08 Apr, 2022
2 commits
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[ Upstream commit 5a06fcb15b43d1f7bf740c672950122331cb5655 ]
test_kernel_ptr() uses access_ok() to figure out if a given address
points to user space instead of kernel space. However on architectures
that set CONFIG_ALTERNATE_USER_ADDRESS_SPACE, a pointer can be valid
for both, and the check always fails because access_ok() returns true.Make the check for user space pointers conditional on the type of
address space layout.Signed-off-by: Arnd Bergmann
Signed-off-by: Sasha Levin -
[ Upstream commit 23fc539e81295b14b50c6ccc5baeb4f3d59d822d ]
On some architectures, access_ok() does not do any argument type
checking, so replacing the definition with a generic one causes
a few warnings for harmless issues that were never caught before.Fix the ones that I found either through my own test builds or
that were reported by the 0-day bot.Reported-by: kernel test robot
Reviewed-by: Christoph Hellwig
Acked-by: Dinh Nguyen
Signed-off-by: Arnd Bergmann
Signed-off-by: Sasha Levin
18 Aug, 2021
2 commits
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The inner parts of certain locks (mutex, rwlocks) changed due to a rework for
RT and non RT code. Most users remain unaffected, but those who fiddle around
in the inner parts need to be updated.Match the struct names to the new layout.
Signed-off-by: Sebastian Andrzej Siewior
Signed-off-by: Thomas Gleixner
Signed-off-by: Peter Zijlstra (Intel)
Signed-off-by: Ingo Molnar
Link: https://lore.kernel.org/r/20210815211305.137982730@linutronix.de -
The wait_lock of mutex is really a low level lock. Convert it to a
raw_spinlock like the wait_lock of rtmutex.[ mingo: backmerged the test_lockup.c build fix by bigeasy. ]
Co-developed-by: Sebastian Andrzej Siewior
Signed-off-by: Sebastian Andrzej Siewior
Signed-off-by: Thomas Gleixner
Signed-off-by: Peter Zijlstra (Intel)
Signed-off-by: Ingo Molnar
Link: https://lore.kernel.org/r/20210815211304.166863404@linutronix.de
16 Dec, 2020
1 commit
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On PREEMPT_RT the locks are quite different so they can't be tested as it
is done below. The alternative is to test for the waitlock within
rtmutex.This is the bare minimun to get it compiled. Problems which exist on
PREEMP_RT:- none of the locks (spinlock_t, rwlock_t, mutex_t, rw_semaphore) may
be acquired with disabled preemption or interrupts.If I read the code correct the it is possible to acquire a mutex_t
with disabled interrupts.I don't know how to obtain a lock pointer. Technically they are not
exported to userland.- memory can not be allocated with disabled preemption or interrupts
even with GFP_ATOMIC.Link: https://lkml.kernel.org/r/20201028181041.xyeothhkouc3p4md@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior
Cc: Konstantin Khlebnikov
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Aug, 2020
2 commits
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Since filp_open() returns an error pointer, we should use IS_ERR() to
check the return value and then return PTR_ERR() if failed to get the
actual return value instead of always -EINVAL.E.g. without this patch:
[root@localhost loongson]# ls no_such_file
ls: cannot access no_such_file: No such file or directory
[root@localhost loongson]# modprobe test_lockup file_path=no_such_file lock_sb_umount time_secs=60 state=S
modprobe: ERROR: could not insert 'test_lockup': Invalid argument
[root@localhost loongson]# dmesg | tail -1
[ 126.100596] test_lockup: cannot find file_pathWith this patch:
[root@localhost loongson]# ls no_such_file
ls: cannot access no_such_file: No such file or directory
[root@localhost loongson]# modprobe test_lockup file_path=no_such_file lock_sb_umount time_secs=60 state=S
modprobe: ERROR: could not insert 'test_lockup': Unknown symbol in module, or unknown parameter (see dmesg)
[root@localhost loongson]# dmesg | tail -1
[ 95.134362] test_lockup: failed to open no_such_file: -2Fixes: aecd42df6d39 ("lib/test_lockup.c: add parameters for locking generic vfs locks")
Signed-off-by: Tiezhu Yang
Signed-off-by: Andrew Morton
Reviewed-by: Guenter Roeck
Cc: Konstantin Khlebnikov
Cc: Kees Cook
Link: http://lkml.kernel.org/r/1595555407-29875-2-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Linus Torvalds -
Fix sparse build warning:
lib/test_lockup.c:403:1: warning:
symbol '__pcpu_scope_test_works' was not declared. Should it be static?Reported-by: Hulk Robot
Signed-off-by: Wei Yongjun
Signed-off-by: Andrew Morton
Link: http://lkml.kernel.org/r/20200707112252.9047-1-weiyongjun1@huawei.com
Signed-off-by: Linus Torvalds
17 Jul, 2020
1 commit
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Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
xargs perl -pi -e \
's/\buninitialized_var\(([^\)]+)\)/\1/g;
s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/Reviewed-by: Leon Romanovsky # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe # IB
Acked-by: Kalle Valo # wireless drivers
Reviewed-by: Chao Yu # erofs
Signed-off-by: Kees Cook
19 Jun, 2020
1 commit
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Better describe what this helper does, and match the naming of
copy_from_kernel_nofault.Also switch the argument order around, so that it acts and looks
like get_user().Signed-off-by: Christoph Hellwig
Signed-off-by: Linus Torvalds
10 Jun, 2020
2 commits
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Convert comments that reference mmap_sem to reference mmap_lock instead.
