Commit Graph

45972 Commits

Author SHA1 Message Date
Linus Torvalds
2b4d25010d - Add PREEMPT_RT maintainers
- Fix another aspect of delayed dequeued tasks wrt determining their state,
   i.e., whether they're runnable or blocked
 
 - Handle delayed dequeued tasks and their migration wrt PSI properly
 
 - Fix the situation where a delayed dequeue task gets enqueued into a new
   class, which should not happen
 
 - Fix a case where memory allocation would happen while the runqueue lock is
   held, which is a no-no
 
 - Do not over-schedule when tasks with shorter slices preempt the currently
   running task
 
 - Make sure delayed to deque entities are properly handled before unthrottling
 
 - Other smaller cleanups and improvements
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmcU3tMACgkQEsHwGGHe
 VUqpuhAAqqyi2NNgrIOlEWh/Ej4NQZL7KleF84cSpKCIBK2somYX5ksgMcUgn82i
 bIuDVErQu/a4lhNAf5zn7TO3yuPA1Q5xd/453qBlWM9ApkH0S69Mp9f0yocVu8F0
 t3XsgXm+/R8A4TYbiv8cB+r1Xt8E5NUP6RkNIKCHbPLAG94gqYF8UZEJ9sAl9ZXw
 qEWc9afpnp+4LQ9PlzePuaM976LWUPB49OoFZMnFmY1VkvFuVjkjXSVzJX6l4qB7
 Omo/+TXOOBSHXVVflNx/68Q16irFHAnqwPPrLCBQWBLIPz3iRiZjV9ptD9tUZkRM
 M+klL7w0jRG+8wa9fTwuqybmBNIBt4Az1/WUw9Lc3ryEWRsCKzkGT8au3lv5FpQY
 CTwIIBSMmUcqQSG40R0HHS3nDR4UBFFD0PAww+8cJQZc0IPd2rT9/hfqYdt3sq2Z
 vV9rmTFOcDlApeDdCGcfC7zJhdgVuBgDVjdTsE5SNRUduBUsBYOeLDnT+0Qi0ArJ
 txVINGxQDm6jz512f4CAB/xzUcYpU4o639Z1Jkd6a8QbO1NBZGX1ioOcvPEMhmFF
 f/qFyM8ctR5Kj6LJCZiDcstqtAZviW1d2uMp48gk2QeSvkCyIUQqrWshItd02iBG
 TZdSYRvSYtYSIz7WYtE/CABUDmrJGjuLtb+jOrR93//TsWwwVdE=
 =1D7H
 -----END PGP SIGNATURE-----

Merge tag 'sched_urgent_for_v6.12_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduling fixes from Borislav Petkov:

 - Add PREEMPT_RT maintainers

 - Fix another aspect of delayed dequeued tasks wrt determining their
   state, i.e., whether they're runnable or blocked

 - Handle delayed dequeued tasks and their migration wrt PSI properly

 - Fix the situation where a delayed dequeue task gets enqueued into a
   new class, which should not happen

 - Fix a case where memory allocation would happen while the runqueue
   lock is held, which is a no-no

 - Do not over-schedule when tasks with shorter slices preempt the
   currently running task

 - Make sure delayed to deque entities are properly handled before
   unthrottling

 - Other smaller cleanups and improvements

* tag 'sched_urgent_for_v6.12_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Add an entry for PREEMPT_RT.
  sched/fair: Fix external p->on_rq users
  sched/psi: Fix mistaken CPU pressure indication after corrupted task state bug
  sched/core: Dequeue PSI signals for blocked tasks that are delayed
  sched: Fix delayed_dequeue vs switched_from_fair()
  sched/core: Disable page allocation in task_tick_mm_cid()
  sched/deadline: Use hrtick_enabled_dl() before start_hrtick_dl()
  sched/eevdf: Fix wakeup-preempt by checking cfs_rq->nr_running
  sched: Fix sched_delayed vs cfs_bandwidth
2024-10-20 11:30:56 -07:00
Linus Torvalds
06526daaff ftrace: A couple of fixes to function graph infrastructure
- Fix allocation of idle shadow stack allocation during hotplug
 
   If function graph tracing is started when a CPU is offline, if it were
   come online during the trace then the idle task that represents the CPU
   will not get a shadow stack allocated for it. This means all function
   graph hooks that happen while that idle task is running (including in
   interrupt mode) will have all its events dropped.
 
   Switch over to the CPU hotplug mechanism that will have any newly
   brought on line CPU get a callback that can allocate the shadow stack
   for its idle task.
 
 - Fix allocation size of the ret_stack_list array
 
   When function graph tracing converted over to allowing more than one
   user at a time, it had to convert its shadow stack from an array of
   ret_stack structures to an array of unsigned longs. The shadow stacks
   are allocated in batches of 32 at a time and assigned to every running
   task. The batch is held by the ret_stack_list array. But when the
   conversion happened, instead of allocating an array of 32 pointers, it
   was allocated as a ret_stack itself (PAGE_SIZE). This ret_stack_list
   gets passed to a function that iterates over what it believes is its
   size defined by the FTRACE_RETSTACK_ALLOC_SIZE macro (which is 32).
 
   Luckily (PAGE_SIZE) is greater than 32 * sizeof(long), otherwise this
   would have been an array overflow. This still should be fixed and the
   ret_stack_list should be allocated to the size it is expected to be as
   someday it may end up being bigger than SHADOW_STACK_SIZE.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZxP8RhQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qmW3AP4qCOvU/g9g6u32gIZmS1oUWqe3q+Rq
 9OKCk0JP6GGc8AD/cF816lbs5vpDiZFdbBvaz5gLHqhfAt35NVU8T5tbJA4=
 =Lh3A
 -----END PGP SIGNATURE-----

Merge tag 'ftrace-v6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace fixes from Steven Rostedt:
 "A couple of fixes to function graph infrastructure:

   - Fix allocation of idle shadow stack allocation during hotplug

     If function graph tracing is started when a CPU is offline, if it
     were come online during the trace then the idle task that
     represents the CPU will not get a shadow stack allocated for it.
     This means all function graph hooks that happen while that idle
     task is running (including in interrupt mode) will have all its
     events dropped.

     Switch over to the CPU hotplug mechanism that will have any newly
     brought on line CPU get a callback that can allocate the shadow
     stack for its idle task.

   - Fix allocation size of the ret_stack_list array

     When function graph tracing converted over to allowing more than
     one user at a time, it had to convert its shadow stack from an
     array of ret_stack structures to an array of unsigned longs. The
     shadow stacks are allocated in batches of 32 at a time and assigned
     to every running task. The batch is held by the ret_stack_list
     array.

     But when the conversion happened, instead of allocating an array of
     32 pointers, it was allocated as a ret_stack itself (PAGE_SIZE).
     This ret_stack_list gets passed to a function that iterates over
     what it believes is its size defined by the
     FTRACE_RETSTACK_ALLOC_SIZE macro (which is 32).

     Luckily (PAGE_SIZE) is greater than 32 * sizeof(long), otherwise
     this would have been an array overflow. This still should be fixed
     and the ret_stack_list should be allocated to the size it is
     expected to be as someday it may end up being bigger than
     SHADOW_STACK_SIZE"

* tag 'ftrace-v6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  fgraph: Allocate ret_stack_list with proper size
  fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks
2024-10-19 12:42:14 -07:00
Steven Rostedt
fae4078c28 fgraph: Allocate ret_stack_list with proper size
The ret_stack_list is an array of ret_stack shadow stacks for the function
graph usage. When the first function graph is enabled, all tasks in the
system get a shadow stack. The ret_stack_list is a 32 element array of
pointers to these shadow stacks. It allocates the shadow stack in batches
(32 stacks at a time), assigns them to running tasks, and continues until
all tasks are covered.

When the function graph shadow stack changed from an array of
ftrace_ret_stack structures to an array of longs, the allocation of
ret_stack_list went from allocating an array of 32 elements to just a
block defined by SHADOW_STACK_SIZE. Luckily, that's defined as PAGE_SIZE
and is much more than enough to hold 32 pointers. But it is way overkill
for the amount needed to allocate.

Change the allocation of ret_stack_list back to a kcalloc() of
FTRACE_RETSTACK_ALLOC_SIZE pointers.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241018215212.23f13f40@rorschach
Fixes: 42675b723b ("function_graph: Convert ret_stack to a series of longs")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-18 21:57:20 -04:00
Steven Rostedt
2c02f7375e fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks
The function graph infrastructure allocates a shadow stack for every task
when enabled. This includes the idle tasks. The first time the function
graph is invoked, the shadow stacks are created and never freed until the
task exits. This includes the idle tasks.

Only the idle tasks that were for online CPUs had their shadow stacks
created when function graph tracing started. If function graph tracing is
enabled and a CPU comes online, the idle task representing that CPU will
not have its shadow stack created, and all function graph tracing for that
idle task will be silently dropped.

Instead, use the CPU hotplug mechanism to allocate the idle shadow stacks.
This will include idle tasks for CPUs that come online during tracing.

This issue can be reproduced by:

 # cd /sys/kernel/tracing
 # echo 0 > /sys/devices/system/cpu/cpu1/online
 # echo 0 > set_ftrace_pid
 # echo function_graph > current_tracer
 # echo 1 > options/funcgraph-proc
 # echo 1 > /sys/devices/system/cpu/cpu1
 # grep '<idle>' per_cpu/cpu1/trace | head

Before, nothing would show up.

