From: Rob Clark <rob.clark@linaro.org>
To: linux-arm-kernel@lists.infradead.org
Cc: patches@linaro.org, linux-kernel@vger.kernel.org,
linux-omap@vger.kernel.org, dri-devel@lists.freedesktop.org,
Arnd Bergmann <arnd@arndb.de>,
Russell King <rmk+kernel@arm.linux.org.uk>,
Rob Clark <rob@ti.com>
Subject: [PATCH] ARM: add get_user() support for 8 byte types
Date: Tue, 13 Nov 2012 09:00:54 -0600 [thread overview]
Message-ID: <1352818854-10958-1-git-send-email-rob.clark@linaro.org> (raw)
From: Rob Clark <rob@ti.com>
A new atomic modeset/pageflip ioctl being developed in DRM requires
get_user() to work for 64bit types (in addition to just put_user()).
v1: original
v2: pass correct size to check_uaccess, and better handling of narrowing
double word read with __get_user_xb() (Russell King's suggestion)
Signed-off-by: Rob Clark <rob@ti.com>
---
arch/arm/include/asm/uaccess.h | 18 +++++++++++++++++-
arch/arm/lib/getuser.S | 17 ++++++++++++++++-
2 files changed, 33 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 7e1f760..e2236ad 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -100,6 +100,7 @@ static inline void set_fs(mm_segment_t fs)
extern int __get_user_1(void *);
extern int __get_user_2(void *);
extern int __get_user_4(void *);
+extern int __get_user_8(void *);
#define __GUP_CLOBBER_1 "lr", "cc"
#ifdef CONFIG_CPU_USE_DOMAINS
@@ -108,6 +109,7 @@ extern int __get_user_4(void *);
#define __GUP_CLOBBER_2 "lr", "cc"
#endif
#define __GUP_CLOBBER_4 "lr", "cc"
+#define __GUP_CLOBBER_8 "lr", "cc"
#define __get_user_x(__r2,__p,__e,__l,__s) \
__asm__ __volatile__ ( \
@@ -118,11 +120,19 @@ extern int __get_user_4(void *);
: "0" (__p), "r" (__l) \
: __GUP_CLOBBER_##__s)
+/* narrowing a double-word get into a single 32bit word register: */
+#ifdef BIG_ENDIAN
+#define __get_user_xb(__r2,__p,__e,__l,__s) \
+ __get_user_x(__r2,(uintptr_t)__p + 4,__e,__l,__s)
+#else
+#define __get_user_xb __get_user_x
+#endif
+
#define __get_user_check(x,p) \
({ \
unsigned long __limit = current_thread_info()->addr_limit - 1; \
register const typeof(*(p)) __user *__p asm("r0") = (p);\
- register unsigned long __r2 asm("r2"); \
+ register typeof(x) __r2 asm("r2"); \
register unsigned long __l asm("r1") = __limit; \
register int __e asm("r0"); \
switch (sizeof(*(__p))) { \
@@ -135,6 +145,12 @@ extern int __get_user_4(void *);
case 4: \
__get_user_x(__r2, __p, __e, __l, 4); \
break; \
+ case 8: \
+ if (sizeof((x)) < 8) \
+ __get_user_xb(__r2, __p, __e, __l, 4); \
+ else \
+ __get_user_x(__r2, __p, __e, __l, 8); \
+ break; \
default: __e = __get_user_bad(); break; \
} \
x = (typeof(*(p))) __r2; \
diff --git a/arch/arm/lib/getuser.S b/arch/arm/lib/getuser.S
index 9b06bb4..ed98707 100644
--- a/arch/arm/lib/getuser.S
+++ b/arch/arm/lib/getuser.S
@@ -18,7 +18,7 @@
* Inputs: r0 contains the address
* r1 contains the address limit, which must be preserved
* Outputs: r0 is the error code
- * r2 contains the zero-extended value
+ * r2, r3 contains the zero-extended value
* lr corrupted
*
* No other registers must be altered. (see <asm/uaccess.h>
@@ -66,6 +66,19 @@ ENTRY(__get_user_4)
mov pc, lr
ENDPROC(__get_user_4)
+ENTRY(__get_user_8)
+ check_uaccess r0, 8, r1, r2, __get_user_bad
+#ifdef CONFIG_THUMB2_KERNEL
+5: TUSER(ldr) r2, [r0]
+6: TUSER(ldr) r3, [r0, #4]
+#else
+5: TUSER(ldr) r2, [r0], #4
+6: TUSER(ldr) r3, [r0]
+#endif
+ mov r0, #0
+ mov pc, lr
+ENDPROC(__get_user_8)
+
__get_user_bad:
mov r2, #0
mov r0, #-EFAULT
@@ -77,4 +90,6 @@ ENDPROC(__get_user_bad)
.long 2b, __get_user_bad
.long 3b, __get_user_bad
.long 4b, __get_user_bad
+ .long 5b, __get_user_bad
+ .long 6b, __get_user_bad
.popsection
--
1.8.0
next reply other threads:[~2012-11-13 15:00 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-13 15:00 Rob Clark [this message]
-- strict thread matches above, loose matches on Subject: below --
2012-11-15 22:01 [PATCH] ARM: add get_user() support for 8 byte types Rob Clark
2012-11-15 22:22 ` Nicolas Pitre
2012-11-16 8:18 ` Arnd Bergmann
2012-11-09 21:17 Rob Clark
2012-11-12 10:46 ` Will Deacon
2012-11-12 13:46 ` Rob Clark
2012-11-12 14:38 ` Will Deacon
2012-11-12 15:09 ` Rob Clark
2012-11-12 19:27 ` Russell King - ARM Linux
2012-11-12 19:58 ` Rob Clark
2012-11-12 23:08 ` Russell King - ARM Linux
2012-11-12 23:33 ` Rob Clark
2012-11-12 23:53 ` Russell King - ARM Linux
2012-11-13 0:31 ` Rob Clark
2012-11-13 9:11 ` Arnd Bergmann
2012-11-13 11:24 ` Russell King - ARM Linux
2012-11-15 9:19 ` Arnd Bergmann
2012-11-15 13:04 ` Rob Clark
2012-11-15 13:39 ` Arnd Bergmann
2012-11-15 13:46 ` Rob Clark
2012-11-15 14:39 ` Arnd Bergmann
2012-11-19 14:32 ` Ville Syrjälä
2012-11-19 14:48 ` Russell King - ARM Linux
2012-11-19 15:18 ` Ville Syrjälä
2012-11-13 11:04 ` Russell King - ARM Linux
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