xtensa: get rid of zeroing, use RAW_COPY_USER
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>zero-colors
Al Viro
parent
0b46a94e84
commit
3a0e75adec
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@ -29,6 +29,7 @@ config XTENSA
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select NO_BOOTMEM
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select PERF_USE_VMALLOC
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select VIRT_TO_BUS
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select ARCH_HAS_RAW_COPY_USER
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help
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Xtensa processors are 32-bit RISC machines designed by Tensilica
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primarily for embedded systems. These processors are both
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@ -234,60 +234,22 @@ __asm__ __volatile__( \
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* Copy to/from user space
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*/
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/*
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* We use a generic, arbitrary-sized copy subroutine. The Xtensa
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* architecture would cause heavy code bloat if we tried to inline
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* these functions and provide __constant_copy_* equivalents like the
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* i386 versions. __xtensa_copy_user is quite efficient. See the
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* .fixup section of __xtensa_copy_user for a discussion on the
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* X_zeroing equivalents for Xtensa.
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*/
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extern unsigned __xtensa_copy_user(void *to, const void *from, unsigned n);
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#define __copy_user(to, from, size) __xtensa_copy_user(to, from, size)
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static inline unsigned long
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__generic_copy_from_user_nocheck(void *to, const void *from, unsigned long n)
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{
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return __copy_user(to, from, n);
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}
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static inline unsigned long
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__generic_copy_to_user_nocheck(void *to, const void *from, unsigned long n)
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{
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return __copy_user(to, from, n);
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}
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static inline unsigned long
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__generic_copy_to_user(void *to, const void *from, unsigned long n)
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{
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prefetch(from);
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if (access_ok(VERIFY_WRITE, to, n))
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return __copy_user(to, from, n);
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return n;
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}
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static inline unsigned long
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__generic_copy_from_user(void *to, const void *from, unsigned long n)
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raw_copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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prefetchw(to);
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if (access_ok(VERIFY_READ, from, n))
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return __copy_user(to, from, n);
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else
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memset(to, 0, n);
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return n;
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return __xtensa_copy_user(to, (__force const void *)from, n);
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}
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#define copy_to_user(to, from, n) __generic_copy_to_user((to), (from), (n))
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#define copy_from_user(to, from, n) __generic_copy_from_user((to), (from), (n))
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#define __copy_to_user(to, from, n) \
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__generic_copy_to_user_nocheck((to), (from), (n))
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#define __copy_from_user(to, from, n) \
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__generic_copy_from_user_nocheck((to), (from), (n))
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#define __copy_to_user_inatomic __copy_to_user
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#define __copy_from_user_inatomic __copy_from_user
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static inline unsigned long
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raw_copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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prefetchw(from);
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return __xtensa_copy_user((__force void *)to, from, n);
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}
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#define INLINE_COPY_FROM_USER
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#define INLINE_COPY_TO_USER
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/*
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* We need to return the number of bytes not cleared. Our memset()
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@ -102,9 +102,9 @@ __xtensa_copy_user:
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bltui a4, 7, .Lbytecopy # do short copies byte by byte
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# copy 1 byte
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EX(l8ui, a6, a3, 0, l_fixup)
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EX(l8ui, a6, a3, 0, fixup)
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addi a3, a3, 1
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EX(s8i, a6, a5, 0, s_fixup)
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EX(s8i, a6, a5, 0, fixup)
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addi a5, a5, 1
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addi a4, a4, -1
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bbci.l a5, 1, .Ldstaligned # if dst is now aligned, then
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@ -112,11 +112,11 @@ __xtensa_copy_user:
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.Ldst2mod4: # dst 16-bit aligned
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# copy 2 bytes
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bltui a4, 6, .Lbytecopy # do short copies byte by byte
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EX(l8ui, a6, a3, 0, l_fixup)
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EX(l8ui, a7, a3, 1, l_fixup)
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EX(l8ui, a6, a3, 0, fixup)
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EX(l8ui, a7, a3, 1, fixup)
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addi a3, a3, 2
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EX(s8i, a6, a5, 0, s_fixup)
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EX(s8i, a7, a5, 1, s_fixup)
