commit f6c052afe6f802d87c74153b7a57c43b2e9faf07 upstream.
Wp-gpios property can be used on NVMEM nodes and the same property can
be also used on MTD NAND nodes. In case of the wp-gpios property is
defined at NAND level node, the GPIO management is done at NAND driver
level. Write protect is disabled when the driver is probed or resumed
and is enabled when the driver is released or suspended.
When no partitions are defined in the NAND DT node, then the NAND DT node
will be passed to NVMEM framework. If wp-gpios property is defined in
this node, the GPIO resource is taken twice and the NAND controller
driver fails to probe.
It would be possible to set config->wp_gpio at MTD level before calling
nvmem_register function but NVMEM framework will toggle this GPIO on
each write when this GPIO should only be controlled at NAND level driver
to ensure that the Write Protect has not been enabled.
A way to fix this conflict is to add a new boolean flag in nvmem_config
named ignore_wp. In case ignore_wp is set, the GPIO resource will
be managed by the provider.
Fixes: 2a127da461a9 ("nvmem: add support for the write-protect pin")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220220151432.16605-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5eaed6eedbe9612f642ad2b880f961d1c6c8ec2b upstream.
The patch in [1] intends to fix a bpf_timer related issue,
but the fix caused existing 'timer' selftest to fail with
hang or some random errors. After some debug, I found
an issue with check_and_init_map_value() in the hashtab.c.
More specifically, in hashtab.c, we have code
l_new = bpf_map_kmalloc_node(&htab->map, ...)
check_and_init_map_value(&htab->map, l_new...)
Note that bpf_map_kmalloc_node() does not do initialization
so l_new contains random value.
The function check_and_init_map_value() intends to zero the
bpf_spin_lock and bpf_timer if they exist in the map.
But I found bpf_spin_lock is zero'ed but bpf_timer is not zero'ed.
With [1], later copy_map_value() skips copying of
bpf_spin_lock and bpf_timer. The non-zero bpf_timer caused
random failures for 'timer' selftest.
Without [1], for both bpf_spin_lock and bpf_timer case,
bpf_timer will be zero'ed, so 'timer' self test is okay.
For check_and_init_map_value(), why bpf_spin_lock is zero'ed
properly while bpf_timer not. In bpf uapi header, we have
struct bpf_spin_lock {
__u32 val;
};
struct bpf_timer {
__u64 :64;
__u64 :64;
} __attribute__((aligned(8)));
The initialization code:
*(struct bpf_spin_lock *)(dst + map->spin_lock_off) =
(struct bpf_spin_lock){};
*(struct bpf_timer *)(dst + map->timer_off) =
(struct bpf_timer){};
It appears the compiler has no obligation to initialize anonymous fields.
For example, let us use clang with bpf target as below:
$ cat t.c
struct bpf_timer {
unsigned long long :64;
};
struct bpf_timer2 {
unsigned long long a;
};
void test(struct bpf_timer *t) {
*t = (struct bpf_timer){};
}
void test2(struct bpf_timer2 *t) {
*t = (struct bpf_timer2){};
}
$ clang -target bpf -O2 -c -g t.c
$ llvm-objdump -d t.o
...
0000000000000000 <test>:
0: 95 00 00 00 00 00 00 00 exit
0000000000000008 <test2>:
1: b7 02 00 00 00 00 00 00 r2 = 0
2: 7b 21 00 00 00 00 00 00 *(u64 *)(r1 + 0) = r2
3: 95 00 00 00 00 00 00 00 exit
gcc11.2 does not have the above issue. But from
INTERNATIONAL STANDARD ©ISO/IEC ISO/IEC 9899:201x
Programming languages — C
http://www.open-std.org/Jtc1/sc22/wg14/www/docs/n1547.pdf
page 157:
Except where explicitly stated otherwise, for the purposes of
this subclause unnamed members of objects of structure and union
type do not participate in initialization. Unnamed members of
structure objects have indeterminate value even after initialization.
To fix the problem, let use memset for bpf_timer case in
check_and_init_map_value(). For consistency, memset is also
used for bpf_spin_lock case.
[1] https://lore.kernel.org/bpf/20220209070324.1093182-2-memxor@gmail.com/
Fixes: 68134668c17f3 ("bpf: Add map side support for bpf timers.")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220211194953.3142152-1-yhs@fb.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a8abb0c3dc1e28454851a00f8b7333d9695d566c upstream.
