Commit graph

41829 commits

Author SHA1 Message Date
Linus Torvalds
fb054096ae 19 hotfixes. 14 are cc:stable and the remainder address issues which were
introduced during this -rc cycle or which were considered inappropriate
 for a backport.
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Merge tag 'mm-hotfixes-stable-2023-06-12-12-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "19 hotfixes. 14 are cc:stable and the remainder address issues which
  were introduced during this development cycle or which were considered
  inappropriate for a backport"

* tag 'mm-hotfixes-stable-2023-06-12-12-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  zswap: do not shrink if cgroup may not zswap
  page cache: fix page_cache_next/prev_miss off by one
  ocfs2: check new file size on fallocate call
  mailmap: add entry for John Keeping
  mm/damon/core: fix divide error in damon_nr_accesses_to_accesses_bp()
  epoll: ep_autoremove_wake_function should use list_del_init_careful
  mm/gup_test: fix ioctl fail for compat task
  nilfs2: reject devices with insufficient block count
  ocfs2: fix use-after-free when unmounting read-only filesystem
  lib/test_vmalloc.c: avoid garbage in page array
  nilfs2: fix possible out-of-bounds segment allocation in resize ioctl
  riscv/purgatory: remove PGO flags
  powerpc/purgatory: remove PGO flags
  x86/purgatory: remove PGO flags
  kexec: support purgatories with .text.hot sections
  mm/uffd: allow vma to merge as much as possible
  mm/uffd: fix vma operation where start addr cuts part of vma
  radix-tree: move declarations to header
  nilfs2: fix incomplete buffer cleanup in nilfs_btnode_abort_change_key()
2023-06-12 16:14:34 -07:00
Ricardo Ribalda
8652d44f46 kexec: support purgatories with .text.hot sections
Patch series "kexec: Fix kexec_file_load for llvm16 with PGO", v7.

When upreving llvm I realised that kexec stopped working on my test
platform.

The reason seems to be that due to PGO there are multiple .text sections
on the purgatory, and kexec does not supports that.


This patch (of 4):

Clang16 links the purgatory text in two sections when PGO is in use:

  [ 1] .text             PROGBITS         0000000000000000  00000040
       00000000000011a1  0000000000000000  AX       0     0     16
  [ 2] .rela.text        RELA             0000000000000000  00003498
       0000000000000648  0000000000000018   I      24     1     8
  ...
  [17] .text.hot.        PROGBITS         0000000000000000  00003220
       000000000000020b  0000000000000000  AX       0     0     1
  [18] .rela.text.hot.   RELA             0000000000000000  00004428
       0000000000000078  0000000000000018   I      24    17     8

And both of them have their range [sh_addr ... sh_addr+sh_size] on the
area pointed by `e_entry`.

This causes that image->start is calculated twice, once for .text and
another time for .text.hot. The second calculation leaves image->start
in a random location.

Because of this, the system crashes immediately after:

kexec_core: Starting new kernel

Link: https://lkml.kernel.org/r/20230321-kexec_clang16-v7-0-b05c520b7296@chromium.org
Link: https://lkml.kernel.org/r/20230321-kexec_clang16-v7-1-b05c520b7296@chromium.org
Fixes: 930457057a ("kernel/kexec_file.c: split up __kexec_load_puragory")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Ross Zwisler <zwisler@google.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Philipp Rudo <prudo@redhat.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Rix <trix@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-12 11:31:50 -07:00
Linus Torvalds
dbfa18c5d7 virtio,vhost,vdpa: bugfixes
A bunch of fixes all over the place
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio bug fixes from Michael Tsirkin:
 "A bunch of fixes all over the place"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  tools/virtio: use canonical ftrace path
  vhost_vdpa: support PACKED when setting-getting vring_base
  vhost: support PACKED when setting-getting vring_base
  vhost: Fix worker hangs due to missed wake up calls
  vhost: Fix crash during early vhost_transport_send_pkt calls
  vhost_net: revert upend_idx only on retriable error
  vhost_vdpa: tell vqs about the negotiated
  vdpa/mlx5: Fix hang when cvq commands are triggered during device unregister
  tools/virtio: Add .gitignore for ringtest
  tools/virtio: Fix arm64 ringtest compilation error
  vduse: avoid empty string for dev name
  vhost: use kzalloc() instead of kmalloc() followed by memset()
2023-06-09 11:04:08 -07:00
Linus Torvalds
9cd6357f10 cgroup: Fixes for v6.4-rc5
* Fix css_set reference leaks on fork failures.
 
 * Fix CPU hotplug locking in cgroup_transfer_tasks() which is used by
   cgroup1 cpuset.
 
 * Doc update.
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Merge tag 'cgroup-for-6.4-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fixes from Tejun Heo:

 - Fix css_set reference leaks on fork failures

 - Fix CPU hotplug locking in cgroup_transfer_tasks() which is used by
   cgroup1 cpuset

 - Doc update

* tag 'cgroup-for-6.4-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: Documentation: Clarify usage of memory limits
  cgroup: always put cset in cgroup_css_set_put_fork
  cgroup: fix missing cpus_read_{lock,unlock}() in cgroup_transfer_tasks()
2023-06-08 18:52:54 -07:00
Mike Christie
4b13cbef79 vhost: Fix worker hangs due to missed wake up calls
We can race where we have added work to the work_list, but
vhost_task_fn has passed that check but not yet set us into
TASK_INTERRUPTIBLE. wake_up_process will see us in TASK_RUNNING and
just return.

This bug was intoduced in commit f9010dbdce ("fork, vhost: Use
CLONE_THREAD to fix freezer/ps regression") when I moved the setting
of TASK_INTERRUPTIBLE to simplfy the code and avoid get_signal from
logging warnings about being in the wrong state. This moves the setting
of TASK_INTERRUPTIBLE back to before we test if we need to stop the
task to avoid a possible race there as well. We then have vhost_worker
set TASK_RUNNING if it finds work similar to before.

Fixes: f9010dbdce ("fork, vhost: Use CLONE_THREAD to fix freezer/ps regression")
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Message-Id: <20230607192338.6041-3-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-06-08 15:43:09 -04:00
Linus Torvalds
25041a4c02 Networking fixes for 6.4-rc6, including fixes from can, wifi, netfilter,
bluetooth and ebpf.
 
 Current release - regressions:
 
   - bpf: sockmap: avoid potential NULL dereference in sk_psock_verdict_data_ready()
 
   - wifi: iwlwifi: fix -Warray-bounds bug in iwl_mvm_wait_d3_notif()
 
   - phylink: actually fix ksettings_set() ethtool call
 
   - eth: dwmac-qcom-ethqos: fix a regression on EMAC < 3
 
 Current release - new code bugs:
 
   - wifi: mt76: fix possible NULL pointer dereference in mt7996_mac_write_txwi()
 
 Previous releases - regressions:
 
   - netfilter: fix NULL pointer dereference in nf_confirm_cthelper
 
   - wifi: rtw88/rtw89: correct PS calculation for SUPPORTS_DYNAMIC_PS
 
   - openvswitch: fix upcall counter access before allocation
 
   - bluetooth:
     - fix use-after-free in hci_remove_ltk/hci_remove_irk
     - fix l2cap_disconnect_req deadlock
 
   - nic: bnxt_en: prevent kernel panic when receiving unexpected PHC_UPDATE event
 
 Previous releases - always broken:
 
   - core: annotate rfs lockless accesses
 
   - sched: fq_pie: ensure reasonable TCA_FQ_PIE_QUANTUM values
 
   - netfilter: add null check for nla_nest_start_noflag() in nft_dump_basechain_hook()
 
   - bpf: fix UAF in task local storage
 
   - ipv4: ping_group_range: allow GID from 2147483648 to 4294967294
 
   - ipv6: rpl: fix route of death.
 
   - tcp: gso: really support BIG TCP
 
   - mptcp: fixes for user-space PM address advertisement
 
   - smc: avoid to access invalid RMBs' MRs in SMCRv1 ADD LINK CONT
 
   - can: avoid possible use-after-free when j1939_can_rx_register fails
 
   - batman-adv: fix UaF while rescheduling delayed work
 
   - eth: qede: fix scheduling while atomic
 
   - eth: ice: make writes to /dev/gnssX synchronous
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from can, wifi, netfilter, bluetooth and ebpf.

