Commit Graph

34276 Commits

Author SHA1 Message Date
David S. Miller
d5d325eae7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2020-09-15

The following pull-request contains BPF updates for your *net* tree.

We've added 12 non-merge commits during the last 19 day(s) which contain
a total of 10 files changed, 47 insertions(+), 38 deletions(-).

The main changes are:

1) docs/bpf fixes, from Andrii.

2) ld_abs fix, from Daniel.

3) socket casting helpers fix, from Martin.

4) hash iterator fixes, from Yonghong.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-15 19:26:21 -07:00
Yonghong Song
ce880cb825 bpf: Fix a rcu warning for bpffs map pretty-print
Running selftest
  ./btf_btf -p
the kernel had the following warning:
  [   51.528185] WARNING: CPU: 3 PID: 1756 at kernel/bpf/hashtab.c:717 htab_map_get_next_key+0x2eb/0x300
  [   51.529217] Modules linked in:
  [   51.529583] CPU: 3 PID: 1756 Comm: test_btf Not tainted 5.9.0-rc1+ #878
  [   51.530346] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-1.el7.centos 04/01/2014
  [   51.531410] RIP: 0010:htab_map_get_next_key+0x2eb/0x300
  ...
  [   51.542826] Call Trace:
  [   51.543119]  map_seq_next+0x53/0x80
  [   51.543528]  seq_read+0x263/0x400
  [   51.543932]  vfs_read+0xad/0x1c0
  [   51.544311]  ksys_read+0x5f/0xe0
  [   51.544689]  do_syscall_64+0x33/0x40
  [   51.545116]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

The related source code in kernel/bpf/hashtab.c:
  709 static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
  710 {
  711         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
  712         struct hlist_nulls_head *head;
  713         struct htab_elem *l, *next_l;
  714         u32 hash, key_size;
  715         int i = 0;
  716
  717         WARN_ON_ONCE(!rcu_read_lock_held());

In kernel/bpf/inode.c, bpffs map pretty print calls map->ops->map_get_next_key()
without holding a rcu_read_lock(), hence causing the above warning.
To fix the issue, just surrounding map->ops->map_get_next_key() with rcu read lock.

Fixes: a26ca7c982 ("bpf: btf: Add pretty print support to the basic arraymap")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200916004401.146277-1-yhs@fb.com
2020-09-15 18:17:39 -07:00
Kees Cook
b6ec413461 core/entry: Report syscall correctly for trace and audit
On v5.8 when doing seccomp syscall rewrites (e.g. getpid into getppid
as seen in the seccomp selftests), trace (and audit) correctly see the
rewritten syscall on entry and exit:

	seccomp_bpf-1307  [000] .... 22974.874393: sys_enter: NR 110 (...
	seccomp_bpf-1307  [000] .N.. 22974.874401: sys_exit: NR 110 = 1304

With mainline we see a mismatched enter and exit (the original syscall
is incorrectly visible on entry):

	seccomp_bpf-1030  [000] ....    21.806766: sys_enter: NR 39 (...
	seccomp_bpf-1030  [000] ....    21.806767: sys_exit: NR 110 = 1027

When ptrace or seccomp change the syscall, this needs to be visible to
trace and audit at that time as well. Update the syscall earlier so they
see the correct value.

Fixes: d88d59b64c ("core/entry: Respect syscall number rewrites")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200912005826.586171-1-keescook@chromium.org
2020-09-14 22:49:51 +02:00
Masami Hiramatsu
bcb53209be kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()
Commit:

  0cb2f1372b ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler")

fixed one bug but the underlying bugs are not completely fixed yet.

If we run a kprobe_module.tc of ftracetest, a warning triggers:

  # ./ftracetest test.d/kprobe/kprobe_module.tc
  === Ftrace unit tests ===
  [1] Kprobe dynamic event - probing module
  ...
   ------------[ cut here ]------------
   Failed to disarm kprobe-ftrace at trace_printk_irq_work+0x0/0x7e [trace_printk] (-2)
   WARNING: CPU: 7 PID: 200 at kernel/kprobes.c:1091 __disarm_kprobe_ftrace.isra.0+0x7e/0xa0

This is because the kill_kprobe() calls disarm_kprobe_ftrace() even
if the given probe is not enabled. In that case, ftrace_set_filter_ip()
fails because the given probe point is not registered to ftrace.

Fix to check the given (going) probe is enabled before invoking
disarm_kprobe_ftrace().

Fixes: 0cb2f1372b ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/159888672694.1411785.5987998076694782591.stgit@devnote2
2020-09-14 11:20:03 +02:00
Sven Schnelle
73ac74c7d4 lockdep: fix order in trace_hardirqs_off_caller()
Switch order so that locking state is consistent even
if the IRQ tracer calls into lockdep again.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-14 10:08:07 +02:00
Marc Zyngier
83cfac95c0 genirq: Allow interrupts to be excluded from /proc/interrupts
A number of architectures implement IPI statistics directly,
duplicating the core kstat_irqs accounting. As we move IPIs to
being actual IRQs, we would end-up with a confusing display
in /proc/interrupts (where the IPIs would appear twice).

In order to solve this, allow interrupts to be flagged as
"hidden", which excludes them from /proc/interrupts.

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-09-13 17:04:38 +01:00
Marc Zyngier
c5e5ec033c genirq: Add fasteoi IPI flow
For irqchips using the fasteoi flow, IPIs are a bit special.
They need to be EOI'd early (before calling the handler), as
funny things may happen in the handler (they do not necessarily
behave like a normal interrupt).

