Commit Graph

43725 Commits

Author SHA1 Message Date
Linus Torvalds
648f575d5e Merge tag 'locking_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Borislav Petkov:

 - Prevent an inconsistent futex operation leading to stale state
   exposure

* tag 'locking_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Prevent the reuse of stale pi_state
2024-01-28 10:38:16 -08:00
Linus Torvalds
0e4363ac1a Merge tag 'irq_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fix from Borislav Petkov:

 - Initialize the resend node of each IRQ descriptor, not only the first
   one

* tag 'irq_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Initialize resend_node hlist for all interrupt descriptors
2024-01-28 10:34:55 -08:00
Linus Torvalds
90db544eba Merge tag 'timers_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Borislav Petkov:

 - Preserve the number of idle calls and sleep entries across CPU
   hotplug events in order to be able to compute correct averages

 - Limit the duration of the clocksource watchdog checking interval as
   too long intervals lead to wrongly marking the TSC as unstable

* tag 'timers_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/sched: Preserve number of idle sleeps across CPU hotplug events
  clocksource: Skip watchdog check for large watchdog intervals
2024-01-28 10:33:14 -08:00
Linus Torvalds
3cb9871f81 Merge tag 'urgent-rcu.2024.01.24a' of https://github.com/neeraju/linux
Pull RCU fix from Neeraj Upadhyay:
 "This fixes RCU grace period stalls, which are observed when an
  outgoing CPU's quiescent state reporting results in wakeup of one of
  the grace period kthreads, to complete the grace period.

  If those kthreads have SCHED_FIFO policy, the wake up can indirectly
  arm the RT bandwith timer to the local offline CPU.

  Earlier migration of the hrtimers from the CPU introduced in commit
  5c0930ccaa ("hrtimers: Push pending hrtimers away from outgoing CPU
  earlier") results in this timer getting ignored.

  If the RCU grace period kthreads are waiting for RT bandwidth to be
  available, they may never be actually scheduled, resulting in RCU
  stall warnings"

* tag 'urgent-rcu.2024.01.24a' of https://github.com/neeraju/linux:
  rcu: Defer RCU kthreads wakeup when CPU is dying
2024-01-25 10:21:21 -08:00
Tim Chen
9a574ea906 tick/sched: Preserve number of idle sleeps across CPU hotplug events
Commit 71fee48f ("tick-sched: Fix idle and iowait sleeptime accounting vs
CPU hotplug") preserved total idle sleep time and iowait sleeptime across
CPU hotplug events.

Similar reasoning applies to the number of idle calls and idle sleeps to
get the proper average of sleep time per idle invocation.

Preserve those fields too.

Fixes: 71fee48f ("tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug")
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240122233534.3094238-1-tim.c.chen@linux.intel.com
2024-01-25 09:52:40 +01:00
Jiri Wiesner
6446495535 clocksource: Skip watchdog check for large watchdog intervals
There have been reports of the watchdog marking clocksources unstable on
machines with 8 NUMA nodes:

  clocksource: timekeeping watchdog on CPU373:
  Marking clocksource 'tsc' as unstable because the skew is too large:
  clocksource:   'hpet' wd_nsec: 14523447520
  clocksource:   'tsc'  cs_nsec: 14524115132

The measured clocksource skew - the absolute difference between cs_nsec
and wd_nsec - was 668 microseconds:

  cs_nsec - wd_nsec = 14524115132 - 14523447520 = 667612

The kernel used 200 microseconds for the uncertainty_margin of both the
clocksource and watchdog, resulting in a threshold of 400 microseconds (the
md variable). Both the cs_nsec and the wd_nsec value indicate that the
readout interval was circa 14.5 seconds.  The observed behaviour is that
watchdog checks failed for large readout intervals on 8 NUMA node
machines. This indicates that the size of the skew was directly proportinal
to the length of the readout interval on those machines. The measured
clocksource skew, 668 microseconds, was evaluated against a threshold (the
md variable) that is suited for readout intervals of roughly
WATCHDOG_INTERVAL, i.e. HZ >> 1, which is 0.5 second.

The intention of 2e27e793e2 ("clocksource: Reduce clocksource-skew
threshold") was to tighten the threshold for evaluating skew and set the
lower bound for the uncertainty_margin of clocksources to twice
WATCHDOG_MAX_SKEW. Later in c37e85c135 ("clocksource: Loosen clocksource
watchdog constraints"), the WATCHDOG_MAX_SKEW constant was increased to
125 microseconds to fit the limit of NTP, which is able to use a
clocksource that suffers from up to 500 microseconds of skew per second.
Both the TSC and the HPET use default uncertainty_margin. When the
readout interval gets stretched the default uncertainty_margin is no
longer a suitable lower bound for evaluating skew - it imposes a limit
that is far stricter than the skew with which NTP can deal.