After:
 1)    <idle>-0    |   0.811 us    |                        __enqueue_entity();
 1)    <idle>-0    |   5.626 us    |                      } /* enqueue_entity */
 1)    <idle>-0    |               |                      dl_server_update_idle_time() {
 1)    <idle>-0    |               |                        dl_scaled_delta_exec() {
 1)    <idle>-0    |   0.450 us    |                          arch_scale_cpu_capacity();
 1)    <idle>-0    |   1.242 us    |                        }
 1)    <idle>-0    |   1.908 us    |                      }
 1)    <idle>-0    |               |                      dl_server_start() {
 1)    <idle>-0    |               |                        enqueue_dl_entity() {
 1)    <idle>-0    |               |                          task_contending() {

Note, if tracing stops and restarts, the old way would then initialize
the onlined CPUs.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20241018214300.6df82178@rorschach
Fixes: 868baf07b1 ("ftrace: Fix memory leak with function graph and cpu hotplug")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-18 21:56:56 -04:00
Linus Torvalds
3d5ad2d4ec BPF fixes:
- Fix BPF verifier to not affect subreg_def marks in its range
   propagation, from Eduard Zingerman.
 
 - Fix a truncation bug in the BPF verifier's handling of
   coerce_reg_to_size_sx, from Dimitar Kanaliev.
 
 - Fix the BPF verifier's delta propagation between linked
   registers under 32-bit addition, from Daniel Borkmann.
 
 - Fix a NULL pointer dereference in BPF devmap due to missing
   rxq information, from Florian Kauer.
 
 - Fix a memory leak in bpf_core_apply, from Jiri Olsa.
 
 - Fix an UBSAN-reported array-index-out-of-bounds in BTF
   parsing for arrays of nested structs, from Hou Tao.
 
 - Fix build ID fetching where memory areas backing the file
   were created with memfd_secret, from Andrii Nakryiko.
 
 - Fix BPF task iterator tid filtering which was incorrectly
   using pid instead of tid, from Jordan Rome.
 
 - Several fixes for BPF sockmap and BPF sockhash redirection
   in combination with vsocks, from Michal Luczaj.
 
 - Fix riscv BPF JIT and make BPF_CMPXCHG fully ordered,
   from Andrea Parri.
 
 - Fix riscv BPF JIT under CONFIG_CFI_CLANG to prevent the
   possibility of an infinite BPF tailcall, from Pu Lehui.
 
 - Fix a build warning from resolve_btfids that bpf_lsm_key_free
   cannot be resolved, from Thomas Weißschuh.
 
 - Fix a bug in kfunc BTF caching for modules where the wrong
   BTF object was returned, from Toke Høiland-Jørgensen.
 
 - Fix a BPF selftest compilation error in cgroup-related tests
   with musl libc, from Tony Ambardar.
 
 - Several fixes to BPF link info dumps to fill missing fields,
   from Tyrone Wu.
 
 - Add BPF selftests for kfuncs from multiple modules, checking
   that the correct kfuncs are called, from Simon Sundberg.
 
 - Ensure that internal and user-facing bpf_redirect flags
   don't overlap, also from Toke Høiland-Jørgensen.
 
 - Switch to use kvzmalloc to allocate BPF verifier environment,
   from Rik van Riel.
 
 - Use raw_spinlock_t in BPF ringbuf to fix a sleep in atomic
   splat under RT, from Wander Lairson Costa.
 
 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
 -----BEGIN PGP SIGNATURE-----
 
 iIsEABYIADMWIQTFp0I1jqZrAX+hPRXbK58LschIgwUCZxK4OhUcZGFuaWVsQGlv
 Z2VhcmJveC5uZXQACgkQ2yufC7HISIOCrwEAib2kC5EEQn5+wKVE/bnZryVX2leT
 YXdfItDCBU6zCYUA+wTU5hGGn9lcDUcZx72l/KZPDyPw7HdzNJ+6iR1zQqoM
 =f9kv
 -----END PGP SIGNATURE-----

Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Pull bpf fixes from Daniel Borkmann:

 - Fix BPF verifier to not affect subreg_def marks in its range
   propagation (Eduard Zingerman)

 - Fix a truncation bug in the BPF verifier's handling of
   coerce_reg_to_size_sx (Dimitar Kanaliev)

 - Fix the BPF verifier's delta propagation between linked registers
   under 32-bit addition (Daniel Borkmann)

 - Fix a NULL pointer dereference in BPF devmap due to missing rxq
   information (Florian Kauer)

 - Fix a memory leak in bpf_core_apply (Jiri Olsa)

 - Fix an UBSAN-reported array-index-out-of-bounds in BTF parsing for
   arrays of nested structs (Hou Tao)

 - Fix build ID fetching where memory areas backing the file were
   created with memfd_secret (Andrii Nakryiko)

 - Fix BPF task iterator tid filtering which was incorrectly using pid
   instead of tid (Jordan Rome)

 - Several fixes for BPF sockmap and BPF sockhash redirection in
   combination with vsocks (Michal Luczaj)

 - Fix riscv BPF JIT and make BPF_CMPXCHG fully ordered (Andrea Parri)

 - Fix riscv BPF JIT under CONFIG_CFI_CLANG to prevent the possibility
   of an infinite BPF tailcall (Pu Lehui)

 - Fix a build warning from resolve_btfids that bpf_lsm_key_free cannot
   be resolved (Thomas Weißschuh)

 - Fix a bug in kfunc BTF caching for modules where the wrong BTF object
   was returned (Toke Høiland-Jørgensen)

 - Fix a BPF selftest compilation error in cgroup-related tests with
   musl libc (Tony Ambardar)

 - Several fixes to BPF link info dumps to fill missing fields (Tyrone
   Wu)

 - Add BPF selftests for kfuncs from multiple modules, checking that the
   correct kfuncs are called (Simon Sundberg)

 - Ensure that internal and user-facing bpf_redirect flags don't overlap
   (Toke Høiland-Jørgensen)

 - Switch to use kvzmalloc to allocate BPF verifier environment (Rik van
   Riel)

 - Use raw_spinlock_t in BPF ringbuf to fix a sleep in atomic splat
   under RT (Wander Lairson Costa)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (38 commits)
  lib/buildid: Handle memfd_secret() files in build_id_parse()
  selftests/bpf: Add test case for delta propagation
  bpf: Fix print_reg_state's constant scalar dump
  bpf: Fix incorrect delta propagation between linked registers
  bpf: Properly test iter/task tid filtering
  bpf: Fix iter/task tid filtering
  riscv, bpf: Make BPF_CMPXCHG fully ordered
  bpf, vsock: Drop static vsock_bpf_prot initialization
  vsock: Update msg_count on read_skb()
  vsock: Update rx_bytes on read_skb()
  bpf, sockmap: SK_DROP on attempted redirects of unsupported af_vsock
  selftests/bpf: Add asserts for netfilter link info
  bpf: Fix link info netfilter flags to populate defrag flag
  selftests/bpf: Add test for sign extension in coerce_subreg_to_size_sx()
  selftests/bpf: Add test for truncation after sign extension in coerce_reg_to_size_sx()
  bpf: Fix truncation bug in coerce_reg_to_size_sx()
  selftests/bpf: Assert link info uprobe_multi count & path_size if unset
  bpf: Fix unpopulated path_size when uprobe_multi fields unset
  selftests/bpf: Fix cross-compiling urandom_read
  selftests/bpf: Add test for kfunc module order
  ...
2024-10-18 16:27:14 -07:00
Daniel Borkmann
3e9e708757 bpf: Fix print_reg_state's constant scalar dump
print_reg_state() should not consider adding reg->off to reg->var_off.value
when dumping scalars. Scalars can be produced with reg->off != 0 through
BPF_ADD_CONST, and thus as-is this can skew the register log dump.

Fixes: 98d7ca374b ("bpf: Track delta between "linked" registers.")
Reported-by: Nathaniel Theis <nathaniel.theis@nccgroup.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241016134913.32249-2-daniel@iogearbox.net
2024-10-17 11:06:34 -07:00
Daniel Borkmann
3878ae04e9 bpf: Fix incorrect delta propagation between linked registers
Nathaniel reported a bug in the linked scalar delta tracking, which can lead
to accepting a program with OOB access. The specific code is related to the
sync_linked_regs() function and the BPF_ADD_CONST flag, which signifies a
constant offset between two scalar registers tracked by the same register id.

The verifier attempts to track "similar" scalars in order to propagate bounds
information learned about one scalar to others. For instance, if r1 and r2
are known to contain the same value, then upon encountering 'if (r1 != 0x1234)
goto xyz', not only does it know that r1 is equal to 0x1234 on the path where
that conditional jump is not taken, it also knows that r2 is.

Additionally, with env->bpf_capable set, the verifier will track scalars
which should be a constant delta apart (if r1 is known to be one greater than
r2, then if r1 is known to be equal to 0x1234, r2 must be equal to 0x1233.)
The code path for the latter in adjust_reg_min_max_vals() is reached when
processing both 32 and 64-bit addition operations. While adjust_reg_min_max_vals()
knows whether dst_reg was produced by a 32 or a 64-bit addition (based on the
alu32 bool), the only information saved in dst_reg is the id of the source
register (reg->id, or'ed by BPF_ADD_CONST) and the value of the constant
offset (reg->off).

Later, the function sync_linked_regs() will attempt to use this information
to propagate bounds information from one register (known_reg) to others,
meaning, for all R in linked_regs, it copies known_reg range (and possibly
adjusting delta) into R for the case of R->id == known_reg->id.