When both bpf_spin_lock and bpf_timer are present in a BPF map value,
copy_map_value needs to skirt both objects when copying a value into and
out of the map. However, the current code does not set both s_off and
t_off in copy_map_value, which leads to a crash when e.g. bpf_spin_lock
is placed in map value with bpf_timer, as bpf_map_update_elem call will
be able to overwrite the other timer object.
When the issue is not fixed, an overwriting can produce the following
splat:
[root@(none) bpf]# ./test_progs -t timer_crash
[ 15.930339] bpf_testmod: loading out-of-tree module taints kernel.
[ 16.037849] ==================================================================
[ 16.038458] BUG: KASAN: user-memory-access in __pv_queued_spin_lock_slowpath+0x32b/0x520
[ 16.038944] Write of size 8 at addr 0000000000043ec0 by task test_progs/325
[ 16.039399]
[ 16.039514] CPU: 0 PID: 325 Comm: test_progs Tainted: G OE 5.16.0+ #278
[ 16.039983] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ArchLinux 1.15.0-1 04/01/2014
[ 16.040485] Call Trace:
[ 16.040645] <TASK>
[ 16.040805] dump_stack_lvl+0x59/0x73
[ 16.041069] ? __pv_queued_spin_lock_slowpath+0x32b/0x520
[ 16.041427] kasan_report.cold+0x116/0x11b
[ 16.041673] ? __pv_queued_spin_lock_slowpath+0x32b/0x520
[ 16.042040] __pv_queued_spin_lock_slowpath+0x32b/0x520
[ 16.042328] ? memcpy+0x39/0x60
[ 16.042552] ? pv_hash+0xd0/0xd0
[ 16.042785] ? lockdep_hardirqs_off+0x95/0xd0
[ 16.043079] __bpf_spin_lock_irqsave+0xdf/0xf0
[ 16.043366] ? bpf_get_current_comm+0x50/0x50
[ 16.043608] ? jhash+0x11a/0x270
[ 16.043848] bpf_timer_cancel+0x34/0xe0
[ 16.044119] bpf_prog_c4ea1c0f7449940d_sys_enter+0x7c/0x81
[ 16.044500] bpf_trampoline_6442477838_0+0x36/0x1000
[ 16.044836] __x64_sys_nanosleep+0x5/0x140
[ 16.045119] do_syscall_64+0x59/0x80
[ 16.045377] ? lock_is_held_type+0xe4/0x140
[ 16.045670] ? irqentry_exit_to_user_mode+0xa/0x40
[ 16.046001] ? mark_held_locks+0x24/0x90
[ 16.046287] ? asm_exc_page_fault+0x1e/0x30
[ 16.046569] ? asm_exc_page_fault+0x8/0x30
[ 16.046851] ? lockdep_hardirqs_on+0x7e/0x100
[ 16.047137] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 16.047405] RIP: 0033:0x7f9e4831718d
[ 16.047602] Code: b4 0c 00 0f 05 eb a9 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b3 6c 0c 00 f7 d8 64 89 01 48
[ 16.048764] RSP: 002b:00007fff488086b8 EFLAGS: 00000206 ORIG_RAX: 0000000000000023
[ 16.049275] RAX: ffffffffffffffda RBX: 00007f9e48683740 RCX: 00007f9e4831718d
[ 16.049747] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fff488086d0
[ 16.050225] RBP: 00007fff488086f0 R08: 00007fff488085d7 R09: 00007f9e4cb594a0
[ 16.050648] R10: 0000000000000000 R11: 0000000000000206 R12: 00007f9e484cde30
[ 16.051124] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 16.051608] </TASK>
[ 16.051762] ==================================================================
Fixes: 68134668c17f ("bpf: Add map side support for bpf timers.")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220209070324.1093182-2-memxor@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1e2c3ef0496e72ba9001da5fd1b7ed56ccb30597 upstream. Exports the two functions teedev_open() and teedev_close_context() in order to make it easier to create a driver internal struct tee_context. Reviewed-by: Sumit Garg <sumit.garg@linaro.org> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit bfb1a7c91fb7758273b4a8d735313d9cc388b502 ]
In __WARN_FLAGS(), we had two asm statements (abbreviated):
asm volatile("ud2");
asm volatile(".pushsection .discard.reachable");
These pair of statements are used to trigger an exception, but then help
objtool understand that for warnings, control flow will be restored
immediately afterwards.