The root causes of the skew being directly proportinal to the length of
the readout interval are:

  * the inaccuracy of the shift/mult pairs of clocksources and the watchdog
  * the conversion to nanoseconds is imprecise for large readout intervals

Prevent this by skipping the current watchdog check if the readout
interval exceeds 2 * WATCHDOG_INTERVAL. Considering the maximum readout
interval of 2 * WATCHDOG_INTERVAL, the current default uncertainty margin
(of the TSC and HPET) corresponds to a limit on clocksource skew of 250
ppm (microseconds of skew per second).  To keep the limit imposed by NTP
(500 microseconds of skew per second) for all possible readout intervals,
the margins would have to be scaled so that the threshold value is
proportional to the length of the actual readout interval.

As for why the readout interval may get stretched: Since the watchdog is
executed in softirq context the expiration of the watchdog timer can get
severely delayed on account of a ksoftirqd thread not getting to run in a
timely manner. Surely, a system with such belated softirq execution is not
working well and the scheduling issue should be looked into but the
clocksource watchdog should be able to deal with it accordingly.

Fixes: 2e27e793e2 ("clocksource: Reduce clocksource-skew threshold")
Suggested-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Jiri Wiesner <jwiesner@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Feng Tang <feng.tang@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240122172350.GA740@incl
2024-01-25 09:13:16 +01:00
Linus Torvalds
cf10015a24 Merge tag 'execve-v6.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull execve fixes from Kees Cook:

 - Fix error handling in begin_new_exec() (Bernd Edlinger)

 - MAINTAINERS: specifically mention ELF (Alexey Dobriyan)

 - Various cleanups related to earlier open() (Askar Safin, Kees Cook)

* tag 'execve-v6.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  exec: Distinguish in_execve from in_exec
  exec: Fix error handling in begin_new_exec()
  exec: Add do_close_execat() helper
  exec: remove useless comment
  ELF, MAINTAINERS: specifically mention ELF
2024-01-24 13:32:29 -08:00
Kees Cook
90383cc078 exec: Distinguish in_execve from in_exec
Just to help distinguish the fs->in_exec flag from the current->in_execve
flag, add comments in check_unsafe_exec() and copy_fs() for more
context. Also note that in_execve is only used by TOMOYO now.

Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-01-24 11:48:52 -08:00
Frederic Weisbecker
e787644caf rcu: Defer RCU kthreads wakeup when CPU is dying
When the CPU goes idle for the last time during the CPU down hotplug
process, RCU reports a final quiescent state for the current CPU. If
this quiescent state propagates up to the top, some tasks may then be
woken up to complete the grace period: the main grace period kthread
and/or the expedited main workqueue (or kworker).

If those kthreads have a SCHED_FIFO policy, the wake up can indirectly
arm the RT bandwith timer to the local offline CPU. Since this happens
after hrtimers have been migrated at CPUHP_AP_HRTIMERS_DYING stage, the
timer gets ignored. Therefore if the RCU kthreads are waiting for RT
bandwidth to be available, they may never be actually scheduled.

This triggers TREE03 rcutorture hangs:

	 rcu: INFO: rcu_preempt self-detected stall on CPU
	 rcu:     4-...!: (1 GPs behind) idle=9874/1/0x4000000000000000 softirq=0/0 fqs=20 rcuc=21071 jiffies(starved)
	 rcu:     (t=21035 jiffies g=938281 q=40787 ncpus=6)
	 rcu: rcu_preempt kthread starved for 20964 jiffies! g938281 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
	 rcu:     Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
	 rcu: RCU grace-period kthread stack dump:
	 task:rcu_preempt     state:R  running task     stack:14896 pid:14    tgid:14    ppid:2      flags:0x00004000
	 Call Trace:
	  <TASK>
	  __schedule+0x2eb/0xa80
	  schedule+0x1f/0x90
	  schedule_timeout+0x163/0x270
	  ? __pfx_process_timeout+0x10/0x10
	  rcu_gp_fqs_loop+0x37c/0x5b0
	  ? __pfx_rcu_gp_kthread+0x10/0x10
	  rcu_gp_kthread+0x17c/0x200
	  kthread+0xde/0x110
	  ? __pfx_kthread+0x10/0x10
	  ret_from_fork+0x2b/0x40
	  ? __pfx_kthread+0x10/0x10
	  ret_from_fork_asm+0x1b/0x30
	  </TASK>

The situation can't be solved with just unpinning the timer. The hrtimer
infrastructure and the nohz heuristics involved in finding the best
remote target for an unpinned timer would then also need to handle
enqueues from an offline CPU in the most horrendous way.

So fix this on the RCU side instead and defer the wake up to an online
CPU if it's too late for the local one.

Reported-by: Paul E. McKenney <paulmck@kernel.org>
Fixes: 5c0930ccaa ("hrtimers: Push pending hrtimers away from outgoing CPU earlier")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.iitr10@gmail.com>
2024-01-24 22:46:17 +05:30
Dawei Li
b184c8c288 genirq: Initialize resend_node hlist for all interrupt descriptors
For a CONFIG_SPARSE_IRQ=n kernel, early_irq_init() is supposed to
initialize all interrupt descriptors.

