commit d7852fbd0f0423937fa287a598bfde188bb68c22 upstream. It turns out that 'access()' (and 'faccessat()') can cause a lot of RCU work because it installs a temporary credential that gets allocated and freed for each system call. The allocation and freeing overhead is mostly benign, but because credentials can be accessed under the RCU read lock, the freeing involves a RCU grace period. Which is not a huge deal normally, but if you have a lot of access() calls, this causes a fair amount of seconday damage: instead of having a nice alloc/free patterns that hits in hot per-CPU slab caches, you have all those delayed free's, and on big machines with hundreds of cores, the RCU overhead can end up being enormous. But it turns out that all of this is entirely unnecessary. Exactly because access() only installs the credential as the thread-local subjective credential, the temporary cred pointer doesn't actually need to be RCU free'd at all. Once we're done using it, we can just free it synchronously and avoid all the RCU overhead. So add a 'non_rcu' flag to 'struct cred', which can be set by users that know they only use it in non-RCU context (there are other potential users for this). We can make it a union with the rcu freeing list head that we need for the RCU case, so this doesn't need any extra storage. Note that this also makes 'get_current_cred()' clear the new non_rcu flag, in case we have filesystems that take a long-term reference to the cred and then expect the RCU delayed freeing afterwards. It's not entirely clear that this is required, but it makes for clear semantics: the subjective cred remains non-RCU as long as you only access it synchronously using the thread-local accessors, but you _can_ use it as a generic cred if you want to. It is possible that we should just remove the whole RCU markings for ->cred entirely. Only ->real_cred is really supposed to be accessed through RCU, and the long-term cred copies that nfs uses might want to explicitly re-enable RCU freeing if required, rather than have get_current_cred() do it implicitly. But this is a "minimal semantic changes" change for the immediate problem. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Paul E. McKenney <paulmck@linux.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Jan Glauber <jglauber@marvell.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Jayachandran Chandrasekharan Nair <jnair@marvell.com> Cc: Greg KH <greg@kroah.com> Cc: Kees Cook <keescook@chromium.org> Cc: David Howells <dhowells@redhat.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 68037aa78208f34bda4e5cd76c357f718b838cbb ]
The usage is now hidden in an #ifdef, so we need to move
the variable itself in there as well to avoid this warning:
kernel/locking/lockdep_proc.c:203:21: error: unused variable 'class' [-Werror,-Wunused-variable]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yuyang Du <duyuyang@gmail.com>
Cc: frederic@kernel.org
Fixes: 68d41d8c94a3 ("locking/lockdep: Fix lock used or unused stats error")
Link: https://lkml.kernel.org/r/20190715092809.736834-1-arnd@arndb.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 68d41d8c94a31dfb8233ab90b9baf41a2ed2da68 ]
The stats variable nr_unused_locks is incremented every time a new lock
class is register and decremented when the lock is first used in
__lock_acquire(). And after all, it is shown and checked in lockdep_stats.
However, under configurations that either CONFIG_TRACE_IRQFLAGS or
CONFIG_PROVE_LOCKING is not defined:
The commit:
091806515124b20 ("locking/lockdep: Consolidate lock usage bit initialization")
missed marking the LOCK_USED flag at IRQ usage initialization because
as mark_usage() is not called. And the commit:
886532aee3cd42d ("locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING")
further made mark_lock() not defined such that the LOCK_USED cannot be
marked at all when the lock is first acquired.
As a result, we fix this by not showing and checking the stats under such
configurations for lockdep_stats.