The problem is that volatile is not a compiler barrier. GCC explicitly
documents this:
> Note that the compiler can move even volatile asm instructions
> relative to other code, including across jump instructions.
Also, no clobbers are specified to prevent instructions from subsequent
statements from being scheduled by compiler before the second asm
statement. This can lead to instructions from subsequent statements
being emitted by the compiler before the second asm statement.
Providing a scheduling model such as via -march= options enables the
compiler to better schedule instructions with known latencies to hide
latencies from data hazards compared to inline asm statements in which
latencies are not estimated.
If an instruction gets scheduled by the compiler between the two asm
statements, then objtool will think that it is not reachable, producing
a warning.
To prevent instructions from being scheduled in between the two asm
statements, merge them.
Also remove an unnecessary unreachable() asm annotation from BUG() in
favor of __builtin_unreachable(). objtool is able to track that the ud2
from BUG() terminates control flow within the function.
Link: https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Volatile
Link: https://github.com/ClangBuiltLinux/linux/issues/1483
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220202205557.2260694-1-ndesaulniers@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7a5428dcb7902700b830e912feee4e845df7c019 upstream.
Various block drivers call blk_set_queue_dying to mark a disk as dead due
to surprise removal events, but since commit 8e141f9eb803 that doesn't
work given that the GD_DEAD flag needs to be set to stop I/O.
Replace the driver calls to blk_set_queue_dying with a new (and properly
documented) blk_mark_disk_dead API, and fold blk_set_queue_dying into the
only remaining caller.
Fixes: 8e141f9eb803 ("block: drain file system I/O on del_gendisk")
Reported-by: Markus Blöchl <markus.bloechl@ipetronik.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Link: https://lore.kernel.org/r/20220217075231.1140-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5891cd5ec46c2c2eb6427cb54d214b149635dd0e upstream.
syzbot found a data-race [1] which lead me to add __rcu
annotations to netdev->qdisc, and proper accessors
to get LOCKDEP support.
[1]
BUG: KCSAN: data-race in dev_activate / qdisc_lookup_rcu
write to 0xffff888168ad6410 of 8 bytes by task 13559 on cpu 1:
attach_default_qdiscs net/sched/sch_generic.c:1167 [inline]
dev_activate+0x2ed/0x8f0 net/sched/sch_generic.c:1221
__dev_open+0x2e9/0x3a0 net/core/dev.c:1416
__dev_change_flags+0x167/0x3f0 net/core/dev.c:8139
rtnl_configure_link+0xc2/0x150 net/core/rtnetlink.c:3150
__rtnl_newlink net/core/rtnetlink.c:3489 [inline]
rtnl_newlink+0xf4d/0x13e0 net/core/rtnetlink.c:3529
rtnetlink_rcv_msg+0x745/0x7e0 net/core/rtnetlink.c:5594
netlink_rcv_skb+0x14e/0x250 net/netlink/af_netlink.c:2494
rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5612
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x602/0x6d0 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x728/0x850 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:705 [inline]
sock_sendmsg net/socket.c:725 [inline]
____sys_sendmsg+0x39a/0x510 net/socket.c:2413
___sys_sendmsg net/socket.c:2467 [inline]
__sys_sendmsg+0x195/0x230 net/socket.c:2496
__do_sys_sendmsg net/socket.c:2505 [inline]
__se_sys_sendmsg net/socket.c:2503 [inline]
__x64_sys_sendmsg+0x42/0x50 net/socket.c:2503
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
read to 0xffff888168ad6410 of 8 bytes by task 13560 on cpu 0:
qdisc_lookup_rcu+0x30/0x2e0 net/sched/sch_api.c:323
__tcf_qdisc_find+0x74/0x3a0 net/sched/cls_api.c:1050
tc_del_tfilter+0x1c7/0x1350 net/sched/cls_api.c:2211
rtnetlink_rcv_msg+0x5ba/0x7e0 net/core/rtnetlink.c:5585
netlink_rcv_skb+0x14e/0x250 net/netlink/af_netlink.c:2494
rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5612
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x602/0x6d0 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x728/0x850 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:705 [inline]
sock_sendmsg net/socket.c:725 [inline]
____sys_sendmsg+0x39a/0x510 net/socket.c:2413
___sys_sendmsg net/socket.c:2467 [inline]
__sys_sendmsg+0x195/0x230 net/socket.c:2496
__do_sys_sendmsg net/socket.c:2505 [inline]
__se_sys_sendmsg net/socket.c:2503 [inline]
__x64_sys_sendmsg+0x42/0x50 net/socket.c:2503
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
value changed: 0xffffffff85dee080 -> 0xffff88815d96ec00
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13560 Comm: syz-executor.2 Not tainted 5.17.0-rc3-syzkaller-00116-gf1baf68e1383-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Fixes: 470502de5bdb ("net: sched: unlock rules update API")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 67d6212afda218d564890d1674bab28e8612170f ]
This reverts commit 774a1221e862b343388347bac9b318767336b20b.