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-09-13 17:04:38 +01:00
Linus Torvalds
ef2e9a563b Merge tag 'seccomp-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull seccomp fixes from Kees Cook:
 "This fixes a rare race condition in seccomp when using TSYNC and
  USER_NOTIF together where a memory allocation would not get freed
  (found by syzkaller, fixed by Tycho).

  Additionally updates Tycho's MAINTAINERS and .mailmap entries for his
  new address"

* tag 'seccomp-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  seccomp: don't leave dangling ->notif if file allocation fails
  mailmap, MAINTAINERS: move to tycho.pizza
  seccomp: don't leak memory when filter install races
2020-09-12 12:58:01 -07:00
Peter Oberparleiter
40249c6962 gcov: add support for GCC 10.1
Using gcov to collect coverage data for kernels compiled with GCC 10.1
causes random malfunctions and kernel crashes.  This is the result of a
changed GCOV_COUNTERS value in GCC 10.1 that causes a mismatch between
the layout of the gcov_info structure created by GCC profiling code and
the related structure used by the kernel.

Fix this by updating the in-kernel GCOV_COUNTERS value.  Also re-enable
config GCOV_KERNEL for use with GCC 10.

Reported-by: Colin Ian King <colin.king@canonical.com>
Reported-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Tested-by: Leon Romanovsky <leonro@nvidia.com>
Tested-and-Acked-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-11 09:33:54 -07:00
Kan Liang
44fae179ce perf/core: Pull pmu::sched_task() into perf_event_context_sched_out()
The pmu::sched_task() is a context switch callback. It passes the
cpuctx->task_ctx as a parameter to the lower code. To find the
cpuctx->task_ctx, the current code iterates a cpuctx list.
The same context will iterated in perf_event_context_sched_out() soon.
Share the cpuctx->task_ctx can avoid the unnecessary iteration of the
cpuctx list.

The pmu::sched_task() is also required for the optimization case for
equivalent contexts.

The task_ctx_sched_out() will eventually disable and reenable the PMU
when schedule out events. Add perf_pmu_disable() and perf_pmu_enable()
around task_ctx_sched_out() don't break anything.

Drop the cpuctx->ctx.lock for the pmu::sched_task(). The lock is for
per-CPU context, which is not necessary for the per-task context
schedule.

No one uses sched_cb_entry, perf_sched_cb_usages, sched_cb_list, and
perf_pmu_sched_task() any more.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200821195754.20159-2-kan.liang@linux.intel.com
2020-09-10 11:19:34 +02:00
Kan Liang
556cccad38 perf/core: Pull pmu::sched_task() into perf_event_context_sched_in()
The pmu::sched_task() is a context switch callback. It passes the
cpuctx->task_ctx as a parameter to the lower code. To find the
cpuctx->task_ctx, the current code iterates a cpuctx list.

The same context was just iterated in perf_event_context_sched_in(),
which is invoked right before the pmu::sched_task().

Reuse the cpuctx->task_ctx from perf_event_context_sched_in() can avoid
the unnecessary iteration of the cpuctx list.

Both pmu::sched_task and perf_event_context_sched_in() have to disable
PMU. Pull the pmu::sched_task into perf_event_context_sched_in() can
also save the overhead from the PMU disable and reenable.

The new and old tasks may have equivalent contexts. The current code
optimize this case by swapping the context, which avoids the scheduling.
For this case, pmu::sched_task() is still required, e.g., restore the
LBR content.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200821195754.20159-1-kan.liang@linux.intel.com
2020-09-10 11:19:34 +02:00
Ahmed S. Darwish
249d053835 timekeeping: Use seqcount_latch_t
Latch sequence counters are a multiversion concurrency control mechanism
where the seqcount_t counter even/odd value is used to switch between
two data storage copies. This allows the seqcount_t read path to safely
interrupt its write side critical section (e.g. from NMIs).

Initially, latch sequence counters were implemented as a single write
function, raw_write_seqcount_latch(), above plain seqcount_t. The read
path was expected to use plain seqcount_t raw_read_seqcount().

A specialized read function was later added, raw_read_seqcount_latch(),
and became the standardized way for latch read paths. Having unique read
and write APIs meant that latch sequence counters are basically a data
type of their own -- just inappropriately overloading plain seqcount_t.
The seqcount_latch_t data type was thus introduced at seqlock.h.

Use that new data type instead of seqcount_raw_spinlock_t. This ensures
that only latch-safe APIs are to be used with the sequence counter.

Note that the use of seqcount_raw_spinlock_t was not very useful in the
first place. Only the "raw_" subset of seqcount_t APIs were used at
timekeeping.c. This subset was created for contexts where lockdep cannot
be used. seqcount_LOCKTYPE_t's raison d'être -- verifying that the
seqcount_t writer serialization lock is held -- cannot thus be done.

References: 0c3351d451 ("seqlock: Use raw_ prefix instead of _no_lockdep")
References: 55f3560df9 ("seqlock: Extend seqcount API with associated locks")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200827114044.11173-6-a.darwish@linutronix.de
2020-09-10 11:19:29 +02:00
Ahmed S. Darwish
a690ed0735 time/sched_clock: Use seqcount_latch_t
Latch sequence counters have unique read and write APIs, and thus
seqcount_latch_t was recently introduced at seqlock.h.

Use that new data type instead of plain seqcount_t. This adds the
necessary type-safety and ensures only latching-safe seqcount APIs are
to be used.

Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200827114044.11173-5-a.darwish@linutronix.de
2020-09-10 11:19:29 +02:00
Ahmed S. Darwish
58faf20a08 time/sched_clock: Use raw_read_seqcount_latch() during suspend
sched_clock uses seqcount_t latching to switch between two storage
places protected by the sequence counter. This allows it to have
interruptible, NMI-safe, seqcount_t write side critical sections.

Since 7fc26327b7 ("seqlock: Introduce raw_read_seqcount_latch()"),
raw_read_seqcount_latch() became the standardized way for seqcount_t
latch read paths. Due to the dependent load, it has one read memory
barrier less than the currently used raw_read_seqcount() API.

Use raw_read_seqcount_latch() for the suspend path.

Commit aadd6e5caa ("time/sched_clock: Use raw_read_seqcount_latch()")
missed changing that instance of raw_read_seqcount().

References: 1809bfa44e ("timers, sched/clock: Avoid deadlock during read from NMI")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200715092345.GA231464@debian-buster-darwi.lab.linutronix.de
2020-09-10 11:19:28 +02:00
Linus Torvalds
7fe10096c1 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fix from Herbert Xu:
 "This fixes a regression in padata"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  padata: fix possible padata_works_lock deadlock
2020-09-09 19:46:22 -07:00
Valentin Schneider
848785df48 sched/topology: Move sd_flag_debug out of #ifdef CONFIG_SYSCTL
The last sd_flag_debug shuffle inadvertently moved its definition within
an #ifdef CONFIG_SYSCTL region. While CONFIG_SYSCTL is indeed required to
produce the sched domain ctl interface (which uses sd_flag_debug to output
flag names), it isn't required to run any assertion on the sched_domain
hierarchy itself.

Move the definition of sd_flag_debug to a CONFIG_SCHED_DEBUG region of
topology.c.

Now at long last we have:

- sd_flag_debug declared in include/linux/sched/topology.h iff
  CONFIG_SCHED_DEBUG=y
- sd_flag_debug defined in kernel/sched/topology.c, conditioned by:
  - CONFIG_SCHED_DEBUG, with an explicit #ifdef block
  - CONFIG_SMP, as a requirement to compile topology.c

With this change, all symbols pertaining to SD flag metadata (with the
exception of __SD_FLAG_CNT) are now defined exclusively within topology.c

Fixes: 8fca9494d4 ("sched/topology: Move sd_flag_debug out of linux/sched/topology.h")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200908184956.23369-1-valentin.schneider@arm.com
2020-09-09 10:09:03 +02:00
Tycho Andersen
e839317900 seccomp: don't leave dangling ->notif if file allocation fails
Christian and Kees both pointed out that this is a bit sloppy to open-code
both places, and Christian points out that we leave a dangling pointer to
->notif if file allocation fails. Since we check ->notif for null in order
to determine if it's ok to install a filter, this means people won't be
able to install a filter if the file allocation fails for some reason, even
if they subsequently should be able to.

To fix this, let's hoist this free+null into its own little helper and use
it.

Reported-by: Kees Cook <keescook@chromium.org>
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200902140953.1201956-1-tycho@tycho.pizza
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-09-08 11:30:16 -07:00
Tycho Andersen
a566a9012a seccomp: don't leak memory when filter install races
In seccomp_set_mode_filter() with TSYNC | NEW_LISTENER, we first initialize
the listener fd, then check to see if we can actually use it later in
seccomp_may_assign_mode(), which can fail if anyone else in our thread
group has installed a filter and caused some divergence. If we can't, we
partially clean up the newly allocated file: we put the fd, put the file,
but don't actually clean up the *memory* that was allocated at
filter->notif. Let's clean that up too.

To accomplish this, let's hoist the actual "detach a notifier from a
filter" code to its own helper out of seccomp_notify_release(), so that in
case anyone adds stuff to init_listener(), they only have to add the
cleanup code in one spot. This does a bit of extra locking and such on the
failure path when the filter is not attached, but it's a slow failure path
anyway.

Fixes: 51891498f2 ("seccomp: allow TSYNC and USER_NOTIF together")
Reported-by: syzbot+3ad9614a12f80994c32e@syzkaller.appspotmail.com
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200902014017.934315-1-tycho@tycho.pizza
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-09-08 11:19:50 -07:00
Masami Hiramatsu
319f0ce284 kprobes: Make local functions static
Since we unified the kretprobe trampoline handler from arch/* code,
some functions and objects do not need to be exported anymore.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/159870618256.1229682.8692046612635810882.stgit@devnote2
2020-09-08 11:52:42 +02:00
Masami Hiramatsu
b338817807 kprobes: Free kretprobe_instance with RCU callback
Free kretprobe_instance with RCU callback instead of directly
freeing the object in the kretprobe handler context.

This will make kretprobe run safer in NMI context.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/159870616685.1229682.11978742048709542226.stgit@devnote2
2020-09-08 11:52:35 +02:00
Masami Hiramatsu
e03b4a084e kprobes: Remove NMI context check
The in_nmi() check in pre_handler_kretprobe() is meant to avoid
recursion, and blindly assumes that anything NMI is recursive.

However, since commit:

  9b38cc704e ("kretprobe: Prevent triggering kretprobe from within kprobe_flush_task")

there is a better way to detect and avoid actual recursion.

By setting a dummy kprobe, any actual exceptions will terminate early
(by trying to handle the dummy kprobe), and recursion will not happen.