It does except for irq_desc::resend_node, which ia only initialized for the
first descriptor.

Use the indexed decriptor and not the base pointer to address that.

Fixes: bc06a9e087 ("genirq: Use hlist for managing resend handlers")
Signed-off-by: Dawei Li <dawei.li@shingroup.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240122085716.2999875-5-dawei.li@shingroup.cn
2024-01-24 14:15:41 +01:00
Petr Pavlu
2b44760609 tracing: Ensure visibility when inserting an element into tracing_map
Running the following two commands in parallel on a multi-processor
AArch64 machine can sporadically produce an unexpected warning about
duplicate histogram entries:

 $ while true; do
     echo hist:key=id.syscall:val=hitcount > \
       /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
     cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
     sleep 0.001
   done
 $ stress-ng --sysbadaddr $(nproc)

The warning looks as follows:

[ 2911.172474] ------------[ cut here ]------------
[ 2911.173111] Duplicates detected: 1
[ 2911.173574] WARNING: CPU: 2 PID: 12247 at kernel/trace/tracing_map.c:983 tracing_map_sort_entries+0x3e0/0x408
[ 2911.174702] Modules linked in: iscsi_ibft(E) iscsi_boot_sysfs(E) rfkill(E) af_packet(E) nls_iso8859_1(E) nls_cp437(E) vfat(E) fat(E) ena(E) tiny_power_button(E) qemu_fw_cfg(E) button(E) fuse(E) efi_pstore(E) ip_tables(E) x_tables(E) xfs(E) libcrc32c(E) aes_ce_blk(E) aes_ce_cipher(E) crct10dif_ce(E) polyval_ce(E) polyval_generic(E) ghash_ce(E) gf128mul(E) sm4_ce_gcm(E) sm4_ce_ccm(E) sm4_ce(E) sm4_ce_cipher(E) sm4(E) sm3_ce(E) sm3(E) sha3_ce(E) sha512_ce(E) sha512_arm64(E) sha2_ce(E) sha256_arm64(E) nvme(E) sha1_ce(E) nvme_core(E) nvme_auth(E) t10_pi(E) sg(E) scsi_mod(E) scsi_common(E) efivarfs(E)
[ 2911.174738] Unloaded tainted modules: cppc_cpufreq(E):1
[ 2911.180985] CPU: 2 PID: 12247 Comm: cat Kdump: loaded Tainted: G            E      6.7.0-default #2 1b58bbb22c97e4399dc09f92d309344f69c44a01
[ 2911.182398] Hardware name: Amazon EC2 c7g.8xlarge/, BIOS 1.0 11/1/2018
[ 2911.183208] pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[ 2911.184038] pc : tracing_map_sort_entries+0x3e0/0x408
[ 2911.184667] lr : tracing_map_sort_entries+0x3e0/0x408
[ 2911.185310] sp : ffff8000a1513900
[ 2911.185750] x29: ffff8000a1513900 x28: ffff0003f272fe80 x27: 0000000000000001
[ 2911.186600] x26: ffff0003f272fe80 x25: 0000000000000030 x24: 0000000000000008
[ 2911.187458] x23: ffff0003c5788000 x22: ffff0003c16710c8 x21: ffff80008017f180
[ 2911.188310] x20: ffff80008017f000 x19: ffff80008017f180 x18: ffffffffffffffff
[ 2911.189160] x17: 0000000000000000 x16: 0000000000000000 x15: ffff8000a15134b8
[ 2911.190015] x14: 0000000000000000 x13: 205d373432323154 x12: 5b5d313131333731
[ 2911.190844] x11: 00000000fffeffff x10: 00000000fffeffff x9 : ffffd1b78274a13c
[ 2911.191716] x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 000000000057ffa8
[ 2911.192554] x5 : ffff0012f6c24ec0 x4 : 0000000000000000 x3 : ffff2e5b72b5d000
[ 2911.193404] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0003ff254480
[ 2911.194259] Call trace:
[ 2911.194626]  tracing_map_sort_entries+0x3e0/0x408
[ 2911.195220]  hist_show+0x124/0x800
[ 2911.195692]  seq_read_iter+0x1d4/0x4e8
[ 2911.196193]  seq_read+0xe8/0x138
[ 2911.196638]  vfs_read+0xc8/0x300
[ 2911.197078]  ksys_read+0x70/0x108
[ 2911.197534]  __arm64_sys_read+0x24/0x38
[ 2911.198046]  invoke_syscall+0x78/0x108
[ 2911.198553]  el0_svc_common.constprop.0+0xd0/0xf8
[ 2911.199157]  do_el0_svc+0x28/0x40
[ 2911.199613]  el0_svc+0x40/0x178
[ 2911.200048]  el0t_64_sync_handler+0x13c/0x158
[ 2911.200621]  el0t_64_sync+0x1a8/0x1b0
[ 2911.201115] ---[ end trace 0000000000000000 ]---

The problem appears to be caused by CPU reordering of writes issued from
__tracing_map_insert().