We need to finish all async code before the module init sequence is
done. In the reverted commit the PF_USED_ASYNC flag was added to mark a
thread that called async_schedule(). Then the PF_USED_ASYNC flag was
used to determine whether or not async_synchronize_full() needs to be
invoked. This works when modprobe thread is calling async_schedule(),
but it does not work if module dispatches init code to a worker thread
which then calls async_schedule().
For example, PCI driver probing is invoked from a worker thread based on
a node where device is attached:
if (cpu < nr_cpu_ids)
error = work_on_cpu(cpu, local_pci_probe, &ddi);
else
error = local_pci_probe(&ddi);
We end up in a situation where a worker thread gets the PF_USED_ASYNC
flag set instead of the modprobe thread. As a result,
async_synchronize_full() is not invoked and modprobe completes without
waiting for the async code to finish.
The issue was discovered while loading the pm80xx driver:
(scsi_mod.scan=async)
modprobe pm80xx worker
...
do_init_module()
...
pci_call_probe()
work_on_cpu(local_pci_probe)
local_pci_probe()
pm8001_pci_probe()
scsi_scan_host()
async_schedule()
worker->flags |= PF_USED_ASYNC;
...
< return from worker >
...
if (current->flags & PF_USED_ASYNC) <--- false
async_synchronize_full();
Commit 21c3c5d28007 ("block: don't request module during elevator init")
fixed the deadlock issue which the reverted commit 774a1221e862
("module, async: async_synchronize_full() on module init iff async is
used") tried to fix.
Since commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
request_module() from async workers") synchronous module loading from
async is not allowed.
Given that the original deadlock issue is fixed and it is no longer
allowed to call synchronous request_module() from async we can remove
PF_USED_ASYNC flag to make module init consistently invoke
async_synchronize_full() unless async module probe is requested.
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Reviewed-by: Changyuan Lyu <changyuanl@google.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0764db9b49c932b89ee4d9e3236dff4bb07b4a66 upstream.
Alexander reported a circular lock dependency revealed by the mmap1 ltp
test:
LOCKDEP_CIRCULAR (suite: ltp, case: mtest06 (mmap1))
WARNING: possible circular locking dependency detected
5.17.0-20220113.rc0.git0.f2211f194038.300.fc35.s390x+debug #1 Not tainted
------------------------------------------------------
mmap1/202299 is trying to acquire lock:
00000001892c0188 (css_set_lock){..-.}-{2:2}, at: obj_cgroup_release+0x4a/0xe0
but task is already holding lock:
00000000ca3b3818 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x38/0x180
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&sighand->siglock){-.-.}-{2:2}:
__lock_acquire+0x604/0xbd8
lock_acquire.part.0+0xe2/0x238
lock_acquire+0xb0/0x200
_raw_spin_lock_irqsave+0x6a/0xd8
__lock_task_sighand+0x90/0x190
cgroup_freeze_task+0x2e/0x90
cgroup_migrate_execute+0x11c/0x608
cgroup_update_dfl_csses+0x246/0x270
cgroup_subtree_control_write+0x238/0x518
kernfs_fop_write_iter+0x13e/0x1e0
new_sync_write+0x100/0x190
vfs_write+0x22c/0x2d8
ksys_write+0x6c/0xf8
__do_syscall+0x1da/0x208
system_call+0x82/0xb0
-> #0 (css_set_lock){..-.}-{2:2}:
check_prev_add+0xe0/0xed8
validate_chain+0x736/0xb20
__lock_acquire+0x604/0xbd8
lock_acquire.part.0+0xe2/0x238
lock_acquire+0xb0/0x200
_raw_spin_lock_irqsave+0x6a/0xd8
obj_cgroup_release+0x4a/0xe0
percpu_ref_put_many.constprop.0+0x150/0x168
drain_obj_stock+0x94/0xe8
refill_obj_stock+0x94/0x278
obj_cgroup_charge+0x164/0x1d8
kmem_cache_alloc+0xac/0x528
__sigqueue_alloc+0x150/0x308
__send_signal+0x260/0x550
send_signal+0x7e/0x348
force_sig_info_to_task+0x104/0x180
