Commit-ID: adb402cd1461eef6e1a21db4532a3b9e6a6be853
Gitweb: http://git.kernel.org/tip/adb402cd1461eef6e1a21db4532a3b9e6a6be853
Author: Borislav Petkov <bp@xxxxxxx>
AuthorDate: Mon, 31 Oct 2016 16:10:15 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 1 Nov 2016 07:41:27 +0100
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@xxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20161031151015.22087-1-bp@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/lib/copy_user_64.S | 47 -------------------------------------------
arch/x86/lib/usercopy.c | 49 +++++++++++++++++++++++++++++++++++++++++++++
arch/x86/lib/usercopy_32.c | 49 ---------------------------------------------
3 files changed, 49 insertions(+), 96 deletions(-)
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index d376e4b..c595957 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -16,53 +16,6 @@
#include <asm/smap.h>
#include <asm/export.h>
-/* Standard copy_to_user with segment limit checking */
-ENTRY(_copy_to_user)
- mov PER_CPU_VAR(current_task), %rax
- movq %rdi,%rcx
- addq %rdx,%rcx
- jc bad_to_user
- cmpq TASK_addr_limit(%rax),%rcx
- ja bad_to_user
- ALTERNATIVE_2 "jmp copy_user_generic_unrolled", \
- "jmp copy_user_generic_string", \
- X86_FEATURE_REP_GOOD, \
- "jmp copy_user_enhanced_fast_string", \
- X86_FEATURE_ERMS
-ENDPROC(_copy_to_user)
-EXPORT_SYMBOL(_copy_to_user)
-
-/* Standard copy_from_user with segment limit checking */
-ENTRY(_copy_from_user)
- mov PER_CPU_VAR(current_task), %rax
- movq %rsi,%rcx
- addq %rdx,%rcx
- jc bad_from_user
- cmpq TASK_addr_limit(%rax),%rcx
- ja bad_from_user
- ALTERNATIVE_2 "jmp copy_user_generic_unrolled", \
- "jmp copy_user_generic_string", \
- X86_FEATURE_REP_GOOD, \
- "jmp copy_user_enhanced_fast_string", \
- X86_FEATURE_ERMS
-ENDPROC(_copy_from_user)
-EXPORT_SYMBOL(_copy_from_user)
-
-
- .section .fixup,"ax"
- /* must zero dest */
-ENTRY(bad_from_user)
-bad_from_user:
- movl %edx,%ecx
- xorl %eax,%eax
- rep
- stosb
-bad_to_user:
- movl %edx,%eax
- ret
-ENDPROC(bad_from_user)
- .previous
-
/*
* copy_user_generic_unrolled - memory copy with exception handling.
* This version is for CPUs like P4 that don't have efficient micro
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c
index b490878..c074799 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);
diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index 3bc7baf..0b28121 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -640,52 +640,3 @@ unsigned long __copy_from_user_ll_nocache_nozero(void *to, const void __user *fr
return n;
}
EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero);
-
-/**
- * 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);
--
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