[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]Signed-off-by: Michel Lespinasse
Signed-off-by: Andrew Morton
Reviewed-by: Vlastimil Babka
Reviewed-by: Daniel Jordan
Cc: Davidlohr Bueso
Cc: David Rientjes
Cc: Hugh Dickins
Cc: Jason Gunthorpe
Cc: Jerome Glisse
Cc: John Hubbard
Cc: Laurent Dufour
Cc: Liam Howlett
Cc: Matthew Wilcox
Cc: Peter Zijlstra
Cc: Ying Han
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds -
This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.The change is generated using coccinelle with the following rule:
// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .
@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)Signed-off-by: Michel Lespinasse
Signed-off-by: Andrew Morton
Reviewed-by: Daniel Jordan
Reviewed-by: Laurent Dufour
Reviewed-by: Vlastimil Babka
Cc: Davidlohr Bueso
Cc: David Rientjes
Cc: Hugh Dickins
Cc: Jason Gunthorpe
Cc: Jerome Glisse
Cc: John Hubbard
Cc: Liam Howlett
Cc: Matthew Wilcox
Cc: Peter Zijlstra
Cc: Ying Han
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds
05 Jun, 2020
1 commit
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Fix the following sparse warning:
lib/test_lockup.c:145:14: warning: symbol 'test_inode' was not declared.
Should it be static?Reported-by: Hulk Robot
Signed-off-by: Jason Yan
Signed-off-by: Andrew Morton
Link: http://lkml.kernel.org/r/20200417074021.46411-1-yanaijie@huawei.com
Signed-off-by: Linus Torvalds
08 Apr, 2020
3 commits
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file_path= defines file or directory to open
lock_inode=Y set lock_rwsem_ptr to inode->i_rwsem
lock_mapping=Y set lock_rwsem_ptr to mapping->i_mmap_rwsem
lock_sb_umount=Y set lock_rwsem_ptr to sb->s_umountThis gives safe and simple way to see how system reacts to contention of
common vfs locks and how syscalls depend on them directly or indirectly.For example to block s_umount for 60 seconds:
# modprobe test_lockup file_path=. lock_sb_umount time_secs=60 state=SThis is useful for checking/testing scalability issues like this:
https://lore.kernel.org/lkml/158497590858.7371.9311902565121473436.stgit@buzz/Signed-off-by: Konstantin Khlebnikov
Signed-off-by: Andrew Morton
Cc: Colin Ian King
Cc: Greg Kroah-Hartman
Cc: Guenter Roeck
Cc: Kees Cook
Cc: Peter Zijlstra
Cc: Petr Mladek
Cc: Sasha Levin
Cc: Sergey Senozhatsky
Cc: Steven Rostedt
Link: http://lkml.kernel.org/r/158498153964.5621.83061779039255681.stgit@buzz
Signed-off-by: Linus Torvalds -
There is a spelling mistake in a pr_notice message. Fix it.
Signed-off-by: Colin Ian King
Signed-off-by: Andrew Morton
Cc: Greg Kroah-Hartman
Cc: Guenter Roeck
Cc: Kees Cook
Cc: Konstantin Khlebnikov
Cc: Peter Zijlstra
Cc: Petr Mladek
Cc: Sasha Levin
Cc: Sergey Senozhatsky
Cc: Steven Rostedt
Link: http://lkml.kernel.org/r/20200221155145.79522-1-colin.king@canonical.com
Signed-off-by: Linus Torvalds -
CONFIG_TEST_LOCKUP=m adds module "test_lockup" that helps to make sure
that watchdogs and lockup detectors are working properly.Depending on module parameters test_lockup could emulate soft or hard
lockup, "hung task", hold arbitrary lock, allocate bunch of pages.Also it could generate series of lockups with cooling-down periods, in
this way it could be used as "ping" for locks or page allocator. Loop
checks signals between iteration thus could be stopped by ^C.# modinfo test_lockup
...
