From: Al Viro Date: Wed, 22 Mar 2017 17:02:41 +0000 (-0400) Subject: xtensa: get rid of zeroing, use RAW_COPY_USER X-Git-Tag: v4.12-rc1~161^2~2^32~1 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3a0e75adecc8da026a5befb2c5828d08c999373c;p=karo-tx-linux.git xtensa: get rid of zeroing, use RAW_COPY_USER Signed-off-by: Al Viro --- diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index f4126cf997a4..043d37d45919 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -29,6 +29,7 @@ config XTENSA select NO_BOOTMEM select PERF_USE_VMALLOC select VIRT_TO_BUS + select ARCH_HAS_RAW_COPY_USER help Xtensa processors are 32-bit RISC machines designed by Tensilica primarily for embedded systems. These processors are both diff --git a/arch/xtensa/include/asm/uaccess.h b/arch/xtensa/include/asm/uaccess.h index 0f338774af99..8e93ed8ad1fe 100644 --- a/arch/xtensa/include/asm/uaccess.h +++ b/arch/xtensa/include/asm/uaccess.h @@ -234,60 +234,22 @@ __asm__ __volatile__( \ * Copy to/from user space */ -/* - * We use a generic, arbitrary-sized copy subroutine. The Xtensa - * architecture would cause heavy code bloat if we tried to inline - * these functions and provide __constant_copy_* equivalents like the - * i386 versions. __xtensa_copy_user is quite efficient. See the - * .fixup section of __xtensa_copy_user for a discussion on the - * X_zeroing equivalents for Xtensa. - */ - extern unsigned __xtensa_copy_user(void *to, const void *from, unsigned n); -#define __copy_user(to, from, size) __xtensa_copy_user(to, from, size) - static inline unsigned long -__generic_copy_from_user_nocheck(void *to, const void *from, unsigned long n) +raw_copy_from_user(void *to, const void __user *from, unsigned long n) { - return __copy_user(to, from, n); -} - -static inline unsigned long -__generic_copy_to_user_nocheck(void *to, const void *from, unsigned long n) -{ - return __copy_user(to, from, n); -} - -static inline unsigned long -__generic_copy_to_user(void *to, const void *from, unsigned long n) -{ - prefetch(from); - if (access_ok(VERIFY_WRITE, to, n)) - return __copy_user(to, from, n); - return n; + prefetchw(to); + return __xtensa_copy_user(to, (__force const void *)from, n); } - static inline unsigned long -__generic_copy_from_user(void *to, const void *from, unsigned long n) +raw_copy_to_user(void __user *to, const void *from, unsigned long n) { - prefetchw(to); - if (access_ok(VERIFY_READ, from, n)) - return __copy_user(to, from, n); - else - memset(to, 0, n); - return n; + prefetchw(from); + return __xtensa_copy_user((__force void *)to, from, n); } - -#define copy_to_user(to, from, n) __generic_copy_to_user((to), (from), (n)) -#define copy_from_user(to, from, n) __generic_copy_from_user((to), (from), (n)) -#define __copy_to_user(to, from, n) \ - __generic_copy_to_user_nocheck((to), (from), (n)) -#define __copy_from_user(to, from, n) \ - __generic_copy_from_user_nocheck((to), (from), (n)) -#define __copy_to_user_inatomic __copy_to_user -#define __copy_from_user_inatomic __copy_from_user - +#define INLINE_COPY_FROM_USER +#define INLINE_COPY_TO_USER /* * We need to return