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| author | Al Viro <viro@zeniv.linux.org.uk> | 2017-03-25 18:36:22 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2017-03-28 18:24:04 -0400 |
| commit | 122b05ddf506e637336dcf64b5a129825f7bf6d4 (patch) | |
| tree | e8addfa4b5747e198698c0d54789b077cf2a92a0 /arch/x86/lib/usercopy.c | |
| parent | d597580d373774b1bdab84b3d26ff0b55162b916 (diff) | |
| download | linux-122b05ddf506e637336dcf64b5a129825f7bf6d4.tar.bz2 | |
amd64: get rid of zeroing
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/x86/lib/usercopy.c')
| -rw-r--r-- | arch/x86/lib/usercopy.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index c074799bddae..a851f3d199c2 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -76,10 +76,11 @@ EXPORT_SYMBOL(_copy_to_user); */ unsigned long _copy_from_user(void *to, const void __user *from, unsigned n) { + unsigned long res = n; if (access_ok(VERIFY_READ, from, n)) - n = __copy_from_user(to, from, n); - else - memset(to, 0, n); - return n; + res = __copy_from_user_inatomic(to, from, n); + if (unlikely(res)) + memset(to + n - res, 0, res); + return res; } EXPORT_SYMBOL(_copy_from_user); |