  Current release - regressions:

   - bpf: sockmap: avoid potential NULL dereference in
     sk_psock_verdict_data_ready()

   - wifi: iwlwifi: fix -Warray-bounds bug in iwl_mvm_wait_d3_notif()

   - phylink: actually fix ksettings_set() ethtool call

   - eth: dwmac-qcom-ethqos: fix a regression on EMAC < 3

  Current release - new code bugs:

   - wifi: mt76: fix possible NULL pointer dereference in
     mt7996_mac_write_txwi()

  Previous releases - regressions:

   - netfilter: fix NULL pointer dereference in nf_confirm_cthelper

   - wifi: rtw88/rtw89: correct PS calculation for SUPPORTS_DYNAMIC_PS

   - openvswitch: fix upcall counter access before allocation

   - bluetooth:
      - fix use-after-free in hci_remove_ltk/hci_remove_irk
      - fix l2cap_disconnect_req deadlock

   - nic: bnxt_en: prevent kernel panic when receiving unexpected
     PHC_UPDATE event

  Previous releases - always broken:

   - core: annotate rfs lockless accesses

   - sched: fq_pie: ensure reasonable TCA_FQ_PIE_QUANTUM values

   - netfilter: add null check for nla_nest_start_noflag() in
     nft_dump_basechain_hook()

   - bpf: fix UAF in task local storage

   - ipv4: ping_group_range: allow GID from 2147483648 to 4294967294

   - ipv6: rpl: fix route of death.

   - tcp: gso: really support BIG TCP

   - mptcp: fixes for user-space PM address advertisement

   - smc: avoid to access invalid RMBs' MRs in SMCRv1 ADD LINK CONT

   - can: avoid possible use-after-free when j1939_can_rx_register fails

   - batman-adv: fix UaF while rescheduling delayed work

   - eth: qede: fix scheduling while atomic

   - eth: ice: make writes to /dev/gnssX synchronous"

* tag 'net-6.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (83 commits)
  bnxt_en: Implement .set_port / .unset_port UDP tunnel callbacks
  bnxt_en: Prevent kernel panic when receiving unexpected PHC_UPDATE event
  bnxt_en: Skip firmware fatal error recovery if chip is not accessible
  bnxt_en: Query default VLAN before VNIC setup on a VF
  bnxt_en: Don't issue AP reset during ethtool's reset operation
  bnxt_en: Fix bnxt_hwrm_update_rss_hash_cfg()
  net: bcmgenet: Fix EEE implementation
  eth: ixgbe: fix the wake condition
  eth: bnxt: fix the wake condition
  lib: cpu_rmap: Fix potential use-after-free in irq_cpu_rmap_release()
  bpf: Add extra path pointer check to d_path helper
  net: sched: fix possible refcount leak in tc_chain_tmplt_add()
  net: sched: act_police: fix sparse errors in tcf_police_dump()
  net: openvswitch: fix upcall counter access before allocation
  net: sched: move rtm_tca_policy declaration to include file
  ice: make writes to /dev/gnssX synchronous
  net: sched: add rcu annotations around qdisc->qdisc_sleeping
  rfs: annotate lockless accesses to RFS sock flow table
  rfs: annotate lockless accesses to sk->sk_rxhash
  virtio_net: use control_buf for coalesce params
  ...
2023-06-08 09:27:19 -07:00
Jakub Kicinski
c9d99cfa66 bpf-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2023-06-07

We've added 7 non-merge commits during the last 7 day(s) which contain
a total of 12 files changed, 112 insertions(+), 7 deletions(-).

The main changes are:

1) Fix a use-after-free in BPF's task local storage, from KP Singh.

2) Make struct path handling more robust in bpf_d_path, from Jiri Olsa.

3) Fix a syzbot NULL-pointer dereference in sockmap, from Eric Dumazet.

4) UAPI fix for BPF_NETFILTER before final kernel ships,
   from Florian Westphal.

5) Fix map-in-map array_map_gen_lookup code generation where elem_size was
   not being set for inner maps, from Rhys Rustad-Elliott.

6) Fix sockopt_sk selftest's NETLINK_LIST_MEMBERSHIPS assertion,
   from Yonghong Song.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Add extra path pointer check to d_path helper
  selftests/bpf: Fix sockopt_sk selftest
  bpf: netfilter: Add BPF_NETFILTER bpf_attach_type
  selftests/bpf: Add access_inner_map selftest
  bpf: Fix elem_size not being set for inner maps
  bpf: Fix UAF in task local storage
  bpf, sockmap: Avoid potential NULL dereference in sk_psock_verdict_data_ready()
====================

Link: https://lore.kernel.org/r/20230607220514.29698-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-07 21:47:11 -07:00
Jiri Olsa
f46fab0e36 bpf: Add extra path pointer check to d_path helper
Anastasios reported crash on stable 5.15 kernel with following
BPF attached to lsm hook:

  SEC("lsm.s/bprm_creds_for_exec")
  int BPF_PROG(bprm_creds_for_exec, struct linux_binprm *bprm)
  {
          struct path *path = &bprm->executable->f_path;
          char p[128] = { 0 };

          bpf_d_path(path, p, 128);
          return 0;
  }

But bprm->executable can be NULL, so bpf_d_path call will crash:

  BUG: kernel NULL pointer dereference, address: 0000000000000018
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
  ...
  RIP: 0010:d_path+0x22/0x280
  ...
  Call Trace:
   <TASK>
   bpf_d_path+0x21/0x60
   bpf_prog_db9cf176e84498d9_bprm_creds_for_exec+0x94/0x99
   bpf_trampoline_6442506293_0+0x55/0x1000
   bpf_lsm_bprm_creds_for_exec+0x5/0x10
   security_bprm_creds_for_exec+0x29/0x40
   bprm_execve+0x1c1/0x900
   do_execveat_common.isra.0+0x1af/0x260
   __x64_sys_execve+0x32/0x40

It's problem for all stable trees with bpf_d_path helper, which was
added in 5.9.

This issue is fixed in current bpf code, where we identify and mark
trusted pointers, so the above code would fail even to load.

For the sake of the stable trees and to workaround potentially broken
verifier in the future, adding the code that reads the path object from
the passed pointer and verifies it's valid in kernel space.

Fixes: 6e22ab9da7 ("bpf: Add d_path helper")
Reported-by: Anastasios Papagiannis <tasos.papagiannnis@gmail.com>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20230606181714.532998-1-jolsa@kernel.org
2023-06-07 15:03:43 +02:00
Florian Westphal
132328e8e8 bpf: netfilter: Add BPF_NETFILTER bpf_attach_type
Andrii Nakryiko writes:

 And we currently don't have an attach type for NETLINK BPF link.
 Thankfully it's not too late to add it. I see that link_create() in
 kernel/bpf/syscall.c just bypasses attach_type check. We shouldn't
 have done that. Instead we need to add BPF_NETLINK attach type to enum
 bpf_attach_type. And wire all that properly throughout the kernel and
 libbpf itself.

This adds BPF_NETFILTER and uses it.  This breaks uabi but this
wasn't in any non-rc release yet, so it should be fine.

v2: check link_attack prog type in link_create too

Fixes: 84601d6ee6 ("bpf: add bpf_link support for BPF_NETFILTER programs")
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/CAEf4BzZ69YgrQW7DHCJUT_X+GqMq_ZQQPBwopaJJVGFD5=d5Vg@mail.gmail.com/
Link: https://lore.kernel.org/bpf/20230605131445.32016-1-fw@strlen.de
2023-06-05 15:01:43 -07:00
Linus Torvalds
51f269a6ec Probes fixes for 6.4-rc4:
- Return NULL if the trace_probe list on trace_probe_event is empty.
 
 - selftests/ftrace: Choose testing symbol name for filtering feature
   from sample data instead of fixed symbol.
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Merge tag 'probes-fixes-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fixes from Masami Hiramatsu:

 - Return NULL if the trace_probe list on trace_probe_event is empty

 - selftests/ftrace: Choose testing symbol name for filtering feature
   from sample data instead of fixed symbol

* tag 'probes-fixes-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  selftests/ftrace: Choose target function for filter test from samples
  tracing/probe: trace_probe_primary_from_call(): checked list_first_entry
2023-06-03 08:23:16 -04:00
Rhys Rustad-Elliott
cba41bb78d bpf: Fix elem_size not being set for inner maps
Commit d937bc3449 ("bpf: make uniform use of array->elem_size
everywhere in arraymap.c") changed array_map_gen_lookup to use
array->elem_size instead of round_up(map->value_size, 8) as the element
size when generating code to access a value in an array map.

array->elem_size, however, is not set by bpf_map_meta_alloc when
initializing an BPF_MAP_TYPE_ARRAY_OF_MAPS or BPF_MAP_TYPE_HASH_OF_MAPS.
This results in array_map_gen_lookup incorrectly outputting code that
always accesses index 0 in the array (as the index will be calculated
via a multiplication with the element size, which is incorrectly set to
0).

Set elem_size on the bpf_array object when allocating an array or hash
of maps to fix this.

Fixes: d937bc3449 ("bpf: make uniform use of array->elem_size everywhere in arraymap.c")
Signed-off-by: Rhys Rustad-Elliott <me@rhysre.net>
Link: https://lore.kernel.org/r/20230602190110.47068-2-me@rhysre.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-06-02 16:22:12 -07:00
KP Singh
b0fd1852bc bpf: Fix UAF in task local storage
When task local storage was generalized for tracing programs, the
bpf_task_local_storage callback was moved from a BPF LSM hook
callback for security_task_free LSM hook to it's own callback. But a
failure case in bad_fork_cleanup_security was missed which, when
triggered, led to a dangling task owner pointer and a subsequent
use-after-free. Move the bpf_task_storage_free to the very end of
free_task to handle all failure cases.

