<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux/kernel/bpf/stackmap.c, branch v5.5</title>
<subtitle>Mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
</subtitle>
<id>https://git.shady.money/linux/atom?h=v5.5</id>
<link rel='self' href='https://git.shady.money/linux/atom?h=v5.5'/>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/'/>
<updated>2019-12-03T17:29:50Z</updated>
<entry>
<title>Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2019-12-03T17:29:50Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-12-03T17:29:50Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=b22bfea7f16cda6e08918a3e9c7b4b99eb95ea70'/>
<id>urn:sha1:b22bfea7f16cda6e08918a3e9c7b4b99eb95ea70</id>
<content type='text'>
Pull irq updates from Ingo Molnar:
 "Most of the IRQ subsystem changes in this cycle were irq-chip driver
  updates:

   - Qualcomm PDC wakeup interrupt support

   - Layerscape external IRQ support

   - Broadcom bcm7038 PM and wakeup support

   - Ingenic driver cleanup and modernization

   - GICv3 ITS preparation for GICv4.1 updates

   - GICv4 fixes

  There's also the series from Frederic Weisbecker that fixes memory
  ordering bugs for the irq-work logic, whose primary fix is to turn
  work-&gt;irq_work.flags into an atomic variable and then convert the
  complex (and buggy) atomic_cmpxchg() loop in irq_work_claim() into a
  much simpler atomic_fetch_or() call.

  There are also various smaller cleanups"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  pinctrl/sdm845: Add PDC wakeup interrupt map for GPIOs
  pinctrl/msm: Setup GPIO chip in hierarchy
  irqchip/qcom-pdc: Add irqchip set/get state calls
  irqchip/qcom-pdc: Add irqdomain for wakeup capable GPIOs
  irqchip/qcom-pdc: Do not toggle IRQ_ENABLE during mask/unmask
  irqchip/qcom-pdc: Update max PDC interrupts
  of/irq: Document properties for wakeup interrupt parent
  genirq: Introduce irq_chip_get/set_parent_state calls
  irqdomain: Add bus token DOMAIN_BUS_WAKEUP
  genirq: Fix function documentation of __irq_alloc_descs()
  irq_work: Fix IRQ_WORK_BUSY bit clearing
  irqchip/ti-sci-inta: Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...))
  irq_work: Slightly simplify IRQ_WORK_PENDING clearing
  irq_work: Fix irq_work_claim() memory ordering
  irq_work: Convert flags to atomic_t
  irqchip: Ingenic: Add process for more than one irq at the same time.
  irqchip: ingenic: Alloc generic chips from IRQ domain
  irqchip: ingenic: Get virq number from IRQ domain
  irqchip: ingenic: Error out if IRQ domain creation failed
  irqchip: ingenic: Drop redundant irq_suspend / irq_resume functions
  ...
</content>
</entry>
<entry>
<title>Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2019-11-27T00:02:40Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-11-27T00:02:40Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=168829ad09ca9cdfdc664b2110d0e3569932c12d'/>
<id>urn:sha1:168829ad09ca9cdfdc664b2110d0e3569932c12d</id>
<content type='text'>
Pull locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - A comprehensive rewrite of the robust/PI futex code's exit handling
     to fix various exit races. (Thomas Gleixner et al)

   - Rework the generic REFCOUNT_FULL implementation using
     atomic_fetch_* operations so that the performance impact of the
     cmpxchg() loops is mitigated for common refcount operations.

     With these performance improvements the generic implementation of
     refcount_t should be good enough for everybody - and this got
     confirmed by performance testing, so remove ARCH_HAS_REFCOUNT and
     REFCOUNT_FULL entirely, leaving the generic implementation enabled
     unconditionally. (Will Deacon)

