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authorBorislav Petkov <bp@suse.de>2016-10-31 16:10:15 +0100
committerIngo Molnar <mingo@kernel.org>2016-11-01 07:41:27 +0100
commitadb402cd1461eef6e1a21db4532a3b9e6a6be853 (patch)
treef87197dc1bd3a20bc15e79aad83fc9a5756b168f /arch/x86/lib/usercopy.c
parent05b93c19d50af2bd0d30fc000d817418ae8d33f1 (diff)
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.c49
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);