the number of bytes not cleared. Our memset() diff --git a/arch/xtensa/lib/usercopy.S b/arch/xtensa/lib/usercopy.S index 7ea4dd68893e..d9cd766bde3e 100644 --- a/arch/xtensa/lib/usercopy.S +++ b/arch/xtensa/lib/usercopy.S @@ -102,9 +102,9 @@ __xtensa_copy_user: bltui a4, 7, .Lbytecopy # do short copies byte by byte # copy 1 byte - EX(l8ui, a6, a3, 0, l_fixup) + EX(l8ui, a6, a3, 0, fixup) addi a3, a3, 1 - EX(s8i, a6, a5, 0, s_fixup) + EX(s8i, a6, a5, 0, fixup) addi a5, a5, 1 addi a4, a4, -1 bbci.l a5, 1, .Ldstaligned # if dst is now aligned, then @@ -112,11 +112,11 @@ __xtensa_copy_user: .Ldst2mod4: # dst 16-bit aligned # copy 2 bytes bltui a4, 6, .Lbytecopy # do short copies byte by byte - EX(l8ui, a6, a3, 0, l_fixup) - EX(l8ui, a7, a3, 1, l_fixup) + EX(l8ui, a6, a3, 0, fixup) + EX(l8ui, a7, a3, 1, fixup) addi a3, a3, 2 - EX(s8i, a6, a5, 0, s_fixup) - EX(s8i, a7, a5, 1, s_fixup) + EX(s8i, a6, a5, 0, fixup) + EX(s8i, a7, a5, 1, fixup) addi a5, a5, 2 addi a4, a4, -2 j .Ldstaligned # dst is now aligned, return to main algorithm @@ -135,9 +135,9 @@ __xtensa_copy_user: add a7, a3, a4 # a7 = end address for source #endif /* !XCHAL_HAVE_LOOPS */ .Lnextbyte: - EX(l8ui, a6, a3, 0, l_fixup) + EX(l8ui, a6, a3, 0, fixup) addi a3, a3, 1 - EX(s8i, a6, a5, 0, s_fixup) + EX(s8i, a6, a5, 0, fixup) addi a5, a5, 1 #if !XCHAL_HAVE_LOOPS blt a3, a7, .Lnextbyte @@ -161,15 +161,15 @@ __xtensa_copy_user: add a8, a8, a3 # a8 = end of last 16B source chunk #endif /* !XCHAL_HAVE_LOOPS */ .Loop1: - EX(l32i, a6, a3, 0, l_fixup) - EX(l32i, a7, a3, 4, l_fixup) - EX(s32i, a6, a5, 0, s_fixup) - EX(l32i, a6, a3, 8, l_fixup) - EX(s32i, a7, a5, 4, s_fixup) - EX(l32i, a7, a3, 12, l_fixup) - EX(s32i, a6, a5, 8, s_fixup) + EX(l32i, a6, a3, 0, fixup) + EX(l32i, a7, a3, 4, fixup) + EX(s32i, a6, a5, 0, fixup) + EX(l32i, a6, a3, 8, fixup) + EX(s32i, a7, a5, 4, fixup) + EX(l32i, a7, a3, 12, fixup) + EX(s32i, a6, a5, 8, fixup) addi a3, a3, 16 - EX(s32i, a7, a5, 12, s_fixup) + EX(s32i, a7, a5, 12, fixup) addi a5, a5, 16 #if !XCHAL_HAVE_LOOPS blt a3, a8, .Loop1 @@ -177,31 +177,31 @@ __xtensa_copy_user: .Loop1done: bbci.l a4, 3, .L2 # copy 8 bytes - EX(l32i, a6, a3, 0, l_fixup) - EX(l32i, a7, a3, 4, l_fixup) + EX(l32i, a6, a3, 0, fixup) + EX(l32i, a7, a3, 4, fixup) addi a3, a3, 8 - EX(s32i, a6, a5, 0, s_fixup) - EX(s32i, a7, a5, 4, s_fixup) + EX(s32i, a6, a5, 0, fixup) + EX(s32i, a7, a5, 4, fixup) addi a5, a5, 8 .L2: bbci.l a4, 2, .L3 # copy 4 bytes - EX(l32i, a6, a3, 0, l_fixup) + EX(l32i, a6, a3, 0, fixup) addi a3, a3, 4 - EX(s32i, a6, a5, 0, s_fixup) + EX(s32i, a6, a5, 0, fixup) addi a5, a5, 4 .L3: bbci.l a4, 1, .L4 # copy 2 bytes - EX(l16ui, a6, a3, 0, l_fixup) + EX(l16ui, a6, a3, 0, fixup) addi a3, a3, 2 - EX(s16i, a6, a5, 0, s_fixup) + EX(s16i, a6, a5, 0, fixup) addi a5, a5, 2 .L4: bbci.l a4, 0, .L5 # copy 1 byte - EX(l8ui, a6, a3, 0, l_fixup) - EX(s8i, a6, a5, 0, s_fixup) + EX(l8ui, a6, a3, 0, fixup) + EX(s8i, a6, a5, 0, fixup) .L5: movi a2, 0 # return success for len bytes copied retw @@ -217,7 +217,7 @@ __xtensa_copy_user: # copy 16 bytes per iteration for word-aligned dst and unaligned src