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1ac2e6ca RR |
1 | /* |
2 | * User address space access functions. | |
3 | * | |
4 | * For licencing details see kernel-base/COPYING | |
5 | */ | |
6 | ||
7 | #include <linux/highmem.h> | |
8 | #include <linux/module.h> | |
9 | ||
92ae03f2 | 10 | #include <asm/word-at-a-time.h> |
db0dc75d | 11 | #include <linux/sched.h> |
92ae03f2 | 12 | |
1ac2e6ca | 13 | /* |
e00b12e6 PZ |
14 | * We rely on the nested NMI work to allow atomic faults from the NMI path; the |
15 | * nested NMI paths are careful to preserve CR2. | |
1ac2e6ca RR |
16 | */ |
17 | unsigned long | |
18 | copy_from_user_nmi(void *to, const void __user *from, unsigned long n) | |
19 | { | |
e00b12e6 | 20 | unsigned long ret; |
1ac2e6ca | 21 | |
25f42985 | 22 | if (__range_not_ok(from, n, TASK_SIZE)) |
e00b12e6 PZ |
23 | return 0; |
24 | ||
25 | /* | |
26 | * Even though this function is typically called from NMI/IRQ context | |
27 | * disable pagefaults so that its behaviour is consistent even when | |
28 | * called form other contexts. | |
29 | */ | |
30 | pagefault_disable(); | |
31 | ret = __copy_from_user_inatomic(to, from, n); | |
32 | pagefault_enable(); | |
33 | ||
0a196848 | 34 | return ret; |
1ac2e6ca RR |
35 | } |
36 | EXPORT_SYMBOL_GPL(copy_from_user_nmi); |