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f1bc96210c
We must avoid any recursion into lockdep if KCSAN is enabled on utilities
used by lockdep. One manifestation of this is corruption of lockdep's
IRQ trace state (if TRACE_IRQFLAGS), resulting in spurious warnings
(see below). This commit fixes this by:
1. Using raw_local_irq{save,restore} in kcsan_setup_watchpoint().
2. Disabling lockdep in kcsan_report().
Tested with:
CONFIG_LOCKDEP=y
CONFIG_DEBUG_LOCKDEP=y
CONFIG_TRACE_IRQFLAGS=y
This fix eliminates spurious warnings such as the following one:
WARNING: CPU: 0 PID: 2 at kernel/locking/lockdep.c:4406 check_flags.part.0+0x101/0x220
Modules linked in:
CPU: 0 PID: 2 Comm: kthreadd Not tainted 5.5.0-rc1+ #11
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:check_flags.part.0+0x101/0x220
<snip>
Call Trace:
lock_is_held_type+0x69/0x150
freezer_fork+0x20b/0x370
cgroup_post_fork+0x2c9/0x5c0
copy_process+0x2675/0x3b40
_do_fork+0xbe/0xa30
? _raw_spin_unlock_irqrestore+0x40/0x50
? match_held_lock+0x56/0x250
? kthread_park+0xf0/0xf0
kernel_thread+0xa6/0xd0
? kthread_park+0xf0/0xf0
kthreadd+0x321/0x3d0
? kthread_create_on_cpu+0x130/0x130
ret_from_fork+0x3a/0x50
irq event stamp: 64
hardirqs last enabled at (63): [<ffffffff9a7995d0>] _raw_spin_unlock_irqrestore+0x40/0x50
hardirqs last disabled at (64): [<ffffffff992a96d2>] kcsan_setup_watchpoint+0x92/0x460
softirqs last enabled at (32): [<ffffffff990489b8>] fpu__copy+0xe8/0x470
softirqs last disabled at (30): [<ffffffff99048939>] fpu__copy+0x69/0x470
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Tested-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
35 lines
1.2 KiB
Makefile
35 lines
1.2 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
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# Any varying coverage in these files is non-deterministic
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# and is generally not a function of system call inputs.
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KCOV_INSTRUMENT := n
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obj-y += mutex.o semaphore.o rwsem.o percpu-rwsem.o
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# Avoid recursion lockdep -> KCSAN -> ... -> lockdep.
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KCSAN_SANITIZE_lockdep.o := n
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ifdef CONFIG_FUNCTION_TRACER
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CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE)
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CFLAGS_REMOVE_lockdep_proc.o = $(CC_FLAGS_FTRACE)
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CFLAGS_REMOVE_mutex-debug.o = $(CC_FLAGS_FTRACE)
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CFLAGS_REMOVE_rtmutex-debug.o = $(CC_FLAGS_FTRACE)
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endif
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obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
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obj-$(CONFIG_LOCKDEP) += lockdep.o
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ifeq ($(CONFIG_PROC_FS),y)
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obj-$(CONFIG_LOCKDEP) += lockdep_proc.o
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endif
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obj-$(CONFIG_SMP) += spinlock.o
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obj-$(CONFIG_LOCK_SPIN_ON_OWNER) += osq_lock.o
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obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
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obj-$(CONFIG_QUEUED_SPINLOCKS) += qspinlock.o
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obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
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obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
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obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
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obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
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obj-$(CONFIG_QUEUED_RWLOCKS) += qrwlock.o
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obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o
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obj-$(CONFIG_WW_MUTEX_SELFTEST) += test-ww_mutex.o
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obj-$(CONFIG_LOCK_EVENT_COUNTS) += lock_events.o
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