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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-08-19 11:02:28 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-08-25 16:14:43 +0100 |
| commit | 3fba7e23f754a9a6e639b640fa2a393712ffe1b8 (patch) | |
| tree | c9a472b59b67700bdde134a4dc707ae607837faa /arch/arm/include/asm/futex.h | |
| parent | 08446b129bbde34665c423d882f857a45b8c3aed (diff) | |
| download | linux-3fba7e23f754a9a6e639b640fa2a393712ffe1b8.tar.bz2 | |
ARM: uaccess: provide uaccess_save_and_enable() and uaccess_restore()
Provide uaccess_save_and_enable() and uaccess_restore() to permit
control of userspace visibility to the kernel, and hook these into
the appropriate places in the kernel where we need to access
userspace.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/futex.h')
| -rw-r--r-- | arch/arm/include/asm/futex.h | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h index 5eed82809d82..6795368ad023 100644 --- a/arch/arm/include/asm/futex.h +++ b/arch/arm/include/asm/futex.h @@ -22,8 +22,11 @@ #ifdef CONFIG_SMP #define __futex_atomic_op(insn, ret, oldval, tmp, uaddr, oparg) \ +({ \ + unsigned int __ua_flags; \ smp_mb(); \ prefetchw(uaddr); \ + __ua_flags = uaccess_save_and_enable(); \ __asm__ __volatile__( \ "1: ldrex %1, [%3]\n" \ " " insn "\n" \ @@ -34,12 +37,15 @@ __futex_atomic_ex_table("%5") \ : "=&r" (ret), "=&r" (oldval), "=&r" (tmp) \ : "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \ - : "cc", "memory") + : "cc", "memory"); \ + uaccess_restore(__ua_flags); \ +}) static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval) { + unsigned int __ua_flags; int ret; u32 val; @@ -49,6 +55,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, smp_mb(); /* Prefetching cannot fault */ prefetchw(uaddr); + __ua_flags = uaccess_save_and_enable(); __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" "1: ldrex %1, [%4]\n" " teq %1, %2\n" @@ -61,6 +68,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, : "=&r" (ret), "=&r" (val) : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) : "cc", "memory"); + uaccess_restore(__ua_flags); smp_mb(); *uval = val; @@ -73,6 +81,8 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, #include <asm/domain.h> #define __futex_atomic_op(insn, ret, oldval, tmp, uaddr, oparg) \ +({ \ + unsigned int __ua_flags = uaccess_save_and_enable(); \ __asm__ __volatile__( \ "1: " TUSER(ldr) " %1, [%3]\n" \ " " insn "\n" \ @@ -81,12 +91,15 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, __futex_atomic_ex_table("%5") \ : "=&r" (ret), "=&r" (oldval), "=&r" (tmp) \ : "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \ - : "cc", "memory") + : "cc", "memory"); \ + uaccess_restore(__ua_flags); \ +}) static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval) { + unsigned int __ua_flags; int ret = 0; u32 val; @@ -94,6 +107,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, return -EFAULT; preempt_disable(); + __ua_flags = uaccess_save_and_enable(); __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" "1: " TUSER(ldr) " %1, [%4]\n" " teq %1, %2\n" @@ -103,6 +117,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, : "+r" (ret), "=&r" (val) : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) : "cc", "memory"); + uaccess_restore(__ua_flags); *uval = val; preempt_enable(); |