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authorAl Viro <viro@zeniv.linux.org.uk>2017-03-22 18:02:41 +0100
committerAl Viro <viro@zeniv.linux.org.uk>2017-03-29 00:24:07 +0200
commit3a0e75adecc8da026a5befb2c5828d08c999373c (patch)
tree3fa4044f96db80cb151bec030505e7df78da0983 /arch/xtensa
parentxtensa: switch to generic extable.h (diff)
downloadlinux-3a0e75adecc8da026a5befb2c5828d08c999373c.tar.xz
linux-3a0e75adecc8da026a5befb2c5828d08c999373c.zip
xtensa: get rid of zeroing, use RAW_COPY_USER
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/xtensa')
-rw-r--r--arch/xtensa/Kconfig1
-rw-r--r--arch/xtensa/include/asm/uaccess.h54
-rw-r--r--arch/xtensa/lib/usercopy.S116
3 files changed, 57 insertions, 114 deletions
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