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Diffstat (limited to 'arch/arm/kernel/traps.c')
-rw-r--r--arch/arm/kernel/traps.c52
1 files changed, 0 insertions, 52 deletions
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