    • Linus Torvalds's avatar
      Merge tag '6.5-rc3-ksmbd-server-fixes' of git://git.samba.org/ksmbd · f40125c0
      Linus Torvalds authored 
      Pull ksmbd server fixes from Steve French:

 - fixes for two possible out of bounds access (in negotiate, and in
   decrypt msg)

 - fix unsigned compared to zero warning

 - fix path lookup crossing a mountpoint

 - fix case when first compound request is a tree connect

 - fix memory leak if reads are compounded

* tag '6.5-rc3-ksmbd-server-fixes' of git://git.samba.org/ksmbd:
  ksmbd: fix out of bounds in init_smb2_rsp_hdr()
  ksmbd: no response from compound read
  ksmbd: validate session id and tree id in compound request
  ksmbd: fix out of bounds in smb3_decrypt_req()
  ksmbd: check if a mount point is crossed during path lookup
  ksmbd: Fix unsigned expression compared with zero
      f40125c0
    • Linus Torvalds's avatar
      mm: suppress mm fault logging if fatal signal already pending · 5f0bc0b0
      Linus Torvalds authored 
      Commit eda00472 ("mm: make the page fault mmap locking killable")
intentionally made it much easier to trigger the "page fault fails
because a fatal signal is pending" situation, by having the mmap locking
fail early in that case.

We have long aborted page faults in other fatal cases when the actual IO
for a page is interrupted by SIGKILL - which is particularly useful for
the traditional case of NFS hanging due to network issues, but local
filesystems could cause it too if you happened to get the SIGKILL while
waiting for a page to be faulted in (eg lock_folio_maybe_drop_mmap()).

So aborting the page fault wasn't a new condition - but it now triggers
earlier, before we even get to 'handle_mm_fault()'.  And as a result the
error doesn't go through our 'fault_signal_pending()' logic, and doesn't
get filtered away there.

Normally you'd never even notice, because if a fatal signal is pending,
the new SIGSEGV we send ends up being ignored anyway.

But it turns out that there is one very noticeable exception: if you
enable 'show_unhandled_signals', the aborted page fault will be logged
in the kernel messages, and you'll get a scary line looking something
like this in your logs:

  pverados[2183248]: segfault at 55e5a00f9ae0 ip 000055e5a00f9ae0 sp 00007ffc0720bea8 error 14 in perl[55e5a00d4000+195000] likely on CPU 10 (core 4, socket 0)

which is rather misleading.  It's not really a segfault at all, it's
just "the thread was killed before the page fault completed, so we
aborted the page fault".

Fix this by just making it clear that a pending fatal signal means that
any new signal coming in after that is implicitly handled.  This will
avoid the misleading logging, since now the signal isn't 'unhandled' any
more.
Reported-and-tested-by: default avatarFiona Ebner <f.ebner@proxmox.com>
Tested-by: default avatarThomas Lamprecht <t.lamprecht@proxmox.com>
Link: https://lore.kernel.org/lkml/8d063a26-43f5-0bb7-3203-c6a04dc159f8@proxmox.com/Acked-by: default avatarOleg Nesterov <oleg@redhat.com>
Fixes: eda00472 ("mm: make the page fault mmap locking killable")
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5f0bc0b0
  5. 25 Jul, 2023 12 commits
  7. 24 Jul, 2023 6 commits
  9. 23 Jul, 2023 17 commits
    • Linus Torvalds's avatar
      Linux 6.5-rc3 · 6eaae198
      Linus Torvalds authored
      6eaae198
    • Linus Torvalds's avatar
      Merge tag 'trace-v6.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace · 3b4e48b8
      Linus Torvalds authored 
      Pull tracing fixes from Steven Rostedt:

 - Swapping the ring buffer for snapshotting (for things like irqsoff)
   can crash if the ring buffer is being resized. Disable swapping when
   this happens. The missed swap will be reported to the tracer

 - Report error if the histogram fails to be created due to an error in
   adding a histogram variable, in event_hist_trigger_parse()

