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-rw-r--r--arch/arm/include/asm/unistd.h7
-rw-r--r--arch/arm/kernel/entry-armv.S33
-rw-r--r--arch/arm/kernel/traps.c52
-rw-r--r--arch/arm/mm/Kconfig12
4 files changed, 3 insertions, 101 deletions
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index 32640c431a08..8f63daf3efa3 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -21,13 +21,6 @@
*/
#define __NR_syscalls (388)
-/*
- * *NOTE*: This is a ghost syscall private to the kernel. Only the
- * __kuser_cmpxchg code in entry-armv.S should be aware of its
- * existence. Don't ever use this from user code.
- */
-#define __ARM_NR_cmpxchg (__ARM_NR_BASE+0x00fff0)
-
#define __ARCH_WANT_STAT64
#define __ARCH_WANT_SYS_GETHOSTNAME
#define __ARCH_WANT_SYS_PAUSE
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 3e1c26eb32b4..3ce377f7251f 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -427,8 +427,7 @@ ENDPROC(__fiq_abt)
.endm
.macro kuser_cmpxchg_check
-#if !defined(CONFIG_CPU_32v6K) && defined(CONFIG_KUSER_HELPERS) && \
- !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
+#if !defined(CONFIG_CPU_32v6K) && defined(CONFIG_KUSER_HELPERS)
#ifndef CONFIG_MMU
#warning "NPTL on non MMU needs fixing"
#else
@@ -859,20 +858,7 @@ __kuser_helper_start:
__kuser_cmpxchg64: @ 0xffff0f60
-#if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
-
- /*
- * Poor you. No fast solution possible...
- * The kernel itself must perform the operation.
- * A special ghost syscall is used for that (see traps.c).
- */
- stmfd sp!, {r7, lr}
- ldr r7, 1f @ it's 20 bits
- swi __ARM_NR_cmpxchg64
- ldmfd sp!, {r7, pc}
-1: .word __ARM_NR_cmpxchg64
-
-#elif defined(CONFIG_CPU_32v6K)
+#if defined(CONFIG_CPU_32v6K)
stmfd sp!, {r4, r5, r6, r7}
ldrd r4, r5, [r0] @ load old val
@@ -948,20 +934,7 @@ __kuser_memory_barrier: @ 0xffff0fa0
__kuser_cmpxchg: @ 0xffff0fc0
-#if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
-
- /*
- * Poor you. No fast solution possible...
- * The kernel itself must perform the operation.
- * A special ghost syscall is used for that (see traps.c).
- */
- stmfd sp!, {r7, lr}
- ldr r7, 1f @ it's 20 bits
- swi __ARM_NR_cmpxchg
- ldmfd sp!, {r7, pc}
-1: .word __ARM_NR_cmpxchg
-
-#elif __LINUX_ARM_ARCH__ < 6
+#if __LINUX_ARM_ARCH__ < 6
#ifdef CONFIG_MMU
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 969f9d9e665f..bc698383e822 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -625,58 +625,6 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
set_tls(regs->ARM_r0);
return 0;
-#ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG
- /*
- * Atomically store r1 in *r2 if *r2 is equal to r0 for user space.
- * Return zero in r0 if *MEM was changed or non-zero if no exchange
- * happened. Also set the user C flag accordingly.
- * If access permissions have to be fixed up then non-zero is
- * returned and the operation has to be re-attempted.
- *
- * *NOTE*: This is a ghost syscall private to the kernel. Only the
- * __kuser_cmpxchg code in entry-armv.S should be aware of its
- * existence. Don't ever use this from user code.
- */
- case NR(cmpxchg):
- for (;;) {
- extern void do_DataAbort(unsigned long addr, unsigned int fsr,
- struct pt_regs *regs);
- unsigned long val;
- unsigned long addr = regs->ARM_r2;
- struct mm_struct *mm = current->mm;
- pgd_t *pgd; pmd_t *pmd; pte_t *pte;
- spinlock_t *ptl;
-
- regs->ARM_cpsr &= ~PSR_C_BIT;
- down_read(&mm->mmap_sem);
- pgd = pgd_offset(mm, addr);
- if (!pgd_present(*pgd))
- goto bad_access;
- pmd = pmd_offset(pgd, addr);
- if (!pmd_present(*pmd))
- goto bad_access;
- pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
- if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) {
- pte_unmap_unlock(pte, ptl);
- goto bad_access;
- }
- val = *(unsigned long *)addr;
- val -= regs->ARM_r0;
- if (val == 0) {
- *(unsigned long *)addr = regs->ARM_r1;
- regs->ARM_cpsr |= PSR_C_BIT;
- }
- pte_unmap_unlock(pte, ptl);
- up_read(&mm->mmap_sem);
- return val;
-
- bad_access:
- up_read(&mm->mmap_sem);
- /* simulate a write access fault */
- do_DataAbort(addr, 15 + (1 << 11), regs);
- }
-#endif
-
default:
/* Calls 9f00xx..9f07ff are defined to return -ENOSYS
if not implemented, rather than raising SIGILL. This
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index df7537f12469..c21941349b3e 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -419,28 +419,24 @@ config CPU_THUMBONLY
config CPU_32v3
bool
select CPU_USE_DOMAINS if MMU
- select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
select NEED_KUSER_HELPERS
select TLS_REG_EMUL if SMP || !MMU
config CPU_32v4
bool
select CPU_USE_DOMAINS if MMU
- select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
select NEED_KUSER_HELPERS
select TLS_REG_EMUL if SMP || !MMU
config CPU_32v4T
bool
select CPU_USE_DOMAINS if MMU
- select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
select NEED_KUSER_HELPERS
select TLS_REG_EMUL if SMP || !MMU
config CPU_32v5
bool
select CPU_USE_DOMAINS if MMU
- select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
select NEED_KUSER_HELPERS
select TLS_REG_EMUL if SMP || !MMU
@@ -805,14 +801,6 @@ config TLS_REG_EMUL
a few prototypes like that in existence) and therefore access to
that required register must be emulated.
-config NEEDS_SYSCALL_FOR_CMPXCHG
- bool
- select NEED_KUSER_HELPERS
- help
- SMP on a pre-ARMv6 processor? Well OK then.
- Forget about fast user space cmpxchg support.
- It is just not possible.
-
config NEED_KUSER_HELPERS
bool