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: arnd@arndb.de
Cc: frederic@kernel.org
Link: https://lkml.kernel.org/r/20190709101522.9117-1-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4b4b077cbd0a998aebaa72c199e06b8a4c8dcfee ] With architectures allowing the kernel to be placed almost arbitrarily in memory (e.g.: ARM64), it is possible to have the kernel resides at physical addresses above 4GB, resulting in neither the default CMA area, nor the atomic pool from successfully allocating. This does not prevent specific peripherals from working though, one example is XHCI, which still operates correctly. Trouble comes when the XHCI driver gets suspended and resumed, since we can now trigger the following NPD: [ 12.664170] usb usb1: root hub lost power or was reset [ 12.669387] usb usb2: root hub lost power or was reset [ 12.674662] Unable to handle kernel NULL pointer dereference at virtual address 00000008 [ 12.682896] pgd = ffffffc1365a7000 [ 12.686386] [00000008] *pgd=0000000136500003, *pud=0000000136500003, *pmd=0000000000000000 [ 12.694897] Internal error: Oops: 96000006 [#1] SMP [ 12.699843] Modules linked in: [ 12.702980] CPU: 0 PID: 1499 Comm: pml Not tainted 4.9.135-1.13pre #51 [ 12.709577] Hardware name: BCM97268DV (DT) [ 12.713736] task: ffffffc136bb6540 task.stack: ffffffc1366cc000 [ 12.719740] PC is at addr_in_gen_pool+0x4/0x48 [ 12.724253] LR is at __dma_free+0x64/0xbc [ 12.728325] pc : [<ffffff80083c0df8>] lr : [<ffffff80080979e0>] pstate: 60000145 [ 12.735825] sp : ffffffc1366cf990 [ 12.739196] x29: ffffffc1366cf990 x28: ffffffc1366cc000 [ 12.744608] x27: 0000000000000000 x26: ffffffc13a8568c8 [ 12.750020] x25: 0000000000000000 x24: ffffff80098f9000 [ 12.755433] x23: 000000013a5ff000 x22: ffffff8009c57000 [ 12.760844] x21: ffffffc13a856810 x20: 0000000000000000 [ 12.766255] x19: 0000000000001000 x18: 000000000000000a [ 12.771667] x17: 0000007f917553e0 x16: 0000000000001002 [ 12.777078] x15: 00000000000a36cb x14: ffffff80898feb77 [ 12.782490] x13: ffffffffffffffff x12: 0000000000000030 [ 12.787899] x11: 00000000fffffffe x10: ffffff80098feb7f [ 12.793311] x9 : 0000000005f5e0ff x8 : 65776f702074736f [ 12.798723] x7 : 6c2062756820746f x6 : ffffff80098febb1 [ 12.804134] x5 : ffffff800809797c x4 : 0000000000000000 [ 12.809545] x3 : 000000013a5ff000 x2 : 0000000000000fff [ 12.814955] x1 : ffffff8009c57000 x0 : 0000000000000000 [ 12.820363] [ 12.821907] Process pml (pid: 1499, stack limit = 0xffffffc1366cc020) [ 12.828421] Stack: (0xffffffc1366cf990 to 0xffffffc1366d0000) [ 12.834240] f980: ffffffc1366cf9e0 ffffff80086004d0 [ 12.842186] f9a0: ffffffc13ab08238 0000000000000010 ffffff80097c2218 ffffffc13a856810 [ 12.850131] f9c0: ffffff8009c57000 000000013a5ff000 0000000000000008 000000013a5ff000 [ 12.858076] f9e0: ffffffc1366cfa50 ffffff80085f9250 ffffffc13ab08238 0000000000000004 [ 12.866021] fa00: ffffffc13ab08000 ffffff80097b6000 ffffffc13ab08130 0000000000000001 [ 12.873966] fa20: 0000000000000008 ffffffc13a8568c8 0000000000000000 ffffffc1366cc000 [ 12.881911] fa40: ffffffc13ab08130 0000000000000001 ffffffc1366cfa90 ffffff80085e3de8 [ 12.889856] fa60: ffffffc13ab08238 0000000000000000 ffffffc136b75b00 