This issue was noticed when a BPF LSM program was attached to the
task_alloc hook on a kernel with KASAN enabled. The program used
bpf_task_storage_get to copy the task local storage from the current
task to the new task being created.

Fixes: a10787e6d5 ("bpf: Enable task local storage for tracing programs")
Reported-by: Kuba Piecuch <jpiecuch@google.com>
Signed-off-by: KP Singh <kpsingh@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230602002612.1117381-1-kpsingh@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-06-02 10:18:07 -07:00
Linus Torvalds
c43a6ff9f9 modules-6.4-rc5-second-pull
A zstd fix by lucas as he tested zstd decompression support
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Merge tag 'modules-6.4-rc5-second-pull' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull modules fix from Luis Chamberlain:
 "A zstd fix by lucas as he tested zstd decompression support"

* tag 'modules-6.4-rc5-second-pull' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  module/decompress: Fix error checking on zstd decompression
2023-06-01 20:48:16 -04:00
Lucas De Marchi
fadb74f9f2 module/decompress: Fix error checking on zstd decompression
While implementing support for in-kernel decompression in kmod,
finit_module() was returning a very suspicious value:

	finit_module(3, "", MODULE_INIT_COMPRESSED_FILE) = 18446744072717407296

It turns out the check for module_get_next_page() failing is wrong,
and hence the decompression was not really taking place. Invert
the condition to fix it.

Fixes: 169a58ad82 ("module/decompress: Support zstd in-kernel decompression")
Cc: stable@kernel.org
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-06-01 14:36:46 -07:00
Mike Christie
f9010dbdce fork, vhost: Use CLONE_THREAD to fix freezer/ps regression
When switching from kthreads to vhost_tasks two bugs were added:
1. The vhost worker tasks's now show up as processes so scripts doing
ps or ps a would not incorrectly detect the vhost task as another
process.  2. kthreads disabled freeze by setting PF_NOFREEZE, but
vhost tasks's didn't disable or add support for them.

To fix both bugs, this switches the vhost task to be thread in the
process that does the VHOST_SET_OWNER ioctl, and has vhost_worker call
get_signal to support SIGKILL/SIGSTOP and freeze signals. Note that
SIGKILL/STOP support is required because CLONE_THREAD requires
CLONE_SIGHAND which requires those 2 signals to be supported.

This is a modified version of the patch written by Mike Christie
<michael.christie@oracle.com> which was a modified version of patch
originally written by Linus.

Much of what depended upon PF_IO_WORKER now depends on PF_USER_WORKER.
Including ignoring signals, setting up the register state, and having
get_signal return instead of calling do_group_exit.

Tidied up the vhost_task abstraction so that the definition of
vhost_task only needs to be visible inside of vhost_task.c.  Making
it easier to review the code and tell what needs to be done where.
As part of this the main loop has been moved from vhost_worker into
vhost_task_fn.  vhost_worker now returns true if work was done.

The main loop has been updated to call get_signal which handles
SIGSTOP, freezing, and collects the message that tells the thread to
exit as part of process exit.  This collection clears
__fatal_signal_pending.  This collection is not guaranteed to
clear signal_pending() so clear that explicitly so the schedule()
sleeps.

For now the vhost thread continues to exist and run work until the
last file descriptor is closed and the release function is called as
part of freeing struct file.  To avoid hangs in the coredump
rendezvous and when killing threads in a multi-threaded exec.  The
coredump code and de_thread have been modified to ignore vhost threads.

Remvoing the special case for exec appears to require teaching
vhost_dev_flush how to directly complete transactions in case
the vhost thread is no longer running.

Removing the special case for coredump rendezvous requires either the
above fix needed for exec or moving the coredump rendezvous into
get_signal.

Fixes: 6e890c5d50 ("vhost: use vhost_tasks for worker threads")
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Co-developed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-06-01 17:15:33 -04:00
Pietro Borrello
81d0fa4cb4 tracing/probe: trace_probe_primary_from_call(): checked list_first_entry
All callers of trace_probe_primary_from_call() check the return
value to be non NULL. However, the function returns
list_first_entry(&tpe->probes, ...) which can never be NULL.
Additionally, it does not check for the list being possibly empty,
possibly causing a type confusion on empty lists.
Use list_first_entry_or_null() which solves both problems.

Link: https://lore.kernel.org/linux-trace-kernel/20230128-list-entry-null-check-v1-1-8bde6a3da2ef@diag.uniroma1.it/

Fixes: 60d53e2c3b ("tracing/probe: Split trace_event related data from trace_probe")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-05-31 18:47:10 +09:00
Linus Torvalds
6d86b56f54 modules-6.4-rc5
A fix is provided for ia64. Even though ia64 is on life support it helps
 to fix issues if we can. Thanks to Linus for doing tons of the ia64
 debugging.
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Merge tag 'modules-6.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull modules fix from Luis Chamberlain:
 "A fix is provided for ia64. Even though ia64 is on life support it
  helps to fix issues if we can. Thanks to Linus for doing tons of the
  ia64 debugging"

* tag 'modules-6.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  module: fix module load for ia64
2023-05-30 15:49:40 -04:00
Song Liu
db3e33dd8b module: fix module load for ia64
Frank reported boot regression in ia64 as:

ELILO v3.16 for EFI/IA-64
..
Uncompressing Linux... done
Loading file AC100221.initrd.img...done
[    0.000000] Linux version 6.4.0-rc3 (root@x4270) (ia64-linux-gcc
(GCC) 12.2.0, GNU ld (GNU Binutils) 2.39) #1 SMP Thu May 25 15:52:20
CEST 2023
[    0.000000] efi: EFI v1.1 by HP
[    0.000000] efi: SALsystab=0x3ee7a000 ACPI 2.0=0x3fe2a000
ESI=0x3ee7b000 SMBIOS=0x3ee7c000 HCDP=0x3fe28000
[    0.000000] PCDP: v3 at 0x3fe28000
[    0.000000] earlycon: uart8250 at MMIO 0x00000000f4050000 (options
'9600n8')
[    0.000000] printk: bootconsole [uart8250] enabled
[    0.000000] ACPI: Early table checksum verification disabled
[    0.000000] ACPI: RSDP 0x000000003FE2A000 000028 (v02 HP    )
[    0.000000] ACPI: XSDT 0x000000003FE2A02C 0000CC (v01 HP     rx2620
00000000 HP   00000000)
[...]
[    3.793350] Run /init as init process
Loading, please wait...
Starting systemd-udevd version 252.6-1
[    3.951100] ------------[ cut here ]------------
[    3.951100] WARNING: CPU: 6 PID: 140 at kernel/module/main.c:1547
__layout_sections+0x370/0x3c0
[    3.949512] Unable to handle kernel paging request at virtual address
1000000000000000
[    3.951100] Modules linked in:
[    3.951100] CPU: 6 PID: 140 Comm: (udev-worker) Not tainted 6.4.0-rc3 #1
[    3.956161] (udev-worker)[142]: Oops 11003706212352 [1]
[    3.951774] Hardware name: hp server rx2620                   , BIOS
04.29
11/30/2007
[    3.951774]
[    3.951774] Call Trace:
[    3.958339] Unable to handle kernel paging request at virtual address
1000000000000000
[    3.956161] Modules linked in:
[    3.951774]  [<a0000001000156d0>] show_stack.part.0+0x30/0x60
[    3.951774]                                 sp=e000000183a67b20
bsp=e000000183a61628
[    3.956161]
[    3.956161]

which bisect to module_memory change [1].

Debug showed that ia64 uses some special sections:

__layout_sections: section .got (sh_flags 10000002) matched to MOD_INVALID
__layout_sections: section .sdata (sh_flags 10000003) matched to MOD_INVALID
__layout_sections: section .sbss (sh_flags 10000003) matched to MOD_INVALID

All these sections are loaded to module core memory before [1].

Fix ia64 boot by loading these sections to MOD_DATA (core rw data).

[1] commit ac3b432839 ("module: replace module_layout with module_memory")

Fixes: ac3b432839 ("module: replace module_layout with module_memory")
Reported-by: Frank Scheiner <frank.scheiner@web.de>
Closes: https://lists.debian.org/debian-ia64/2023/05/msg00010.html
Closes: https://marc.info/?l=linux-ia64&m=168509859125505
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Song Liu <song@kernel.org>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-05-30 09:29:40 -07:00
Linus Torvalds
8b817fded4 Tracing fixes:
User events:
 
  - Use long instead of int for storing the enable set/clear bit, as it was
    found that big endian machines could end up using the wrong bits.
 
  - Split allocating mm and attaching it. This keeps the allocation separate
    from the registration and avoids various races.
 
  - Remove RCU locking around pin_user_pages_remote() as that can schedule. The
    RCU protection is no longer needed with the above split of mm allocation and
    attaching.
 
  - Rename the "link" fields of the various structs to something more
    meaningful.
 