 - Remove unused declaration of tracing_map_set_field_descr()

* tag 'trace-v6.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/histograms: Return an error if we fail to add histogram to hist_vars list
  ring-buffer: Do not swap cpu_buffer during resize process
  tracing: Remove unused extern declaration tracing_map_set_field_descr()
      3b4e48b8
    • Linus Torvalds's avatar
      Merge tag 'kbuild-fixes-v6.5' of... · 12a5336c
      Linus Torvalds authored 
      Merge tag 'kbuild-fixes-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix stale help text in gconfig

 - Support *.S files in compile_commands.json

 - Flatten KBUILD_CFLAGS

 - Fix external module builds with Rust so that temporary files are
   created in the modules directories instead of the kernel tree

* tag 'kbuild-fixes-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: rust: avoid creating temporary files
  kbuild: flatten KBUILD_CFLAGS
  gen_compile_commands: add assembly files to compilation database
  kconfig: gconfig: correct program name in help text
  kconfig: gconfig: drop the Show Debug Info help text
      12a5336c
    • Miguel Ojeda's avatar
      kbuild: rust: avoid creating temporary files · df01b7cf
      Miguel Ojeda authored 
      `rustc` outputs by default the temporary files (i.e. the ones saved
by `-Csave-temps`, such as `*.rcgu*` files) in the current working
directory when `-o` and `--out-dir` are not given (even if
`--emit=x=path` is given, i.e. it does not use those for temporaries).

Since out-of-tree modules are compiled from the `linux` tree,
`rustc` then tries to create them there, which may not be accessible.

Thus pass `--out-dir` explicitly, even if it is just for the temporary
files.

Similarly, do so for Rust host programs too.
Reported-by: default avatarRaphael Nestler <raphael.nestler@gmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/1015Reported-by: default avatarAndrea Righi <andrea.righi@canonical.com>
Tested-by: Raphael Nestler <raphael.nestler@gmail.com> # non-hostprogs
Tested-by: Andrea Righi <andrea.righi@canonical.com> # non-hostprogs
Fixes: 295d8398 ("kbuild: specify output names separately for each emission type from rustc")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarMiguel Ojeda <ojeda@kernel.org>
Tested-by: default avatarMartin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      df01b7cf
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · 269f4a4b
      Linus Torvalds authored 
      Pull kvm fixes from Paolo Bonzini:
 "ARM:

   - Avoid pKVM finalization if KVM initialization fails

   - Add missing BTI instructions in the hypervisor, fixing an early
     boot failure on BTI systems

   - Handle MMU notifiers correctly for non hugepage-aligned memslots

   - Work around a bug in the architecture where hypervisor timer
     controls have UNKNOWN behavior under nested virt

   - Disable preemption in kvm_arch_hardware_enable(), fixing a kernel
     BUG in cpu hotplug resulting from per-CPU accessor sanity checking

   - Make WFI emulation on GICv4 systems robust w.r.t. preemption,
     consistently requesting a doorbell interrupt on vcpu_put()

   - Uphold RES0 sysreg behavior when emulating older PMU versions

   - Avoid macro expansion when initializing PMU register names,
     ensuring the tracepoints pretty-print the sysreg

  s390:

   - Two fixes for asynchronous destroy

  x86 fixes will come early next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: s390: pv: fix index value of replaced ASCE
  KVM: s390: pv: simplify shutdown and fix race
  KVM: arm64: Fix the name of sys_reg_desc related to PMU
  KVM: arm64: Correctly handle RES0 bits PMEVTYPER<n>_EL0.evtCount
  KVM: arm64: vgic-v4: Make the doorbell request robust w.r.t preemption
  KVM: arm64: Add missing BTI instructions
  KVM: arm64: Correctly handle page aging notifiers for unaligned memslot
  KVM: arm64: Disable preemption in kvm_arch_hardware_enable()
  KVM: arm64: Handle kvm_arm_init failure correctly in finalize_pkvm
  KVM: arm64: timers: Use CNTHCTL_EL2 when setting non-CNTKCTL_EL1 bits
      269f4a4b
    • Linus Torvalds's avatar
      Merge tag 'ext4_for_linus-6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 · 15b593ba
      Linus Torvalds authored 
      Pull ext4 fixes from Ted Ts'o:
 "Bug and regression fixes for 6.5-rc3 for ext4's mballoc and jbd2's
  checkpoint code"