0000000000000000 [ 12.897801] fa80: 0000000000000010 ffffff80089ccb92 ffffffc1366cfac0 ffffff80084ad040 [ 12.905746] faa0: ffffffc13a856810 0000000000000000 ffffff80084ad004 ffffff80084b91a8 [ 12.913691] fac0: ffffffc1366cfae0 ffffff80084b91b4 ffffffc13a856810 ffffff80080db5cc [ 12.921636] fae0: ffffffc1366cfb20 ffffff80084b96bc ffffffc13a856810 0000000000000010 [ 12.929581] fb00: ffffffc13a856870 0000000000000000 ffffffc13a856810 ffffff800984d2b8 [ 12.937526] fb20: ffffffc1366cfb50 ffffff80084baa70 ffffff8009932ad0 ffffff800984d260 [ 12.945471] fb40: 0000000000000010 00000002eff0a065 ffffffc1366cfbb0 ffffff80084bafbc [ 12.953415] fb60: 0000000000000010 0000000000000003 ffffff80098fe000 0000000000000000 [ 12.961360] fb80: ffffff80097b6000 ffffff80097b6dc8 ffffff80098c12b8 ffffff80098c12f8 [ 12.969306] fba0: ffffff8008842000 ffffff80097b6dc8 ffffffc1366cfbd0 ffffff80080e0d88 [ 12.977251] fbc0: 00000000fffffffb ffffff80080e10bc ffffffc1366cfc60 ffffff80080e16a8 [ 12.985196] fbe0: 0000000000000000 0000000000000003 ffffff80097b6000 ffffff80098fe9f0 [ 12.993140] fc00: ffffff80097d4000 ffffff8008983802 0000000000000123 0000000000000040 [ 13.001085] fc20: ffffff8008842000 ffffffc1366cc000 ffffff80089803c2 00000000ffffffff [ 13.009029] fc40: 0000000000000000 0000000000000000 ffffffc1366cfc60 0000000000040987 [ 13.016974] fc60: ffffffc1366cfcc0 ffffff80080dfd08 0000000000000003 0000000000000004 [ 13.024919] fc80: 0000000000000003 ffffff80098fea08 ffffffc136577ec0 ffffff80089803c2 [ 13.032864] fca0: 0000000000000123 0000000000000001 0000000500000002 0000000000040987 [ 13.040809] fcc0: ffffffc1366cfd00 ffffff80083a89d4 0000000000000004 ffffffc136577ec0 [ 13.048754] fce0: ffffffc136610cc0 ffffffffffffffea ffffffc1366cfeb0 ffffffc136610cd8 [ 13.056700] fd00: ffffffc1366cfd10 ffffff800822a614 ffffffc1366cfd40 ffffff80082295d4 [ 13.064645] fd20: 0000000000000004 ffffffc136577ec0 ffffffc136610cc0 0000000021670570 [ 13.072590] fd40: ffffffc1366cfd80 ffffff80081b5d10 ffffff80097b6000 ffffffc13aae4200 [ 13.080536] fd60: ffffffc1366cfeb0 0000000000000004 0000000021670570 0000000000000004 [ 13.088481] fd80: ffffffc1366cfe30 ffffff80081b6b20 ffffffc13aae4200 0000000000000000 [ 13.096427] fda0: 0000000000000004 0000000021670570 ffffffc1366cfeb0 ffffffc13a838200 [ 13.104371] fdc0: 0000000000000000 000000000000000a ffffff80097b6000 0000000000040987 [ 13.112316] fde0: ffffffc1366cfe20 ffffff80081b3af0 ffffffc13a838200 0000000000000000 [ 13.120261] fe00: ffffffc1366cfe30 ffffff80081b6b0c ffffffc13aae4200 0000000000000000 [ 13.128206] fe20: 0000000000000004 0000000000040987 ffffffc1366cfe70 ffffff80081b7dd8 [ 13.136151] fe40: ffffff80097b6000 ffffffc13aae4200 ffffffc13aae4200 fffffffffffffff7 [ 13.144096] fe60: 0000000021670570 ffffffc13a8c63c0 0000000000000000 ffffff8008083180 [ 13.152042] fe80: ffffffffffffff1d 0000000021670570 ffffffffffffffff 0000007f917ad9b8 [ 13.159986] fea0: 0000000020000000 0000000000000015 0000000000000000 0000000000040987 [ 13.167930] fec0: 0000000000000001 0000000021670570 0000000000000004 0000000000000000 [ 13.175874] fee0: 0000000000000888 0000440110000000 000000000000006d 0000000000000003 [ 13.183819] ff00: 