diff options
Diffstat (limited to 'arch/arm/kernel/traps.c')
| -rw-r--r-- | arch/arm/kernel/traps.c | 52 |
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 |