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| author | David Hildenbrand <dahi@linux.vnet.ibm.com> | 2015-05-11 17:52:08 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-05-19 08:39:14 +0200 |
| commit | b3c395ef5556a6c60f4426cc060f5b7bdcf82d5b (patch) | |
| tree | 55e89d5396f6a42444f91973ed65884530ad45e9 /lib | |
| parent | sched/preempt, mm/fault: Trigger might_sleep() in might_fault() with disabled... (diff) | |
| download | linux-b3c395ef5556a6c60f4426cc060f5b7bdcf82d5b.tar.xz linux-b3c395ef5556a6c60f4426cc060f5b7bdcf82d5b.zip | |
mm/uaccess, mm/fault: Clarify that uaccess may only sleep if pagefaults are enabled
In general, non-atomic variants of user access functions must not sleep
if pagefaults are disabled.
Let's update all relevant comments in uaccess code. This also reflects
the might_sleep() checks in might_fault().
Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Link: http://lkml.kernel.org/r/1431359540-32227-4-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/strnlen_user.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c index a28df5206d95..36c15a2889e4 100644 --- a/lib/strnlen_user.c +++ b/lib/strnlen_user.c @@ -84,7 +84,8 @@ static inline long do_strnlen_user(const char __user *src, unsigned long count, * @str: The string to measure. * @count: Maximum count (including NUL character) * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are + * enabled. * * Get the size of a NUL-terminated string in user space. * @@ -113,7 +114,8 @@ EXPORT_SYMBOL(strnlen_user); * strlen_user: - Get the size of a user string INCLUDING final NUL. * @str: The string to measure. * - * Context: User context only. This function may sleep. + * Context: User context only. This function may sleep if pagefaults are + * enabled. * * Get the size of a NUL-terminated string in user space. * |