   - Other misc changes, fixes, cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
  lkdtm: Remove references to CONFIG_REFCOUNT_FULL
  locking/refcount: Remove unused 'refcount_error_report()' function
  locking/refcount: Consolidate implementations of refcount_t
  locking/refcount: Consolidate REFCOUNT_{MAX,SATURATED} definitions
  locking/refcount: Move saturation warnings out of line
  locking/refcount: Improve performance of generic REFCOUNT_FULL code
  locking/refcount: Move the bulk of the REFCOUNT_FULL implementation into the &lt;linux/refcount.h&gt; header
  locking/refcount: Remove unused refcount_*_checked() variants
  locking/refcount: Ensure integer operands are treated as signed
  locking/refcount: Define constants for saturation and max refcount values
  futex: Prevent exit livelock
  futex: Provide distinct return value when owner is exiting
  futex: Add mutex around futex exit
  futex: Provide state handling for exec() as well
  futex: Sanitize exit state handling
  futex: Mark the begin of futex exit explicitly
  futex: Set task::futex_state to DEAD right after handling futex exit
  futex: Split futex_mm_release() for exit/exec
  exit/exec: Seperate mm_release()
  futex: Replace PF_EXITPIDONE with a state
  ...
</content>
</entry>
<entry>
<title>irq_work: Convert flags to atomic_t</title>
<updated>2019-11-11T08:02:56Z</updated>
<author>
<name>Frederic Weisbecker</name>
<email>frederic@kernel.org</email>
</author>
<published>2019-11-08T16:08:55Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=153bedbac2ebd475e1c7c2d2fa0c042f5525927d'/>
<id>urn:sha1:153bedbac2ebd475e1c7c2d2fa0c042f5525927d</id>
<content type='text'>
We need to convert flags to atomic_t in order to later fix an ordering
issue on atomic_cmpxchg() failure. This will allow us to use atomic_fetch_or().

Also clarify the nature of those flags.

[ mingo: Converted two more usage site the original patch missed. ]

Signed-off-by: Frederic Weisbecker &lt;frederic@kernel.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Paul E . McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lkml.kernel.org/r/20191108160858.31665-2-frederic@kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf/stackmap: Fix deadlock with rq_lock in bpf_get_stack()</title>
<updated>2019-10-16T17:37:52Z</updated>
<author>
<name>Song Liu</name>
<email>songliubraving@fb.com</email>
</author>
<published>2019-10-14T17:12:23Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=eac9153f2b584c702cea02c1f1a57d85aa9aea42'/>
<id>urn:sha1:eac9153f2b584c702cea02c1f1a57d85aa9aea42</id>
<content type='text'>
bpf stackmap with build-id lookup (BPF_F_STACK_BUILD_ID) can trigger A-A
deadlock on rq_lock():

rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[...]
Call Trace:
 try_to_wake_up+0x1ad/0x590
 wake_up_q+0x54/0x80
 rwsem_wake+0x8a/0xb0
 bpf_get_stack+0x13c/0x150
 bpf_prog_fbdaf42eded9fe46_on_event+0x5e3/0x1000
 bpf_overflow_handler+0x60/0x100
 __perf_event_overflow+0x4f/0xf0
 perf_swevent_overflow+0x99/0xc0
 ___perf_sw_event+0xe7/0x120
 __schedule+0x47d/0x620
 schedule+0x29/0x90
 futex_wait_queue_me+0xb9/0x110
 futex_wait+0x139/0x230
 do_futex+0x2ac/0xa50
 __x64_sys_futex+0x13c/0x180
 do_syscall_64+0x42/0x100
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

This can be reproduced by:
1. Start a multi-thread program that does parallel mmap() and malloc();
2. taskset the program to 2 CPUs;
3. Attach bpf program to trace_sched_switch and gather stackmap with
   build-id, e.g. with trace.py from bcc tools:
   trace.py -U -p &lt;pid&gt; -s &lt;some-bin,some-lib&gt; t:sched:sched_switch

A sample reproducer is attached at the end.

This could also trigger deadlock with other locks that are nested with
rq_lock.

Fix this by checking whether irqs are disabled. Since rq_lock and all
other nested locks are irq safe, it is safe to do up_read() when irqs are
not disable. If the irqs are disabled, postpone up_read() in irq_work.