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EX(s8i, a6, a5, 0, fixup)
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EX(s8i, a7, a5, 1, fixup)
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addi a5, a5, 2
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addi a4, a4, -2
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j .Ldstaligned # dst is now aligned, return to main algorithm
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@ -135,9 +135,9 @@ __xtensa_copy_user:
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add a7, a3, a4 # a7 = end address for source
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#endif /* !XCHAL_HAVE_LOOPS */
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.Lnextbyte:
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EX(l8ui, a6, a3, 0, l_fixup)
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EX(l8ui, a6, a3, 0, fixup)
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addi a3, a3, 1
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EX(s8i, a6, a5, 0, s_fixup)
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EX(s8i, a6, a5, 0, fixup)
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addi a5, a5, 1
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#if !XCHAL_HAVE_LOOPS
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blt a3, a7, .Lnextbyte
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@ -161,15 +161,15 @@ __xtensa_copy_user:
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add a8, a8, a3 # a8 = end of last 16B source chunk
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#endif /* !XCHAL_HAVE_LOOPS */
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.Loop1:
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EX(l32i, a6, a3, 0, l_fixup)
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EX(l32i, a7, a3, 4, l_fixup)
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EX(s32i, a6, a5, 0, s_fixup)
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EX(l32i, a6, a3, 8, l_fixup)
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EX(s32i, a7, a5, 4, s_fixup)
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EX(l32i, a7, a3, 12, l_fixup)
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EX(s32i, a6, a5, 8, s_fixup)
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EX(l32i, a6, a3, 0, fixup)
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EX(l32i, a7, a3, 4, fixup)
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EX(s32i, a6, a5, 0, fixup)
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EX(l32i, a6, a3, 8, fixup)
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EX(s32i, a7, a5, 4, fixup)
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EX(l32i, a7, a3, 12, fixup)
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EX(s32i, a6, a5, 8, fixup)
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addi a3, a3, 16
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EX(s32i, a7, a5, 12, s_fixup)
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EX(s32i, a7, a5, 12, fixup)
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addi a5, a5, 16
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#if !XCHAL_HAVE_LOOPS
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blt a3, a8, .Loop1
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@ -177,31 +177,31 @@ __xtensa_copy_user:
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.Loop1done:
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bbci.l a4, 3, .L2
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# copy 8 bytes
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EX(l32i, a6, a3, 0, l_fixup)
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EX(l32i, a7, a3, 4, l_fixup)
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EX(l32i, a6, a3, 0, fixup)
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EX(l32i, a7, a3, 4, fixup)
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addi a3, a3, 8
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EX(s32i, a6, a5, 0, s_fixup)
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EX(s32i, a7, a5, 4, s_fixup)
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EX(s32i, a6, a5, 0, fixup)
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EX(s32i, a7, a5, 4, fixup)
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addi a5, a5, 8
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.L2:
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bbci.l a4, 2, .L3
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# copy 4 bytes
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EX(l32i, a6, a3, 0, l_fixup)
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EX(l32i, a6, a3, 0, fixup)
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addi a3, a3, 4
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EX(s32i, a6, a5, 0, s_fixup)
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EX(s32i, a6, a5, 0, fixup)
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addi a5, a5, 4
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.L3:
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bbci.l a4, 1, .L4
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# copy 2 bytes
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EX(l16ui, a6, a3, 0, l_fixup)
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EX(l16ui, a6, a3, 0, fixup)
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addi a3, a3, 2
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EX(s16i, a6, a5, 0, s_fixup)
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EX(s16i, a6, a5, 0, fixup)
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addi a5, a5, 2
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.L4:
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bbci.l a4, 0, .L5
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# copy 1 byte
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EX(l8ui, a6, a3, 0, l_fixup)
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EX(s8i, a6, a5, 0, s_fixup)
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EX(l8ui, a6, a3, 0, fixup)
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EX(s8i, a6, a5, 0, fixup)
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.L5:
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movi a2, 0 # return success for len bytes copied
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retw
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@ -217,7 +217,7 @@ __xtensa_copy_user:
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# copy 16 bytes per iteration for word-aligned dst and unaligned src
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and a10, a3, a8 # save unalignment offset for below
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sub a3, a3, a10 # align a3 (to avoid sim warnings only; not needed for hardware)
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EX(l32i, a6, a3, 0, l_fixup) # load first word
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EX(l32i, a6, a3, 0, fixup) # load first word
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#if XCHAL_HAVE_LOOPS
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loopnez a7, .Loop2done
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#else /* !XCHAL_HAVE_LOOPS */
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@ -226,19 +226,19 @@ __xtensa_copy_user:
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add a12, a12, a3 # a12 = end of last 16B source chunk
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#endif /* !XCHAL_HAVE_LOOPS */
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.Loop2:
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EX(l32i, a7, a3, 4, l_fixup)
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EX(l32i, a8, a3, 8, l_fixup)
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EX(l32i, a7, a3, 4, fixup)