and a10, a3, a8 # save unalignment offset for below sub a3, a3, a10 # align a3 (to avoid sim warnings only; not needed for hardware) - EX(l32i, a6, a3, 0, l_fixup) # load first word + EX(l32i, a6, a3, 0, fixup) # load first word #if XCHAL_HAVE_LOOPS loopnez a7, .Loop2done #else /* !XCHAL_HAVE_LOOPS */ @@ -226,19 +226,19 @@ __xtensa_copy_user: add a12, a12, a3 # a12 = end of last 16B source chunk #endif /* !XCHAL_HAVE_LOOPS */ .Loop2: - EX(l32i, a7, a3, 4, l_fixup) - EX(l32i, a8, a3, 8, l_fixup) + EX(l32i, a7, a3, 4, fixup) + EX(l32i, a8, a3, 8, fixup) ALIGN( a6, a6, a7) - EX(s32i, a6, a5, 0, s_fixup) - EX(l32i, a9, a3, 12, l_fixup) + EX(s32i, a6, a5, 0, fixup) + EX(l32i, a9, a3, 12, fixup) ALIGN( a7, a7, a8) - EX(s32i, a7, a5, 4, s_fixup) - EX(l32i, a6, a3, 16, l_fixup) + EX(s32i, a7, a5, 4, fixup) + EX(l32i, a6, a3, 16, fixup) ALIGN( a8, a8, a9) - EX(s32i, a8, a5, 8, s_fixup) + EX(s32i, a8, a5, 8, fixup) addi a3, a3, 16 ALIGN( a9, a9, a6) - EX(s32i, a9, a5, 12, s_fixup) + EX(s32i, a9, a5, 12, fixup) addi a5, a5, 16 #if !XCHAL_HAVE_LOOPS blt a3, a12, .Loop2 @@ -246,39 +246,39 @@ __xtensa_copy_user: .Loop2done: bbci.l a4, 3, .L12 # copy 8 bytes - EX(l32i, a7, a3, 4, l_fixup) - EX(l32i, a8, a3, 8, l_fixup) + EX(l32i, a7, a3, 4, fixup) + EX(l32i, a8, a3, 8, fixup) ALIGN( a6, a6, a7) - EX(s32i, a6, a5, 0, s_fixup) + EX(s32i, a6, a5, 0, fixup) addi a3, a3, 8 ALIGN( a7, a7, a8) - EX(s32i, a7, a5, 4, s_fixup) + EX(s32i, a7, a5, 4, fixup) addi a5, a5, 8 mov a6, a8 .L12: bbci.l a4, 2, .L13 # copy 4 bytes - EX(l32i, a7, a3, 4, l_fixup) + EX(l32i, a7, a3, 4, fixup) addi a3, a3, 4 ALIGN( a6, a6, a7) - EX(s32i, a6, a5, 0, s_fixup) + EX(s32i, a6, a5, 0, fixup) addi a5, a5, 4 mov a6, a7 .L13: add a3, a3, a10 # readjust a3 with correct misalignment bbci.l a4, 1, .L14 # copy 2 bytes - EX(l8ui, a6, a3, 0, l_fixup) - EX(l8ui, a7, a3, 1, l_fixup) + EX(l8ui, a6, a3, 0, fixup) + EX(l8ui, a7, a3, 1, fixup) addi a3, a3, 2 - EX(s8i, a6, a5, 0, s_fixup) - EX(s8i, a7, a5, 1, s_fixup) + EX(s8i, a6, a5, 0, fixup) + EX(s8i, a7, a5, 1, fixup) addi a5, a5, 2 .L14: bbci.l a4, 0, .L15 # copy 1 byte - EX(l8ui, a6, a3, 0, l_fixup) - EX(s8i, a6, a5, 0, s_fixup) + EX(l8ui, a6, a3, 0, fixup) + EX(s8i, a6, a5, 0, fixup) .L15: movi a2, 0 # return success for len bytes copied retw @@ -291,30 +291,10 @@ __xtensa_copy_user: * bytes_copied = a5 - a2 * retval = bytes_not_copied = original len - bytes_copied * retval = a11 - (a5 - a2) - * - * Clearing the remaining pieces of kernel memory plugs security - * holes. This functionality is the equivalent of the *_zeroing - * functions that some architectures provide. */ -.Lmemset: - .word memset -s_fixup: +fixup: sub a2, a5, a2 /* a2 <-- bytes copied */ sub a2, a11, a2 /* a2 <-- bytes not copied */ retw - -l_fixup: - sub a2, a5, a2 /* a2 <-- bytes copied */ - sub a2, a11, a2 /* a2 <-- bytes not copied == return value */ - - /* void *memset(void *s, int c, size_t n); */ - mov a6, a5 /* s */ - movi a7, 0 /* c */ - mov a8, a2 /* n */ - l32r a4, .Lmemset - callx4 a4 - /* Ignore memset return value in a6. */ - /* a2 still contains bytes not copied. */ - retw