0000000000000040 ffffff80ffffffc8 0000000000000000 0000000000000020 [ 13.191762] ff20: 0000000000000000 0000000000000000 0000000000000001 0000000000000000 [ 13.199707] ff40: 0000000000000000 0000007f917553e0 0000000000000000 0000000000000004 [ 13.207651] ff60: 0000000021670570 0000007f91835480 0000000000000004 0000007f91831638 [ 13.215595] ff80: 0000000000000004 00000000004b0de0 00000000004b0000 0000000000000000 [ 13.223539] ffa0: 0000000000000000 0000007fc92ac8c0 0000007f9175d178 0000007fc92ac8c0 [ 13.231483] ffc0: 0000007f917ad9b8 0000000020000000 0000000000000001 0000000000000040 [ 13.239427] ffe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 13.247360] Call trace: [ 13.249866] Exception stack(0xffffffc1366cf7a0 to 0xffffffc1366cf8d0) [ 13.256386] f7a0: 0000000000001000 0000007fffffffff ffffffc1366cf990 ffffff80083c0df8 [ 13.264331] f7c0: 0000000060000145 ffffff80089b5001 ffffffc13ab08130 0000000000000001 [ 13.272275] f7e0: 0000000000000008 ffffffc13a8568c8 0000000000000000 0000000000000000 [ 13.280220] f800: ffffffc1366cf960 ffffffc1366cf960 ffffffc1366cf930 00000000ffffffd8 [ 13.288165] f820: ffffff8009931ac0 4554535953425553 4544006273753d4d 3831633d45434956 [ 13.296110] f840: ffff003832313a39 ffffff800845926c ffffffc1366cf880 0000000000040987 [ 13.304054] f860: 0000000000000000 ffffff8009c57000 0000000000000fff 000000013a5ff000 [ 13.311999] f880: 0000000000000000 ffffff800809797c ffffff80098febb1 6c2062756820746f [ 13.319944] f8a0: 65776f702074736f 0000000005f5e0ff ffffff80098feb7f 00000000fffffffe [ 13.327884] f8c0: 0000000000000030 ffffffffffffffff [ 13.332835] [<ffffff80083c0df8>] addr_in_gen_pool+0x4/0x48 [ 13.338398] [<ffffff80086004d0>] xhci_mem_cleanup+0xc8/0x51c [ 13.344137] [<ffffff80085f9250>] xhci_resume+0x308/0x65c [ 13.349524] [<ffffff80085e3de8>] xhci_brcm_resume+0x84/0x8c [ 13.355174] [<ffffff80084ad040>] platform_pm_resume+0x3c/0x64 [ 13.360997] [<ffffff80084b91b4>] dpm_run_callback+0x5c/0x15c [ 13.366732] [<ffffff80084b96bc>] device_resume+0xc0/0x190 [ 13.372205] [<ffffff80084baa70>] dpm_resume+0x144/0x2cc [ 13.377504] [<ffffff80084bafbc>] dpm_resume_end+0x20/0x34 [ 13.382980] [<ffffff80080e0d88>] suspend_devices_and_enter+0x104/0x704 [ 13.389585] [<ffffff80080e16a8>] pm_suspend+0x320/0x53c [ 13.394881] [<ffffff80080dfd08>] state_store+0xbc/0xe0 [ 13.400094] [<ffffff80083a89d4>] kobj_attr_store+0x14/0x24 [ 13.405655] [<ffffff800822a614>] sysfs_kf_write+0x60/0x70 [ 13.411128] [<ffffff80082295d4>] kernfs_fop_write+0x130/0x194 [ 13.416954] [<ffffff80081b5d10>] __vfs_write+0x60/0x150 [ 13.422254] [<ffffff80081b6b20>] vfs_write+0xc8/0x164 [ 13.427376] [<ffffff80081b7dd8>] SyS_write+0x70/0xc8 [ 13.432412] [<ffffff8008083180>] el0_svc_naked+0x34/0x38 [ 13.437800] Code: 92800173 97f6fb9e 17fffff5 d1000442 (f8408c03) [ 13.444033] ---[ end trace 2effe12f909ce205 ]--- The call path leading to this problem is xhci_mem_cleanup() -> dma_free_coherent() -> dma_free_from_pool() -> addr_in_gen_pool. If the atomic_pool is NULL, we can't possibly have the address in the atomic pool anyway, so guard against that. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1cf8dfe8a661f0462925df943140e9f6d1ea5233 upstream.