The check for the presence of an element with a given key in this
function is:

 val = READ_ONCE(entry->val);
 if (val && keys_match(key, val->key, map->key_size)) ...

The write of a new entry is:

 elt = get_free_elt(map);
 memcpy(elt->key, key, map->key_size);
 entry->val = elt;

The "memcpy(elt->key, key, map->key_size);" and "entry->val = elt;"
stores may become visible in the reversed order on another CPU. This
second CPU might then incorrectly determine that a new key doesn't match
an already present val->key and subsequently insert a new element,
resulting in a duplicate.

Fix the problem by adding a write barrier between
"memcpy(elt->key, key, map->key_size);" and "entry->val = elt;", and for
good measure, also use WRITE_ONCE(entry->val, elt) for publishing the
element. The sequence pairs with the mentioned "READ_ONCE(entry->val);"
and the "val->key" check which has an address dependency.

The barrier is placed on a path executed when adding an element for
a new key. Subsequent updates targeting the same key remain unaffected.

From the user's perspective, the issue was introduced by commit
c193707dde ("tracing: Remove code which merges duplicates"), which
followed commit cbf4100efb ("tracing: Add support to detect and avoid
duplicates"). The previous code operated differently; it inherently
expected potential races which result in duplicates but merged them
later when they occurred.

Link: https://lore.kernel.org/linux-trace-kernel/20240122150928.27725-1-petr.pavlu@suse.com

Fixes: c193707dde ("tracing: Remove code which merges duplicates")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-01-22 17:15:40 -05:00
Linus Torvalds
4fbbed7872 Merge tag 'timers-core-2024-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
 "Updates for time and clocksources:

   - A fix for the idle and iowait time accounting vs CPU hotplug.

     The time is reset on CPU hotplug which makes the accumulated
     systemwide time jump backwards.

   - Assorted fixes and improvements for clocksource/event drivers"

* tag 'timers-core-2024-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug
  clocksource/drivers/ep93xx: Fix error handling during probe
  clocksource/drivers/cadence-ttc: Fix some kernel-doc warnings
  clocksource/drivers/timer-ti-dm: Fix make W=n kerneldoc warnings
  clocksource/timer-riscv: Add riscv_clock_shutdown callback
  dt-bindings: timer: Add StarFive JH8100 clint
  dt-bindings: timer: thead,c900-aclint-mtimer: separate mtime and mtimecmp regs
2024-01-21 11:14:40 -08:00
Heiko Carstens
71fee48fb7 tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug
When offlining and onlining CPUs the overall reported idle and iowait
times as reported by /proc/stat jump backward and forward:

cpu  132 0 176 225249 47 6 6 21 0 0
cpu0 80 0 115 112575 33 3 4 18 0 0
cpu1 52 0 60 112673 13 3 1 2 0 0

cpu  133 0 177 226681 47 6 6 21 0 0
cpu0 80 0 116 113387 33 3 4 18 0 0

cpu  133 0 178 114431 33 6 6 21 0 0 <---- jump backward
cpu0 80 0 116 114247 33 3 4 18 0 0
cpu1 52 0 61 183 0 3 1 2 0 0        <---- idle + iowait start with 0

cpu  133 0 178 228956 47 6 6 21 0 0 <---- jump forward
cpu0 81 0 117 114929 33 3 4 18 0 0

Reason for this is that get_idle_time() in fs/proc/stat.c has different
sources for both values depending on if a CPU is online or offline:

- if a CPU is online the values may be taken from its per cpu
  tick_cpu_sched structure

- if a CPU is offline the values are taken from its per cpu cpustat
  structure

The problem is that the per cpu tick_cpu_sched structure is set to zero on
CPU offline. See tick_cancel_sched_timer() in kernel/time/tick-sched.c.

Therefore when a CPU is brought offline and online afterwards both its idle
and iowait sleeptime will be zero, causing a jump backward in total system
idle and iowait sleeptime. In a similar way if a CPU is then brought
offline again the total idle and iowait sleeptimes will jump forward.

It looks like this behavior was introduced with commit 4b0c0f294f
("tick: Cleanup NOHZ per cpu data on cpu down").

This was only noticed now on s390, since we switched to generic idle time
reporting with commit be76ea6144 ("s390/idle: remove arch_cpu_idle_time()
and corresponding code").

Fix this by preserving the values of idle_sleeptime and iowait_sleeptime
members of the per-cpu tick_sched structure on CPU hotplug.

Fixes: 4b0c0f294f ("tick: Cleanup NOHZ per cpu data on cpu down")
Reported-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240115163555.1004144-1-hca@linux.ibm.com
2024-01-19 16:40:38 +01:00
Sebastian Andrzej Siewior
e626cb02ee futex: Prevent the reuse of stale pi_state
Jiri Slaby reported a futex state inconsistency resulting in -EINVAL during
a lock operation for a PI futex. It requires that the a lock process is
interrupted by a timeout or signal:

  T1 Owns the futex in user space.

  T2 Tries to acquire the futex in kernel (futex_lock_pi()). Allocates a
     pi_state and attaches itself to it.