* tag 'ext4_for_linus-6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix rbtree traversal bug in ext4_mb_use_preallocated
  ext4: fix off by one issue in ext4_mb_choose_next_group_best_avail()
  ext4: correct inline offset when handling xattrs in inode body
  jbd2: remove __journal_try_to_free_buffer()
  jbd2: fix a race when checking checkpoint buffer busy
  jbd2: Fix wrongly judgement for buffer head removing while doing checkpoint
  jbd2: remove journal_clean_one_cp_list()
  jbd2: remove t_checkpoint_io_list
  jbd2: recheck chechpointing non-dirty buffer
      15b593ba
    • Linus Torvalds's avatar
      Merge tag '6.5-rc2-smb3-client-fixes-ver2' of git://git.samba.org/sfrench/cifs-2.6 · 8266f53b
      Linus Torvalds authored 
      Pull smb client fix from Steve French:
 "Add minor debugging improvement.

  The change improves ability to read a network trace to debug problems
  on encrypted connections which are very common (e.g. using wireshark
  or tcpdump).

  That works today with tools like 'smbinfo keys /mnt/file' but requires
  passing in a filename on the mount (see e.g. [1]), but it often makes
  more sense to just pass in the mount point path (ie a directory not a
  filename).

  So this fix was needed to debug some types of problems (an obvious
  example is on an encrypted connection failing operations on an empty
  share or with no files in the root of the directory) - so you can
  simply pass in the 'smbinfo keys <mntpoint>' and get the information
  that wireshark needs"

Link: https://wiki.samba.org/index.php/Wireshark_Decryption [1]

* tag '6.5-rc2-smb3-client-fixes-ver2' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal module version number for cifs.ko
  cifs: allow dumping keys for directories too
      8266f53b
    • Paolo Bonzini's avatar
      Merge tag 'kvm-s390-master-6.5-1' of... · 0c189708
      Paolo Bonzini authored 
      Merge tag 'kvm-s390-master-6.5-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

Two fixes for asynchronous destroy
      0c189708
    • Paolo Bonzini's avatar
      Merge tag 'kvmarm-fixes-6.5-1' of... · 675a15f4
      Paolo Bonzini authored 
      Merge tag 'kvmarm-fixes-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.5, part #1

 - Avoid pKVM finalization if KVM initialization fails

 - Add missing BTI instructions in the hypervisor, fixing an early boot
   failure on BTI systems

 - Handle MMU notifiers correctly for non hugepage-aligned memslots

 - Work around a bug in the architecture where hypervisor timer controls
   have UNKNOWN behavior under nested virt.

 - Disable preemption in kvm_arch_hardware_enable(), fixing a kernel BUG
   in cpu hotplug resulting from per-CPU accessor sanity checking.

 - Make WFI emulation on GICv4 systems robust w.r.t. preemption,
   consistently requesting a doorbell interrupt on vcpu_put()

 - Uphold RES0 sysreg behavior when emulating older PMU versions

 - Avoid macro expansion when initializing PMU register names, ensuring
   the tracepoints pretty-print the sysreg.
      675a15f4
    • Namjae Jeon's avatar
      ksmbd: fix out of bounds in init_smb2_rsp_hdr() · 536bb492
      Namjae Jeon authored 
      If client send smb2 negotiate request and then send smb1 negotiate
request, init_smb2_rsp_hdr is called for smb1 negotiate request since
need_neg is set to false. This patch ignore smb1 packets after ->need_neg
is set to false.

Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21541
Signed-off-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      536bb492
    • Namjae Jeon's avatar
      ksmbd: no response from compound read · e202a1e8
      Namjae Jeon authored 
      ksmbd doesn't support compound read. If client send read-read in
compound to ksmbd, there can be memory leak from read buffer.
Windows and linux clients doesn't send it to server yet. For now,
No response from compound read. compound read will be supported soon.

Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21587, ZDI-CAN-21588
Signed-off-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      e202a1e8
    • Namjae Jeon's avatar
      ksmbd: validate session id and tree id in compound request · 3df0411e
      Namjae Jeon authored 
      `smb2_get_msg()` in smb2_get_ksmbd_tcon() and smb2_check_user_session()
will always return the first request smb2 header in a compound request.
if `SMB2_TREE_CONNECT_HE` is the first command in compound request, will
return 0, i.e. The tree id check is skipped.
This patch use ksmbd_req_buf_next() to get current command in compound.

Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21506
Signed-off-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      3df0411e
    • Namjae Jeon's avatar
      ksmbd: fix out of bounds in smb3_decrypt_req() · dc318846
      Namjae Jeon authored 
      smb3_decrypt_req() validate if pdu_length is smaller than
smb2_transform_hdr size.

Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21589
Signed-off-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      dc318846
    • Namjae Jeon's avatar
      ksmbd: check if a mount point is crossed during path lookup · 2b57a432
      Namjae Jeon authored 
      Since commit 74d7970f ("ksmbd: fix racy issue from using ->d_parent and
->d_name"), ksmbd can not lookup cross mount points. If last component is
a cross mount point during path lookup, check if it is crossed to follow it
down. And allow path lookup to cross a mount point when a crossmnt
parameter is set to 'yes' in smb.conf.

Cc: stable@vger.kernel.org
Fixes: 74d7970f ("ksmbd: fix racy issue from using ->d_parent and ->d_name")
Signed-off-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      2b57a432
    • Mohamed Khalfella's avatar
      tracing/histograms: Return an error if we fail to add histogram to hist_vars list · 4b8b3905
      Mohamed Khalfella authored 
      Commit 6018b585 ("tracing/histograms: Add histograms to hist_vars if
they have referenced variables") added a check to fail histogram creation
if save_hist_vars() failed to add histogram to hist_vars list. But the
commit failed to set ret to failed return code before jumping to
unregister histogram, fix it.

Link: https://lore.kernel.org/linux-trace-kernel/20230714203341.51396-1-mkhalfella@purestorage.com

Cc: stable@vger.kernel.org
Fixes: 6018b585 ("tracing/histograms: Add histograms to hist_vars if they have referenced variables")
Signed-off-by: default avatarMohamed Khalfella <mkhalfella@purestorage.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
      4b8b3905
    • Chen Lin's avatar
      ring-buffer: Do not swap cpu_buffer during resize process · 8a96c028
      Chen Lin authored 
      When ring_buffer_swap_cpu was called during resize process,
the cpu buffer was swapped in the middle, resulting in incorrect state.
Continuing to run in the wrong state will result in oops.

This issue can be easily reproduced using the following two scripts:
/tmp # cat test1.sh
//#! /bin/sh
for i in `seq 0 100000`
do
         echo 2000 > /sys/kernel/debug/tracing/buffer_size_kb
         sleep 0.5
         echo 5000 > /sys/kernel/debug/tracing/buffer_size_kb
         sleep 0.5
done
/tmp # cat test2.sh
//#! /bin/sh
for i in `seq 0 100000`
do
        echo irqsoff > /sys/kernel/debug/tracing/current_tracer
        sleep 1
        echo nop > /sys/kernel/debug/tracing/current_tracer
        sleep 1
done
/tmp # ./test1.sh &
/tmp # ./test2.sh &

A typical oops log is as follows, sometimes with other different oops logs.