force_sig_fault+0x48/0x58
__do_pgm_check+0x120/0x1f0
pgm_check_handler+0x11e/0x180
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sighand->siglock);
lock(css_set_lock);
lock(&sighand->siglock);
lock(css_set_lock);
*** DEADLOCK ***
2 locks held by mmap1/202299:
#0: 00000000ca3b3818 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x38/0x180
#1: 00000001892ad560 (rcu_read_lock){....}-{1:2}, at: percpu_ref_put_many.constprop.0+0x0/0x168
stack backtrace:
CPU: 15 PID: 202299 Comm: mmap1 Not tainted 5.17.0-20220113.rc0.git0.f2211f194038.300.fc35.s390x+debug #1
Hardware name: IBM 3906 M04 704 (LPAR)
Call Trace:
dump_stack_lvl+0x76/0x98
check_noncircular+0x136/0x158
check_prev_add+0xe0/0xed8
validate_chain+0x736/0xb20
__lock_acquire+0x604/0xbd8
lock_acquire.part.0+0xe2/0x238
lock_acquire+0xb0/0x200
_raw_spin_lock_irqsave+0x6a/0xd8
obj_cgroup_release+0x4a/0xe0
percpu_ref_put_many.constprop.0+0x150/0x168
drain_obj_stock+0x94/0xe8
refill_obj_stock+0x94/0x278
obj_cgroup_charge+0x164/0x1d8
kmem_cache_alloc+0xac/0x528
__sigqueue_alloc+0x150/0x308
__send_signal+0x260/0x550
send_signal+0x7e/0x348
force_sig_info_to_task+0x104/0x180
force_sig_fault+0x48/0x58
__do_pgm_check+0x120/0x1f0
pgm_check_handler+0x11e/0x180
INFO: lockdep is turned off.
In this example a slab allocation from __send_signal() caused a
refilling and draining of a percpu objcg stock, resulted in a releasing
of another non-related objcg. Objcg release path requires taking the
css_set_lock, which is used to synchronize objcg lists.
This can create a circular dependency with the sighandler lock, which is
taken with the locked css_set_lock by the freezer code (to freeze a
task).
In general it seems that using css_set_lock to synchronize objcg lists
makes any slab allocations and deallocation with the locked css_set_lock
and any intervened locks risky.
To fix the problem and make the code more robust let's stop using
css_set_lock to synchronize objcg lists and use a new dedicated spinlock
instead.
Link: https://lkml.kernel.org/r/Yfm1IHmoGdyUR81T@carbon.dhcp.thefacebook.com
Fixes: bf4f059954dc ("mm: memcg/slab: obj_cgroup API")
Signed-off-by: Roman Gushchin <guro@fb.com>
Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cb1f65c1e1424a4b5e4a86da8aa3b8fd8459c8ec upstream.
After commit e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race
related to the EC GPE") wakeup interrupts occurring immediately after
the one discarded by acpi_s2idle_wake() may be missed. Moreover, if
the SCI triggers again immediately after the rearming in
acpi_s2idle_wake(), that wakeup may be missed too.
The problem is that pm_system_irq_wakeup() only calls pm_system_wakeup()
when pm_wakeup_irq is 0, but that's not the case any more after the
interrupt causing acpi_s2idle_wake() to run until pm_wakeup_irq is
cleared by the pm_wakeup_clear() call in s2idle_loop(). However,
there may be wakeup interrupts occurring in that time frame and if
that happens, they will be missed.
To address that issue first move the clearing of pm_wakeup_irq to
the point at which it is known that the interrupt causing
acpi_s2idle_wake() to tun will be discarded, before rearming the SCI
for wakeup. Moreover, because that only reduces the size of the
time window in which the issue may manifest itself, allow
pm_system_irq_wakeup() to register two second wakeup interrupts in
a row and, when discarding the first one, replace it with the second
one. [Of course, this assumes that only one wakeup interrupt can be
discarded in one go, but currently that is the case and I am not
aware of any plans to change that.]
Fixes: e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race related to the EC GPE")
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>