  T2 Times out and removes its rt_waiter from the rt_mutex. Drops the
     rtmutex lock and tries to acquire the hash bucket lock to remove
     the futex_q. The lock is contended and T2 schedules out.

  T1 Unlocks the futex (futex_unlock_pi()). Finds a futex_q but no
     rt_waiter. Unlocks the futex (do_uncontended) and makes it available
     to user space.

  T3 Acquires the futex in user space.

  T4 Tries to acquire the futex in kernel (futex_lock_pi()). Finds the
     existing futex_q of T2 and tries to attach itself to the existing
     pi_state.  This (attach_to_pi_state()) fails with -EINVAL because uval
     contains the TID of T3 but pi_state points to T1.

It's incorrect to unlock the futex and make it available for user space to
acquire as long as there is still an existing state attached to it in the
kernel.

T1 cannot hand over the futex to T2 because T2 already gave up and started
to clean up and is blocked on the hash bucket lock, so T2's futex_q with
the pi_state pointing to T1 is still queued.

T2 observes the futex_q, but ignores it as there is no waiter on the
corresponding rt_mutex and takes the uncontended path which allows the
subsequent caller of futex_lock_pi() (T4) to observe that stale state.

To prevent this the unlock path must dequeue all futex_q entries which
point to the same pi_state when there is no waiter on the rt mutex. This
requires obviously to make the dequeue conditional in the locking path to
prevent a double dequeue. With that it's guaranteed that user space cannot
observe an uncontended futex which has kernel state attached.

Fixes: fbeb558b0d ("futex/pi: Fix recursive rt_mutex waiter state")
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240118115451.0TkD_ZhB@linutronix.de
Closes: https://lore.kernel.org/all/4611bcf2-44d0-4c34-9b84-17406f881003@kernel.org
2024-01-19 12:58:17 +01:00
Linus Torvalds
2a668d2176 Merge tag 'kgdb-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux
Pull kgdb update from Daniel Thompson:
 "The entire changeset for kgdb this cycle is a single two-line change
  to remove some deadcode that, had it not been dead, would have called
  strncpy() in an unsafe manner.

  To be fair there were other modest clean ups were discussed this cycle
  but they are not finalized and will have to wait until next time"

* tag 'kgdb-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
  kdb: Fix a potential buffer overflow in kdb_local()
2024-01-18 17:53:22 -08:00
Linus Torvalds
736b5545d3 Merge tag 'net-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf and netfilter.

  Previous releases - regressions:

   - Revert "net: rtnetlink: Enslave device before bringing it up",
     breaks the case inverse to the one it was trying to fix

   - net: dsa: fix oob access in DSA's netdevice event handler
     dereference netdev_priv() before check its a DSA port

   - sched: track device in tcf_block_get/put_ext() only for clsact
     binder types

   - net: tls, fix WARNING in __sk_msg_free when record becomes full
     during splice and MORE hint set

   - sfp-bus: fix SFP mode detect from bitrate

   - drv: stmmac: prevent DSA tags from breaking COE

  Previous releases - always broken:

   - bpf: fix no forward progress in in bpf_iter_udp if output buffer is
     too small

   - bpf: reject variable offset alu on registers with a type of
     PTR_TO_FLOW_KEYS to prevent oob access

   - netfilter: tighten input validation

   - net: add more sanity check in virtio_net_hdr_to_skb()

   - rxrpc: fix use of Don't Fragment flag on RESPONSE packets, avoid
     infinite loop

   - amt: do not use the portion of skb->cb area which may get clobbered

   - mptcp: improve validation of the MPTCPOPT_MP_JOIN MCTCP option

  Misc:

   - spring cleanup of inactive maintainers"

* tag 'net-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (88 commits)
  i40e: Include types.h to some headers
  ipv6: mcast: fix data-race in ipv6_mc_down / mld_ifc_work
  selftests: mlxsw: qos_pfc: Adjust the test to support 8 lanes
  selftests: mlxsw: qos_pfc: Remove wrong description
  mlxsw: spectrum_router: Register netdevice notifier before nexthop
  mlxsw: spectrum_acl_tcam: Fix stack corruption
  mlxsw: spectrum_acl_tcam: Fix NULL pointer dereference in error path
  mlxsw: spectrum_acl_erp: Fix error flow of pool allocation failure
  ethtool: netlink: Add missing ethnl_ops_begin/complete
  selftests: bonding: Add more missing config options
  selftests: netdevsim: add a config file
  libbpf: warn on unexpected __arg_ctx type when rewriting BTF
  selftests/bpf: add tests confirming type logic in kernel for __arg_ctx
  bpf: enforce types for __arg_ctx-tagged arguments in global subprogs
  bpf: extract bpf_ctx_convert_map logic and make it more reusable
  libbpf: feature-detect arg:ctx tag support in kernel
  ipvs: avoid stat macros calls from preemptible context
  netfilter: nf_tables: reject NFT_SET_CONCAT with not field length description
  netfilter: nf_tables: skip dead set elements in netlink dump
  netfilter: nf_tables: do not allow mismatch field size and set key length
  ...
2024-01-18 17:33:50 -08:00
Linus Torvalds
17e232b6d2 Merge tag 'dma-mapping-6.8-2024-01-18' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fixes from Christoph Hellwig:

 - fix kerneldoc warnings (Randy Dunlap)

 - better bounds checking in swiotlb (ZhangPeng)

* tag 'dma-mapping-6.8-2024-01-18' of git://git.infradead.org/users/hch/dma-mapping:
  dma-debug: fix kernel-doc warnings
  swiotlb: check alloc_size before the allocation of a new memory pool
2024-01-18 16:49:34 -08:00
Linus Torvalds
0dde2bf67b Merge tag 'iommu-updates-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull iommu updates from Joerg Roedel:
 "Core changes:
   - Fix race conditions in device probe path
   - Retire IOMMU bus_ops
   - Support for passing custom allocators to page table drivers
   - Clean up Kconfig around IOMMU_SVA
   - Support for sharing SVA domains with all devices bound to a mm
   - Firmware data parsing cleanup
   - Tracing improvements for iommu-dma code
   - Some smaller fixes and cleanups

  ARM-SMMU drivers:
   - Device-tree binding updates:
      - Add additional compatible strings for Qualcomm SoCs
      - Document Adreno clocks for Qualcomm's SM8350 SoC
   - SMMUv2:
      - Implement support for the ->domain_alloc_paging() callback
      - Ensure Secure context is restored following suspend of Qualcomm
        SMMU implementation
   - SMMUv3:
      - Disable stalling mode for the "quiet" context descriptor
      - Minor refactoring and driver cleanups

  Intel VT-d driver:
   - Cleanup and refactoring

  AMD IOMMU driver:
   - Improve IO TLB invalidation logic
   - Small cleanups and improvements

  Rockchip IOMMU driver:
   - DT binding update to add Rockchip RK3588

  Apple DART driver:
   - Apple M1 USB4/Thunderbolt DART support
   - Cleanups

  Virtio IOMMU driver:
   - Add support for iotlb_sync_map
   - Enable deferred IO TLB flushes"

* tag 'iommu-updates-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (66 commits)
  iommu: Don't reserve 0-length IOVA region
  iommu/vt-d: Move inline helpers to header files
  iommu/vt-d: Remove unused vcmd interfaces
  iommu/vt-d: Remove unused parameter of intel_pasid_setup_pass_through()
  iommu/vt-d: Refactor device_to_iommu() to retrieve iommu directly
  iommu/sva: Fix memory leak in iommu_sva_bind_device()
  dt-bindings: iommu: rockchip: Add Rockchip RK3588
  iommu/dma: Trace bounce buffer usage when mapping buffers
  iommu/arm-smmu: Convert to domain_alloc_paging()
  iommu/arm-smmu: Pass arm_smmu_domain to internal functions
  iommu/arm-smmu: Implement IOMMU_DOMAIN_BLOCKED
  iommu/arm-smmu: Convert to a global static identity domain
  iommu/arm-smmu: Reorganize arm_smmu_domain_add_master()
  iommu/arm-smmu-v3: Remove ARM_SMMU_DOMAIN_NESTED
  iommu/arm-smmu-v3: Master cannot be NULL in arm_smmu_write_strtab_ent()
  iommu/arm-smmu-v3: Add a type for the STE
  iommu/arm-smmu-v3: disable stall for quiet_cd
  iommu/qcom: restore IOMMU state if needed
  iommu/arm-smmu-qcom: Add QCM2290 MDSS compatible
  iommu/arm-smmu-qcom: Add missing GMU entry to match table
  ...
2024-01-18 15:16:57 -08:00
Linus Torvalds
a2ded784cd Merge tag 'trace-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:

 - Allow kernel trace instance creation to specify what events are
   created

   Inside the kernel, a subsystem may create a tracing instance that it
   can use to send events to user space. This sub-system may not care
   about the thousands of events that exist in eventfs. Allow the
   sub-system to specify what sub-systems of events it cares about, and
   only those events are exposed to this instance.

 - Allow the ring buffer to be broken up into bigger sub-buffers than
   just the architecture page size.

   A new tracefs file called "buffer_subbuf_size_kb" is created. The
   user can now specify a minimum size the sub-buffer may be in
   kilobytes. Note, that the implementation currently make the
   sub-buffer size a power of 2 pages (1, 2, 4, 8, 16, ...) but the user
   only writes in kilobyte size, and the sub-buffer will be updated to
   the next size that it will can accommodate it. If the user writes in
   10, it will change the size to be 4 pages on x86 (16K), as that is
   the next available size that can hold 10K pages.

 - Update the debug output when a corrupt time is detected in the ring
   buffer. If the ring buffer detects inconsistent timestamps, there's a
   debug config options that will dump the contents of the meta data of
   the sub-buffer that is used for debugging. Add some more information
   to this dump that helps with debugging.