  - Add comments around user_event_mm struct usage and locking requirements.
 
 Timerlat tracer:
 
  - Fix missed wakeup of timerlat thread caused by the timerlat interrupt
    triggering when tracing is off. The timer interrupt handler needs to always
    wake up the timerlat thread regardless if tracing is enabled or not,
    otherwise, it will never wake up.
 
 Histograms:
 
  - Fix regression of breaking the "stacktrace" modifier for variables. That
    modifier cannot be used for values, but can be used for variables that are
    passed from one histogram to the next. This was broken when adding the
    restriction to values as the variable logic used the same code.
 
  - Rename the special field "stacktrace" to "common_stacktrace". Special fields
    (that are not actually part of the event, but can act just like event
    fields, like 'comm' and 'timestamp') should be prefixed with 'common_' for
    consistency. To keep backward compatibility, 'stacktrace' can still be used
    (as with the special field 'cpu'), but can be overridden if the event has a
    field called 'stacktrace'.
 
  - Update the synthetic event selftests to use the new name (synthetic events
    are created by histograms)
 
 Tracing bootup selftests:
 
  - Reorganize the code to keep artifacts of the selftests not compiled in when
    selftests are not configured.
 
  - Add various cond_resched() around the selftest code, as the softlock
    watchdog was triggering much more often. It appears that the kernel runs
    slower now with full debugging enabled.
 
  - While debugging ftrace with ftrace (using an instance ring buffer instead of
    the top level one), I found that the selftests were disabling prints to the
    debug instance. This should not happen, as the selftests only disable
    printing to the main buffer as the selftests examine the main buffer to see
    if it has what it expects, and prints can make the tests fail. Make the
    selftests only disable printing to the toplevel buffer, and leave the
    instance buffers alone.
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Merge tag 'trace-v6.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:
 "User events:

   - Use long instead of int for storing the enable set/clear bit, as it
     was found that big endian machines could end up using the wrong
     bits.

   - Split allocating mm and attaching it. This keeps the allocation
     separate from the registration and avoids various races.

   - Remove RCU locking around pin_user_pages_remote() as that can
     schedule. The RCU protection is no longer needed with the above
     split of mm allocation and attaching.

   - Rename the "link" fields of the various structs to something more
     meaningful.

   - Add comments around user_event_mm struct usage and locking
     requirements.

  Timerlat tracer:

   - Fix missed wakeup of timerlat thread caused by the timerlat
     interrupt triggering when tracing is off. The timer interrupt
     handler needs to always wake up the timerlat thread regardless if
     tracing is enabled or not, otherwise, it will never wake up.

  Histograms:

   - Fix regression of breaking the "stacktrace" modifier for variables.
     That modifier cannot be used for values, but can be used for
     variables that are passed from one histogram to the next. This was
     broken when adding the restriction to values as the variable logic
     used the same code.

   - Rename the special field "stacktrace" to "common_stacktrace".

     Special fields (that are not actually part of the event, but can
     act just like event fields, like 'comm' and 'timestamp') should be
     prefixed with 'common_' for consistency. To keep backward
     compatibility, 'stacktrace' can still be used (as with the special
     field 'cpu'), but can be overridden if the event has a field called
     'stacktrace'.

   - Update the synthetic event selftests to use the new name (synthetic
     events are created by histograms)

  Tracing bootup selftests:

   - Reorganize the code to keep artifacts of the selftests not compiled
     in when selftests are not configured.

   - Add various cond_resched() around the selftest code, as the
     softlock watchdog was triggering much more often. It appears that
     the kernel runs slower now with full debugging enabled.

   - While debugging ftrace with ftrace (using an instance ring buffer
     instead of the top level one), I found that the selftests were
     disabling prints to the debug instance.

     This should not happen, as the selftests only disable printing to
     the main buffer as the selftests examine the main buffer to see if
     it has what it expects, and prints can make the tests fail.

     Make the selftests only disable printing to the toplevel buffer,
     and leave the instance buffers alone"

* tag 'trace-v6.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Have function_graph selftest call cond_resched()
  tracing: Only make selftest conditionals affect the global_trace
  tracing: Make tracing_selftest_running/delete nops when not used
  tracing: Have tracer selftests call cond_resched() before running
  tracing: Move setting of tracing_selftest_running out of register_tracer()
  tracing/selftests: Update synthetic event selftest to use common_stacktrace
  tracing: Rename stacktrace field to common_stacktrace
  tracing/histograms: Allow variables to have some modifiers
  tracing/user_events: Document user_event_mm one-shot list usage
  tracing/user_events: Rename link fields for clarity
  tracing/user_events: Remove RCU lock while pinning pages
  tracing/user_events: Split up mm alloc and attach
  tracing/timerlat: Always wakeup the timerlat thread
  tracing/user_events: Use long vs int for atomic bit ops
2023-05-29 07:20:13 -04:00
Linus Torvalds
ac2263b588 Revert "module: error out early on concurrent load of the same module file"
This reverts commit 9828ed3f69.

Sadly, it does seem to cause failures to load modules. Johan Hovold reports:

 "This change breaks module loading during boot on the Lenovo Thinkpad
  X13s (aarch64).

  Specifically it results in indefinite probe deferral of the display
  and USB (ethernet) which makes it a pain to debug. Typing in the dark
  to acquire some logs reveals that other modules are missing as well"

Since this was applied late as a "let's try this", I'm reverting it
asap, and we can try to figure out what goes wrong later.  The excessive
parallel module loading problem is annoying, but not noticeable in
normal situations, and this was only meant as an optimistic workaround
for a user-space bug.

One possible solution may be to do the optimistic exclusive open first,
and then use a lock to serialize loading if that fails.

Reported-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/lkml/ZHRpH-JXAxA6DnzR@hovoldconsulting.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-05-29 06:40:33 -04:00
Steven Rostedt (Google)
a2d910f022 tracing: Have function_graph selftest call cond_resched()
When all kernel debugging is enabled (lockdep, KSAN, etc), the function
graph enabling and disabling can take several seconds to complete. The
function_graph selftest enables and disables function graph tracing
several times. With full debugging enabled, the soft lockup watchdog was
triggering because the selftest was running without ever scheduling.

Add cond_resched() throughout the test to make sure it does not trigger
the soft lockup detector.

Link: https://lkml.kernel.org/r/20230528051742.1325503-6-rostedt@goodmis.org

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-28 21:15:46 -04:00
Steven Rostedt (Google)
ac9d2cb1d5 tracing: Only make selftest conditionals affect the global_trace
The tracing_selftest_running and tracing_selftest_disabled variables were
to keep trace_printk() and other writes from affecting the tracing
selftests, as the tracing selftests would examine the ring buffer to see
if it contained what it expected or not. trace_printk() and friends could
add to the ring buffer and cause the selftests to fail (and then disable
the tracer that was being tested). To keep that from happening, these
variables were added and would keep trace_printk() and friends from
writing to the ring buffer while the tests were going on.

But this was only the top level ring buffer (owned by the global_trace
instance). There is no reason to prevent writing into ring buffers of
other instances via the trace_array_printk() and friends. For the
functions that could be used by other instances, check if the global_trace
is the tracer instance that is being written to before deciding to not
allow the write.

Link: https://lkml.kernel.org/r/20230528051742.1325503-5-rostedt@goodmis.org

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-28 21:15:33 -04:00
Steven Rostedt (Google)
a3ae76d7ff tracing: Make tracing_selftest_running/delete nops when not used
There's no reason to test the condition variables tracing_selftest_running
or tracing_selftest_delete when tracing selftests are not enabled. Make
them define 0s when not the selftests are not configured in.

Link: https://lkml.kernel.org/r/20230528051742.1325503-4-rostedt@goodmis.org

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-28 21:15:26 -04:00
Steven Rostedt (Google)
9da705d432 tracing: Have tracer selftests call cond_resched() before running
As there are more and more internal selftests being added to the Linux
kernel (KSAN, lockdep, etc) the selftests are taking longer to run when
these are enabled. Add a cond_resched() to the calling of
do_run_tracer_selftest() to force a schedule if NEED_RESCHED is set,
otherwise the soft lockup watchdog may trigger on boot up.

Link: https://lkml.kernel.org/r/20230528051742.1325503-3-rostedt@goodmis.org

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-28 21:15:17 -04:00
Steven Rostedt (Google)
e8352cf577 tracing: Move setting of tracing_selftest_running out of register_tracer()
The variables tracing_selftest_running and tracing_selftest_disabled are
only used for when CONFIG_FTRACE_STARTUP_TEST is enabled. Make them only
visible within the selftest code. The setting of those variables are in
the register_tracer() call, and set in a location where they do not need
to be. Create a wrapper around run_tracer_selftest() called
do_run_tracer_selftest() which sets those variables, and have
register_tracer() call that instead.

Having those variables only set within the CONFIG_FTRACE_STARTUP_TEST
scope gets rid of them (and also the ability to remove testing against
them) when the startup tests are not enabled (most cases).