For the delta adjustment, meaning, matching reg->id with BPF_ADD_CONST, the
verifier adjusts the register as reg = known_reg; reg += delta where delta
is computed as (s32)reg->off - (s32)known_reg->off and placed as a scalar
into a fake_reg to then simulate the addition of reg += fake_reg. This is
only correct, however, if the value in reg was created by a 64-bit addition.
When reg contains the result of a 32-bit addition operation, its upper 32
bits will always be zero. sync_linked_regs() on the other hand, may cause
the verifier to believe that the addition between fake_reg and reg overflows
into those upper bits. For example, if reg was generated by adding the
constant 1 to known_reg using a 32-bit alu operation, then reg->off is 1
and known_reg->off is 0. If known_reg is known to be the constant 0xFFFFFFFF,
sync_linked_regs() will tell the verifier that reg is equal to the constant
0x100000000. This is incorrect as the actual value of reg will be 0, as the
32-bit addition will wrap around.

Example:

  0: (b7) r0 = 0;             R0_w=0
  1: (18) r1 = 0x80000001;    R1_w=0x80000001
  3: (37) r1 /= 1;            R1_w=scalar()
  4: (bf) r2 = r1;            R1_w=scalar(id=1) R2_w=scalar(id=1)
  5: (bf) r4 = r1;            R1_w=scalar(id=1) R4_w=scalar(id=1)
  6: (04) w2 += 2147483647;   R2_w=scalar(id=1+2147483647,smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
  7: (04) w4 += 0 ;           R4_w=scalar(id=1+0,smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
  8: (15) if r2 == 0x0 goto pc+1
 10: R0=0 R1=0xffffffff80000001 R2=0x7fffffff R4=0xffffffff80000001 R10=fp0

What can be seen here is that r1 is copied to r2 and r4, such that {r1,r2,r4}.id
are all the same which later lets sync_linked_regs() to be invoked. Then, in
a next step constants are added with alu32 to r2 and r4, setting their ->off,
as well as id |= BPF_ADD_CONST. Next, the conditional will bind r2 and
propagate ranges to its linked registers. The verifier now believes the upper
32 bits of r4 are r4=0xffffffff80000001, while actually r4=r1=0x80000001.

One approach for a simple fix suitable also for stable is to limit the constant
delta tracking to only 64-bit alu addition. If necessary at some later point,
BPF_ADD_CONST could be split into BPF_ADD_CONST64 and BPF_ADD_CONST32 to avoid
mixing the two under the tradeoff to further complicate sync_linked_regs().
However, none of the added tests from dedf56d775 ("selftests/bpf: Add tests
for add_const") make this necessary at this point, meaning, BPF CI also passes
with just limiting tracking to 64-bit alu addition.

Fixes: 98d7ca374b ("bpf: Track delta between "linked" registers.")
Reported-by: Nathaniel Theis <nathaniel.theis@nccgroup.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20241016134913.32249-1-daniel@iogearbox.net
2024-10-17 11:06:34 -07:00
Jordan Rome
9495a5b731 bpf: Fix iter/task tid filtering
In userspace, you can add a tid filter by setting
the "task.tid" field for "bpf_iter_link_info".
However, `get_pid_task` when called for the
`BPF_TASK_ITER_TID` type should have been using
`PIDTYPE_PID` (tid) instead of `PIDTYPE_TGID` (pid).

Fixes: f0d74c4da1 ("bpf: Parameterize task iterators.")
Signed-off-by: Jordan Rome <linux@jordanrome.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241016210048.1213935-1-linux@jordanrome.com
2024-10-17 10:52:18 -07:00
Linus Torvalds
07d6bf634b No contributions from subtrees.
Current release - new code bugs:
 
   - eth: mlx5: HWS, don't destroy more bwc queue locks than allocated
 
 Previous releases - regressions:
 
   - ipv4: give an IPv4 dev to blackhole_netdev
 
   - udp: compute L4 checksum as usual when not segmenting the skb
 
   - tcp/dccp: don't use timer_pending() in reqsk_queue_unlink().
 
   - eth: mlx5e: don't call cleanup on profile rollback failure
 
   - eth: microchip: vcap api: fix memory leaks in vcap_api_encode_rule_test()
 
   - eth: enetc: disable Tx BD rings after they are empty
 
   - eth: macb: avoid 20s boot delay by skipping MDIO bus registration for fixed-link PHY
 
 Previous releases - always broken:
 
   - posix-clock: fix missing timespec64 check in pc_clock_settime()
 
   - genetlink: hold RCU in genlmsg_mcast()
 
   - mptcp: prevent MPC handshake on port-based signal endpoints
 
   - eth: vmxnet3: fix packet corruption in vmxnet3_xdp_xmit_frame
 
   - eth: stmmac: dwmac-tegra: fix link bring-up sequence
 
   - eth: bcmasp: fix potential memory leak in bcmasp_xmit()
 
 Misc:
 
   - add Andrew Lunn as a co-maintainer of all networking drivers
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCAAwFiEEg1AjqC77wbdLX2LbKSR5jcyPE6QFAmcRDoMSHHBhYmVuaUBy
 ZWRoYXQuY29tAAoJECkkeY3MjxOklXoP/2VKcUDYMfP03vB6a60riiqMcD+GVZzm
 lLaa9xBiDdEsnL+4dcQLF7tecYbqpIqh+0ZeEe0aXgp0HjIm2Im1eiXv5cB7INxK
 n1lxVibI/zD2j2M9cy2NDTeeYSI29GH98g0IkLrU9vnfsrp5jRuXFttrCmotzesZ
 tYb200cVMR/nt9rrG3aNAxTUHjaykgpKh/zSvFC0MRStXFfUbIia88LzcQOQzEK3
 jcWMj8jsJHkDLhUHS8LVZEV1JDYIb+QeEjGz5LxMpQV5/T5sP7Ki4ISPxpUbYNrZ
 QWwSrFSg2ivaq8PkQ2LBTKAtiHyGlcEJtnlSf7Y50cpc9RNphClq8YMSBUCcGTEi
 3W18eVIZ0aj1omTeHEQLbMkqT0soTwYxskDW0uCCFKf/SRCQm1ixrpQiA6PGP266
 e0q7mMD7v4S9ZdO5VF+oYzf1fF0OhaOkZtUEsWjxHite6ujh8719EPbUoee4cqPL
 ofoHYF338BlYl4YIZERZMff8HJD4+PR0R8c9SIBXQcGUMvf2mQdvaD9q2MGySSJd
 4mlH6bE8Ckj4KVp9llxB8zyw/5OmJdMZ+ar4o7+CX2Z3Wrs1SMSTy7qAADcV2B2G
 S9kvwNDffak+N94N/MqswQM4se5yo8dmyUnhqChBFYPFWc4N7v6wwKelROigqLL7
 7Xhj2TXRBGKs
 =ukTi
 -----END PGP SIGNATURE-----

Merge tag 'net-6.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Current release - new code bugs:

   - eth: mlx5: HWS, don't destroy more bwc queue locks than allocated

  Previous releases - regressions:

   - ipv4: give an IPv4 dev to blackhole_netdev

   - udp: compute L4 checksum as usual when not segmenting the skb

   - tcp/dccp: don't use timer_pending() in reqsk_queue_unlink().

   - eth: mlx5e: don't call cleanup on profile rollback failure

   - eth: microchip: vcap api: fix memory leaks in
     vcap_api_encode_rule_test()

   - eth: enetc: disable Tx BD rings after they are empty

   - eth: macb: avoid 20s boot delay by skipping MDIO bus registration
     for fixed-link PHY

  Previous releases - always broken:

   - posix-clock: fix missing timespec64 check in pc_clock_settime()

   - genetlink: hold RCU in genlmsg_mcast()

   - mptcp: prevent MPC handshake on port-based signal endpoints

   - eth: vmxnet3: fix packet corruption in vmxnet3_xdp_xmit_frame

   - eth: stmmac: dwmac-tegra: fix link bring-up sequence

   - eth: bcmasp: fix potential memory leak in bcmasp_xmit()

  Misc:

   - add Andrew Lunn as a co-maintainer of all networking drivers"

* tag 'net-6.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (47 commits)
  net/mlx5e: Don't call cleanup on profile rollback failure
  net/mlx5: Unregister notifier on eswitch init failure
  net/mlx5: Fix command bitmask initialization
  net/mlx5: Check for invalid vector index on EQ creation
  net/mlx5: HWS, use lock classes for bwc locks
  net/mlx5: HWS, don't destroy more bwc queue locks than allocated
  net/mlx5: HWS, fixed double free in error flow of definer layout
  net/mlx5: HWS, removed wrong access to a number of rules variable
  mptcp: pm: fix UaF read in mptcp_pm_nl_rm_addr_or_subflow
  net: ethernet: mtk_eth_soc: fix memory corruption during fq dma init
  vmxnet3: Fix packet corruption in vmxnet3_xdp_xmit_frame
  net: dsa: vsc73xx: fix reception from VLAN-unaware bridges
  net: ravb: Only advertise Rx/Tx timestamps if hardware supports it
  net: microchip: vcap api: Fix memory leaks in vcap_api_encode_rule_test()
  net: phy: mdio-bcm-unimac: Add BCM6846 support
  dt-bindings: net: brcm,unimac-mdio: Add bcm6846-mdio
  udp: Compute L4 checksum as usual when not segmenting the skb
  genetlink: hold RCU in genlmsg_mcast()
  net: dsa: mv88e6xxx: Fix the max_vid definition for the MV88E6361
  tcp/dccp: Don't use timer_pending() in reqsk_queue_unlink().
  ...
2024-10-17 09:31:18 -07:00
Ingo Molnar
be602cde65 Merge branch 'linus' into sched/urgent, to resolve conflict
Conflicts:
	kernel/sched/ext.c

There's a context conflict between this upstream commit:

  3fdb9ebcec sched_ext: Start schedulers with consistent p->scx.slice values

... and this fix in sched/urgent:

  98442f0ccd sched: Fix delayed_dequeue vs switched_from_fair()

Resolve it.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-10-17 09:58:07 +02:00
Linus Torvalds
dff6584301 sched_ext: Fixes for v6.12-rc3
- More issues reported in the enable/disable paths on large machines with
   many tasks due to scx_tasks_lock being held too long. Break up the task
   iterations.
 