[  231.711293] WARNING: CPU: 0 PID: 9 at kernel/trace/ring_buffer.c:2026 rb_update_pages+0x378/0x3f8
[  231.713375] Modules linked in:
[  231.714735] CPU: 0 PID: 9 Comm: kworker/0:1 Tainted: G        W          6.5.0-rc1-00276-g20edcec2 #15
[  231.716750] Hardware name: linux,dummy-virt (DT)
[  231.718152] Workqueue: events update_pages_handler
[  231.719714] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  231.721171] pc : rb_update_pages+0x378/0x3f8
[  231.722212] lr : rb_update_pages+0x25c/0x3f8
[  231.723248] sp : ffff800082b9bd50
[  231.724169] x29: ffff800082b9bd50 x28: ffff8000825f7000 x27: 0000000000000000
[  231.726102] x26: 0000000000000001 x25: fffffffffffff010 x24: 0000000000000ff0
[  231.728122] x23: ffff0000c3a0b600 x22: ffff0000c3a0b5c0 x21: fffffffffffffe0a
[  231.730203] x20: ffff0000c3a0b600 x19: ffff0000c0102400 x18: 0000000000000000
[  231.732329] x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffffe7aa8510
[  231.734212] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000002
[  231.736291] x11: ffff8000826998a8 x10: ffff800082b9baf0 x9 : ffff800081137558
[  231.738195] x8 : fffffc00030e82c8 x7 : 0000000000000000 x6 : 0000000000000001
[  231.740192] x5 : ffff0000ffbafe00 x4 : 0000000000000000 x3 : 0000000000000000
[  231.742118] x2 : 00000000000006aa x1 : 0000000000000001 x0 : ffff0000c0007208
[  231.744196] Call trace:
[  231.744892]  rb_update_pages+0x378/0x3f8
[  231.745893]  update_pages_handler+0x1c/0x38
[  231.746893]  process_one_work+0x1f0/0x468
[  231.747852]  worker_thread+0x54/0x410
[  231.748737]  kthread+0x124/0x138
[  231.749549]  ret_from_fork+0x10/0x20
[  231.750434] ---[ end trace 0000000000000000 ]---
[  233.720486] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[  233.721696] Mem abort info:
[  233.721935]   ESR = 0x0000000096000004
[  233.722283]   EC = 0x25: DABT (current EL), IL = 32 bits
[  233.722596]   SET = 0, FnV = 0
[  233.722805]   EA = 0, S1PTW = 0
[  233.723026]   FSC = 0x04: level 0 translation fault
[  233.723458] Data abort info:
[  233.723734]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[  233.724176]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[  233.724589]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[  233.725075] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000104943000
[  233.725592] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
[  233.726231] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[  233.726720] Modules linked in:
[  233.727007] CPU: 0 PID: 9 Comm: kworker/0:1 Tainted: G        W          6.5.0-rc1-00276-g20edcec2 #15
[  233.727777] Hardware name: linux,dummy-virt (DT)
[  233.728225] Workqueue: events update_pages_handler
[  233.728655] pstate: 200000c5 (nzCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  233.729054] pc : rb_update_pages+0x1a8/0x3f8
[  233.729334] lr : rb_update_pages+0x154/0x3f8
[  233.729592] sp : ffff800082b9bd50
[  233.729792] x29: ffff800082b9bd50 x28: ffff8000825f7000 x27: 0000000000000000
[  233.730220] x26: 0000000000000000 x25: ffff800082a8b840 x24: ffff0000c0102418
[  233.730653] x23: 0000000000000000 x22: fffffc000304c880 x21: 0000000000000003
[  233.731105] x20: 00000000000001f4 x19: ffff0000c0102400 x18: ffff800082fcbc58
[  233.731727] x17: 0000000000000000 x16: 0000000000000001 x15: 0000000000000001
[  233.732282] x14: ffff8000825fe0c8 x13: 0000000000000001 x12: 0000000000000000
[  233.732709] x11: ffff8000826998a8 x10: 0000000000000ae0 x9 : ffff8000801b760c
[  233.733148] x8 : fefefefefefefeff x7 : 0000000000000018 x6 : ffff0000c03298c0
[  233.733553] x5 : 0000000000000002 x4 : 0000000000000000 x3 : 0000000000000000
[  233.733972] x2 : ffff0000c3a0b600 x1 : 0000000000000000 x0 : 0000000000000000
[  233.734418] Call trace:
[  233.734593]  rb_update_pages+0x1a8/0x3f8
[  233.734853]  update_pages_handler+0x1c/0x38
[  233.735148]  process_one_work+0x1f0/0x468
[  233.735525]  worker_thread+0x54/0x410
[  233.735852]  kthread+0x124/0x138
[  233.736064]  ret_from_fork+0x10/0x20
[  233.736387] Code: 92400000 910006b5 aa000021 aa0303f7 (f9400060)
[  233.736959] ---[ end trace 0000000000000000 ]---