Link: https://lkml.kernel.org/r/20230528051742.1325503-2-rostedt@goodmis.org

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-28 21:15:04 -04:00
Linus Torvalds
d8f14b84fe Two fixes for debugobjects:
- Prevent that the allocation path wakes up kswapd. That's a long
     standing issue due to the GFP_ATOMIC allocation flag. As debug objects
     can be invoked from pretty much any context waking kswapd can end up
     in arbitrary lock chains versus the waitqueue lock.
 
   - Correct the explicit lockdep wait-type violation in
     debug_object_fill_pool().
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Merge tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull debugobjects fixes from Thomas Gleixner:
 "Two fixes for debugobjects:

   - Prevent the allocation path from waking up kswapd.

     That's a long standing issue due to the GFP_ATOMIC allocation flag.
     As debug objects can be invoked from pretty much any context waking
     kswapd can end up in arbitrary lock chains versus the waitqueue
     lock

   - Correct the explicit lockdep wait-type violation in
     debug_object_fill_pool()"

* tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  debugobjects: Don't wake up kswapd from fill_pool()
  debugobjects,locking: Annotate debug_object_fill_pool() wait type violation
2023-05-28 07:15:33 -04:00
Linus Torvalds
4e893b5aa4 xen: branch for v6.4-rc4
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Merge tag 'for-linus-6.4-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:

 - a double free fix in the Xen pvcalls backend driver

 - a fix for a regression causing the MSI related sysfs entries to not
   being created in Xen PV guests

 - a fix in the Xen blkfront driver for handling insane input data
   better

* tag 'for-linus-6.4-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/pci/xen: populate MSI sysfs entries
  xen/pvcalls-back: fix double frees with pvcalls_new_active_socket()
  xen/blkfront: Only check REQ_FUA for writes
2023-05-27 09:42:56 -07:00
Linus Torvalds
9828ed3f69 module: error out early on concurrent load of the same module file
It turns out that udev under certain circumstances will concurrently try
to load the same modules over-and-over excessively.  This isn't a kernel
bug, but it ends up affecting the kernel, to the point that under
certain circumstances we can fail to boot, because the kernel uses a lot
of memory to read all the module data all at once.

Note that it isn't a memory leak, it's just basically a thundering herd
problem happening at bootup with a lot of CPUs, with the worst cases
then being pretty bad.

Admittedly the worst situations are somewhat contrived: lots and lots of
CPUs, not a lot of memory, and KASAN enabled to make it all slower and
as such (unintentionally) exacerbate the problem.

Luis explains: [1]

 "My best assessment of the situation is that each CPU in udev ends up
  triggering a load of duplicate set of modules, not just one, but *a
  lot*. Not sure what heuristics udev uses to load a set of modules per
  CPU."

Petr Pavlu chimes in: [2]

 "My understanding is that udev workers are forked. An initial kmod
  context is created by the main udevd process but no sharing happens
  after the fork. It means that the mentioned memory pool logic doesn't
  really kick in.

  Multiple parallel load requests come from multiple udev workers, for
  instance, each handling an udev event for one CPU device and making
  the exactly same requests as all others are doing at the same time.

  The optimization idea would be to recognize these duplicate requests
  at the udevd/kmod level and converge them"

Note that module loading has tried to mitigate this issue before, see
for example commit 064f4536d1 ("module: avoid allocation if module is
already present and ready"), which has a few ASCII graphs on memory use
due to this same issue.

However, while that noticed that the module was already loaded, and
exited with an error early before spending any more time on setting up
the module, it didn't handle the case of multiple concurrent module
loads all being active - but not complete - at the same time.

Yes, one of them will eventually win the race and finalize its copy, and
the others will then notice that the module already exists and error
out, but while this all happens, we have tons of unnecessary concurrent
work being done.

Again, the real fix is for udev to not do that (maybe it should use
threads instead of fork, and have actual shared data structures and not
cause duplicate work). That real fix is apparently not trivial.

But it turns out that the kernel already has a pretty good model for
dealing with concurrent access to the same file: the i_writecount of the
inode.

In fact, the module loading already indirectly uses 'i_writecount' ,
because 'kernel_file_read()' will in fact do

	ret = deny_write_access(file);
	if (ret)
		return ret;
	...
	allow_write_access(file);

around the read of the file data.  We do not allow concurrent writes to
the file, and return -ETXTBUSY if the file was open for writing at the
same time as the module data is loaded from it.

And the solution to the reader concurrency problem is to simply extend
this "no concurrent writers" logic to simply be "exclusive access".

Note that "exclusive" in this context isn't really some absolute thing:
it's only exclusion from writers and from other "special readers" that
do this writer denial.  So we simply introduce a variation of that
"deny_write_access()" logic that not only denies write access, but also
requires that this is the _only_ such access that denies write access.

Which means that you can't start loading a module that is already being
loaded as a module by somebody else, or you will get the same -ETXTBSY
error that you would get if there were writers around.

[ It also means that you can't try to load a currently executing
  executable as a module, for the same reason: executables do that same
  "deny_write_access()" thing, and that's obviously where the whole
  ETXTBSY logic traditionally came from.

  This is not a problem for kernel modules, since the set of normal
  executable files and kernel module files is entirely disjoint. ]

This new function is called "exclusive_deny_write_access()", and the
implementation is trivial, in that it's just an atomic decrement of
i_writecount if it was 0 before.

To use that new exclusivity check, all we then do is wrap the module
loading with that exclusive_deny_write_access()() / allow_write_access()
pair.  The actual patch is a bit bigger than that, because we want to
surround not just the "load file data" part, but the whole module setup,
to get maximum exclusion.

So this ends up splitting up "finit_module()" into a few helper
functions to make it all very clear and legible.

In Luis' test-case (bringing up 255 vcpu's in a virtual machine [3]),
the "wasted vmalloc" space (ie module data read into a vmalloc'ed area
in order to be loaded as a module, but then discarded because somebody
else loaded the same module instead) dropped from 1.8GiB to 474kB.  Yes,
that's gigabytes to kilobytes.

It doesn't drop completely to zero, because even with this change, you
can still end up having completely serial pointless module loads, where
one udev process has loaded a module fully (and thus the kernel has
released that exclusive lock on the module file), and then another udev
process tries to load the same module again.

So while we cannot fully get rid of the fundamental bug in user space,
we _can_ get rid of the excessive concurrent thundering herd effect.

A couple of final side notes on this all:

 - This tweak only affects the "finit_module()" system call, which gives
   the kernel a file descriptor with the module data.

   You can also just feed the module data as raw data from user space
   with "init_module()" (note the lack of 'f' at the beginning), and
   obviously for that case we do _not_ have any "exclusive read" logic.

   So if you absolutely want to do things wrong in user space, and try
   to load the same module multiple times, and error out only later when
   the kernel ends up saying "you can't load the same module name
   twice", you can still do that.

   And in fact, some distros will do exactly that, because they will
   uncompress the kernel module data in user space before feeding it to
   the kernel (mainly because they haven't started using the new kernel
   side decompression yet).

   So this is not some absolute "you can't do concurrent loads of the
   same module". It's literally just a very simple heuristic that will
   catch it early in case you try to load the exact same module file at
   the same time, and in that case avoid a potentially nasty situation.

 - There is another user of "deny_write_access()": the verity code that
   enables fs-verity on a file (the FS_IOC_ENABLE_VERITY ioctl).

   If you use fs-verity and you care about verifying the kernel modules
   (which does make sense), you should do it *before* loading said
   kernel module. That may sound obvious, but now the implementation
   basically requires it. Because if you try to do it concurrently, the
   kernel may refuse to load the module file that is being set up by the
   fs-verity code.

 - This all will obviously mean that if you insist on loading the same
   module in parallel, only one module load will succeed, and the others
   will return with an error.

   That was true before too, but what is different is that the -ETXTBSY
   error can be returned *before* the success case of another process
   fully loading and instantiating the module.

   Again, that might sound obvious, and it is indeed the whole point of
   the whole change: we are much quicker to notice the whole "you're
   already in the process of loading this module".

   So it's very much intentional, but it does mean that if you just
   spray the kernel with "finit_module()", and expect that the module is
   immediately loaded afterwards without checking the return value, you
   are doing something horribly horribly wrong.

   I'd like to say that that would never happen, but the whole _reason_
   for this commit is that udev is currently doing something horribly
   horribly wrong, so ...