Employ this to avoid the kretprobe_table_lock() recursion, replacing
the over-eager in_nmi() check.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/159870615628.1229682.6087311596892125907.stgit@devnote2
2020-09-08 11:52:35 +02:00
Masami Hiramatsu
66ada2ccae kprobes: Add generic kretprobe trampoline handler
Add a generic kretprobe trampoline handler for unifying
the all cloned /arch/* kretprobe trampoline handlers.

The generic kretprobe trampoline handler is based on the
x86 implementation, because it is the latest implementation.
It has frame pointer checking, kprobe_busy_begin/end and
return address fixup for user handlers.

[ mingo: Minor edits. ]

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/159870600138.1229682.3424065380448088833.stgit@devnote2
2020-09-08 11:52:31 +02:00
Wang Hai
e75ad2cc41 blktrace: make function blk_trace_bio_get_cgid() static
The sparse tool complains as follows:

kernel/trace/blktrace.c:796:5: warning:
 symbol 'blk_trace_bio_get_cgid' was not declared. Should it be static?

This function is not used outside of blktrace.c, so this commit
marks it static.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-07 20:11:15 -06:00
Linus Torvalds
015b3155c4 Merge tag 'x86-urgent-2020-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:

 - more generic entry code ABI fallout

 - debug register handling bugfixes

 - fix vmalloc mappings on 32-bit kernels

 - kprobes instrumentation output fix on 32-bit kernels

 - fix over-eager WARN_ON_ONCE() on !SMAP hardware

 - NUMA debugging fix

 - fix Clang related crash on !RETPOLINE kernels

* tag 'x86-urgent-2020-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry: Unbreak 32bit fast syscall
  x86/debug: Allow a single level of #DB recursion
  x86/entry: Fix AC assertion
  tracing/kprobes, x86/ptrace: Fix regs argument order for i386
  x86, fakenuma: Fix invalid starting node ID
  x86/mm/32: Bring back vmalloc faulting on x86_32
  x86/cmdline: Disable jump tables for cmdline.c
2020-09-06 10:28:00 -07:00
Marc Zyngier
cd1752d34e genirq: Walk the irq_data hierarchy when resending an interrupt
On resending an interrupt, we only check the outermost irqchip for
a irq_retrigger callback. However, this callback could be implemented
at an inner level. Use irq_chip_retrigger_hierarchy() in this case.

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-09-06 18:25:23 +01:00
Linus Torvalds
7514c0362f Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "19 patches.

  Subsystems affected by this patch series: MAINTAINERS, ipc, fork,
  checkpatch, lib, and mm (memcg, slub, pagemap, madvise, migration,
  hugetlb)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  include/linux/log2.h: add missing () around n in roundup_pow_of_two()
  mm/khugepaged.c: fix khugepaged's request size in collapse_file
  mm/hugetlb: fix a race between hugetlb sysctl handlers
  mm/hugetlb: try preferred node first when alloc gigantic page from cma
  mm/migrate: preserve soft dirty in remove_migration_pte()
  mm/migrate: remove unnecessary is_zone_device_page() check
  mm/rmap: fixup copying of soft dirty and uffd ptes
  mm/migrate: fixup setting UFFD_WP flag
  mm: madvise: fix vma user-after-free
  checkpatch: fix the usage of capture group ( ... )
  fork: adjust sysctl_max_threads definition to match prototype
  ipc: adjust proc_ipc_sem_dointvec definition to match prototype
  mm: track page table modifications in __apply_to_page_range()
  MAINTAINERS: IA64: mark Status as Odd Fixes only
  MAINTAINERS: add LLVM maintainers
  MAINTAINERS: update Cavium/Marvell entries
  mm: slub: fix conversion of freelist_corrupted()
  mm: memcg: fix memcg reclaim soft lockup
  memcg: fix use-after-free in uncharge_batch
2020-09-05 13:28:40 -07:00
Tobias Klauser
b0daa2c73f fork: adjust sysctl_max_threads definition to match prototype
Commit 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel pointer.  Adjust the
definition of sysctl_max_threads to match its prototype in
linux/sysctl.h which fixes the following sparse error/warning:

  kernel/fork.c:3050:47: warning: incorrect type in argument 3 (different address spaces)
  kernel/fork.c:3050:47:    expected void *
  kernel/fork.c:3050:47:    got void [noderef] __user *buffer
  kernel/fork.c:3036:5: error: symbol 'sysctl_max_threads' redeclared with different type (incompatible argument 3 (different address spaces)):
  kernel/fork.c:3036:5:    int extern [addressable] [signed] [toplevel] sysctl_max_threads( ... )
  kernel/fork.c: note: in included file (through include/linux/key.h, include/linux/cred.h, include/linux/sched/signal.h, include/linux/sched/cputime.h):
  include/linux/sysctl.h:242:5: note: previously declared as:
  include/linux/sysctl.h:242:5:    int extern [addressable] [signed] [toplevel] sysctl_max_threads( ... )

Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/20200825093647.24263-1-tklauser@distanz.ch
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-05 12:14:29 -07:00
Leon Romanovsky
cfc905f158 gcov: Disable gcov build with GCC 10
GCOV built with GCC 10 doesn't initialize n_function variable.  This
produces different kernel panics as was seen by Colin in Ubuntu and me
in FC 32.