 - Add more timestamp debugging checks (only triggers when the config is
   enabled)

 - Increase the trace_seq iterator to 2 page sizes.

 - Allow strings written into tracefs_marker to be larger. Up to just
   under 2 page sizes (based on what trace_seq can hold).

 - Increase the trace_maker_raw write to be as big as a sub-buffer can
   hold.

 - Remove 32 bit time stamp logic, now that the rb_time_cmpxchg() has
   been removed.

 - More selftests were added.

 - Some code clean ups as well.

* tag 'trace-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (29 commits)
  ring-buffer: Remove stale comment from ring_buffer_size()
  tracing histograms: Simplify parse_actions() function
  tracing/selftests: Remove exec permissions from trace_marker.tc test
  ring-buffer: Use subbuf_order for buffer page masking
  tracing: Update subbuffer with kilobytes not page order
  ringbuffer/selftest: Add basic selftest to test changing subbuf order
  ring-buffer: Add documentation on the buffer_subbuf_order file
  ring-buffer: Just update the subbuffers when changing their allocation order
  ring-buffer: Keep the same size when updating the order
  tracing: Stop the tracing while changing the ring buffer subbuf size
  tracing: Update snapshot order along with main buffer order
  ring-buffer: Make sure the spare sub buffer used for reads has same size
  ring-buffer: Do no swap cpu buffers if order is different
  ring-buffer: Clear pages on error in ring_buffer_subbuf_order_set() failure
  ring-buffer: Read and write to ring buffers with custom sub buffer size
  ring-buffer: Set new size of the ring buffer sub page
  ring-buffer: Add interface for configuring trace sub buffer size
  ring-buffer: Page size per ring buffer
  ring-buffer: Have ring_buffer_print_page_header() be able to access ring_buffer_iter
  ring-buffer: Check if absolute timestamp goes backwards
  ...
2024-01-18 14:35:29 -08:00
Linus Torvalds
5b890ad456 Merge tag 'probes-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes update from Masami Hiramatsu:

 - Update the Kprobes trace event to show the actual function name in
   notrace-symbol warning.

   Instead of using the user specified symbol name, use "%ps" printk
   format to show the actual symbol at the probe address. Since kprobe
   event accepts the offset from symbol which is bigger than the symbol
   size, the user specified symbol may not be the actual probed symbol.

* tag 'probes-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  trace/kprobe: Display the actual notrace function when rejecting a probe
2024-01-18 14:21:22 -08:00
Linus Torvalds
b0d326da46 Merge tag 'sched-urgent-2024-01-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Ingo Molnar:
 "Fix a cpufreq related performance regression on certain systems, where
  the CPU would remain at the lowest frequency, degrading performance
  substantially"

* tag 'sched-urgent-2024-01-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix frequency selection for non-invariant case
2024-01-18 11:57:33 -08:00
Linus Torvalds
80955ae955 Merge tag 'driver-core-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
 "Here are the set of driver core and kernfs changes for 6.8-rc1.
  Nothing major in here this release cycle, just lots of small cleanups
  and some tweaks on kernfs that in the very end, got reverted and will
  come back in a safer way next release cycle.

  Included in here are:

   - more driver core 'const' cleanups and fixes

   - fw_devlink=rpm is now the default behavior

   - kernfs tiny changes to remove some string functions

   - cpu handling in the driver core is updated to work better on many
     systems that add topologies and cpus after booting

   - other minor changes and cleanups

  All of the cpu handling patches have been acked by the respective
  maintainers and are coming in here in one series. Everything has been
  in linux-next for a while with no reported issues"

* tag 'driver-core-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (51 commits)
  Revert "kernfs: convert kernfs_idr_lock to an irq safe raw spinlock"
  kernfs: convert kernfs_idr_lock to an irq safe raw spinlock
  class: fix use-after-free in class_register()
  PM: clk: make pm_clk_add_notifier() take a const pointer
  EDAC: constantify the struct bus_type usage
  kernfs: fix reference to renamed function
  driver core: device.h: fix Excess kernel-doc description warning
  driver core: class: fix Excess kernel-doc description warning
  driver core: mark remaining local bus_type variables as const
  driver core: container: make container_subsys const
  driver core: bus: constantify subsys_register() calls
  driver core: bus: make bus_sort_breadthfirst() take a const pointer
  kernfs: d_obtain_alias(NULL) will do the right thing...
  driver core: Better advertise dev_err_probe()
  kernfs: Convert kernfs_path_from_node_locked() from strlcpy() to strscpy()
  kernfs: Convert kernfs_name_locked() from strlcpy() to strscpy()
  kernfs: Convert kernfs_walk_ns() from strlcpy() to strscpy()
  initramfs: Expose retained initrd as sysfs file
  fs/kernfs/dir: obey S_ISGID
  kernel/cgroup: use kernfs_create_dir_ns()
  ...
2024-01-18 09:48:40 -08:00
Andrii Nakryiko
0ba971511d bpf: enforce types for __arg_ctx-tagged arguments in global subprogs
Add enforcement of expected types for context arguments tagged with
arg:ctx (__arg_ctx) tag.