Link: https://lore.kernel.org/all/ZEGopJ8VAYnE7LQ2@bombadil.infradead.org/ [1]
Link: https://lore.kernel.org/all/23bd0ce6-ef78-1cd8-1f21-0e706a00424a@suse.com/ [2]
Link: https://lore.kernel.org/lkml/ZG%2Fa+nrt4%2FAAUi5z@bombadil.infradead.org/ [3]
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Tested-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-05-25 17:07:57 -07:00
Linus Torvalds
50fb587e6a Networking fixes for 6.4-rc4, including fixes from bluetooth and bpf
Current release - regressions:
 
   - net: fix skb leak in __skb_tstamp_tx()
 
   - eth: mtk_eth_soc: fix QoS on DSA MAC on non MTK_NETSYS_V2 SoCs
 
 Current release - new code bugs:
 
   - handshake:
     - fix sock->file allocation
     - fix handshake_dup() ref counting
 
   - bluetooth:
     - fix potential double free caused by hci_conn_unlink
     - fix UAF in hci_conn_hash_flush
 
 Previous releases - regressions:
 
   - core: fix stack overflow when LRO is disabled for virtual interfaces
 
   - tls: fix strparser rx issues
 
   - bpf:
     - fix many sockmap/TCP related issues
     - fix a memory leak in the LRU and LRU_PERCPU hash maps
     - init the offload table earlier
 
   - eth: mlx5e:
     - do as little as possible in napi poll when budget is 0
     - fix using eswitch mapping in nic mode
     - fix deadlock in tc route query code
 
 Previous releases - always broken:
 
   - udplite: fix NULL pointer dereference in __sk_mem_raise_allocated()
 
   - raw: fix output xfrm lookup wrt protocol
 
   - smc: reset connection when trying to use SMCRv2 fails
 
   - phy: mscc: enable VSC8501/2 RGMII RX clock
 
   - eth: octeontx2-pf: fix TSOv6 offload
 
   - eth: cdc_ncm: deal with too low values of dwNtbOutMaxSize
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from bluetooth and bpf.

  Current release - regressions:

   - net: fix skb leak in __skb_tstamp_tx()

   - eth: mtk_eth_soc: fix QoS on DSA MAC on non MTK_NETSYS_V2 SoCs

  Current release - new code bugs:

   - handshake:
      - fix sock->file allocation
      - fix handshake_dup() ref counting

   - bluetooth:
      - fix potential double free caused by hci_conn_unlink
      - fix UAF in hci_conn_hash_flush

  Previous releases - regressions:

   - core: fix stack overflow when LRO is disabled for virtual
     interfaces

   - tls: fix strparser rx issues

   - bpf:
      - fix many sockmap/TCP related issues
      - fix a memory leak in the LRU and LRU_PERCPU hash maps
      - init the offload table earlier

   - eth: mlx5e:
      - do as little as possible in napi poll when budget is 0
      - fix using eswitch mapping in nic mode
      - fix deadlock in tc route query code

  Previous releases - always broken:

   - udplite: fix NULL pointer dereference in __sk_mem_raise_allocated()

   - raw: fix output xfrm lookup wrt protocol

   - smc: reset connection when trying to use SMCRv2 fails

   - phy: mscc: enable VSC8501/2 RGMII RX clock

   - eth: octeontx2-pf: fix TSOv6 offload

   - eth: cdc_ncm: deal with too low values of dwNtbOutMaxSize"

* tag 'net-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (79 commits)
  udplite: Fix NULL pointer dereference in __sk_mem_raise_allocated().
  net: phy: mscc: enable VSC8501/2 RGMII RX clock
  net: phy: mscc: remove unnecessary phydev locking
  net: phy: mscc: add support for VSC8501
  net: phy: mscc: add VSC8502 to MODULE_DEVICE_TABLE
  net/handshake: Enable the SNI extension to work properly
  net/handshake: Unpin sock->file if a handshake is cancelled
  net/handshake: handshake_genl_notify() shouldn't ignore @flags
  net/handshake: Fix uninitialized local variable
  net/handshake: Fix handshake_dup() ref counting
  net/handshake: Remove unneeded check from handshake_dup()
  ipv6: Fix out-of-bounds access in ipv6_find_tlv()
  net: ethernet: mtk_eth_soc: fix QoS on DSA MAC on non MTK_NETSYS_V2 SoCs
  docs: netdev: document the existence of the mail bot
  net: fix skb leak in __skb_tstamp_tx()
  r8169: Use a raw_spinlock_t for the register locks.
  page_pool: fix inconsistency for page_pool_ring_[un]lock()
  bpf, sockmap: Test progs verifier error with latest clang
  bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer with drops
  bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer
  ...
2023-05-25 10:55:26 -07:00
Jakub Kicinski
0c615f1cc3 bpf-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2023-05-24

We've added 19 non-merge commits during the last 10 day(s) which contain
a total of 20 files changed, 738 insertions(+), 448 deletions(-).

The main changes are:

1) Batch of BPF sockmap fixes found when running against NGINX TCP tests,
   from John Fastabend.

2) Fix a memleak in the LRU{,_PERCPU} hash map when bucket locking fails,
   from Anton Protopopov.

3) Init the BPF offload table earlier than just late_initcall,
   from Jakub Kicinski.

4) Fix ctx access mask generation for 32-bit narrow loads of 64-bit fields,
   from Will Deacon.

5) Remove a now unsupported __fallthrough in BPF samples,
   from Andrii Nakryiko.

6) Fix a typo in pkg-config call for building sign-file,
   from Jeremy Sowden.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf, sockmap: Test progs verifier error with latest clang
  bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer with drops
  bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer
  bpf, sockmap: Test shutdown() correctly exits epoll and recv()=0
  bpf, sockmap: Build helper to create connected socket pair
  bpf, sockmap: Pull socket helpers out of listen test for general use
  bpf, sockmap: Incorrectly handling copied_seq
  bpf, sockmap: Wake up polling after data copy
  bpf, sockmap: TCP data stall on recv before accept
  bpf, sockmap: Handle fin correctly
  bpf, sockmap: Improved check for empty queue
  bpf, sockmap: Reschedule is now done through backlog
  bpf, sockmap: Convert schedule_work into delayed_work
  bpf, sockmap: Pass skb ownership through read_skb
  bpf: fix a memory leak in the LRU and LRU_PERCPU hash maps
  bpf: Fix mask generation for 32-bit narrow loads of 64-bit fields
  samples/bpf: Drop unnecessary fallthrough
  bpf: netdev: init the offload table earlier
  selftests/bpf: Fix pkg-config call building sign-file
====================

Link: https://lore.kernel.org/r/20230524170839.13905-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-24 21:57:57 -07:00
Maximilian Heyne
335b422346 x86/pci/xen: populate MSI sysfs entries
Commit bf5e758f02 ("genirq/msi: Simplify sysfs handling") reworked the
creation of sysfs entries for MSI IRQs. The creation used to be in
msi_domain_alloc_irqs_descs_locked after calling ops->domain_alloc_irqs.
Then it moved into __msi_domain_alloc_irqs which is an implementation of
domain_alloc_irqs. However, Xen comes with the only other implementation
of domain_alloc_irqs and hence doesn't run the sysfs population code
anymore.

Commit 6c796996ee ("x86/pci/xen: Fixup fallout from the PCI/MSI
overhaul") set the flag MSI_FLAG_DEV_SYSFS for the xen msi_domain_info
but that doesn't actually have an effect because Xen uses it's own
domain_alloc_irqs implementation.

Fix this by making use of the fallback functions for sysfs population.

Fixes: bf5e758f02 ("genirq/msi: Simplify sysfs handling")
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230503131656.15928-1-mheyne@amazon.de
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-05-24 18:08:49 +02:00
Steven Rostedt (Google)
4b512860bd tracing: Rename stacktrace field to common_stacktrace
The histogram and synthetic events can use a pseudo event called
"stacktrace" that will create a stacktrace at the time of the event and
use it just like it was a normal field. We have other pseudo events such
as "common_cpu" and "common_timestamp". To stay consistent with that,
convert "stacktrace" to "common_stacktrace". As this was used in older
kernels, to keep backward compatibility, this will act just like
"common_cpu" did with "cpu". That is, "cpu" will be the same as
"common_cpu" unless the event has a "cpu" field. In which case, the
event's field is used. The same is true with "stacktrace".

Also update the documentation to reflect this change.

Link: https://lore.kernel.org/linux-trace-kernel/20230523230913.6860e28d@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-23 23:38:23 -04:00
Steven Rostedt (Google)
e30fbc618e tracing/histograms: Allow variables to have some modifiers
Modifiers are used to change the behavior of keys. For instance, they
can grouped into buckets, converted to syscall names (from the syscall
identifier), show task->comm of the current pid, be an array of longs
that represent a stacktrace, and more.

It was found that nothing stopped a value from taking a modifier. As
values are simple counters. If this happened, it would call code that
was not expecting a modifier and crash the kernel. This was fixed by
having the ___create_val_field() function test if a modifier was present
and fail if one was. This fixed the crash.

Now there's a problem with variables. Variables are used to pass fields
from one event to another. Variables are allowed to have some modifiers,
as the processing may need to happen at the time of the event (like
stacktraces and comm names of the current pid). The issue is that it too
uses __create_val_field(). Now that fails on modifiers, variables can no
longer use them (this is a regression).

As not all modifiers are for variables, have them use a separate check.