As a workaround, let's disable GCOV build for broken GCC 10 version.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1891288
Link: https://lore.kernel.org/lkml/20200827133932.3338519-1-leon@kernel.org
Link: https://lore.kernel.org/lkml/CAHk-=whbijeSdSvx-Xcr0DPMj0BiwhJ+uiNnDSVZcr_h_kg7UA@mail.gmail.com/
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-04 09:19:49 -07:00
Thomas Gleixner
4facb95b7a x86/entry: Unbreak 32bit fast syscall
Andy reported that the syscall treacing for 32bit fast syscall fails:

# ./tools/testing/selftests/x86/ptrace_syscall_32
...
[RUN] SYSEMU
[FAIL] Initial args are wrong (nr=224, args=10 11 12 13 14 4289172732)
...
[RUN] SYSCALL
[FAIL] Initial args are wrong (nr=29, args=0 0 0 0 0 4289172732)
 
The eason is that the conversion to generic entry code moved the retrieval
of the sixth argument (EBP) after the point where the syscall entry work
runs, i.e. ptrace, seccomp, audit...

Unbreak it by providing a split up version of syscall_enter_from_user_mode().

- syscall_enter_from_user_mode_prepare() establishes state and enables
  interrupts

- syscall_enter_from_user_mode_work() runs the entry work

Replace the call to syscall_enter_from_user_mode() in the 32bit fast
syscall C-entry with the split functions and stick the EBP retrieval
between them.

Fixes: 27d6b4d14f ("x86/entry: Use generic syscall entry function")
Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87k0xdjbtt.fsf@nanos.tec.linutronix.de
2020-09-04 15:50:14 +02:00
Daniel Jordan
1b0df11fde padata: fix possible padata_works_lock deadlock
syzbot reports,

  WARNING: inconsistent lock state
  5.9.0-rc2-syzkaller #0 Not tainted
  --------------------------------
  inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
  syz-executor.0/26715 takes:
  (padata_works_lock){+.?.}-{2:2}, at: padata_do_parallel kernel/padata.c:220
  {IN-SOFTIRQ-W} state was registered at:
    spin_lock include/linux/spinlock.h:354 [inline]
    padata_do_parallel kernel/padata.c:220
    ...
    __do_softirq kernel/softirq.c:298
    ...
    sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1091
    asm_sysvec_apic_timer_interrupt arch/x86/include/asm/idtentry.h:581

   Possible unsafe locking scenario:

         CPU0
         ----
    lock(padata_works_lock);
    <Interrupt>
      lock(padata_works_lock);

padata_do_parallel() takes padata_works_lock with softirqs enabled, so a
deadlock is possible if, on the same CPU, the lock is acquired in
process context and then softirq handling done in an interrupt leads to
the same path.

Fix by leaving softirqs disabled while do_parallel holds
padata_works_lock.

Reported-by: syzbot+f4b9f49e38e25eb4ef52@syzkaller.appspotmail.com
Fixes: 4611ce2246 ("padata: allocate work structures for parallel jobs from a pool")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-09-04 17:51:55 +10:00
Linus Torvalds
3e8d3bdc2a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Use netif_rx_ni() when necessary in batman-adv stack, from Jussi
    Kivilinna.

 2) Fix loss of RTT samples in rxrpc, from David Howells.

 3) Memory leak in hns_nic_dev_probe(), from Dignhao Liu.

 4) ravb module cannot be unloaded, fix from Yuusuke Ashizuka.

 5) We disable BH for too lokng in sctp_get_port_local(), add a
    cond_resched() here as well, from Xin Long.

 6) Fix memory leak in st95hf_in_send_cmd, from Dinghao Liu.

 7) Out of bound access in bpf_raw_tp_link_fill_link_info(), from
    Yonghong Song.

 8) Missing of_node_put() in mt7530 DSA driver, from Sumera
    Priyadarsini.

 9) Fix crash in bnxt_fw_reset_task(), from Michael Chan.

10) Fix geneve tunnel checksumming bug in hns3, from Yi Li.

11) Memory leak in rxkad_verify_response, from Dinghao Liu.

12) In tipc, don't use smp_processor_id() in preemptible context. From
    Tuong Lien.

13) Fix signedness issue in mlx4 memory allocation, from Shung-Hsi Yu.

14) Missing clk_disable_prepare() in gemini driver, from Dan Carpenter.

15) Fix ABI mismatch between driver and firmware in nfp, from Louis
    Peens.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (110 commits)
  net/smc: fix sock refcounting in case of termination
  net/smc: reset sndbuf_desc if freed
  net/smc: set rx_off for SMCR explicitly
  net/smc: fix toleration of fake add_link messages
  tg3: Fix soft lockup when tg3_reset_task() fails.
  doc: net: dsa: Fix typo in config code sample
  net: dp83867: Fix WoL SecureOn password
  nfp: flower: fix ABI mismatch between driver and firmware
  tipc: fix shutdown() of connectionless socket
  ipv6: Fix sysctl max for fib_multipath_hash_policy
  drivers/net/wan/hdlc: Change the default of hard_header_len to 0
  net: gemini: Fix another missing clk_disable_unprepare() in probe
  net: bcmgenet: fix mask check in bcmgenet_validate_flow()
  amd-xgbe: Add support for new port mode
  net: usb: dm9601: Add USB ID of Keenetic Plus DSL
  vhost: fix typo in error message
  net: ethernet: mlx4: Fix memory allocation in mlx4_buddy_init()
  pktgen: fix error message with wrong function name
  net: ethernet: ti: am65-cpsw: fix rmii 100Mbit link mode
  cxgb4: fix thermal zone device registration
  ...
2020-09-03 18:50:48 -07:00
Yonghong Song
dc0988bbe1 bpf: Do not use bucket_lock for hashmap iterator
Currently, for hashmap, the bpf iterator will grab a bucket lock, a
spinlock, before traversing the elements in the bucket. This can ensure
all bpf visted elements are valid. But this mechanism may cause
deadlock if update/deletion happens to the same bucket of the
visited map in the program. For example, if we added bpf_map_update_elem()
call to the same visited element in selftests bpf_iter_bpf_hash_map.c,
we will have the following deadlock:

  ============================================
  WARNING: possible recursive locking detected
  5.9.0-rc1+ #841 Not tainted
  --------------------------------------------
  test_progs/1750 is trying to acquire lock:
  ffff9a5bb73c5e70 (&htab->buckets[i].raw_lock){....}-{2:2}, at: htab_map_update_elem+0x1cf/0x410

  but task is already holding lock:
  ffff9a5bb73c5e20 (&htab->buckets[i].raw_lock){....}-{2:2}, at: bpf_hash_map_seq_find_next+0x94/0x120

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&htab->buckets[i].raw_lock);
    lock(&htab->buckets[i].raw_lock);

   *** DEADLOCK ***
   ...
  Call Trace:
   dump_stack+0x78/0xa0
   __lock_acquire.cold.74+0x209/0x2e3
   lock_acquire+0xba/0x380
   ? htab_map_update_elem+0x1cf/0x410
   ? __lock_acquire+0x639/0x20c0
   _raw_spin_lock_irqsave+0x3b/0x80
   ? htab_map_update_elem+0x1cf/0x410
   htab_map_update_elem+0x1cf/0x410
   ? lock_acquire+0xba/0x380
   bpf_prog_ad6dab10433b135d_dump_bpf_hash_map+0x88/0xa9c
   ? find_held_lock+0x34/0xa0
   bpf_iter_run_prog+0x81/0x16e
   __bpf_hash_map_seq_show+0x145/0x180
   bpf_seq_read+0xff/0x3d0
   vfs_read+0xad/0x1c0
   ksys_read+0x5f/0xe0
   do_syscall_64+0x33/0x40
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  ...

The bucket_lock first grabbed in seq_ops->next() called by bpf_seq_read(),
and then grabbed again in htab_map_update_elem() in the bpf program, causing
deadlocks.

Actually, we do not need bucket_lock here, we can just use rcu_read_lock()
similar to netlink iterator where the rcu_read_{lock,unlock} likes below:
 seq_ops->start():
     rcu_read_lock();
 seq_ops->next():
     rcu_read_unlock();
     /* next element */
     rcu_read_lock();
 seq_ops->stop();
     rcu_read_unlock();

Compared to old bucket_lock mechanism, if concurrent updata/delete happens,
we may visit stale elements, miss some elements, or repeat some elements.
I think this is a reasonable compromise. For users wanting to avoid
stale, missing/repeated accesses, bpf_map batch access syscall interface
can be used.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200902235340.2001375-1-yhs@fb.com
2020-09-03 17:36:41 -07:00
peterz@infradead.org
23870f1227 locking/lockdep: Fix "USED" <- "IN-NMI" inversions
During the LPC RCU BoF Paul asked how come the "USED" <- "IN-NMI"
detector doesn't trip over rcu_read_lock()'s lockdep annotation.

Looking into this I found a very embarrasing typo in
verify_lock_unused():

	-	if (!(class->usage_mask & LOCK_USED))
	+	if (!(class->usage_mask & LOCKF_USED))

fixing that will indeed cause rcu_read_lock() to insta-splat :/

The above typo means that instead of testing for: 0x100 (1 <<
LOCK_USED), we test for 8 (LOCK_USED), which corresponds to (1 <<
LOCK_ENABLED_HARDIRQ).

So instead of testing for _any_ used lock, it will only match any lock
used with interrupts enabled.

The rcu_read_lock() annotation uses .check=0, which means it will not
set any of the interrupt bits and will thus never match.

In order to properly fix the situation and allow rcu_read_lock() to
correctly work, split LOCK_USED into LOCK_USED and LOCK_USED_READ and by
having .read users set USED_READ and test USED, pure read-recursive
locks are permitted.

Fixes: f6f48e1804 ("lockdep: Teach lockdep about "USED" <- "IN-NMI" inversions")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20200902160323.GK1362448@hirez.programming.kicks-ass.net
2020-09-03 11:19:42 +02:00
Steven Rostedt (VMware)
d25e37d89d tracepoint: Optimize using static_call()
Currently the tracepoint site will iterate a vector and issue indirect
calls to however many handlers are registered (ie. the vector is
long).

Using static_call() it is possible to optimize this for the common
case of only having a single handler registered. In this case the
static_call() can directly call this handler. Otherwise, if the vector
is longer than 1, call a function that iterates the whole vector like
the current code.

[peterz: updated to new interface]

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20200818135805.279421092@infradead.org
2020-09-01 09:58:06 +02:00
Peter Zijlstra
a945c8345e static_call: Allow early init
In order to use static_call() to wire up x86_pmu, we need to
initialize earlier, specifically before memory allocation works; copy
some of the tricks from jump_label to enable this.

Primarily we overload key->next to store a sites pointer when there
are no modules, this avoids having to use kmalloc() to initialize the
sites and allows us to run much earlier.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20200818135805.220737930@infradead.org
2020-09-01 09:58:06 +02:00
Peter Zijlstra
5b06fd3bb9 static_call: Handle tail-calls
GCC can turn our static_call(name)(args...) into a tail call, in which
case we get a JMP.d32 into the trampoline (which then does a further
tail-call).