 - Remove ops.select_cpu() dependency in bypass mode so that a misbehaving
   implementation can't live-lock the machine by pushing all tasks to few
   CPUs in bypass mode.
 
 - Other misc fixes.
 -----BEGIN PGP SIGNATURE-----
 
 iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCZw7SMw4cdGpAa2VybmVs
 Lm9yZwAKCRCxYfJx3gVYGU6+AQDZKNsyRw0c8+rd7eASAtCzvzBU1KGf3RPrsbNF
 pb3IGgEA4/uVBlVny10ZyeKaQ4A3L2G4ROyJwNEygUvhkvbfcgk=
 =z7d9
 -----END PGP SIGNATURE-----

Merge tag 'sched_ext-for-6.12-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext fixes from Tejun Heo:

 - More issues reported in the enable/disable paths on large machines
   with many tasks due to scx_tasks_lock being held too long. Break up
   the task iterations

 - Remove ops.select_cpu() dependency in bypass mode so that a
   misbehaving implementation can't live-lock the machine by pushing all
   tasks to few CPUs in bypass mode

 - Other misc fixes

* tag 'sched_ext-for-6.12-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: Remove unnecessary cpu_relax()
  sched_ext: Don't hold scx_tasks_lock for too long
  sched_ext: Move scx_tasks_lock handling into scx_task_iter helpers
  sched_ext: bypass mode shouldn't depend on ops.select_cpu()
  sched_ext: Move scx_buildin_idle_enabled check to scx_bpf_select_cpu_dfl()
  sched_ext: Start schedulers with consistent p->scx.slice values
  Revert "sched_ext: Use shorter slice while bypassing"
  sched_ext: use correct function name in pick_task_scx() warning message
  selftests: sched_ext: Add sched_ext as proper selftest target
2024-10-15 19:47:19 -07:00
Linus Torvalds
2f87d0916c ring-buffer: Fixes for v6.12
- Fix ref counter of buffers assigned at boot up
 
   A tracing instance can be created from the kernel command line.
   If it maps to memory, it is considered permanent and should not
   be deleted, or bad things can happen. If it is not mapped to memory,
   then the user is fine to delete it via rmdir from the instances
   directory. But the ref counts assumed 0 was free to remove and
   greater than zero was not. But this was not the case. When an
   instance is created, it should have the reference of 1, and if
   it should not be removed, it must be greater than 1. The boot up
   code set normal instances with a ref count of 0, which could get
   removed if something accessed it and then released it. And memory
   mapped instances had a ref count of 1 which meant it could be deleted,
   and bad things happen. Keep normal instances ref count as 1, and
   set memory mapped instances ref count to 2.
 
 - Protect sub buffer size (order) updates from other modifications
 
   When a ring buffer is changing the size of its sub-buffers, no other
   operations should be performed on the ring buffer. That includes
   reading it. But the locking only grabbed the buffer->mutex that
   keeps some operations from touching the ring buffer. It also must
   hold the cpu_buffer->reader_lock as well when updates happen as
   other paths use that to do some operations on the ring buffer.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZw6LSRQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qr8NAP4ggN51IEEDLINUctXvTnJAbRdRiZcC
 Z/q/5hfPS2+uAgEArSfVRCMdCCiVMZv+R9i6YPzn1Ux2OTGbcOHz56lZKgY=
 =GwKu
 -----END PGP SIGNATURE-----

Merge tag 'trace-ringbuffer-v6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ring-buffer fixes from Steven Rostedt:

 - Fix ref counter of buffers assigned at boot up

   A tracing instance can be created from the kernel command line. If it
   maps to memory, it is considered permanent and should not be deleted,
   or bad things can happen. If it is not mapped to memory, then the
   user is fine to delete it via rmdir from the instances directory. But
   the ref counts assumed 0 was free to remove and greater than zero was
   not. But this was not the case. When an instance is created, it
   should have the reference of 1, and if it should not be removed, it
   must be greater than 1. The boot up code set normal instances with a
   ref count of 0, which could get removed if something accessed it and
   then released it. And memory mapped instances had a ref count of 1
   which meant it could be deleted, and bad things happen. Keep normal
   instances ref count as 1, and set memory mapped instances ref count
   to 2.

 - Protect sub buffer size (order) updates from other modifications

   When a ring buffer is changing the size of its sub-buffers, no other
   operations should be performed on the ring buffer. That includes
   reading it. But the locking only grabbed the buffer->mutex that keeps
   some operations from touching the ring buffer. It also must hold the
   cpu_buffer->reader_lock as well when updates happen as other paths
   use that to do some operations on the ring buffer.

* tag 'trace-ringbuffer-v6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Fix reader locking when changing the sub buffer order
  ring-buffer: Fix refcount setting of boot mapped buffers
2024-10-15 11:18:44 -07:00
Dimitar Kanaliev
ae67b9fb8c bpf: Fix truncation bug in coerce_reg_to_size_sx()
coerce_reg_to_size_sx() updates the register state after a sign-extension
operation. However, there's a bug in the assignment order of the unsigned
min/max values, leading to incorrect truncation:

  0: (85) call bpf_get_prandom_u32#7    ; R0_w=scalar()
  1: (57) r0 &= 1                       ; R0_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=1,var_off=(0x0; 0x1))
  2: (07) r0 += 254                     ; R0_w=scalar(smin=umin=smin32=umin32=254,smax=umax=smax32=umax32=255,var_off=(0xfe; 0x1))
  3: (bf) r0 = (s8)r0                   ; R0_w=scalar(smin=smin32=-2,smax=smax32=-1,umin=umin32=0xfffffffe,umax=0xffffffff,var_off=(0xfffffffffffffffe; 0x1))

In the current implementation, the unsigned 32-bit min/max values
(u32_min_value and u32_max_value) are assigned directly from the 64-bit
signed min/max values (s64_min and s64_max):

  reg->umin_value = reg->u32_min_value = s64_min;
  reg->umax_value = reg->u32_max_value = s64_max;

Due to the chain assigmnent, this is equivalent to:

  reg->u32_min_value = s64_min;  // Unintended truncation
  reg->umin_value = reg->u32_min_value;
  reg->u32_max_value = s64_max;  // Unintended truncation
  reg->umax_value = reg->u32_max_value;

Fixes: 1f9a1ea821 ("bpf: Support new sign-extension load insns")
Reported-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Reported-by: Zac Ecob <zacecob@protonmail.com>
Signed-off-by: Dimitar Kanaliev <dimitar.kanaliev@siteground.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Reviewed-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://lore.kernel.org/r/20241014121155.92887-2-dimitar.kanaliev@siteground.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-15 11:16:24 -07:00
Petr Pavlu
09661f75e7 ring-buffer: Fix reader locking when changing the sub buffer order
The function ring_buffer_subbuf_order_set() updates each
ring_buffer_per_cpu and installs new sub buffers that match the requested
page order. This operation may be invoked concurrently with readers that
rely on some of the modified data, such as the head bit (RB_PAGE_HEAD), or
the ring_buffer_per_cpu.pages and reader_page pointers. However, no
exclusive access is acquired by ring_buffer_subbuf_order_set(). Modifying
the mentioned data while a reader also operates on them can then result in
incorrect memory access and various crashes.

Fix the problem by taking the reader_lock when updating a specific
ring_buffer_per_cpu in ring_buffer_subbuf_order_set().

Link: https://lore.kernel.org/linux-trace-kernel/20240715145141.5528-1-petr.pavlu@suse.com/
Link: https://lore.kernel.org/linux-trace-kernel/20241010195849.2f77cc3f@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20241011112850.17212b25@gandalf.local.home/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241015112440.26987-1-petr.pavlu@suse.com
Fixes: 8e7b58c27b ("ring-buffer: Just update the subbuffers when changing their allocation order")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-15 11:18:51 -04:00
Jinjie Ruan
d8794ac20a posix-clock: Fix missing timespec64 check in pc_clock_settime()
As Andrew pointed out, it will make sense that the PTP core
checked timespec64 struct's tv_sec and tv_nsec range before calling
ptp->info->settime64().

As the man manual of clock_settime() said, if tp.tv_sec is negative or
tp.tv_nsec is outside the range [0..999,999,999], it should return EINVAL,
which include dynamic clocks which handles PTP clock, and the condition is
consistent with timespec64_valid(). As Thomas suggested, timespec64_valid()
only check the timespec is valid, but not ensure that the time is
in a valid range, so check it ahead using timespec64_valid_strict()
in pc_clock_settime() and return -EINVAL if not valid.

There are some drivers that use tp->tv_sec and tp->tv_nsec directly to
write registers without validity checks and assume that the higher layer
has checked it, which is dangerous and will benefit from this, such as
hclge_ptp_settime(), igb_ptp_settime_i210(), _rcar_gen4_ptp_settime(),
and some drivers can remove the checks of itself.

Cc: stable@vger.kernel.org
Fixes: 0606f422b4 ("posix clocks: Introduce dynamic clocks")
Acked-by: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Andrew Lunn <andrew@lunn.ch>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patch.msgid.link/20241009072302.1754567-2-ruanjinjie@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-14 17:22:43 -07:00
David Vernet
60e339be10 sched_ext: Remove unnecessary cpu_relax()
As described in commit b07996c7ab ("sched_ext: Don't hold
scx_tasks_lock for too long"), we're doing a cond_resched() every 32
calls to scx_task_iter_next() to avoid RCU and other stalls. That commit
also added a cpu_relax() to the codepath where we drop and reacquire the
lock, but as Waiman described in [0], cpu_relax() should only be
necessary in busy loops to avoid pounding on a cacheline (or to allow a
hypertwin to more fully utilize a core).