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EX(l32i, a8, a3, 8, fixup)
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ALIGN( a6, a6, a7)
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EX(s32i, a6, a5, 0, s_fixup)
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EX(l32i, a9, a3, 12, l_fixup)
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EX(s32i, a6, a5, 0, fixup)
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EX(l32i, a9, a3, 12, fixup)
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ALIGN( a7, a7, a8)
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EX(s32i, a7, a5, 4, s_fixup)
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EX(l32i, a6, a3, 16, l_fixup)
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EX(s32i, a7, a5, 4, fixup)
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EX(l32i, a6, a3, 16, fixup)
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ALIGN( a8, a8, a9)
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EX(s32i, a8, a5, 8, s_fixup)
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EX(s32i, a8, a5, 8, fixup)
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addi a3, a3, 16
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ALIGN( a9, a9, a6)
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EX(s32i, a9, a5, 12, s_fixup)
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EX(s32i, a9, a5, 12, fixup)
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addi a5, a5, 16
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#if !XCHAL_HAVE_LOOPS
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blt a3, a12, .Loop2
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@ -246,39 +246,39 @@ __xtensa_copy_user:
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.Loop2done:
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bbci.l a4, 3, .L12
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# copy 8 bytes
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EX(l32i, a7, a3, 4, l_fixup)
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EX(l32i, a8, a3, 8, l_fixup)
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EX(l32i, a7, a3, 4, fixup)
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EX(l32i, a8, a3, 8, fixup)
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ALIGN( a6, a6, a7)
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EX(s32i, a6, a5, 0, s_fixup)
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EX(s32i, a6, a5, 0, fixup)
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addi a3, a3, 8
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ALIGN( a7, a7, a8)
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EX(s32i, a7, a5, 4, s_fixup)
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EX(s32i, a7, a5, 4, fixup)
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addi a5, a5, 8
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mov a6, a8
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.L12:
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bbci.l a4, 2, .L13
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# copy 4 bytes
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EX(l32i, a7, a3, 4, l_fixup)
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EX(l32i, a7, a3, 4, fixup)
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addi a3, a3, 4
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ALIGN( a6, a6, a7)
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EX(s32i, a6, a5, 0, s_fixup)
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EX(s32i, a6, a5, 0, fixup)
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addi a5, a5, 4
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mov a6, a7
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.L13:
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add a3, a3, a10 # readjust a3 with correct misalignment
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bbci.l a4, 1, .L14
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# copy 2 bytes
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EX(l8ui, a6, a3, 0, l_fixup)
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EX(l8ui, a7, a3, 1, l_fixup)
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EX(l8ui, a6, a3, 0, fixup)
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EX(l8ui, a7, a3, 1, fixup)
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addi a3, a3, 2
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EX(s8i, a6, a5, 0, s_fixup)
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EX(s8i, a7, a5, 1, s_fixup)
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EX(s8i, a6, a5, 0, fixup)
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EX(s8i, a7, a5, 1, fixup)
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addi a5, a5, 2
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.L14:
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bbci.l a4, 0, .L15
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# copy 1 byte
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EX(l8ui, a6, a3, 0, l_fixup)
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EX(s8i, a6, a5, 0, s_fixup)
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EX(l8ui, a6, a3, 0, fixup)
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EX(s8i, a6, a5, 0, fixup)
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.L15:
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movi a2, 0 # return success for len bytes copied
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retw
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@ -291,30 +291,10 @@ __xtensa_copy_user:
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* bytes_copied = a5 - a2
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* retval = bytes_not_copied = original len - bytes_copied
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* retval = a11 - (a5 - a2)
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*
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* Clearing the remaining pieces of kernel memory plugs security
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* holes. This functionality is the equivalent of the *_zeroing
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* functions that some architectures provide.
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*/
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.Lmemset:
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.word memset
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s_fixup:
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fixup:
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sub a2, a5, a2 /* a2 <-- bytes copied */
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sub a2, a11, a2 /* a2 <-- bytes not copied */
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retw
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l_fixup:
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sub a2, a5, a2 /* a2 <-- bytes copied */
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sub a2, a11, a2 /* a2 <-- bytes not copied == return value */
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/* void *memset(void *s, int c, size_t n); */
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mov a6, a5 /* s */
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movi a7, 0 /* c */
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mov a8, a2 /* n */
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l32r a4, .Lmemset
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callx4 a4
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/* Ignore memset return value in a6. */
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/* a2 still contains bytes not copied. */
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retw
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