From 23504bae7f3edd1484c4d470362f2b12bcd298f9 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 21 Mar 2017 14:27:36 -0400 Subject: [PATCH] tile: get rid of zeroing, switch to RAW_COPY_USER Signed-off-by: Al Viro --- arch/tile/Kconfig | 1 + arch/tile/include/asm/uaccess.h | 143 ++------------------------------ arch/tile/lib/exports.c | 7 +- arch/tile/lib/memcpy_32.S | 41 +++------ arch/tile/lib/memcpy_user_64.c | 15 +--- 5 files changed, 27 insertions(+), 180 deletions(-) diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig index 4583c0320059..27808d86eb57 100644 --- a/arch/tile/Kconfig +++ b/arch/tile/Kconfig @@ -33,6 +33,7 @@ config TILE select USER_STACKTRACE_SUPPORT select USE_PMC if PERF_EVENTS select VIRT_TO_BUS + select ARCH_HAS_RAW_COPY_USER config MMU def_bool y diff --git a/arch/tile/include/asm/uaccess.h b/arch/tile/include/asm/uaccess.h index ef3a1fd07946..a803f6bb4d92 100644 --- a/arch/tile/include/asm/uaccess.h +++ b/arch/tile/include/asm/uaccess.h @@ -313,145 +313,16 @@ extern int __put_user_bad(void) ((x) = 0, -EFAULT); \ }) -/** - * __copy_to_user() - copy data into user space, with less checking. - * @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. Caller must check - * the specified block with access_ok() before calling this function. - * - * Returns number of bytes that could not be copied. - * On success, this will be zero. - * - * An alternate version - __copy_to_user_inatomic() - is designed - * to be called from atomic context, typically bracketed by calls - * to pagefault_disable() and pagefault_enable(). - */ -extern unsigned long __must_check __copy_to_user_inatomic( - void __user *to, const void *from, unsigned long n); - -static inline unsigned long __must_check -__copy_to_user(void __user *to, const void *from, unsigned long n) -{ - might_fault(); - return __copy_to_user_inatomic(to, from, n); -} - -static inline unsigned long __must_check -copy_to_user(void __user *to, const void *from, unsigned long n) -{ - if (access_ok(VERIFY_WRITE, to, n)) - n = __copy_to_user(to, from, n); - return n; -} - -/** - * __copy_from_user() - copy data from user space, with less checking. - * @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. Caller must check - * the specified block with access_ok() before calling this function. - * - * 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. - * - * An alternate version - __copy_from_user_inatomic() - is designed - * to be called from atomic context, typically bracketed by calls - * to pagefault_disable() and pagefault_enable(). This version - * does *NOT* pad with zeros. - */ -extern unsigned long __must_check __copy_from_user_inatomic( - void *to, const void __user *from, unsigned long n); -extern unsigned long __must_check __copy_from_user_zeroing( - void *to, const void __user *from, unsigned long n); - -static inline unsigned long __must_check -__copy_from_user(void *to, const void __user *from, unsigned long n) -{ - might_fault(); - return __copy_from_user_zeroing(to, from, n); -} - -static inline unsigned long __must_check -_copy_from_user(void *to, const void __user *from, unsigned long n) -{ - if (access_ok(VERIFY_READ, from, n)) - n = __copy_from_user(to, from, n); - else - memset(to, 0, n); - return n; -} - -extern void __compiletime_error("usercopy buffer size is too small") -__bad_copy_user(void); - -static inline void copy_user_overflow(int size, unsigned long count) -{ - WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); -} - -static inline unsigned long __must_check copy_from_user(void *to, - const void __user *from, - unsigned long n) -{ - int sz = __compiletime_object_size(to); - - if (likely(sz == -1 || sz >= n)) - n = _copy_from_user(to, from, n); - else if (!__builtin_constant_p(n)) - copy_user_overflow(sz, n); - else - __bad_copy_user(); - - return n; -} +extern unsigned long __must_check +raw_copy_to_user(void __user *to, const void *from, unsigned long n); +extern unsigned long __must_check +raw_copy_from_user(void *to, const void __user *from, unsigned long n); +#define INLINE_COPY_FROM_USER +#define INLINE_COPY_TO_USER #ifdef __tilegx__ -/** - * __copy_in_user() - copy data within user space, with less checking. - * @to: Destination address, in user 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 user space. Caller must check - * the specified blocks with access_ok() before calling this function. - * - * Returns number of bytes that could not be copied. - * On success, this will be zero. - */ -extern unsigned long __copy_in_user_inatomic( +extern unsigned long raw_copy_in_user( void __user *to, const void __user *from, unsigned long n); - -static inline unsigned long __must_check -__copy_in_user(void __user *to, const void __user *from, unsigned long n) -{ - might_fault(); - return __copy_in_user_inatomic(to, from, n); -} - -static