Let's remove the unnecessary cpu_relax().

[0]: https://lore.kernel.org/all/35b3889b-904a-4d26-981f-c8aa1557a7c7@redhat.com/

Cc: Waiman Long <llong@redhat.com>
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-10-14 13:23:49 -10:00
Steven Rostedt
2cf9733891 ring-buffer: Fix refcount setting of boot mapped buffers
A ring buffer which has its buffered mapped at boot up to fixed memory
should not be freed. Other buffers can be. The ref counting setup was
wrong for both. It made the not mapped buffers ref count have zero, and the
boot mapped buffer a ref count of 1. But an normally allocated buffer
should be 1, where it can be removed.

Keep the ref count of a normal boot buffer with its setup ref count (do
not decrement it), and increment the fixed memory boot mapped buffer's ref
count.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241011165224.33dd2624@gandalf.local.home
Fixes: e645535a95 ("tracing: Add option to use memmapped memory for trace boot instance")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-14 14:30:59 -04:00
Peter Zijlstra
cd9626e9eb sched/fair: Fix external p->on_rq users
Sean noted that ever since commit 152e11f6df ("sched/fair: Implement
delayed dequeue") KVM's preemption notifiers have started
mis-classifying preemption vs blocking.

Notably p->on_rq is no longer sufficient to determine if a task is
runnable or blocked -- the aforementioned commit introduces tasks that
remain on the runqueue even through they will not run again, and
should be considered blocked for many cases.

Add the task_is_runnable() helper to classify things and audit all
external users of the p->on_rq state. Also add a few comments.

Fixes: 152e11f6df ("sched/fair: Implement delayed dequeue")
Reported-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20241010091843.GK33184@noisy.programming.kicks-ass.net
2024-10-14 09:14:35 +02:00
Johannes Weiner
c650812419 sched/psi: Fix mistaken CPU pressure indication after corrupted task state bug
Since sched_delayed tasks remain queued even after blocking, the load
balancer can migrate them between runqueues while PSI considers them
to be asleep. As a result, it misreads the migration requeue followed
by a wakeup as a double queue:

  psi: inconsistent task state! task=... cpu=... psi_flags=4 clear=. set=4

First, call psi_enqueue() after p->sched_class->enqueue_task(). A
wakeup will clear p->se.sched_delayed while a migration will not, so
psi can use that flag to tell them apart.

Then teach psi to migrate any "sleep" state when delayed-dequeue tasks
are being migrated.

Delayed-dequeue tasks can be revived by ttwu_runnable(), which will
call down with a new ENQUEUE_DELAYED. Instead of further complicating
the wakeup conditional in enqueue_task(), identify migration contexts
instead and default to wakeup handling for all other cases.

It's not just the warning in dmesg, the task state corruption causes a
permanent CPU pressure indication, which messes with workload/machine
health monitoring.

Debugged-by-and-original-fix-by: K Prateek Nayak <kprateek.nayak@amd.com>
Fixes: 152e11f6df ("sched/fair: Implement delayed dequeue")
Closes: https://lore.kernel.org/lkml/20240830123458.3557-1-spasswolf@web.de/
Closes: https://lore.kernel.org/all/cd67fbcd-d659-4822-bb90-7e8fbb40a856@molgen.mpg.de/
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lkml.kernel.org/r/20241010193712.GC181795@cmpxchg.org
2024-10-14 09:11:42 +02:00
Linus Torvalds
a1029768f3 RCU fix for v6.12
Fix rcuog kthread wakeup invocation from softirq context on a CPU
 which has been marked offline. This can happen when new callbacks
 are enqueued from a softirq on an offline CPU before it calls
 rcutree_report_cpu_dead(). When this happens on NOCB configuration,
 the rcuog wake-up is deferred through an IPI to an online CPU.
 This is done to avoid call into the scheduler which can risk
 arming the RT-bandwidth after hrtimers have been migrated out
 and disabled. However, doing IPI call from softirq is not allowed
 Fix this by forcing deferred rcuog wakeup through the NOCB timer
 when the CPU is offline.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQSi2tPIQIc2VEtjarIAHS7/6Z0wpQUCZwjWYAAKCRAAHS7/6Z0w
 pQ8iAP9vbhWlWuwlfZqQJK8Xb5b0kVx3nJjAin/5pY/lbWV7IgEA1DUzTAZKXU5Z
 yZmjM3l9RpMAxLSgevJKoJD+vR0POQA=
 =EVin
 -----END PGP SIGNATURE-----

Merge tag 'rcu.fixes.6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux

Pull RCU fix from Neeraj Upadhyay:
 "Fix rcuog kthread wakeup invocation from softirq context on a CPU
  which has been marked offline.

  This can happen when new callbacks are enqueued from a softirq on an
  offline CPU before it calls rcutree_report_cpu_dead(). When this
  happens on NOCB configuration, the rcuog wake-up is deferred through
  an IPI to an online CPU. This is done to avoid call into the scheduler
  which can risk arming the RT-bandwidth after hrtimers have been
  migrated out and disabled.

  However, doing IPI call from softirq is not allowed: Fix this by
  forcing deferred rcuog wakeup through the NOCB timer when the CPU is
  offline"

* tag 'rcu.fixes.6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux:
  rcu/nocb: Fix rcuog wake-up from offline softirq
2024-10-11 14:42:27 -07:00
Peter Zijlstra
f5aaff7bfa sched/core: Dequeue PSI signals for blocked tasks that are delayed
psi_dequeue() in for blocked task expects psi_sched_switch() to clear
the TSK_.*RUNNING PSI flags and set the TSK_IOWAIT flags however
psi_sched_switch() uses "!task_on_rq_queued(prev)" to detect if the task
is blocked or still runnable which is no longer true with DELAY_DEQUEUE
since a blocking task can be left queued on the runqueue.

This can lead to PSI splats similar to:

    psi: inconsistent task state! task=... cpu=... psi_flags=4 clear=0 set=4

when the task is requeued since the TSK_RUNNING flag was not cleared
when the task was blocked.

Explicitly communicate that the task was blocked to psi_sched_switch()
even if it was delayed and is still on the runqueue.

  [ prateek: Broke off the relevant part from [1], commit message ]

Fixes: 152e11f6df ("sched/fair: Implement delayed dequeue")
Closes: https://lore.kernel.org/lkml/20240830123458.3557-1-spasswolf@web.de/
Closes: https://lore.kernel.org/all/cd67fbcd-d659-4822-bb90-7e8fbb40a856@molgen.mpg.de/
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Not-yet-signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lore.kernel.org/lkml/20241004123506.GR18071@noisy.programming.kicks-ass.net/ [1]
2024-10-11 10:49:33 +02:00
Peter Zijlstra
98442f0ccd sched: Fix delayed_dequeue vs switched_from_fair()
Commit 2e0199df25 ("sched/fair: Prepare exit/cleanup paths for delayed_dequeue")
and its follow up fixes try to deal with a rather unfortunate
situation where is task is enqueued in a new class, even though it
shouldn't have been. Mostly because the existing ->switched_to/from()
hooks are in the wrong place for this case.

This all led to Paul being able to trigger failures at something like
once per 10k CPU hours of RCU torture.

For now, do the ugly thing and move the code to the right place by
ignoring the switch hooks.

Note: Clean up the whole sched_class::switch*_{to,from}() thing.

Fixes: 2e0199df25 ("sched/fair: Prepare exit/cleanup paths for delayed_dequeue")
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20241003185037.GA5594@noisy.programming.kicks-ass.net
2024-10-11 10:49:32 +02:00
Waiman Long
73ab05aa46 sched/core: Disable page allocation in task_tick_mm_cid()
With KASAN and PREEMPT_RT enabled, calling task_work_add() in
task_tick_mm_cid() may cause the following splat.

[   63.696416] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
[   63.696416] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 610, name: modprobe
[   63.696416] preempt_count: 10001, expected: 0
[   63.696416] RCU nest depth: 1, expected: 1

This problem is caused by the following call trace.

  sched_tick() [ acquire rq->__lock ]
   -> task_tick_mm_cid()
    -> task_work_add()
     -> __kasan_record_aux_stack()
      -> kasan_save_stack()
       -> stack_depot_save_flags()
        -> alloc_pages_mpol_noprof()
         -> __alloc_pages_noprof()
	  -> get_page_from_freelist()
	   -> rmqueue()
	    -> rmqueue_pcplist()
	     -> __rmqueue_pcplist()
	      -> rmqueue_bulk()
	       -> rt_spin_lock()

The rq lock is a raw_spinlock_t. We can't sleep while holding
it. IOW, we can't call alloc_pages() in stack_depot_save_flags().

The task_tick_mm_cid() function with its task_work_add() call was
introduced by commit 223baf9d17 ("sched: Fix performance regression
introduced by mm_cid") in v6.4 kernel.

Fortunately, there is a kasan_record_aux_stack_noalloc() variant that
calls stack_depot_save_flags() while not allowing it to allocate
new pages.  To allow task_tick_mm_cid() to use task_work without
page allocation, a new TWAF_NO_ALLOC flag is added to enable calling
kasan_record_aux_stack_noalloc() instead of kasan_record_aux_stack()
if set. The task_tick_mm_cid() function is modified to add this new flag.