Syzcaller reported the following Use-after-Free bug:
close() clone()
copy_process()
perf_event_init_task()
perf_event_init_context()
mutex_lock(parent_ctx->mutex)
inherit_task_group()
inherit_group()
inherit_event()
mutex_lock(event->child_mutex)
// expose event on child list
list_add_tail()
mutex_unlock(event->child_mutex)
mutex_unlock(parent_ctx->mutex)
...
goto bad_fork_*
bad_fork_cleanup_perf:
perf_event_free_task()
perf_release()
perf_event_release_kernel()
list_for_each_entry()
mutex_lock(ctx->mutex)
mutex_lock(event->child_mutex)
// event is from the failing inherit
// on the other CPU
perf_remove_from_context()
list_move()
mutex_unlock(event->child_mutex)
mutex_unlock(ctx->mutex)
mutex_lock(ctx->mutex)
list_for_each_entry_safe()
// event already stolen
mutex_unlock(ctx->mutex)
delayed_free_task()
free_task()
list_for_each_entry_safe()
list_del()
free_event()
_free_event()
// and so event->hw.target
// is the already freed failed clone()
if (event->hw.target)
put_task_struct(event->hw.target)
// WHOOPSIE, already quite dead
Which puts the lie to the the comment on perf_event_free_task():
'unexposed, unused context' not so much.
Which is a 'fun' confluence of fail; copy_process() doing an
unconditional free_task() and not respecting refcounts, and perf having
creative locking. In particular:
82d94856fa22 ("perf/core: Fix lock inversion between perf,trace,cpuhp")
seems to have overlooked this 'fun' parade.
Solve it by using the fact that detached events still have a reference
count on their (previous) context. With this perf_event_free_task()
can detect when events have escaped and wait for their destruction.
Debugged-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reported-by: syzbot+a24c397a29ad22d86c98@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 82d94856fa22 ("perf/core: Fix lock inversion between perf,trace,cpuhp")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8a58ddae23796c733c5dfbd717538d89d036c5bd upstream.
So far, we tried to disallow grouping exclusive events for the fear of
complications they would cause with moving between contexts. Specifically,
moving a software group to a hardware context would violate the exclusivity
rules if both groups contain matching exclusive events.
This attempt was, however, unsuccessful: the check that we have in the
perf_event_open() syscall is both wrong (looks at wrong PMU) and
insufficient (group leader may still be exclusive), as can be illustrated
by running:
$ perf record -e '{intel_pt//,cycles}' uname
$ perf record -e '{cycles,intel_pt//}' uname
ultimately successfully.
Furthermore, we are completely free to trigger the exclusivity violation
by:
perf -e '{cycles,intel_pt//}' -e '{intel_pt//,instructions}'
even though the helpful perf record will not allow that, the ABI will.
The warning later in the perf_event_open() path will also not trigger, because
it's also wrong.
Fix all this by validating the original group before moving, getting rid
of broken safeguards and placing a useful one to perf_install_in_context().
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: mathieu.poirier@linaro.org
Cc: will.deacon@arm.com
Fixes: bed5b25ad9c8a ("perf: Add a pmu capability for "exclusive" events")
Link: https://lkml.kernel.org/r/20190701110755.24646-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 49f17c26c123b60fd1c74629eef077740d16ffc2 upstream.
Since resources can be removed, locking should ensure that the resource
is not removed while accessing it. However, find_next_iomem_res() does
not hold the lock while copying the data of the resource.
Keep holding the lock while the data is copied. While at it, change the
return value to a more informative value. It is disregarded by the
callers.
[akpm@linux-foundation.org: fix find_next_iomem_res() documentation]
Link: http://lkml.kernel.org/r/20190613045903.4922-2-namit@vmware.com
Fixes: ff3cc952d3f00 ("resource: Add remove_resource interface")
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Ingo Molnar <mingo@kernel.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 9bd3bb6703d8c0a5fb8aec8e3287bd55b7341dcd upstream.