inline unsigned long __must_check -copy_in_user(void __user *to, const void __user *from, unsigned long n) -{ - if (access_ok(VERIFY_WRITE, to, n) && access_ok(VERIFY_READ, from, n)) - n = __copy_in_user(to, from, n); - return n; -} #endif diff --git a/arch/tile/lib/exports.c b/arch/tile/lib/exports.c index c5369fe643c7..ecce8e177e3f 100644 --- a/arch/tile/lib/exports.c +++ b/arch/tile/lib/exports.c @@ -38,11 +38,10 @@ EXPORT_SYMBOL(__mcount); /* arch/tile/lib/, various memcpy files */ EXPORT_SYMBOL(memcpy); -EXPORT_SYMBOL(__copy_to_user_inatomic); -EXPORT_SYMBOL(__copy_from_user_inatomic); -EXPORT_SYMBOL(__copy_from_user_zeroing); +EXPORT_SYMBOL(raw_copy_to_user); +EXPORT_SYMBOL(raw_copy_from_user); #ifdef __tilegx__ -EXPORT_SYMBOL(__copy_in_user_inatomic); +EXPORT_SYMBOL(raw_copy_in_user); #endif /* hypervisor glue */ diff --git a/arch/tile/lib/memcpy_32.S b/arch/tile/lib/memcpy_32.S index a2771ae5da53..270f1267cd18 100644 --- a/arch/tile/lib/memcpy_32.S +++ b/arch/tile/lib/memcpy_32.S @@ -24,7 +24,6 @@ #define IS_MEMCPY 0 #define IS_COPY_FROM_USER 1 -#define IS_COPY_FROM_USER_ZEROING 2 #define IS_COPY_TO_USER -1 .section .text.memcpy_common, "ax" @@ -42,40 +41,31 @@ 9 -/* __copy_from_user_inatomic takes the kernel target address in r0, +/* raw_copy_from_user takes the kernel target address in r0, * the user source in r1, and the bytes to copy in r2. * It returns the number of uncopiable bytes (hopefully zero) in r0. */ -ENTRY(__copy_from_user_inatomic) -.type __copy_from_user_inatomic, @function - FEEDBACK_ENTER_EXPLICIT(__copy_from_user_inatomic, \ +ENTRY(raw_copy_from_user) +.type raw_copy_from_user, @function + FEEDBACK_ENTER_EXPLICIT(raw_copy_from_user, \ .text.memcpy_common, \ - .Lend_memcpy_common - __copy_from_user_inatomic) + .Lend_memcpy_common - raw_copy_from_user) { movei r29, IS_COPY_FROM_USER; j memcpy_common } - .size __copy_from_user_inatomic, . - __copy_from_user_inatomic + .size raw_copy_from_user, . - raw_copy_from_user -/* __copy_from_user_zeroing is like __copy_from_user_inatomic, but - * any uncopiable bytes are zeroed in the target. - */ -ENTRY(__copy_from_user_zeroing) -.type __copy_from_user_zeroing, @function - FEEDBACK_REENTER(__copy_from_user_inatomic) - { movei r29, IS_COPY_FROM_USER_ZEROING; j memcpy_common } - .size __copy_from_user_zeroing, . - __copy_from_user_zeroing - -/* __copy_to_user_inatomic takes the user target address in r0, +/* raw_copy_to_user takes the user target address in r0, * the kernel source in r1, and the bytes to copy in r2. * It returns the number of uncopiable bytes (hopefully zero) in r0. */ -ENTRY(__copy_to_user_inatomic) -.type __copy_to_user_inatomic, @function - FEEDBACK_REENTER(__copy_from_user_inatomic) +ENTRY(raw_copy_to_user) +.type raw_copy_to_user, @function + FEEDBACK_REENTER(raw_copy_from_user) { movei r29, IS_COPY_TO_USER; j memcpy_common } - .size __copy_to_user_inatomic, . - __copy_to_user_inatomic + .size raw_copy_to_user, . - raw_copy_to_user ENTRY(memcpy) .type memcpy, @function - FEEDBACK_REENTER(__copy_from_user_inatomic) + FEEDBACK_REENTER(raw_copy_from_user) { movei r29, IS_MEMCPY } .size memcpy, . - memcpy /* Fall through */ @@ -520,12 +510,7 @@ copy_from_user_fixup_loop: { bnzt r2, copy_from_user_fixup_loop } .Lcopy_from_user_fixup_zero_remainder: - { bbs r29, 2f } /* low bit set means IS_COPY_FROM_USER */ - /* byte-at-a-time loop faulted, so zero the rest. */ - { move r3, r2; bz r2, 2f /* should be impossible, but handle it. */ } -1: { sb r0, zero; addi r0, r0, 1; addi r3, r3, -1 } - { bnzt r3, 1b } -2: move lr, r27 + move lr, r27 { move r0, r2; jrp lr } copy_to_user_fixup_loop: diff --git a/arch/tile/lib/memcpy_user_64.c b/arch/tile/lib/memcpy_user_64.c index 97bbb6060b25..a3fea9fd973e 100644 --- a/arch/tile/lib/memcpy_user_64.c +++ b/arch/tile/lib/memcpy_user_64.c @@ -51,7 +51,7 @@ __v; \ }) -#define USERCOPY_FUNC __copy_to_user_inatomic +#define USERCOPY_FUNC raw_copy_to_user #define ST1(p, v) _ST((p), st1, (v)) #define ST2(p, v) _ST((p), st2, (v)) #define ST4(p, v) _ST((p), st4, (v)) @@ -62,7 +62,7 @@ #define LD8 LD #include "memcpy_64.c" -#define USERCOPY_FUNC __copy_from_user_inatomic +#define USERCOPY_FUNC raw_copy_from_user #define ST1 ST #define ST2 ST #define ST4 ST @@ -73,7 +73,7 @@ #define LD8(p) _LD((p), ld) #include "memcpy_64.c" -#define USERCOPY_FUNC __copy_in_user_inatomic +#define USERCOPY_FUNC raw_copy_in_user #define ST1(p, v) _ST((p), st1, (v)) #define ST2(p, v) _ST((p), st2, (v)) #define ST4(p, v) _ST((p), st4, (v)) @@ -83,12 +83,3 @@ #define LD4(p) _LD((p), ld4u) #define LD8(p) _LD((p), ld) #include "memcpy_64.c" - -unsigned long __copy_from_user_zeroing(void *to, const void __user *from, - unsigned long n) -{ - unsigned long rc = __copy_from_user_inatomic(to, from, n); - if (unlikely(rc)) - memset(to + n - rc, 0, rc); - return rc; -} -- 2.20.1