The possible downside is the missing stack trace in a KASAN report due
to new page allocation required when task_work_add_noallloc() is called
which should be rare.

Fixes: 223baf9d17 ("sched: Fix performance regression introduced by mm_cid")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20241010014432.194742-1-longman@redhat.com
2024-10-11 10:49:32 +02:00
Phil Auld
d16b7eb6f5 sched/deadline: Use hrtick_enabled_dl() before start_hrtick_dl()
The deadline server code moved one of the start_hrtick_dl() calls
but dropped the dl specific hrtick_enabled check. This causes hrticks
to get armed even when sched_feat(HRTICK_DL) is false. Fix it.

Fixes: 63ba8422f8 ("sched/deadline: Introduce deadline servers")
Signed-off-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/r/20241004123729.460668-1-pauld@redhat.com
2024-10-11 10:49:32 +02:00
Tyrone Wu
ad6b5b6ea9 bpf: Fix unpopulated path_size when uprobe_multi fields unset
Previously when retrieving `bpf_link_info.uprobe_multi` with `path` and
`path_size` fields unset, the `path_size` field is not populated
(remains 0). This behavior was inconsistent with how other input/output
string buffer fields work, as the field should be populated in cases
when:
- both buffer and length are set (currently works as expected)
- both buffer and length are unset (not working as expected)

This patch now fills the `path_size` field when `path` and `path_size`
are unset.

Fixes: e56fdbfb06 ("bpf: Add link_info support for uprobe multi link")
Signed-off-by: Tyrone Wu <wudevelops@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241011000803.681190-1-wudevelops@gmail.com
2024-10-10 19:11:28 -07:00
Tejun Heo
b07996c7ab sched_ext: Don't hold scx_tasks_lock for too long
While enabling and disabling a BPF scheduler, every task is iterated a
couple times by walking scx_tasks. Except for one, all iterations keep
holding scx_tasks_lock. On multi-socket systems under heavy rq lock
contention and high number of threads, this can can lead to RCU and other
stalls.

The following is triggered on a 2 x AMD EPYC 7642 system (192 logical CPUs)
running `stress-ng --workload 150 --workload-threads 10` with >400k idle
threads and RCU stall period reduced to 5s:

  rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
  rcu:     91-...!: (10 ticks this GP) idle=0754/1/0x4000000000000000 softirq=18204/18206 fqs=17
  rcu:     186-...!: (17 ticks this GP) idle=ec54/1/0x4000000000000000 softirq=25863/25866 fqs=17
  rcu:     (detected by 80, t=10042 jiffies, g=89305, q=33 ncpus=192)
  Sending NMI from CPU 80 to CPUs 91:
  NMI backtrace for cpu 91
  CPU: 91 UID: 0 PID: 284038 Comm: sched_ext_ops_h Kdump: loaded Not tainted 6.12.0-rc2-work-g6bf5681f7ee2-dirty #471
  Hardware name: Supermicro Super Server/H11DSi, BIOS 2.8 12/14/2023
  Sched_ext: simple (disabling+all)
  RIP: 0010:queued_spin_lock_slowpath+0x17b/0x2f0
  Code: 02 c0 10 03 00 83 79 08 00 75 08 f3 90 83 79 08 00 74 f8 48 8b 11 48 85 d2 74 09 0f 0d 0a eb 0a 31 d2 eb 06 31 d2 eb 02 f3 90 <8b> 07 66 85 c0 75 f7 39 d8 75 0d be 01 00 00 00 89 d8 f0 0f b1 37
  RSP: 0018:ffffc9000fadfcb8 EFLAGS: 00000002
  RAX: 0000000001700001 RBX: 0000000001700000 RCX: ffff88bfcaaf10c0
  RDX: 0000000000000000 RSI: 0000000000000101 RDI: ffff88bfca8f0080
  RBP: 0000000001700000 R08: 0000000000000090 R09: ffffffffffffffff
  R10: ffff88a74761b268 R11: 0000000000000000 R12: ffff88a6b6765460
  R13: ffffc9000fadfd60 R14: ffff88bfca8f0080 R15: ffff88bfcaac0000
  FS:  0000000000000000(0000) GS:ffff88bfcaac0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f5c55f526a0 CR3: 0000000afd474000 CR4: 0000000000350eb0
  Call Trace:
   <NMI>
   </NMI>
   <TASK>
   do_raw_spin_lock+0x9c/0xb0
   task_rq_lock+0x50/0x190
   scx_task_iter_next_locked+0x157/0x170
   scx_ops_disable_workfn+0x2c2/0xbf0
   kthread_worker_fn+0x108/0x2a0
   kthread+0xeb/0x110
   ret_from_fork+0x36/0x40
   ret_from_fork_asm+0x1a/0x30
   </TASK>
  Sending NMI from CPU 80 to CPUs 186:
  NMI backtrace for cpu 186
  CPU: 186 UID: 0 PID: 51248 Comm: fish Kdump: loaded Not tainted 6.12.0-rc2-work-g6bf5681f7ee2-dirty #471

scx_task_iter can safely drop locks while iterating. Make
scx_task_iter_next() drop scx_tasks_lock every 32 iterations to avoid
stalls.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-10-10 11:41:44 -10:00
Tejun Heo
967da57832 sched_ext: Move scx_tasks_lock handling into scx_task_iter helpers
Iterating with scx_task_iter involves scx_tasks_lock and optionally the rq
lock of the task being iterated. Both locks can be released during iteration
and the iteration can be continued after re-grabbing scx_tasks_lock.
Currently, all lock handling is pushed to the caller which is a bit
cumbersome and makes it difficult to add lock-aware behaviors. Make the
scx_task_iter helpers handle scx_tasks_lock.

- scx_task_iter_init/scx_taks_iter_exit() now grabs and releases
  scx_task_lock, respectively. Renamed to
  scx_task_iter_start/scx_task_iter_stop() to more clearly indicate that
  there are non-trivial side-effects.

- Add __ prefix to scx_task_iter_rq_unlock() to indicate that the function
  is internal.

- Add scx_task_iter_unlock/relock(). The former drops both rq lock (if held)
  and scx_tasks_lock and the latter re-locks only scx_tasks_lock.

This doesn't cause behavior changes and will be used to implement stall
avoidance.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-10-10 11:41:44 -10:00
Tejun Heo
aebe7ae4cb sched_ext: bypass mode shouldn't depend on ops.select_cpu()
Bypass mode was depending on ops.select_cpu() which can't be trusted as with
the rest of the BPF scheduler. Always enable and use scx_select_cpu_dfl() in
bypass mode.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-10-10 11:41:44 -10:00
Tejun Heo
cc3e1caca9 sched_ext: Move scx_buildin_idle_enabled check to scx_bpf_select_cpu_dfl()
Move the sanity check from the inner function scx_select_cpu_dfl() to the
exported kfunc scx_bpf_select_cpu_dfl(). This doesn't cause behavior
differences and will allow using scx_select_cpu_dfl() in bypass mode
regardless of scx_builtin_idle_enabled.

Signed-off-by: Tejun Heo <tj@kernel.org>
2024-10-10 11:41:44 -10:00
Tejun Heo
3fdb9ebcec sched_ext: Start schedulers with consistent p->scx.slice values
The disable path caps p->scx.slice to SCX_SLICE_DFL. As the field is already
being ignored at this stage during disable, the only effect this has is that
when the next BPF scheduler is loaded, it won't see unreasonable left-over
slices. Ultimately, this shouldn't matter but it's better to start in a
known state. Drop p->scx.slice capping from the disable path and instead
reset it to SCX_SLICE_DFL in the enable path.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-10-10 11:41:44 -10:00
Tejun Heo
54baa7ac0c Revert "sched_ext: Use shorter slice while bypassing"
This reverts commit 6f34d8d382.

Slice length is ignored while bypassing and tasks are switched on every tick
and thus the patch does not make any difference. The perceived difference
was from test noise.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-10-10 11:41:44 -10:00
Linus Torvalds
0edab8d132 ring-buffer: Fix for 6.12
- Do not have boot-mapped buffers use CPU hotplug callbacks
 
   When a ring buffer is mapped to memory assigned at boot, it
   also splits it up evenly between the possible CPUs. But the
   allocation code still attached a CPU notifier callback to this
   ring buffer. When a CPU is added, the callback will happen and
   another per-cpu buffer is created for the ring buffer. But for
   boot mapped buffers, there is no room to add another one (as
   they were all created already). The result of calling the CPU
   hotplug notifier on a boot mapped ring buffer is unpredictable
   and could lead to a system crash. If the ring buffer is boot mapped
   simply do not attach the CPU notifier to it.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZwfxchQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qrduAQC2xZ+lqeoDJ3o+H201bqshgx/YDANF
 p1q1BFmC0yFlOAD/XB/I9o4UFNHAb9D05zPADS+8bF1RxdisJJjqUae1TgM=
 =lBZ/
 -----END PGP SIGNATURE-----

Merge tag 'trace-ringbuffer-v6.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fix from Steven Rostedt:
 "Ring-buffer fix: do not have boot-mapped buffers use CPU hotplug
  callbacks

  When a ring buffer is mapped to memory assigned at boot, it also
  splits it up evenly between the possible CPUs. But the allocation code
  still attached a CPU notifier callback to this ring buffer. When a CPU
  is added, the callback will happen and another per-cpu buffer is
  created for the ring buffer.

  But for boot mapped buffers, there is no room to add another one (as
  they were all created already). The result of calling the CPU hotplug
  notifier on a boot mapped ring buffer is unpredictable and could lead
  to a system crash.