Fixes: 615755a77b24 ("bpf: extend stackmap to save binary_build_id+offset instead of address")
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20191014171223.357174-1-songliubraving@fb.com

Reproducer:
============================ 8&lt; ============================

char *filename;

void *worker(void *p)
{
        void *ptr;
        int fd;
        char *pptr;

        fd = open(filename, O_RDONLY);
        if (fd &lt; 0)
                return NULL;
        while (1) {
                struct timespec ts = {0, 1000 + rand() % 2000};

                ptr = mmap(NULL, 4096 * 64, PROT_READ, MAP_PRIVATE, fd, 0);
                usleep(1);
                if (ptr == MAP_FAILED) {
                        printf("failed to mmap\n");
                        break;
                }
                munmap(ptr, 4096 * 64);
                usleep(1);
                pptr = malloc(1);
                usleep(1);
                pptr[0] = 1;
                usleep(1);
                free(pptr);
                usleep(1);
                nanosleep(&amp;ts, NULL);
        }
        close(fd);
        return NULL;
}

int main(int argc, char *argv[])
{
        void *ptr;
        int i;
        pthread_t threads[THREAD_COUNT];

        if (argc &lt; 2)
                return 0;

        filename = argv[1];

        for (i = 0; i &lt; THREAD_COUNT; i++) {
                if (pthread_create(threads + i, NULL, worker, NULL)) {
                        fprintf(stderr, "Error creating thread\n");
                        return 0;
                }
        }

        for (i = 0; i &lt; THREAD_COUNT; i++)
                pthread_join(threads[i], NULL);
        return 0;
}
============================ 8&lt; ============================
</content>
</entry>
<entry>
<title>locking/lockdep: Remove unused @nested argument from lock_release()</title>
<updated>2019-10-09T10:46:10Z</updated>
<author>
<name>Qian Cai</name>
<email>cai@lca.pw</email>
</author>
<published>2019-09-19T16:09:40Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=5facae4f3549b5cf7c0e10ec312a65ffd43b5726'/>
<id>urn:sha1:5facae4f3549b5cf7c0e10ec312a65ffd43b5726</id>
<content type='text'>
Since the following commit:

  b4adfe8e05f1 ("locking/lockdep: Remove unused argument in __lock_release")

@nested is no longer used in lock_release(), so remove it from all
lock_release() calls and friends.

Signed-off-by: Qian Cai &lt;cai@lca.pw&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Will Deacon &lt;will@kernel.org&gt;
Acked-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: alexander.levin@microsoft.com
Cc: daniel@iogearbox.net
Cc: davem@davemloft.net
Cc: dri-devel@lists.freedesktop.org
Cc: duyuyang@gmail.com
Cc: gregkh@linuxfoundation.org
Cc: hannes@cmpxchg.org
Cc: intel-gfx@lists.freedesktop.org
Cc: jack@suse.com
Cc: jlbec@evilplan.or
Cc: joonas.lahtinen@linux.intel.com
Cc: joseph.qi@linux.alibaba.com
Cc: jslaby@suse.com
Cc: juri.lelli@redhat.com
Cc: maarten.lankhorst@linux.intel.com
Cc: mark@fasheh.com
Cc: mhocko@kernel.org
Cc: mripard@kernel.org
Cc: ocfs2-devel@oss.oracle.com
Cc: rodrigo.vivi@intel.com
Cc: sean@poorly.run
Cc: st@kernel.org
Cc: tj@kernel.org
Cc: tytso@mit.edu
Cc: vdavydov.dev@gmail.com
Cc: vincent.guittot@linaro.org
Cc: viro@zeniv.linux.org.uk
Link: https://lkml.kernel.org/r/1568909380-32199-1-git-send-email-cai@lca.pw
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2019-06-07T18:00:14Z</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2019-06-07T18:00:14Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=a6cdeeb16bff89c8486324f53577db058cbe81ba'/>
<id>urn:sha1:a6cdeeb16bff89c8486324f53577db058cbe81ba</id>
<content type='text'>
Some ISDN files that got removed in net-next had some changes
done in mainline, take the removals.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>bpf: move memory size checks to bpf_map_charge_init()</title>
<updated>2019-05-31T23:52:56Z</updated>
<author>
<name>Roman Gushchin</name>
<email>guro@fb.com</email>
</author>
<published>2019-05-30T01:03:59Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=c85d69135a9175c50a823d04d62d932312d037b3'/>
<id>urn:sha1:c85d69135a9175c50a823d04d62d932312d037b3</id>
<content type='text'>
Most bpf map types doing similar checks and bytes to pages
conversion during memory allocation and charging.

