Commit 4f627af8 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

ptrace: Remove the unnecessary arguments from arch_ptrace_stop 

Both arch_ptrace_stop_needed and arch_ptrace_stop are called with an
exit_code and a siginfo structure.  Neither argument is used by any of
the implementations so just remove the unneeded arguments.

The two arechitectures that implement arch_ptrace_stop are ia64 and
sparc.  Both architectures flush their register stacks before a
ptrace_stack so that all of the register information can be accessed
by debuggers.

As the question of if a register stack needs to be flushed is
independent of why ptrace is stopping not needing arguments make sense.

Cc: David Miller <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Link: https://lkml.kernel.org/r/87lf3mx290.fsf@disp2133


Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent 7d613f9f

arch/ia64/include/asm/ptrace.h

+2 −2
Original line number Diff line number Diff line
@@ -129,9 +129,9 @@ static inline long regs_return_value(struct pt_regs *regs) 
  extern void ia64_decrement_ip (struct pt_regs *pt);



  extern void ia64_ptrace_stop(void);

  #define arch_ptrace_stop(code, info) \

  #define arch_ptrace_stop() \

	ia64_ptrace_stop()

  #define arch_ptrace_stop_needed(code, info) \

  #define arch_ptrace_stop_needed() \

	(!test_thread_flag(TIF_RESTORE_RSE))



  extern void ptrace_attach_sync_user_rbs (struct task_struct *);

arch/sparc/include/asm/ptrace.h

+4 −4
Original line number Diff line number Diff line
@@ -26,12 +26,12 @@ static inline bool pt_regs_clear_syscall(struct pt_regs *regs) 
	return (regs->tstate &= ~TSTATE_SYSCALL);

}



#define arch_ptrace_stop_needed(exit_code, info) \

#define arch_ptrace_stop_needed() \

({	flush_user_windows(); \

	get_thread_wsaved() != 0; \

})



#define arch_ptrace_stop(exit_code, info) \

#define arch_ptrace_stop() \

	synchronize_user_stack()



#define current_pt_regs() \
@@ -129,12 +129,12 @@ static inline bool pt_regs_clear_syscall(struct pt_regs *regs) 
	return (regs->psr &= ~PSR_SYSCALL);

}



#define arch_ptrace_stop_needed(exit_code, info) \

#define arch_ptrace_stop_needed() \

({	flush_user_windows(); \

	current_thread_info()->w_saved != 0;	\

})



#define arch_ptrace_stop(exit_code, info) \

#define arch_ptrace_stop() \

	synchronize_user_stack()



#define current_pt_regs() \

include/linux/ptrace.h

+9 −13
Original line number Diff line number Diff line
@@ -362,29 +362,25 @@ static inline void user_single_step_report(struct pt_regs *regs) 
#ifndef arch_ptrace_stop_needed

/**

 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called

 * @code:	current->exit_code value ptrace will stop with

 * @info:	siginfo_t pointer (or %NULL) for signal ptrace will stop with

 *

 * This is called with the siglock held, to decide whether or not it's

 * necessary to release the siglock and call arch_ptrace_stop() with the

 * same @code and @info arguments.  It can be defined to a constant if

 * arch_ptrace_stop() is never required, or always is.  On machines where

 * this makes sense, it should be defined to a quick test to optimize out

 * calling arch_ptrace_stop() when it would be superfluous.  For example,

 * if the thread has not been back to user mode since the last stop, the

 * thread state might indicate that nothing needs to be done.

 * necessary to release the siglock and call arch_ptrace_stop().  It can be

 * defined to a constant if arch_ptrace_stop() is never required, or always

 * is.  On machines where this makes sense, it should be defined to a quick

 * test to optimize out calling arch_ptrace_stop() when it would be

 * superfluous.  For example, if the thread has not been back to user mode

 * since the last stop, the thread state might indicate that nothing needs

 * to be done.

 *

 * This is guaranteed to be invoked once before a task stops for ptrace and

 * may include arch-specific operations necessary prior to a ptrace stop.

 */

#define arch_ptrace_stop_needed(code, info)	(0)

#define arch_ptrace_stop_needed()	(0)

#endif



#ifndef arch_ptrace_stop

/**

 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace

 * @code:	current->exit_code value ptrace will stop with

 * @info:	siginfo_t pointer (or %NULL) for signal ptrace will stop with

 *

 * This is called with no locks held when arch_ptrace_stop_needed() has

 * just returned nonzero.  It is allowed to block, e.g. for user memory
@@ -394,7 +390,7 @@ static inline void user_single_step_report(struct pt_regs *regs) 
 * we only do it when the arch requires it for this particular stop, as

 * indicated by arch_ptrace_stop_needed().

 */

#define arch_ptrace_stop(code, info)		do { } while (0)

#define arch_ptrace_stop()		do { } while (0)

#endif



#ifndef current_pt_regs

kernel/signal.c

+2 −2
Original line number Diff line number Diff line
@@ -2200,7 +2200,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t 
{

	bool gstop_done = false;



	if (arch_ptrace_stop_needed(exit_code, info)) {

	if (arch_ptrace_stop_needed()) {

		/*

		 * The arch code has something special to do before a

		 * ptrace stop.  This is allowed to block, e.g. for faults
@@ -2210,7 +2210,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t 
		 * any signal bookkeeping like checking group_stop_count.

		 */

		spin_unlock_irq(&current->sighand->siglock);

		arch_ptrace_stop(exit_code, info);

		arch_ptrace_stop();

		spin_lock_irq(&current->sighand->siglock);

	}