Architectures like powerpc use different address range to map ioremap
and vmalloc range. The memunmap() check used by the nvdimm layer was
wrongly using is_vmalloc_addr() to check for ioremap range which fails
for ppc64. This result in ppc64 not freeing the ioremap mapping. The
side effect of this is an unbind failure during module unload with
papr_scm nvdimm driver
Link: http://lkml.kernel.org/r/20190701134038.14165-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions")
Cc: Dan Williams <dan.j.williams@intel.com>
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 cf144f81a99d1a3928f90b0936accfd3f45c9a0a upstream.
Testing padata with the tcrypt module on a 5.2 kernel...
# modprobe tcrypt alg="pcrypt(rfc4106(gcm(aes)))" type=3
# modprobe tcrypt mode=211 sec=1
...produces this splat:
INFO: task modprobe:10075 blocked for more than 120 seconds.
Not tainted 5.2.0-base+ #16
modprobe D 0 10075 10064 0x80004080
Call Trace:
? __schedule+0x4dd/0x610
? ring_buffer_unlock_commit+0x23/0x100
schedule+0x6c/0x90
schedule_timeout+0x3b/0x320
? trace_buffer_unlock_commit_regs+0x4f/0x1f0
wait_for_common+0x160/0x1a0
? wake_up_q+0x80/0x80
{ crypto_wait_req } # entries in braces added by hand
{ do_one_aead_op }
{ test_aead_jiffies }
test_aead_speed.constprop.17+0x681/0xf30 [tcrypt]
do_test+0x4053/0x6a2b [tcrypt]
? 0xffffffffa00f4000
tcrypt_mod_init+0x50/0x1000 [tcrypt]
...
The second modprobe command never finishes because in padata_reorder,
CPU0's load of reorder_objects is executed before the unlocking store in
spin_unlock_bh(pd->lock), causing CPU0 to miss CPU1's increment:
CPU0 CPU1
padata_reorder padata_do_serial
LOAD reorder_objects // 0
INC reorder_objects // 1
padata_reorder
TRYLOCK pd->lock // failed
UNLOCK pd->lock
CPU0 deletes the timer before returning from padata_reorder and since no
other job is submitted to padata, modprobe waits indefinitely.
Add a pair of full barriers to guarantee proper ordering:
CPU0 CPU1
padata_reorder padata_do_serial
UNLOCK pd->lock
smp_mb()
LOAD reorder_objects
INC reorder_objects
smp_mb__after_atomic()
padata_reorder
TRYLOCK pd->lock
smp_mb__after_atomic is needed so the read part of the trylock operation
comes after the INC, as Andrea points out. Thanks also to Andrea for
help with writing a litmus test.
Fixes: 16295bec6398 ("padata: Generic parallelization/serialization interface")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: <stable@vger.kernel.org>
Cc: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7a0cf094944e2540758b7f957eb6846d5126f535 upstream.
The function send_signal was split from __send_signal so that it would
be possible to bypass the namespace logic based upon current[1]. As it
turns out the si_pid and the si_uid fixup are both inappropriate in
the case of kill_pid_usb_asyncio so move that logic into send_signal.
It is difficult to arrange but possible for a signal with an si_code
of SI_TIMER or SI_SIGIO to be sent across namespace boundaries. In
which case tests for when it is ok to change si_pid and si_uid based
on SI_FROMUSER are incorrect. Replace the use of SI_FROMUSER with a
new test has_si_pid_and_used based on siginfo_layout.
Now that the uid fixup is no longer present after expanding
SEND_SIG_NOINFO properly calculate the si_uid that the target
task needs to read.
[1] 7978b567d315 ("signals: add from_ancestor_ns parameter to send_signal()")
Cc: stable@vger.kernel.org
Fixes: 6588c1e3ff01 ("signals: SI_USER: Masquerade si_pid when crossing pid ns boundary")
Fixes: 6b550f949594 ("user namespace: make signal.c respect user namespaces")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>