x86: some lock annotations for user copy paths, v2
- introduce might_fault() - handle the atomic user copy paths correctly [ mingo@elte.hu: move might_sleep() outside of in_atomic(). ] Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Nick Piggin
Ingo Molnar
parent
c10d38dda1
commit
3ee1afa308
@ -32,9 +32,7 @@ static inline int __movsl_is_ok(unsigned long a1, unsigned long a2, unsigned lon
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#define __do_strncpy_from_user(dst, src, count, res) \
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do { \
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int __d0, __d1, __d2; \
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might_sleep(); \
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if (current->mm) \
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might_lock_read(¤t->mm->mmap_sem); \
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might_fault(); \
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__asm__ __volatile__( \
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" testl %1,%1\n" \
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" jz 2f\n" \
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@ -121,9 +119,7 @@ EXPORT_SYMBOL(strncpy_from_user);
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#define __do_clear_user(addr,size) \
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do { \
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int __d0; \
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might_sleep(); \
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if (current->mm) \
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might_lock_read(¤t->mm->mmap_sem); \
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might_fault(); \
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__asm__ __volatile__( \
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"0: rep; stosl\n" \
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" movl %2,%0\n" \
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@ -193,9 +189,7 @@ long strnlen_user(const char __user *s, long n)
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unsigned long mask = -__addr_ok(s);
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unsigned long res, tmp;
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might_sleep();
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if (current->mm)
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might_lock_read(¤t->mm->mmap_sem);
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might_fault();
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__asm__ __volatile__(
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" testl %0, %0\n"
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@ -15,9 +15,7 @@
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#define __do_strncpy_from_user(dst,src,count,res) \
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do { \
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long __d0, __d1, __d2; \
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might_sleep(); \
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if (current->mm) \
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might_lock_read(¤t->mm->mmap_sem); \
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might_fault(); \
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__asm__ __volatile__( \
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" testq %1,%1\n" \
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" jz 2f\n" \
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@ -66,9 +64,7 @@ EXPORT_SYMBOL(strncpy_from_user);
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unsigned long __clear_user(void __user *addr, unsigned long size)
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{
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long __d0;
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might_sleep();
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if (current->mm)
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might_lock_read(¤t->mm->mmap_sem);
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might_fault();
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/* no memory constraint because it doesn't change any memory gcc knows
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about */
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asm volatile(
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@ -8,8 +8,6 @@
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#include <linux/thread_info.h>
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#include <linux/prefetch.h>
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#include <linux/string.h>
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#include <linux/lockdep.h>
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#include <linux/sched.h>
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#include <asm/asm.h>
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#include <asm/page.h>
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@ -159,9 +157,7 @@ extern int __get_user_bad(void);
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int __ret_gu; \
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unsigned long __val_gu; \
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__chk_user_ptr(ptr); \
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might_sleep(); \
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if (current->mm) \
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might_lock_read(¤t->mm->mmap_sem); \
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might_fault(); \
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switch (sizeof(*(ptr))) { \
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case 1: \
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__get_user_x(1, __ret_gu, __val_gu, ptr); \
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@ -246,9 +242,7 @@ extern void __put_user_8(void);
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int __ret_pu; \
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__typeof__(*(ptr)) __pu_val; \
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__chk_user_ptr(ptr); \
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might_sleep(); \
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if (current->mm) \
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might_lock_read(¤t->mm->mmap_sem); \
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might_fault(); \
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__pu_val = x; \
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switch (sizeof(*(ptr))) { \
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case 1: \
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@ -273,9 +267,7 @@ extern void __put_user_8(void);
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#define __put_user_size(x, ptr, size, retval, errret) \
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do { \
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retval = 0; \
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might_sleep(); \
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if (current->mm) \
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might_lock_read(¤t->mm->mmap_sem); \
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might_fault(); \
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__chk_user_ptr(ptr); \
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switch (size) { \
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case 1: \
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@ -328,9 +320,7 @@ do { \
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#define __get_user_size(x, ptr, size, retval, errret) \
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do { \
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retval = 0; \
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might_sleep(); \
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if (current->mm) \
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might_lock_read(¤t->mm->mmap_sem); \
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might_fault(); \
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__chk_user_ptr(ptr); \
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switch (size) { \
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case 1: \
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@ -82,9 +82,7 @@ __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
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static __always_inline unsigned long __must_check
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__copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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might_sleep();
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if (current->mm)
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might_lock_read(¤t->mm->mmap_sem);
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might_fault();
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return __copy_to_user_inatomic(to, from, n);
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}
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@ -139,9 +137,7 @@ __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
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static __always_inline unsigned long
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__copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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might_sleep();
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if (current->mm)
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might_lock_read(¤t->mm->mmap_sem);
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might_fault();
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if (__builtin_constant_p(n)) {
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unsigned long ret;
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@ -163,9 +159,7 @@ __copy_from_user(void *to, const void __user *from, unsigned long n)
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static __always_inline unsigned long __copy_from_user_nocache(void *to,
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const void __user *from, unsigned long n)
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{
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might_sleep();
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if (current->mm)
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might_lock_read(¤t->mm->mmap_sem);
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might_fault();
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if (__builtin_constant_p(n)) {
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unsigned long ret;
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@ -29,9 +29,7 @@ int __copy_from_user(void *dst, const void __user *src, unsigned size)
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{
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int ret = 0;
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might_sleep();
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if (current->mm)
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might_lock_read(¤t->mm->mmap_sem);
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might_fault();
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if (!__builtin_constant_p(size))
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return copy_user_generic(dst, (__force void *)src, size);
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switch (size) {
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@ -75,9 +73,7 @@ int __copy_to_user(void __user *dst, const void *src, unsigned size)
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{
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int ret = 0;
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might_sleep();
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if (current->mm)
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might_lock_read(¤t->mm->mmap_sem);
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might_fault();
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if (!__builtin_constant_p(size))
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return copy_user_generic((__force void *)dst, src, size);
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switch (size) {
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@ -121,9 +117,7 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
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{
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int ret = 0;
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might_sleep();
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if (current->mm)
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might_lock_read(¤t->mm->mmap_sem);
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might_fault();
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if (!__builtin_constant_p(size))
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return copy_user_generic((__force void *)dst,
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(__force void *)src, size);
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@ -140,6 +140,15 @@ extern int _cond_resched(void);
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(__x < 0) ? -__x : __x; \
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})
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#ifdef CONFIG_PROVE_LOCKING
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void might_fault(void);
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#else
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static inline void might_fault(void)
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{
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might_sleep();
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}
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#endif
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extern struct atomic_notifier_head panic_notifier_list;
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extern long (*panic_blink)(long time);
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NORET_TYPE void panic(const char * fmt, ...)
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15
mm/memory.c
15
mm/memory.c
@ -3016,3 +3016,18 @@ void print_vma_addr(char *prefix, unsigned long ip)
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}
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up_read(¤t->mm->mmap_sem);
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}
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#ifdef CONFIG_PROVE_LOCKING
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void might_fault(void)
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{
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might_sleep();
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/*
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* it would be nicer only to annotate paths which are not under
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* pagefault_disable, however that requires a larger audit and
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* providing helpers like get_user_atomic.
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*/
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if (!in_atomic() && current->mm)
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might_lock_read(¤t->mm->mmap_sem);
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}
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EXPORT_SYMBOL(might_fault);
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#endif
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