Link: https://lore.kernel.org/linux-trace-kernel/20230523221108.064a5d82@rorschach.local.home

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: e0213434fe ("tracing: Do not let histogram values have some modifiers")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-23 22:56:55 -04:00
Beau Belgrave
ff9e1632d6 tracing/user_events: Document user_event_mm one-shot list usage
During 6.4 development it became clear that the one-shot list used by
the user_event_mm's next field was confusing to others. It is not clear
how this list is protected or what the next field usage is for unless
you are familiar with the code.

Add comments into the user_event_mm struct indicating lock requirement
and usage. Also document how and why this approach was used via comments
in both user_event_enabler_update() and user_event_mm_get_all() and the
rules to properly use it.

Link: https://lkml.kernel.org/r/20230519230741.669-5-beaub@linux.microsoft.com
Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wicngggxVpbnrYHjRTwGE0WYscPRM+L2HO2BF8ia1EXgQ@mail.gmail.com/

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-23 21:08:33 -04:00
Beau Belgrave
dcbd1ac266 tracing/user_events: Rename link fields for clarity
Currently most list_head fields of various structs within user_events
are simply named link. This causes folks to keep additional context in
their head when working with the code, which can be confusing.

Instead of using link, describe what the actual link is, for example:
list_del_rcu(&mm->link);

Changes into:
list_del_rcu(&mm->mms_link);

The reader now is given a hint the link is to the mms global list
instead of having to remember or spot check within the code.

Link: https://lkml.kernel.org/r/20230519230741.669-4-beaub@linux.microsoft.com
Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wicngggxVpbnrYHjRTwGE0WYscPRM+L2HO2BF8ia1EXgQ@mail.gmail.com/

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-23 21:08:33 -04:00
Linus Torvalds
aaecdaf922 tracing/user_events: Remove RCU lock while pinning pages
pin_user_pages_remote() can reschedule which means we cannot hold any
RCU lock while using it. Now that enablers are not exposed out to the
tracing register callbacks during fork(), there is clearly no need to
require the RCU lock as event_mutex is enough to protect changes.

Remove unneeded RCU usages when pinning pages and walking enablers with
event_mutex held. Cleanup a misleading "safe" list walk that is not
needed. During fork() duplication, remove unneeded RCU list add, since
the list is not exposed yet.

Link: https://lkml.kernel.org/r/20230519230741.669-3-beaub@linux.microsoft.com
Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wiiBfT4zNS29jA0XEsy8EmbqTH1hAPdRJCDAJMD8Gxt5A@mail.gmail.com/

Fixes: 7235759084 ("tracing/user_events: Use remote writes for event enablement")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ change log written by Beau Belgrave ]
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-23 21:05:04 -04:00
Linus Torvalds
3e0fea09b1 tracing/user_events: Split up mm alloc and attach
When a new mm is being created in a fork() path it currently is
allocated and then attached in one go. This leaves the mm exposed out to
the tracing register callbacks while any parent enabler locations are
copied in. This should not happen.

Split up mm alloc and attach as unique operations. When duplicating
enablers, first alloc, then duplicate, and only upon success, attach.
This prevents any timing window outside of the event_reg mutex for
enablement walking. This allows for dropping RCU requirement for
enablement walking in later patches.

Link: https://lkml.kernel.org/r/20230519230741.669-2-beaub@linux.microsoft.com
Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=whTBvXJuoi_kACo3qi5WZUmRrhyA-_=rRFsycTytmB6qw@mail.gmail.com/

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ change log written by Beau Belgrave ]
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-23 20:58:17 -04:00
Daniel Bristot de Oliveira
632478a058 tracing/timerlat: Always wakeup the timerlat thread
While testing rtla timerlat auto analysis, I reach a condition where
the interface was not receiving tracing data. I was able to manually
reproduce the problem with these steps:

  # echo 0 > tracing_on                 # disable trace
  # echo 1 > osnoise/stop_tracing_us    # stop trace if timerlat irq > 1 us
  # echo timerlat > current_tracer      # enable timerlat tracer
  # sleep 1                             # wait... that is the time when rtla
                                        # apply configs like prio or cgroup
  # echo 1 > tracing_on                 # start tracing
  # cat trace
  # tracer: timerlat
  #
  #                                _-----=> irqs-off
  #                               / _----=> need-resched
  #                              | / _---=> hardirq/softirq
  #                              || / _--=> preempt-depth
  #                              ||| / _-=> migrate-disable
  #                              |||| /     delay
  #                              |||||            ACTIVATION
  #           TASK-PID      CPU# |||||   TIMESTAMP   ID            CONTEXT                 LATENCY
  #              | |         |   |||||      |         |                  |                       |
        NOTHING!

Then, trying to enable tracing again with echo 1 > tracing_on resulted
in no change: the trace was still not tracing.

This problem happens because the timerlat IRQ hits the stop tracing
condition while tracing is off, and do not wake up the timerlat thread,
so the timerlat threads are kept sleeping forever, resulting in no
trace, even after re-enabling the tracer.

Avoid this condition by always waking up the threads, even after stopping
tracing, allowing the tracer to return to its normal operating after
a new tracing on.

Link: https://lore.kernel.org/linux-trace-kernel/1ed8f830638b20a39d535d27d908e319a9a3c4e2.1683822622.git.bristot@kernel.org

Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: stable@vger.kernel.org
Fixes: a955d7eac1 ("trace: Add timerlat tracer")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-23 11:54:31 -04:00
Beau Belgrave
ee7751b564 tracing/user_events: Use long vs int for atomic bit ops
Each event stores a int to track which bit to set/clear when enablement
changes. On big endian 64-bit configurations, it's possible this could
cause memory corruption when it's used for atomic bit operations.

Use unsigned long for enablement values to ensure any possible
corruption cannot occur. Downcast to int after mask for the bit target.

Link: https://lore.kernel.org/all/6f758683-4e5e-41c3-9b05-9efc703e827c@kili.mountain/
Link: https://lore.kernel.org/linux-trace-kernel/20230505205855.6407-1-beaub@linux.microsoft.com

Fixes: dcb8177c13 ("tracing/user_events: Add ioctl for disabling addresses")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-23 10:40:34 -04:00
John Sperbeck
2bd1103392 cgroup: always put cset in cgroup_css_set_put_fork
A successful call to cgroup_css_set_fork() will always have taken
a ref on kargs->cset (regardless of CLONE_INTO_CGROUP), so always
do a corresponding put in cgroup_css_set_put_fork().

Without this, a cset and its contained css structures will be
leaked for some fork failures.  The following script reproduces
the leak for a fork failure due to exceeding pids.max in the
pids controller.  A similar thing can happen if we jump to the
bad_fork_cancel_cgroup label in copy_process().

[ -z "$1" ] && echo "Usage $0 pids-root" && exit 1
PID_ROOT=$1
CGROUP=$PID_ROOT/foo

[ -e $CGROUP ] && rmdir -f $CGROUP
mkdir $CGROUP
echo 5 > $CGROUP/pids.max
echo $$ > $CGROUP/cgroup.procs

fork_bomb()
{
	set -e
	for i in $(seq 10); do
		/bin/sleep 3600 &
	done
}

(fork_bomb) &
wait
echo $$ > $PID_ROOT/cgroup.procs
kill $(cat $CGROUP/cgroup.procs)
rmdir $CGROUP

Fixes: ef2c41cf38 ("clone3: allow spawning processes into cgroups")
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-05-22 13:59:37 -10:00
Harshit Mogalapalli
d36f6efbe0 module: Fix use-after-free bug in read_file_mod_stats()
Smatch warns:
	kernel/module/stats.c:394 read_file_mod_stats()
	warn: passing freed memory 'buf'

We are passing 'buf' to simple_read_from_buffer() after freeing it.

Fix this by changing the order of 'simple_read_from_buffer' and 'kfree'.

Fixes: df3e764d8e ("module: add debug stats to help identify memory pressure")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-05-22 14:13:13 -07:00
Qi Zheng
ab1de7ead8 cgroup: fix missing cpus_read_{lock,unlock}() in cgroup_transfer_tasks()
The commit 4f7e723643 ("cgroup: Fix threadgroup_rwsem <-> cpus_read_lock()
deadlock") fixed the deadlock between cgroup_threadgroup_rwsem and
cpus_read_lock() by introducing cgroup_attach_{lock,unlock}() and removing
cpus_read_{lock,unlock}() from cpuset_attach(). But cgroup_transfer_tasks()
was missed and not handled, which will cause th following warning:

 WARNING: CPU: 0 PID: 589 at kernel/cpu.c:526 lockdep_assert_cpus_held+0x32/0x40
 CPU: 0 PID: 589 Comm: kworker/1:4 Not tainted 6.4.0-rc2-next-20230517 #50
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
 Workqueue: events cpuset_hotplug_workfn
 RIP: 0010:lockdep_assert_cpus_held+0x32/0x40
 <...>
 Call Trace:
  <TASK>
  cpuset_attach+0x40/0x240
  cgroup_migrate_execute+0x452/0x5e0
  ? _raw_spin_unlock_irq+0x28/0x40
  cgroup_transfer_tasks+0x1f3/0x360
  ? find_held_lock+0x32/0x90
  ? cpuset_hotplug_workfn+0xc81/0xed0
  cpuset_hotplug_workfn+0xcb1/0xed0
  ? process_one_work+0x248/0x5b0
  process_one_work+0x2b9/0x5b0
  worker_thread+0x56/0x3b0
  ? process_one_work+0x5b0/0x5b0
  kthread+0xf1/0x120
  ? kthread_complete_and_exit+0x20/0x20
  ret_from_fork+0x1f/0x30
  </TASK>

So just use the cgroup_attach_{lock,unlock}() helper to fix it.

