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Commit 290ba3ae authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Linus Torvalds
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cris arch-v32: use generic ptrace_resume code 



Use the generic ptrace_resume code for PTRACE_SYSCALL, PTRACE_CONT,
PTRACE_KILL and PTRACE_SINGLESTEP.  This implies defining
arch_has_single_step in <asm/ptrace.h> and implementing the
user_enable_single_step and user_disable_single_step functions, which also
causes the breakpoint information to be cleared on fork, which could be
considered a bug fix.

Also the TIF_SYSCALL_TRACE thread flag is now cleared on PTRACE_KILL which
it previously wasn't which is consistent with all architectures using the
modern ptrace code.

The way breakpoints are disabled is entirely inconsistent currently, I
tried to make some sense of it, but I suspect all of the content of
ptrace_disable should be moved into user_disable_single_step, this
defintively needs some revisting as the current patch changes behaviour in
not quite designed ways.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8313809e

arch/cris/arch-v32/kernel/ptrace.c

+30 −79
Original line number Diff line number Diff line
@@ -78,6 +78,35 @@ int put_reg(struct task_struct *task, unsigned int regno, unsigned long data) 
	return 0;

}



void user_enable_single_step(struct task_struct *child)

{

	unsigned long tmp;



	/*

	 * Set up SPC if not set already (in which case we have no other

	 * choice but to trust it).

	 */

	if (!get_reg(child, PT_SPC)) {

		/* In case we're stopped in a delay slot. */

		tmp = get_reg(child, PT_ERP) & ~1;

		put_reg(child, PT_SPC, tmp);

	}

	tmp = get_reg(child, PT_CCS) | SBIT_USER;

	put_reg(child, PT_CCS, tmp);

}



void user_disable_single_step(struct task_struct *child)

{

	put_reg(child, PT_SPC, 0);



	if (!get_debugreg(child->pid, PT_BP_CTRL)) {

		unsigned long tmp;

		/* If no h/w bp configured, disable S bit. */

		tmp = get_reg(child, PT_CCS) & ~SBIT_USER;

		put_reg(child, PT_CCS, tmp);

	}

}



/*

 * Called by kernel/ptrace.c when detaching.

 *
@@ -89,8 +118,7 @@ ptrace_disable(struct task_struct *child) 
	unsigned long tmp;



	/* Deconfigure SPC and S-bit. */

	tmp = get_reg(child, PT_CCS) & ~SBIT_USER;

	put_reg(child, PT_CCS, tmp);

	user_disable_single_step(child);

	put_reg(child, PT_SPC, 0);



	/* Deconfigure any watchpoints associated with the child. */
@@ -169,83 +197,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data) 
			ret = 0;

			break;



		case PTRACE_SYSCALL:

		case PTRACE_CONT:

			ret = -EIO;



			if (!valid_signal(data))

				break;



			/* Continue means no single-step. */

			put_reg(child, PT_SPC, 0);



			if (!get_debugreg(child->pid, PT_BP_CTRL)) {

				unsigned long tmp;

				/* If no h/w bp configured, disable S bit. */

				tmp = get_reg(child, PT_CCS) & ~SBIT_USER;

				put_reg(child, PT_CCS, tmp);

			}



			if (request == PTRACE_SYSCALL) {

				set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

			}

			else {

				clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

			}



			child->exit_code = data;



			/* TODO: make sure any pending breakpoint is killed */

			wake_up_process(child);

			ret = 0;



			break;



		/* Make the child exit by sending it a sigkill. */

		case PTRACE_KILL:

			ret = 0;



			if (child->exit_state == EXIT_ZOMBIE)

				break;



			child->exit_code = SIGKILL;



			/* Deconfigure single-step and h/w bp. */

			ptrace_disable(child);



			/* TODO: make sure any pending breakpoint is killed */

			wake_up_process(child);

			break;



		/* Set the trap flag. */

		case PTRACE_SINGLESTEP:	{

			unsigned long tmp;

			ret = -EIO;



			/* Set up SPC if not set already (in which case we have

			   no other choice but to trust it). */

			if (!get_reg(child, PT_SPC)) {

				/* In case we're stopped in a delay slot. */

				tmp = get_reg(child, PT_ERP) & ~1;

				put_reg(child, PT_SPC, tmp);

			}

			tmp = get_reg(child, PT_CCS) | SBIT_USER;

			put_reg(child, PT_CCS, tmp);



			if (!valid_signal(data))

				break;



			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);



			/* TODO: set some clever breakpoint mechanism... */



			child->exit_code = data;

			wake_up_process(child);

			ret = 0;

			break;



		}



		/* Get all GP registers from the child. */

		case PTRACE_GETREGS: {

			int i;

arch/cris/include/arch-v32/arch/ptrace.h

+1 −0
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ struct switch_stack { 


#ifdef __KERNEL__



#define arch_has_single_step() (1)

#define user_mode(regs) (((regs)->ccs & (1 << (U_CCS_BITNR + CCS_SHIFT))) != 0)

#define instruction_pointer(regs) ((regs)->erp)

extern void show_regs(struct pt_regs *);