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author | Borislav Petkov <bp@suse.de> | 2016-10-31 16:10:15 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2016-11-01 07:41:27 +0100 |
commit | adb402cd1461eef6e1a21db4532a3b9e6a6be853 (patch) | |
tree | f87197dc1bd3a20bc15e79aad83fc9a5756b168f /arch/x86/lib/usercopy.c | |
parent | 05b93c19d50af2bd0d30fc000d817418ae8d33f1 (diff) | |
download | linux-adb402cd1461eef6e1a21db4532a3b9e6a6be853.tar.bz2 |
x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants
We already have the same functionality in usercopy_32.c. Share it with
64-bit and get rid of some more asm glue which is not needed anymore.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161031151015.22087-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/lib/usercopy.c')
-rw-r--r-- | arch/x86/lib/usercopy.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index b4908789484e..c074799bddae 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -34,3 +34,52 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) return ret; } EXPORT_SYMBOL_GPL(copy_from_user_nmi); + +/** + * copy_to_user: - Copy a block of data into user space. + * @to: Destination address, in user space. + * @from: Source address, in kernel space. + * @n: Number of bytes to copy. + * + * Context: User context only. This function may sleep if pagefaults are + * enabled. + * + * Copy data from kernel space to user space. + * + * Returns number of bytes that could not be copied. + * On success, this will be zero. + */ +unsigned long _copy_to_user(void __user *to, const void *from, unsigned n) +{ + if (access_ok(VERIFY_WRITE, to, n)) + n = __copy_to_user(to, from, n); + return n; +} +EXPORT_SYMBOL(_copy_to_user); + +/** + * copy_from_user: - Copy a block of data from user space. + * @to: Destination address, in kernel space. + * @from: Source address, in user space. + * @n: Number of bytes to copy. + * + * Context: User context only. This function may sleep if pagefaults are + * enabled. + * + * Copy data from user space to kernel space. + * + * Returns number of bytes that could not be copied. + * On success, this will be zero. + * + * If some data could not be copied, this function will pad the copied + * data to the requested size using zero bytes. + */ +unsigned long _copy_from_user(void *to, const void __user *from, unsigned n) +{ + if (access_ok(VERIFY_READ, from, n)) + n = __copy_from_user(to, from, n); + else + memset(to, 0, n); + return n; +} +EXPORT_SYMBOL(_copy_from_user); |