Teach objtool to recognise and mark these in .static_call_sites and
adjust the code patching to deal with this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20200818135805.101186767@infradead.org
2020-09-01 09:58:06 +02:00
Peter Zijlstra
f03c412915 static_call: Add simple self-test for static calls
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200818135804.922581202@infradead.org
2020-09-01 09:58:05 +02:00
Peter Zijlstra
6333e8f73b static_call: Avoid kprobes on inline static_call()s
Similar to how we disallow kprobes on any other dynamic text
(ftrace/jump_label) also disallow kprobes on inline static_call()s.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200818135804.744920586@infradead.org
2020-09-01 09:58:04 +02:00
Josh Poimboeuf
9183c3f9ed static_call: Add inline static call infrastructure
Add infrastructure for an arch-specific CONFIG_HAVE_STATIC_CALL_INLINE
option, which is a faster version of CONFIG_HAVE_STATIC_CALL.  At
runtime, the static call sites are patched directly, rather than using
the out-of-line trampolines.

Compared to out-of-line static calls, the performance benefits are more
modest, but still measurable.  Steven Rostedt did some tracepoint
measurements:

  https://lkml.kernel.org/r/20181126155405.72b4f718@gandalf.local.home

This code is heavily inspired by the jump label code (aka "static
jumps"), as some of the concepts are very similar.

For more details, see the comments in include/linux/static_call.h.

[peterz: simplified interface; merged trampolines]

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20200818135804.684334440@infradead.org
2020-09-01 09:58:04 +02:00
Peter Zijlstra
0db6e3734b jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved()
Nothing ensures the module exists while we're iterating
mod->jump_entries in __jump_label_mod_text_reserved(), take a module
reference to ensure the module sticks around.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20200818135804.504501338@infradead.org
2020-09-01 09:58:04 +02:00
Peter Zijlstra
59cc8e0a90 module: Properly propagate MODULE_STATE_COMING failure
Now that notifiers got unbroken; use the proper interface to handle
notifier errors and propagate them.

There were already MODULE_STATE_COMING notifiers that failed; notably:

 - jump_label_module_notifier()
 - tracepoint_module_notify()
 - bpf_event_notify()

By propagating this error, we fix those users.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20200818135804.444372853@infradead.org
2020-09-01 09:58:04 +02:00
Peter Zijlstra
0340a6b7fb module: Fix up module_notifier return values
While auditing all module notifiers I noticed a whole bunch of fail
wrt the return value. Notifiers have a 'special' return semantics.

As is; NOTIFY_DONE vs NOTIFY_OK is a bit vague; but
notifier_from_errno(0) results in NOTIFY_OK and NOTIFY_DONE has a
comment that says "Don't care".

From this I've used NOTIFY_DONE when the function completely ignores
the callback and notifier_to_error() isn't used.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Robert Richter <rric@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20200818135804.385360407@infradead.org
2020-09-01 09:58:03 +02:00
Peter Zijlstra
70d9329857 notifier: Fix broken error handling pattern
The current notifiers have the following error handling pattern all
over the place:

	int err, nr;

	err = __foo_notifier_call_chain(&chain, val_up, v, -1, &nr);
	if (err & NOTIFIER_STOP_MASK)
		__foo_notifier_call_chain(&chain, val_down, v, nr-1, NULL)

And aside from the endless repetition thereof, it is broken. Consider
blocking notifiers; both calls take and drop the rwsem, this means
that the notifier list can change in between the two calls, making @nr
meaningless.

Fix this by replacing all the __foo_notifier_call_chain() functions
with foo_notifier_call_chain_robust() that embeds the above pattern,
but ensures it is inside a single lock region.

Note: I switched atomic_notifier_call_chain_robust() to use
      the spinlock, since RCU cannot provide the guarantee
      required for the recovery.

Note: software_resume() error handling was broken afaict.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20200818135804.325626653@infradead.org
2020-09-01 09:58:03 +02:00
Marco Elver
cd290ec246 kcsan: Use tracing-safe version of prandom
In the core runtime, we must minimize any calls to external library
functions to avoid any kind of recursion. This can happen even though
instrumentation is disabled for called functions, but tracing is
enabled.

Most recently, prandom_u32() added a tracepoint, which can cause
problems for KCSAN even if the rcuidle variant is used. For example:
	kcsan -> prandom_u32() -> trace_prandom_u32_rcuidle ->
	srcu_read_lock_notrace -> __srcu_read_lock -> kcsan ...

While we could disable KCSAN in kcsan_setup_watchpoint(), this does not
solve other unexpected behaviour we may get due recursing into functions
that may not be tolerant to such recursion:
	__srcu_read_lock -> kcsan -> ... -> __srcu_read_lock

Therefore, switch to using prandom_u32_state(), which is uninstrumented,
and does not have a tracepoint.

Link: https://lkml.kernel.org/r/20200821063043.1949509-1-elver@google.com
Link: https://lkml.kernel.org/r/20200820172046.GA177701@elver.google.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-08-30 21:50:13 -07:00
Linus Torvalds
dcc5c6f013 Merge tag 'x86-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "Three interrupt related fixes for X86:

   - Move disabling of the local APIC after invoking fixup_irqs() to
     ensure that interrupts which are incoming are noted in the IRR and
     not ignored.

   - Unbreak affinity setting.