Reported-by: Zhao Gongyi <zhaogongyi@bytedance.com>
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Fixes: 05c7b7a92c ("cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug")
Cc: stable@vger.kernel.org # v5.17+
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-05-22 08:42:14 -10:00
Anton Protopopov
b34ffb0c6d bpf: fix a memory leak in the LRU and LRU_PERCPU hash maps
The LRU and LRU_PERCPU maps allocate a new element on update before locking the
target hash table bucket. Right after that the maps try to lock the bucket.
If this fails, then maps return -EBUSY to the caller without releasing the
allocated element. This makes the element untracked: it doesn't belong to
either of free lists, and it doesn't belong to the hash table, so can't be
re-used; this eventually leads to the permanent -ENOMEM on LRU map updates,
which is unexpected. Fix this by returning the element to the local free list
if bucket locking fails.

Fixes: 20b6cc34ea ("bpf: Avoid hashtab deadlock with map_locked")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Link: https://lore.kernel.org/r/20230522154558.2166815-1-aspsk@isovalent.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-05-22 10:26:39 -07:00
Will Deacon
0613d8ca9a bpf: Fix mask generation for 32-bit narrow loads of 64-bit fields
A narrow load from a 64-bit context field results in a 64-bit load
followed potentially by a 64-bit right-shift and then a bitwise AND
operation to extract the relevant data.

In the case of a 32-bit access, an immediate mask of 0xffffffff is used
to construct a 64-bit BPP_AND operation which then sign-extends the mask
value and effectively acts as a glorified no-op. For example:

0:	61 10 00 00 00 00 00 00	r0 = *(u32 *)(r1 + 0)

results in the following code generation for a 64-bit field:

	ldr	x7, [x7]	// 64-bit load
	mov	x10, #0xffffffffffffffff
	and	x7, x7, x10

Fix the mask generation so that narrow loads always perform a 32-bit AND
operation:

	ldr	x7, [x7]	// 64-bit load
	mov	w10, #0xffffffff
	and	w7, w7, w10

Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Krzesimir Nowak <krzesimir@kinvolk.io>
Cc: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Fixes: 31fd85816d ("bpf: permits narrower load from bpf program context fields")
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230518102528.1341-1-will@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-19 09:58:37 -07:00
Linus Torvalds
2d1bcbc6cd Probes fixes for 6.4-rc1:
- Initialize 'ret' local variables on fprobe_handler() to fix the smatch
   warning. With this, fprobe function exit handler is not working
   randomly.
 
 - Fix to use preempt_enable/disable_notrace for rethook handler to
   prevent recursive call of fprobe exit handler (which is based on
   rethook)
 
 - Fix recursive call issue on fprobe_kprobe_handler().
 
 - Fix to detect recursive call on fprobe_exit_handler().
 
 - Fix to make all arch-dependent rethook code notrace.
   (the arch-independent code is already notrace)
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Merge tag 'probes-fixes-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fixes from Masami Hiramatsu:

 - Initialize 'ret' local variables on fprobe_handler() to fix the
   smatch warning. With this, fprobe function exit handler is not
   working randomly.

 - Fix to use preempt_enable/disable_notrace for rethook handler to
   prevent recursive call of fprobe exit handler (which is based on
   rethook)

 - Fix recursive call issue on fprobe_kprobe_handler()

 - Fix to detect recursive call on fprobe_exit_handler()

 - Fix to make all arch-dependent rethook code notrace (the
   arch-independent code is already notrace)"

* tag 'probes-fixes-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  rethook, fprobe: do not trace rethook related functions
  fprobe: add recursion detection in fprobe_exit_handler
  fprobe: make fprobe_kprobe_handler recursion free
  rethook: use preempt_{disable, enable}_notrace in rethook_trampoline_handler
  tracing: fprobe: Initialize ret valiable to fix smatch error
2023-05-18 09:04:45 -07:00
Ze Gao
2752741080 fprobe: add recursion detection in fprobe_exit_handler
fprobe_hander and fprobe_kprobe_handler has guarded ftrace recursion
detection but fprobe_exit_handler has not, which possibly introduce
recursive calls if the fprobe exit callback calls any traceable
functions. Checking in fprobe_hander or fprobe_kprobe_handler
is not enough and misses this case.

So add recursion free guard the same way as fprobe_hander. Since
ftrace recursion check does not employ ip(s), so here use entry_ip and
entry_parent_ip the same as fprobe_handler.

Link: https://lore.kernel.org/all/20230517034510.15639-4-zegao@tencent.com/

Fixes: 5b0ab78998 ("fprobe: Add exit_handler support")
Signed-off-by: Ze Gao <zegao@tencent.com>
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-05-18 07:08:01 +09:00
Ze Gao
3cc4e2c5fb fprobe: make fprobe_kprobe_handler recursion free
Current implementation calls kprobe related functions before doing
ftrace recursion check in fprobe_kprobe_handler, which opens door
to kernel crash due to stack recursion if preempt_count_{add, sub}
is traceable in kprobe_busy_{begin, end}.

Things goes like this without this patch quoted from Steven:
"
fprobe_kprobe_handler() {
   kprobe_busy_begin() {
      preempt_disable() {
         preempt_count_add() {  <-- trace
            fprobe_kprobe_handler() {
		[ wash, rinse, repeat, CRASH!!! ]
"

By refactoring the common part out of fprobe_kprobe_handler and
fprobe_handler and call ftrace recursion detection at the very beginning,
the whole fprobe_kprobe_handler is free from recursion.

[ Fix the indentation of __fprobe_handler() parameters. ]

Link: https://lore.kernel.org/all/20230517034510.15639-3-zegao@tencent.com/

Fixes: ab51e15d53 ("fprobe: Introduce FPROBE_FL_KPROBE_SHARED flag for fprobe")
Signed-off-by: Ze Gao <zegao@tencent.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-05-18 07:08:01 +09:00
Ze Gao
be243bacfb rethook: use preempt_{disable, enable}_notrace in rethook_trampoline_handler
This patch replaces preempt_{disable, enable} with its corresponding
notrace version in rethook_trampoline_handler so no worries about stack
recursion or overflow introduced by preempt_count_{add, sub} under
fprobe + rethook context.

Link: https://lore.kernel.org/all/20230517034510.15639-2-zegao@tencent.com/

Fixes: 54ecbe6f1e ("rethook: Add a generic return hook")
Signed-off-by: Ze Gao <zegao@tencent.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-05-18 07:08:01 +09:00
Masami Hiramatsu (Google)
6049674b57 tracing: fprobe: Initialize ret valiable to fix smatch error
The commit 39d954200b ("fprobe: Skip exit_handler if entry_handler returns
!0") introduced a hidden dependency of 'ret' local variable in the
fprobe_handler(), Smatch warns the `ret` can be accessed without
initialization.

	kernel/trace/fprobe.c:59 fprobe_handler()
	error: uninitialized symbol 'ret'.

kernel/trace/fprobe.c
    49                 fpr->entry_ip = ip;
    50                 if (fp->entry_data_size)
    51                         entry_data = fpr->data;
    52         }
    53
    54         if (fp->entry_handler)
    55                 ret = fp->entry_handler(fp, ip, ftrace_get_regs(fregs), entry_data);

ret is only initialized if there is an ->entry_handler

    56
    57         /* If entry_handler returns !0, nmissed is not counted. */
    58         if (rh) {

rh is only true if there is an ->exit_handler.  Presumably if you have
and ->exit_handler that means you also have a ->entry_handler but Smatch
is not smart enough to figure it out.

--> 59                 if (ret)
                           ^^^
Warning here.

    60                         rethook_recycle(rh);
    61                 else
    62                         rethook_hook(rh, ftrace_get_regs(fregs), true);
    63         }
    64 out:
    65         ftrace_test_recursion_unlock(bit);
    66 }

Link: https://lore.kernel.org/all/168100731160.79534.374827110083836722.stgit@devnote2/

Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/all/85429a5c-a4b9-499e-b6c0-cbd313291c49@kili.mountain
Fixes: 39d954200b ("fprobe: Skip exit_handler if entry_handler returns !0")
Acked-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-05-17 20:42:59 +09:00
Jakub Kicinski
e1505c1cc8 bpf: netdev: init the offload table earlier
Some netdevices may get unregistered before late_initcall(),
we have to move the hashtable init earlier.

Fixes: f1fc43d039 ("bpf: Move offload initialization into late_initcall")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217399
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230505215836.491485-1-kuba@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-15 07:07:41 -07:00