From 5723aa993d83803157c22327e90cd59e3dcbe879 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 26 May 2012 11:09:53 -0700 Subject: [PATCH] x86: use the new generic strnlen_user() function This throws away the old x86-specific functions in favor of the generic optimized version. Signed-off-by: Linus Torvalds --- arch/x86/Kconfig | 1 + arch/x86/include/asm/uaccess.h | 3 ++ arch/x86/include/asm/uaccess_32.h | 17 ----------- arch/x86/include/asm/uaccess_64.h | 3 -- arch/x86/lib/usercopy_32.c | 41 -------------------------- arch/x86/lib/usercopy_64.c | 48 ------------------------------- 6 files changed, 4 insertions(+), 109 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 3220d44e24d..d700811785e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -94,6 +94,7 @@ config X86 select GENERIC_TIME_VSYSCALL if X86_64 select KTIME_SCALAR if X86_32 select GENERIC_STRNCPY_FROM_USER + select GENERIC_STRNLEN_USER config INSTRUCTION_DECODER def_bool (KPROBES || PERF_EVENTS || UPROBES) diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 1354facd8f6..04cd6882308 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -566,6 +566,9 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n); extern __must_check long strncpy_from_user(char *dst, const char __user *src, long count); +extern __must_check long strlen_user(const char __user *str); +extern __must_check long strnlen_user(const char __user *str, long n); + /* * movsl can be slow when source and dest are not both 8-byte aligned */ diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h index 8084bc73b18..576e39bca6a 100644 --- a/arch/x86/include/asm/uaccess_32.h +++ b/arch/x86/include/asm/uaccess_32.h @@ -213,23 +213,6 @@ static inline unsigned long __must_check copy_from_user(void *to, return n; } -/** - * strlen_user: - Get the size of a string in user space. - * @str: The string to measure. - * - * Context: User context only. This function may sleep. - * - * Get the size of a NUL-terminated string in user space. - * - * Returns the size of the string INCLUDING the terminating NUL. - * On exception, returns 0. - * - * If there is a limit on the length of a valid string, you may wish to - * consider using strnlen_user() instead. - */ -#define strlen_user(str) strnlen_user(str, LONG_MAX) - -long strnlen_user(const char __user *str, long n); unsigned long __must_check clear_user(void __user *mem, unsigned long len); unsigned long __must_check __clear_user(void __user *mem, unsigned long len); diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index fcd4b6f3ef0..8e796fbbf9c 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -208,9 +208,6 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size) } } -__must_check long strnlen_user(const char __user *str, long n); -__must_check long __strnlen_user(const char __user *str, long n); -__must_check long strlen_user(const char __user *str); __must_check unsigned long clear_user(void __user *mem, unsigned long len); __must_check unsigned long __clear_user(void __user *mem, unsigned long len); diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c index 883b216c60b..1781b2f950e 100644 --- a/arch/x86/lib/usercopy_32.c +++ b/arch/x86/lib/usercopy_32.c @@ -95,47 +95,6 @@ __clear_user(void __user *to, unsigned long n) } EXPORT_SYMBOL(__clear_user); -/** - * strnlen_user: - Get the size of a string in user space. - * @s: The string to measure. - * @n: The maximum valid length - * - * Get the size of a NUL-terminated string in user space. - * - * Returns the size of the string INCLUDING the terminating NUL. - * On exception, returns 0. - * If the string is too long, returns a value greater than @n. - */ -long strnlen_user(const char __user *s, long n) -{ - unsigned long mask = -__addr_ok(s); - unsigned long res, tmp; - - might_fault(); - - __asm__ __volatile__( - " testl %0, %0\n" - " jz 3f\n" - " andl %0,%%ecx\n" - "0: repne; scasb\n" - " setne %%al\n" - " subl %%ecx,%0\n" - " addl %0,%%eax\n" - "1:\n" - ".section .fixup,\"ax\"\n" - "2: xorl %%eax,%%eax\n" - " jmp 1b\n" - "3: movb $1,%%al\n" - " jmp 1b\n" - ".previous\n" - _ASM_EXTABLE(0b,2b) - :"=&r" (n), "=&D" (s), "=&a" (res), "=&c" (tmp) - :"0" (n), "1" (s), "2" (0), "3" (mask) - :"cc"); - return res & mask; -} -EXPORT_SYMBOL(strnlen_user); - #ifdef CONFIG_X86_INTEL_USERCOPY static unsigned long __copy_user_intel(void __user *to, const void *from, unsigned long size) diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c index 0d0326f388c..e5b130bc2d0 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -52,54 +52,6 @@ unsigned long clear_user(void __user *to, unsigned long n) } EXPORT_SYMBOL(clear_user); -/* - * Return the size of a string (including the ending 0) - * - * Return 0 on exception, a value greater than N if too long - */ - -long __strnlen_user(const char __user *s, long n) -{ - long res = 0; - char c; - - while (1) { - if (res>n) - return n+1; - if (__get_user(c, s)) - return 0; - if (!c) - return res+1; - res++; - s++; - } -} -EXPORT_SYMBOL(__strnlen_user); - -long strnlen_user(const char __user *s, long n) -{ - if (!access_ok(VERIFY_READ, s, 1)) - return 0; - return __strnlen_user(s, n); -} -EXPORT_SYMBOL(strnlen_user); - -long strlen_user(const char __user *s) -{ - long res = 0; - char c; - - for (;;) { - if (get_user(c, s)) - return 0; - if (!c) - return res+1; - res++; - s++; - } -} -EXPORT_SYMBOL(strlen_user); - unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len) { if (access_ok(VERIFY_WRITE, to, len) && access_ok(VERIFY_READ, from, len)) { -- 2.20.1