  If the ring buffer is boot mapped simply do not attach the CPU
  notifier to it"

* tag 'trace-ringbuffer-v6.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Do not have boot mapped buffers hook to CPU hotplug
2024-10-10 12:25:32 -07:00
Toke Høiland-Jørgensen
6cb86a0fde bpf: fix kfunc btf caching for modules
The verifier contains a cache for looking up module BTF objects when
calling kfuncs defined in modules. This cache uses a 'struct
bpf_kfunc_btf_tab', which contains a sorted list of BTF objects that
were already seen in the current verifier run, and the BTF objects are
looked up by the offset stored in the relocated call instruction using
bsearch().

The first time a given offset is seen, the module BTF is loaded from the
file descriptor passed in by libbpf, and stored into the cache. However,
there's a bug in the code storing the new entry: it stores a pointer to
the new cache entry, then calls sort() to keep the cache sorted for the
next lookup using bsearch(), and then returns the entry that was just
stored through the stored pointer. However, because sort() modifies the
list of entries in place *by value*, the stored pointer may no longer
point to the right entry, in which case the wrong BTF object will be
returned.

The end result of this is an intermittent bug where, if a BPF program
calls two functions with the same signature in two different modules,
the function from the wrong module may sometimes end up being called.
Whether this happens depends on the order of the calls in the BPF
program (as that affects whether sort() reorders the array of BTF
objects), making it especially hard to track down. Simon, credited as
reporter below, spent significant effort analysing and creating a
reproducer for this issue. The reproducer is added as a selftest in a
subsequent patch.

The fix is straight forward: simply don't use the stored pointer after
calling sort(). Since we already have an on-stack pointer to the BTF
object itself at the point where the function return, just use that, and
populate it from the cache entry in the branch where the lookup
succeeds.

Fixes: 2357672c54 ("bpf: Introduce BPF support for kernel module function calls")
Reported-by: Simon Sundberg <simon.sundberg@kau.se>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20241010-fix-kfunc-btf-caching-for-modules-v2-1-745af6c1af98@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-10 10:44:03 -07:00
Frederic Weisbecker
f7345ccc62 rcu/nocb: Fix rcuog wake-up from offline softirq
After a CPU has set itself offline and before it eventually calls
rcutree_report_cpu_dead(), there are still opportunities for callbacks
to be enqueued, for example from a softirq. When that happens on NOCB,
the rcuog wake-up is deferred through an IPI to an online CPU in order
not to call into the scheduler and risk arming the RT-bandwidth after
hrtimers have been migrated out and disabled.

But performing a synchronized IPI from a softirq is buggy as reported in
the following scenario:

        WARNING: CPU: 1 PID: 26 at kernel/smp.c:633 smp_call_function_single
        Modules linked in: rcutorture torture
        CPU: 1 UID: 0 PID: 26 Comm: migration/1 Not tainted 6.11.0-rc1-00012-g9139f93209d1 #1
        Stopper: multi_cpu_stop+0x0/0x320 <- __stop_cpus+0xd0/0x120
        RIP: 0010:smp_call_function_single
        <IRQ>
        swake_up_one_online
        __call_rcu_nocb_wake
        __call_rcu_common
        ? rcu_torture_one_read
        call_timer_fn
        __run_timers
        run_timer_softirq
        handle_softirqs
        irq_exit_rcu
        ? tick_handle_periodic
        sysvec_apic_timer_interrupt
        </IRQ>

Fix this with forcing deferred rcuog wake up through the NOCB timer when
the CPU is offline. The actual wake up will happen from
rcutree_report_cpu_dead().

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202409231644.4c55582d-lkp@intel.com
Fixes: 9139f93209 ("rcu/nocb: Fix RT throttling hrtimer armed from offline CPU")
Reviewed-by: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
2024-10-10 22:18:19 +05:30
Honglei Wang
c425180d88 sched_ext: use correct function name in pick_task_scx() warning message
pick_next_task_scx() was turned into pick_task_scx() since
commit 753e2836d1 ("sched_ext: Unify regular and core-sched pick
task paths"). Update the outdated message.

Signed-off-by: Honglei Wang <jameshongleiwang@126.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-10-10 06:35:28 -10:00
Tyrone Wu
4deecdd29c bpf: fix unpopulated name_len field in perf_event link info
Previously when retrieving `bpf_link_info.perf_event` for
kprobe/uprobe/tracepoint, the `name_len` field was not populated by the
kernel, leaving it to reflect the value initially set by the user. This
behavior was inconsistent with how other input/output string buffer
fields function (e.g. `raw_tracepoint.tp_name_len`).

This patch fills `name_len` with the actual size of the string name.

Fixes: 1b715e1b0e ("bpf: Support ->fill_link_info for perf_event")
Signed-off-by: Tyrone Wu <wudevelops@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20241008164312.46269-1-wudevelops@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-09 18:17:16 -07:00
Rik van Riel
434247637c bpf: use kvzmalloc to allocate BPF verifier environment
The kzmalloc call in bpf_check can fail when memory is very fragmented,
which in turn can lead to an OOM kill.

Use kvzmalloc to fall back to vmalloc when memory is too fragmented to
allocate an order 3 sized bpf verifier environment.

Admittedly this is not a very common case, and only happens on systems
where memory has already been squeezed close to the limit, but this does
not seem like much of a hot path, and it's a simple enough fix.

Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Link: https://lore.kernel.org/r/20241008170735.16766766@imladris.surriel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-09 18:13:05 -07:00
Hou Tao
797d73ee23 bpf: Check the remaining info_cnt before repeating btf fields
When trying to repeat the btf fields for array of nested struct, it
doesn't check the remaining info_cnt. The following splat will be
reported when the value of ret * nelems is greater than BTF_FIELDS_MAX:

  ------------[ cut here ]------------
  UBSAN: array-index-out-of-bounds in ../kernel/bpf/btf.c:3951:49
  index 11 is out of range for type 'btf_field_info [11]'
  CPU: 6 UID: 0 PID: 411 Comm: test_progs ...... 6.11.0-rc4+ #1
  Tainted: [O]=OOT_MODULE
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ...
  Call Trace:
   <TASK>
   dump_stack_lvl+0x57/0x70
   dump_stack+0x10/0x20
   ubsan_epilogue+0x9/0x40
   __ubsan_handle_out_of_bounds+0x6f/0x80
   ? kallsyms_lookup_name+0x48/0xb0
   btf_parse_fields+0x992/0xce0
   map_create+0x591/0x770
   __sys_bpf+0x229/0x2410
   __x64_sys_bpf+0x1f/0x30
   x64_sys_call+0x199/0x9f0
   do_syscall_64+0x3b/0xc0
   entry_SYSCALL_64_after_hwframe+0x4b/0x53
  RIP: 0033:0x7fea56f2cc5d
  ......
   </TASK>
  ---[ end trace ]---

Fix it by checking the remaining info_cnt in btf_repeat_fields() before
repeating the btf fields.

Fixes: 64e8ee8148 ("bpf: look into the types of the fields of a struct type recursively.")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20241008071114.3718177-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-09 16:32:46 -07:00
Linus Torvalds
d3d1556696 12 hotfixes, 5 of which are c:stable. All singletons, about half of which
are MM.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZwcILgAKCRDdBJ7gKXxA
 jjnMAQDRl+UfscRUeMippi7wnL3ee6MKyhhZVOhoxP24uB7yBwD/Ulq4oE+mLHml
 YTlK/wj5qTZIsdxGaBzM1yifqp3L7gU=
 =lFmJ
 -----END PGP SIGNATURE-----

Merge tag 'mm-hotfixes-stable-2024-10-09-15-46' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "12 hotfixes, 5 of which are c:stable. All singletons, about half of
  which are MM"

* tag 'mm-hotfixes-stable-2024-10-09-15-46' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm: zswap: delete comments for "value" member of 'struct zswap_entry'.
  CREDITS: sort alphabetically by name
  secretmem: disable memfd_secret() if arch cannot set direct map
  .mailmap: update Fangrui's email
  mm/huge_memory: check pmd_special() only after pmd_present()
  resource, kunit: fix user-after-free in resource_test_region_intersects()
  fs/proc/kcore.c: allow translation of physical memory addresses
  selftests/mm: fix incorrect buffer->mirror size in hmm2 double_map test
  device-dax: correct pgoff align in dax_set_mapping()
  kthread: unpark only parked kthread
  Revert "mm: introduce PF_MEMALLOC_NORECLAIM, PF_MEMALLOC_NOWARN"
  bcachefs: do not use PF_MEMALLOC_NORECLAIM
2024-10-09 16:01:40 -07:00
Huang Ying
0665d7a39b resource, kunit: fix user-after-free in resource_test_region_intersects()
In resource_test_insert_resource(), the pointer is used in error message
after kfree().  This is user-after-free.  To fix this, we need to call
kunit_add_action_or_reset() to schedule memory freeing after usage.  But
kunit_add_action_or_reset() itself may fail and free the memory.  So, its
return value should be checked and abort the test for failure.  Then, we
found that other usage of kunit_add_action_or_reset() in
resource_test_region_intersects() needs to be fixed too.  We fix all these
user-after-free bugs in this patch.

Link: https://lkml.kernel.org/r/20240930070611.353338-1-ying.huang@intel.com
Fixes: 99185c10d5 ("resource, kunit: add test case for region_intersects()")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reported-by: Kees Bakker <kees@ijzerbout.nl>
Closes: https://lore.kernel.org/lkml/87ldzaotcg.fsf@yhuang6-desk2.ccr.corp.intel.com/
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-09 12:47:19 -07:00
Frederic Weisbecker
214e01ad4e kthread: unpark only parked kthread
Calling into kthread unparking unconditionally is mostly harmless when
the kthread is already unparked. The wake up is then simply ignored
because the target is not in TASK_PARKED state.

