diff --git a/arch/x86/kernel/ptrace_32.c b/arch/x86/kernel/ptrace_32.c index bd3668c2421a..a1425e9ad028 100644 --- a/arch/x86/kernel/ptrace_32.c +++ b/arch/x86/kernel/ptrace_32.c @@ -37,53 +37,20 @@ */ #define FLAG_MASK 0x00050dd5 -/* - * Offset of eflags on child stack.. - */ -#define EFL_OFFSET offsetof(struct pt_regs, eflags) - -static inline struct pt_regs *get_child_regs(struct task_struct *task) +static long *pt_regs_access(struct pt_regs *regs, unsigned long regno) { - void *stack_top = (void *)task->thread.esp0; - return stack_top - sizeof(struct pt_regs); -} - -/* - * This routine will get a word off of the processes privileged stack. - * the offset is bytes into the pt_regs structure on the stack. - * This routine assumes that all the privileged stacks are in our - * data space. - */ -static inline int get_stack_long(struct task_struct *task, int offset) -{ - unsigned char *stack; - - stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs); - stack += offset; - return (*((int *)stack)); -} - -/* - * This routine will put a word on the processes privileged stack. - * the offset is bytes into the pt_regs structure on the stack. - * This routine assumes that all the privileged stacks are in our - * data space. - */ -static inline int put_stack_long(struct task_struct *task, int offset, - unsigned long data) -{ - unsigned char * stack; - - stack = (unsigned char *)task->thread.esp0 - sizeof(struct pt_regs); - stack += offset; - *(unsigned long *) stack = data; - return 0; + BUILD_BUG_ON(offsetof(struct pt_regs, ebx) != 0); + if (regno > FS) + --regno; + return ®s->ebx + regno; } static int putreg(struct task_struct *child, unsigned long regno, unsigned long value) { - switch (regno >> 2) { + struct pt_regs *regs = task_pt_regs(child); + regno >>= 2; + switch (regno) { case GS: if (value && (value & 3) != 3) return -EIO; @@ -113,26 +80,25 @@ static int putreg(struct task_struct *child, clear_tsk_thread_flag(child, TIF_FORCED_TF); else if (test_tsk_thread_flag(child, TIF_FORCED_TF)) value |= X86_EFLAGS_TF; - value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK; + value |= regs->eflags & ~FLAG_MASK; break; } - if (regno > FS*4) - regno -= 1*4; - put_stack_long(child, regno, value); + *pt_regs_access(regs, regno) = value; return 0; } -static unsigned long getreg(struct task_struct *child, - unsigned long regno) +static unsigned long getreg(struct task_struct *child, unsigned long regno) { + struct pt_regs *regs = task_pt_regs(child); unsigned long retval = ~0UL; - switch (regno >> 2) { + regno >>= 2; + switch (regno) { case EFL: /* * If the debugger set TF, hide it from the readout. */ - retval = get_stack_long(child, EFL_OFFSET); + retval = regs->eflags; if (test_tsk_thread_flag(child, TIF_FORCED_TF)) retval &= ~X86_EFLAGS_TF; break; @@ -147,9 +113,7 @@ static unsigned long getreg(struct task_struct *child, retval = 0xffff; /* fall through */ default: - if (regno > FS*4) - regno -= 1*4; - retval &= get_stack_long(child, regno); + retval &= *pt_regs_access(regs, regno); } return retval; }