Let's unify these checks by moving them into bpf_map_charge_init().

Signed-off-by: Roman Gushchin &lt;guro@fb.com&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: rework memlock-based memory accounting for maps</title>
<updated>2019-05-31T23:52:56Z</updated>
<author>
<name>Roman Gushchin</name>
<email>guro@fb.com</email>
</author>
<published>2019-05-30T01:03:58Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=b936ca643ade11f265fa10e5fb71c20d9c5243f1'/>
<id>urn:sha1:b936ca643ade11f265fa10e5fb71c20d9c5243f1</id>
<content type='text'>
In order to unify the existing memlock charging code with the
memcg-based memory accounting, which will be added later, let's
rework the current scheme.

Currently the following design is used:
  1) .alloc() callback optionally checks if the allocation will likely
     succeed using bpf_map_precharge_memlock()
  2) .alloc() performs actual allocations
  3) .alloc() callback calculates map cost and sets map.memory.pages
  4) map_create() calls bpf_map_init_memlock() which sets map.memory.user
     and performs actual charging; in case of failure the map is
     destroyed
  &lt;map is in use&gt;
  1) bpf_map_free_deferred() calls bpf_map_release_memlock(), which
     performs uncharge and releases the user
  2) .map_free() callback releases the memory

The scheme can be simplified and made more robust:
  1) .alloc() calculates map cost and calls bpf_map_charge_init()
  2) bpf_map_charge_init() sets map.memory.user and performs actual
    charge
  3) .alloc() performs actual allocations
  &lt;map is in use&gt;
  1) .map_free() callback releases the memory
  2) bpf_map_charge_finish() performs uncharge and releases the user

The new scheme also allows to reuse bpf_map_charge_init()/finish()
functions for memcg-based accounting. Because charges are performed
before actual allocations and uncharges after freeing the memory,
no bogus memory pressure can be created.

In cases when the map structure is not available (e.g. it's not
created yet, or is already destroyed), on-stack bpf_map_memory
structure is used. The charge can be transferred with the
bpf_map_charge_move() function.

Signed-off-by: Roman Gushchin &lt;guro@fb.com&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: group memory related fields in struct bpf_map_memory</title>
<updated>2019-05-31T23:52:56Z</updated>
<author>
<name>Roman Gushchin</name>
<email>guro@fb.com</email>
</author>
<published>2019-05-30T01:03:57Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=3539b96e041c06e4317082816d90ec09160aeb11'/>
<id>urn:sha1:3539b96e041c06e4317082816d90ec09160aeb11</id>
<content type='text'>
Group "user" and "pages" fields of bpf_map into the bpf_map_memory
structure. Later it can be extended with "memcg" and other related
information.

The main reason for a such change (beside cosmetics) is to pass
bpf_map_memory structure to charging functions before the actual
allocation of bpf_map.

Signed-off-by: Roman Gushchin &lt;guro@fb.com&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
</entry>
<entry>
<title>treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206</title>
<updated>2019-05-30T18:29:53Z</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-05-28T17:10:09Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=25763b3c864cf517d686661012d184ee47a49b4c'/>
<id>urn:sha1:25763b3c864cf517d686661012d184ee47a49b4c</id>
<content type='text'>
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of version 2 of the gnu general public license as
  published by the free software foundation

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 107 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Reviewed-by: Richard Fontana &lt;rfontana@redhat.com&gt;
Reviewed-by: Steve Winslow &lt;swinslow@gmail.com&gt;
Reviewed-by: Alexios Zavras &lt;alexios.zavras@intel.com&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.615055994@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