However if the kthread is per CPU, the wake up is preceded by a call
to kthread_bind() which expects the task to be inactive and in
TASK_PARKED state, which obviously isn't the case if it is unparked.

As a result, calling kthread_stop() on an unparked per-cpu kthread
triggers such a warning:

	WARNING: CPU: 0 PID: 11 at kernel/kthread.c:525 __kthread_bind_mask kernel/kthread.c:525
	 <TASK>
	 kthread_stop+0x17a/0x630 kernel/kthread.c:707
	 destroy_workqueue+0x136/0xc40 kernel/workqueue.c:5810
	 wg_destruct+0x1e2/0x2e0 drivers/net/wireguard/device.c:257
	 netdev_run_todo+0xe1a/0x1000 net/core/dev.c:10693
	 default_device_exit_batch+0xa14/0xa90 net/core/dev.c:11769
	 ops_exit_list net/core/net_namespace.c:178 [inline]
	 cleanup_net+0x89d/0xcc0 net/core/net_namespace.c:640
	 process_one_work kernel/workqueue.c:3231 [inline]
	 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
	 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393
	 kthread+0x2f0/0x390 kernel/kthread.c:389
	 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
	 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
	 </TASK>

Fix this with skipping unecessary unparking while stopping a kthread.

Link: https://lkml.kernel.org/r/20240913214634.12557-1-frederic@kernel.org
Fixes: 5c25b5ff89 ("workqueue: Tag bound workers with KTHREAD_IS_PER_CPU")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reported-by: syzbot+943d34fa3cf2191e3068@syzkaller.appspotmail.com
Tested-by: syzbot+943d34fa3cf2191e3068@syzkaller.appspotmail.com
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-09 12:47:19 -07:00
Steven Rostedt
912da2c384 ring-buffer: Do not have boot mapped buffers hook to CPU hotplug
The boot mapped ring buffer has its buffer mapped at a fixed location
found at boot up. It is not dynamic. It cannot grow or be expanded when
new CPUs come online.

Do not hook fixed memory mapped ring buffers to the CPU hotplug callback,
otherwise it can cause a crash when it tries to add the buffer to the
memory that is already fully occupied.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241008143242.25e20801@gandalf.local.home
Fixes: be68d63a13 ("ring-buffer: Add ring_buffer_alloc_range()")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-09 09:24:35 -04:00
Linus Torvalds
75b607fab3 sched_ext: Fixes for v6.12-rc2
- ops.enqueue() didn't have a way to tell whether select_task_rq_scx() and
   thus ops.select() were skipped. Some schedulers were incorrectly using
   SCX_ENQ_WAKEUP. Add SCX_ENQ_CPU_SELECTED and fix scx_qmap using it.
 
 - Remove a spurious WARN_ON_ONCE() in scx_cgroup_exit().
 
 - Fix error information clobbering during load.
 
 - Add missing __weak markers to BPF helper declarations.
 
 - Doc update.
 -----BEGIN PGP SIGNATURE-----
 
 iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCZwWKkA4cdGpAa2VybmVs
 Lm9yZwAKCRCxYfJx3gVYGelnAQDTA8GSIahTEHKM0c3yXE6K1/M56zo8Spp5OOA7
 kXHR3AD/Y0RcXgaCvMI13aozmQWq756gyB6/qczN0+X3jx6wZwI=
 =6xbe
 -----END PGP SIGNATURE-----

Merge tag 'sched_ext-for-6.12-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext fixes from Tejun Heo:

 - ops.enqueue() didn't have a way to tell whether select_task_rq_scx()
   and thus ops.select() were skipped. Some schedulers were incorrectly
   using SCX_ENQ_WAKEUP. Add SCX_ENQ_CPU_SELECTED and fix scx_qmap using
   it.

 - Remove a spurious WARN_ON_ONCE() in scx_cgroup_exit()

 - Fix error information clobbering during load

 - Add missing __weak markers to BPF helper declarations

 - Doc update

* tag 'sched_ext-for-6.12-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: Documentation: Update instructions for running example schedulers
  sched_ext, scx_qmap: Add and use SCX_ENQ_CPU_SELECTED
  sched/core: Add ENQUEUE_RQ_SELECTED to indicate whether ->select_task_rq() was called
  sched/core: Make select_task_rq() take the pointer to wake_flags instead of value
  sched_ext: scx_cgroup_exit() may be called without successful scx_cgroup_init()
  sched_ext: Improve error reporting during loading
  sched_ext: Add __weak markers to BPF helper function decalarations
2024-10-08 12:54:04 -07:00
Thomas Weißschuh
b24d7f0da6 bpf, lsm: Remove bpf_lsm_key_free hook
The key_free LSM hook has been removed.
Remove the corresponding BPF hook.

Avoid warnings during the build:
  BTFIDS  vmlinux
WARN: resolve_btfids: unresolved symbol bpf_lsm_key_free

Fixes: 5f8d28f6d7 ("lsm: infrastructure management of the key security blob")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20241005-lsm-key_free-v1-1-42ea801dbd63@weissschuh.net
2024-10-08 12:52:40 -07:00
Jiri Olsa
45126b155e bpf: Fix memory leak in bpf_core_apply
We need to free specs properly.

Fixes: 3d2786d65a ("bpf: correctly handle malformed BPF_CORE_TYPE_ID_LOCAL relos")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20241007160958.607434-1-jolsa@kernel.org
2024-10-07 20:28:24 -07:00
Tejun Heo
9b671793c7 sched_ext, scx_qmap: Add and use SCX_ENQ_CPU_SELECTED
scx_qmap and other schedulers in the SCX repo are using SCX_ENQ_WAKEUP to
tell whether ops.select_cpu() was called. This is incorrect as
ops.select_cpu() can be skipped in the wakeup path and leads to e.g.
incorrectly skipping direct dispatch for tasks that are bound to a single
CPU.

sched core has been updated to specify ENQUEUE_RQ_SELECTED if
->select_task_rq() was called. Map it to SCX_ENQ_CPU_SELECTED and update
scx_qmap to test it instead of SCX_ENQ_WAKEUP.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Cc: Daniel Hodges <hodges.daniel.scott@gmail.com>
Cc: Changwoo Min <multics69@gmail.com>
Cc: Andrea Righi <andrea.righi@linux.dev>
Cc: Dan Schatzberg <schatzberg.dan@gmail.com>
2024-10-07 10:16:18 -10:00
Tejun Heo
f207dc2dcd sched/core: Add ENQUEUE_RQ_SELECTED to indicate whether ->select_task_rq() was called
During ttwu, ->select_task_rq() can be skipped if only one CPU is allowed or
migration is disabled. sched_ext schedulers may perform operations such as
direct dispatch from ->select_task_rq() path and it is useful for them to
know whether ->select_task_rq() was skipped in the ->enqueue_task() path.

Currently, sched_ext schedulers are using ENQUEUE_WAKEUP for this purpose
and end up assuming incorrectly that ->select_task_rq() was called for tasks
that are bound to a single CPU or migration disabled.

Make select_task_rq() indicate whether ->select_task_rq() was called by
setting WF_RQ_SELECTED in *wake_flags and make ttwu_do_activate() map that
to ENQUEUE_RQ_SELECTED for ->enqueue_task().

This will be used by sched_ext to fix ->select_task_rq() skip detection.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-10-07 10:16:18 -10:00
Tejun Heo
b62933eee4 sched/core: Make select_task_rq() take the pointer to wake_flags instead of value
This will be used to allow select_task_rq() to indicate whether
->select_task_rq() was called by modifying *wake_flags.

This makes try_to_wake_up() call all functions that take wake_flags with
WF_TTWU set. Previously, only select_task_rq() was. Using the same flags is
more consistent, and, as the flag is only tested by ->select_task_rq()
implementations, it doesn't cause any behavior differences.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
2024-10-07 10:16:18 -10:00
Tejun Heo
ec010333ce sched_ext: scx_cgroup_exit() may be called without successful scx_cgroup_init()
568894edbe ("sched_ext: Add scx_cgroup_enabled to gate cgroup operations
and fix scx_tg_online()") assumed that scx_cgroup_exit() is only called
after scx_cgroup_init() finished successfully. This isn't true.
scx_cgroup_exit() can be called without scx_cgroup_init() being called at
all or after scx_cgroup_init() failed in the middle.

As init state is tracked per cgroup, scx_cgroup_exit() can be used safely to
clean up in all cases. Remove the incorrect WARN_ON_ONCE().

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 568894edbe ("sched_ext: Add scx_cgroup_enabled to gate cgroup operations and fix scx_tg_online()")
2024-10-04 10:12:11 -10:00
Tejun Heo
cc9877fb76 sched_ext: Improve error reporting during loading
When the BPF scheduler fails, ops.exit() allows rich error reporting through
scx_exit_info. Use scx.exit() path consistently for all failures which can
be caused by the BPF scheduler:

- scx_ops_error() is called after ops.init() and ops.cgroup_init() failure
  to record error information.

- ops.init_task() failure now uses scx_ops_error() instead of pr_err().

- The err_disable path updated to automatically trigger scx_ops_error() to
  cover cases that the error message hasn't already been generated and
  always return 0 indicating init success so that the error is reported
  through ops.exit().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Vernet <void@manifault.com>
Cc: Daniel Hodges <hodges.daniel.scott@gmail.com>
Cc: Changwoo Min <multics69@gmail.com>
Cc: Andrea Righi <andrea.righi@linux.dev>
Cc: Dan Schatzberg <schatzberg.dan@gmail.com>
2024-10-04 10:11:43 -10:00