After analysis, the seq of the error is as follows [1-5]:

int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
			int cpu_id)
{
	for_each_buffer_cpu(buffer, cpu) {
		cpu_buffer = buffer->buffers[cpu];
		//1. get cpu_buffer, aka cpu_buffer(A)
		...
		...
		schedule_work_on(cpu,
		 &cpu_buffer->update_pages_work);
		//2. 'update_pages_work' is queue on 'cpu', cpu_buffer(A) is passed to
		// update_pages_handler, do the update process, set 'update_done' in
		// complete(&cpu_buffer->update_done) and to wakeup resize process.
	//---->
		//3. Just at this moment, ring_buffer_swap_cpu is triggered,
		//cpu_buffer(A) be swaped to cpu_buffer(B), the max_buffer.
		//ring_buffer_swap_cpu is called as the 'Call trace' below.

		Call trace:
		 dump_backtrace+0x0/0x2f8
		 show_stack+0x18/0x28
		 dump_stack+0x12c/0x188
		 ring_buffer_swap_cpu+0x2f8/0x328
		 update_max_tr_single+0x180/0x210
		 check_critical_timing+0x2b4/0x2c8
		 tracer_hardirqs_on+0x1c0/0x200
		 trace_hardirqs_on+0xec/0x378
		 el0_svc_common+0x64/0x260
		 do_el0_svc+0x90/0xf8
		 el0_svc+0x20/0x30
		 el0_sync_handler+0xb0/0xb8
		 el0_sync+0x180/0x1c0
	//<----

	/* wait for all the updates to complete */
	for_each_buffer_cpu(buffer, cpu) {
		cpu_buffer = buffer->buffers[cpu];
		//4. get cpu_buffer, cpu_buffer(B) is used in the following process,
		//the state of cpu_buffer(A) and cpu_buffer(B) is totally wrong.
		//for example, cpu_buffer(A)->update_done will leave be set 1, and will
		//not 'wait_for_completion' at the next resize round.
		  if (!cpu_buffer->nr_pages_to_update)
			continue;

		if (cpu_online(cpu))
			wait_for_completion(&cpu_buffer->update_done);
		cpu_buffer->nr_pages_to_update = 0;
	}
	...
}
	//5. the state of cpu_buffer(A) and cpu_buffer(B) is totally wrong,
	//Continuing to run in the wrong state, then oops occurs.

Link: https://lore.kernel.org/linux-trace-kernel/202307191558478409990@zte.com.cnSigned-off-by: default avatarChen Lin <chen.lin5@zte.com.cn>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
      8a96c028
    • YueHaibing's avatar
      tracing: Remove unused extern declaration tracing_map_set_field_descr() · 1faf7e4a
      YueHaibing authored 
      Since commit 08d43a5f ("tracing: Add lock-free tracing_map"),
this is never used, so can be removed.

Link: https://lore.kernel.org/linux-trace-kernel/20230722032123.24664-1-yuehaibing@huawei.com

Cc: <mhiramat@kernel.org>
Signed-off-by: default avatarYueHaibing <yuehaibing@huawei.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
      1faf7e4a
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