First, any program type will accept generic `void *` context type when
combined with __arg_ctx tag.

Besides accepting "canonical" struct names and `void *`, for a bunch of
program types for which program context is actually a named struct, we
allows a bunch of pragmatic exceptions to match real-world and expected
usage:

  - for both kprobes and perf_event we allow `bpf_user_pt_regs_t *` as
    canonical context argument type, where `bpf_user_pt_regs_t` is a
    *typedef*, not a struct;
  - for kprobes, we also always accept `struct pt_regs *`, as that's what
    actually is passed as a context to any kprobe program;
  - for perf_event, we resolve typedefs (unless it's `bpf_user_pt_regs_t`)
    down to actual struct type and accept `struct pt_regs *`, or
    `struct user_pt_regs *`, or `struct user_regs_struct *`, depending
    on the actual struct type kernel architecture points `bpf_user_pt_regs_t`
    typedef to; otherwise, canonical `struct bpf_perf_event_data *` is
    expected;
  - for raw_tp/raw_tp.w programs, `u64/long *` are accepted, as that's
    what's expected with BPF_PROG() usage; otherwise, canonical
    `struct bpf_raw_tracepoint_args *` is expected;
  - tp_btf supports both `struct bpf_raw_tracepoint_args *` and `u64 *`
    formats, both are coded as expections as tp_btf is actually a TRACING
    program type, which has no canonical context type;
  - iterator programs accept `struct bpf_iter__xxx *` structs, currently
    with no further iterator-type specific enforcement;
  - fentry/fexit/fmod_ret/lsm/struct_ops all accept `u64 *`;
  - classic tracepoint programs, as well as syscall and freplace
    programs allow any user-provided type.

In all other cases kernel will enforce exact match of struct name to
expected canonical type. And if user-provided type doesn't match that
expectation, verifier will emit helpful message with expected type name.

Note a bit unnatural way the check is done after processing all the
arguments. This is done to avoid conflict between bpf and bpf-next
trees. Once trees converge, a small follow up patch will place a simple
btf_validate_prog_ctx_type() check into a proper ARG_PTR_TO_CTX branch
(which bpf-next tree patch refactored already), removing duplicated
arg:ctx detection logic.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240118033143.3384355-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-17 20:20:06 -08:00
Andrii Nakryiko
66967a32d3 bpf: extract bpf_ctx_convert_map logic and make it more reusable
Refactor btf_get_prog_ctx_type() a bit to allow reuse of
bpf_ctx_convert_map logic in more than one places. Simplify interface by
returning btf_type instead of btf_member (field reference in BTF).

To do the above we need to touch and start untangling
btf_translate_to_vmlinux() implementation. We do the bare minimum to
not regress anything for btf_translate_to_vmlinux(), but its
implementation is very questionable for what it claims to be doing.
Mapping kfunc argument types to kernel corresponding types conceptually
is quite different from recognizing program context types. Fixing this
is out of scope for this change though.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240118033143.3384355-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-17 20:20:05 -08:00
Linus Torvalds
296455ade1 Merge tag 'char-misc-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc and other driver updates from Greg KH:
 "Here is the big set of char/misc and other driver subsystem changes
  for 6.8-rc1.

  Other than lots of binder driver changes (as you can see by the merge
  conflicts) included in here are:

   - lots of iio driver updates and additions

   - spmi driver updates

   - eeprom driver updates

   - firmware driver updates

   - ocxl driver updates

   - mhi driver updates

   - w1 driver updates

   - nvmem driver updates

   - coresight driver updates

   - platform driver remove callback api changes

   - tags.sh script updates

   - bus_type constant marking cleanups

   - lots of other small driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (341 commits)
  android: removed duplicate linux/errno
  uio: Fix use-after-free in uio_open
  drivers: soc: xilinx: add check for platform
  firmware: xilinx: Export function to use in other module
  scripts/tags.sh: remove find_sources
  scripts/tags.sh: use -n to test archinclude
  scripts/tags.sh: add local annotation
  scripts/tags.sh: use more portable -path instead of -wholename
  scripts/tags.sh: Update comment (addition of gtags)
  firmware: zynqmp: Convert to platform remove callback returning void
  firmware: turris-mox-rwtm: Convert to platform remove callback returning void
  firmware: stratix10-svc: Convert to platform remove callback returning void
  firmware: stratix10-rsu: Convert to platform remove callback returning void
  firmware: raspberrypi: Convert to platform remove callback returning void
  firmware: qemu_fw_cfg: Convert to platform remove callback returning void
  firmware: mtk-adsp-ipc: Convert to platform remove callback returning void
  firmware: imx-dsp: Convert to platform remove callback returning void
  firmware: coreboot_table: Convert to platform remove callback returning void
  firmware: arm_scpi: Convert to platform remove callback returning void
  firmware: arm_scmi: Convert to platform remove callback returning void
  ...
2024-01-17 16:47:17 -08:00