     The rework of the entry code reused the regular exception entry
     code for device interrupts. The vector number is pushed into the
     errorcode slot on the stack which is then lifted into an argument
     and set to -1 because that's regs->orig_ax which is used in quite
     some places to check whether the entry came from a syscall.

     But it was overlooked that orig_ax is used in the affinity cleanup
     code to validate whether the interrupt has arrived on the new
     target. It turned out that this vector check is pointless because
     interrupts are never moved from one vector to another on the same
     CPU. That check is a historical leftover from the time where x86
     supported multi-CPU affinities, but not longer needed with the now
     strict single CPU affinity. Famous last words ...

   - Add a missing check for an empty cpumask into the matrix allocator.

     The affinity change added a warning to catch the case where an
     interrupt is moved on the same CPU to a different vector. This
     triggers because a condition with an empty cpumask returns an
     assignment from the allocator as the allocator uses for_each_cpu()
     without checking the cpumask for being empty. The historical
     inconsistent for_each_cpu() behaviour of ignoring the cpumask and
     unconditionally claiming that CPU0 is in the mask struck again.
     Sigh.

  plus a new entry into the MAINTAINER file for the HPE/UV platform"

* tag 'x86-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/matrix: Deal with the sillyness of for_each_cpu() on UP
  x86/irq: Unbreak interrupt affinity setting
  x86/hotplug: Silence APIC only after all interrupts are migrated
  MAINTAINERS: Add entry for HPE Superdome Flex (UV) maintainers
2020-08-30 12:01:23 -07:00
Linus Torvalds
b69bea8a65 Merge tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
 "A set of fixes for lockdep, tracing and RCU:

   - Prevent recursion by using raw_cpu_* operations

   - Fixup the interrupt state in the cpu idle code to be consistent

   - Push rcu_idle_enter/exit() invocations deeper into the idle path so
     that the lock operations are inside the RCU watching sections

   - Move trace_cpu_idle() into generic code so it's called before RCU
     goes idle.

   - Handle raw_local_irq* vs. local_irq* operations correctly

   - Move the tracepoints out from under the lockdep recursion handling
     which turned out to be fragile and inconsistent"

* tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep,trace: Expose tracepoints
  lockdep: Only trace IRQ edges
  mips: Implement arch_irqs_disabled()
  arm64: Implement arch_irqs_disabled()
  nds32: Implement arch_irqs_disabled()
  locking/lockdep: Cleanup
  x86/entry: Remove unused THUNKs
  cpuidle: Move trace_cpu_idle() into generic code
  cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic
  sched,idle,rcu: Push rcu_idle deeper into the idle path
  cpuidle: Fixup IRQ state
  lockdep: Use raw_cpu_*() for per-cpu variables
2020-08-30 11:43:50 -07:00
Thomas Gleixner
784a083037 genirq/matrix: Deal with the sillyness of for_each_cpu() on UP
Most of the CPU mask operations behave the same way, but for_each_cpu() and
it's variants ignore the cpumask argument and claim that CPU0 is always in
the mask. This is historical, inconsistent and annoying behaviour.

The matrix allocator uses for_each_cpu() and can be called on UP with an
empty cpumask. The calling code does not expect that this succeeds but
until commit e027fffff7 ("x86/irq: Unbreak interrupt affinity setting")
this went unnoticed. That commit added a WARN_ON() to catch cases which
move an interrupt from one vector to another on the same CPU. The warning
triggers on UP.

Add a check for the cpumask being empty to prevent this.

Fixes: 2f75d9e1c9 ("genirq: Implement bitmap matrix allocator")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
2020-08-30 19:17:28 +02:00
Dan Carpenter
892fc9f683 dma-pool: Fix an uninitialized variable bug in atomic_pool_expand()
The "page" pointer can be used with out being initialized.

Fixes: d7e673ec2c ("dma-pool: Only allocate from CMA when in same memory zone")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-08-27 09:22:56 +02:00
Boqun Feng
f611e8cf98 lockdep: Take read/write status in consideration when generate chainkey
Currently, the chainkey of a lock chain is a hash sum of the class_idx
of all the held locks, the read/write status are not taken in to
consideration while generating the chainkey. This could result into a
problem, if we have:

	P1()
	{
		read_lock(B);
		lock(A);
	}

	P2()
	{
		lock(A);
		read_lock(B);
	}

	P3()
	{
		lock(A);
		write_lock(B);
	}

, and P1(), P2(), P3() run one by one. And when running P2(), lockdep
detects such a lock chain A -> B is not a deadlock, then it's added in
the chain cache, and then when running P3(), even if it's a deadlock, we
could miss it because of the hit of chain cache. This could be confirmed
by self testcase "chain cached mixed R-L/L-W ".

To resolve this, we use concept "hlock_id" to generate the chainkey, the
hlock_id is a tuple (hlock->class_idx, hlock->read), which fits in a u16
type. With this, the chainkeys are different is the lock sequences have
the same locks but different read/write status.

Besides, since we use "hlock_id" to generate chainkeys, the chain_hlocks
array now store the "hlock_id"s rather than lock_class indexes.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200807074238.1632519-15-boqun.feng@gmail.com
2020-08-26 12:42:06 +02:00
Boqun Feng
621c9dac0e lockdep: Add recursive read locks into dependency graph
Since we have all the fundamental to handle recursive read locks, we now
add them into the dependency graph.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200807074238.1632519-13-boqun.feng@gmail.com
2020-08-26 12:42:06 +02:00