parm: time_secs:lockup time in seconds, default 0 (uint)
parm: time_nsecs:nanoseconds part of lockup time, default 0 (uint)
parm: cooldown_secs:cooldown time between iterations in seconds, default 0 (uint)
parm: cooldown_nsecs:nanoseconds part of cooldown, default 0 (uint)
parm: iterations:lockup iterations, default 1 (uint)
parm: all_cpus:trigger lockup at all cpus at once (bool)
parm: state:wait in 'R' running (default), 'D' uninterruptible, 'K' killable, 'S' interruptible state (charp)
parm: use_hrtimer:use high-resolution timer for sleeping (bool)
parm: iowait:account sleep time as iowait (bool)
parm: lock_read:lock read-write locks for read (bool)
parm: lock_single:acquire locks only at one cpu (bool)
parm: reacquire_locks:release and reacquire locks/irq/preempt between iterations (bool)
parm: touch_softlockup:touch soft-lockup watchdog between iterations (bool)
parm: touch_hardlockup:touch hard-lockup watchdog between iterations (bool)
parm: call_cond_resched:call cond_resched() between iterations (bool)
parm: measure_lock_wait:measure lock wait time (bool)
parm: lock_wait_threshold:print lock wait time longer than this in nanoseconds, default off (ulong)
parm: disable_irq:disable interrupts: generate hard-lockups (bool)
parm: disable_softirq:disable bottom-half irq handlers (bool)
parm: disable_preempt:disable preemption: generate soft-lockups (bool)
parm: lock_rcu:grab rcu_read_lock: generate rcu stalls (bool)
parm: lock_mmap_sem:lock mm->mmap_sem: block procfs interfaces (bool)
parm: lock_rwsem_ptr:lock rw_semaphore at address (ulong)
parm: lock_mutex_ptr:lock mutex at address (ulong)
parm: lock_spinlock_ptr:lock spinlock at address (ulong)
parm: lock_rwlock_ptr:lock rwlock at address (ulong)
parm: alloc_pages_nr:allocate and free pages under locks (uint)
parm: alloc_pages_order:page order to allocate (uint)
parm: alloc_pages_gfp:allocate pages with this gfp_mask, default GFP_KERNEL (uint)
parm: alloc_pages_atomic:allocate pages with GFP_ATOMIC (bool)
parm: reallocate_pages:free and allocate pages between iterations (bool)Parameters for locking by address are unsafe and taints kernel. With
CONFIG_DEBUG_SPINLOCK=y they at least check magics for embedded spinlocks.Examples:
task hang in D-state:
modprobe test_lockup time_secs=1 iterations=60 state=Dtask hang in io-wait D-state:
modprobe test_lockup time_secs=1 iterations=60 state=D iowaitsoftlockup:
modprobe test_lockup time_secs=1 iterations=60 state=Rhardlockup:
modprobe test_lockup time_secs=1 iterations=60 state=R disable_irqsystem-wide hardlockup:
modprobe test_lockup time_secs=1 iterations=60 state=R \
disable_irq all_cpusrcu stall:
modprobe test_lockup time_secs=1 iterations=60 state=R \
lock_rcu touch_softlockuplock mmap_sem / block procfs interfaces:
modprobe test_lockup time_secs=1 iterations=60 state=S lock_mmap_semlock tasklist_lock for read / block forks:
TASKLIST_LOCK=$(awk '$3 == "tasklist_lock" {print "0x"$1}' /proc/kallsyms)
modprobe test_lockup time_secs=1 iterations=60 state=R \
disable_irq lock_read lock_rwlock_ptr=$TASKLIST_LOCKlock namespace_sem / block vfs mount operations:
NAMESPACE_SEM=$(awk '$3 == "namespace_sem" {print "0x"$1}' /proc/kallsyms)
modprobe test_lockup time_secs=1 iterations=60 state=S \
lock_rwsem_ptr=$NAMESPACE_SEMlock cgroup mutex / block cgroup operations:
CGROUP_MUTEX=$(awk '$3 == "cgroup_mutex" {print "0x"$1}' /proc/kallsyms)
modprobe test_lockup time_secs=1 iterations=60 state=S \
lock_mutex_ptr=$CGROUP_MUTEXping cgroup_mutex every second and measure maximum lock wait time:
modprobe test_lockup cooldown_secs=1 iterations=60 state=S \
lock_mutex_ptr=$CGROUP_MUTEX reacquire_locks measure_lock_wait[linux@roeck-us.net: rename disable_irq to fix build error]
Link: http://lkml.kernel.org/r/20200317133614.23152-1-linux@roeck-us.net
Signed-off-by: Konstantin Khlebnikov
Signed-off-by: Guenter Roeck
Signed-off-by: Andrew Morton
Cc: Sasha Levin
Cc: Petr Mladek
Cc: Kees Cook
Cc: Peter Zijlstra
Cc: Greg Kroah-Hartman
Cc: Steven Rostedt
Cc: Sergey Senozhatsky
Cc: Dmitry Monakhov
Cc: Guenter Roeck
Link: http://lkml.kernel.org/r/158132859146.2797.525923171323227836.stgit@buzz
Signed-off-by: Linus Torvalds
