From: Borislav Petkov Date: Mon, 31 Oct 2016 15:10:15 +0000 (+0100) Subject: x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=adb402cd1461eef6e1a21db4532a3b9e6a6be853;p=openwrt%2Fstaging%2Fblogic.git 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 Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20161031151015.22087-1-bp@alien8.de Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index d376e4b48f88..c5959576c315 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -16,53 +16,6 @@ #include #include -/* 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 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); diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c index 3bc7baf2a711..0b281217c890 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);