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Commit c35ff848 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Greg Kroah-Hartman
Browse files

ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP 



commit 4a3d2717d140401df7501a95e454180831a0c5af upstream.

xtensa is the last user of the PT_SINGLESTEP flag.  Changing tsk->ptrace in
user_enable_single_step and user_disable_single_step without locking could
potentiallly cause problems.

So use a thread info flag instead of a flag in tsk->ptrace.  Use TIF_SINGLESTEP
that xtensa already had defined but unused.

Remove the definitions of PT_SINGLESTEP and PT_BLOCKSTEP as they have no more users.

Cc: stable@vger.kernel.org
Acked-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
Tested-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarOleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20220505182645.497868-4-ebiederm@xmission.com


Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0956f87c

arch/xtensa/kernel/ptrace.c

+2 −2
Original line number Diff line number Diff line
@@ -35,12 +35,12 @@ 


void user_enable_single_step(struct task_struct *child)

{

	child->ptrace |= PT_SINGLESTEP;

	set_tsk_thread_flag(child, TIF_SINGLESTEP);

}



void user_disable_single_step(struct task_struct *child)

{

	child->ptrace &= ~PT_SINGLESTEP;

	clear_tsk_thread_flag(child, TIF_SINGLESTEP);

}



/*

arch/xtensa/kernel/signal.c

+2 −2
Original line number Diff line number Diff line
@@ -455,7 +455,7 @@ static void do_signal(struct pt_regs *regs) 
		/* Set up the stack frame */

		ret = setup_frame(&ksig, sigmask_to_save(), regs);

		signal_setup_done(ret, &ksig, 0);

		if (current->ptrace & PT_SINGLESTEP)

		if (test_thread_flag(TIF_SINGLESTEP))

			task_pt_regs(current)->icountlevel = 1;



		return;
@@ -481,7 +481,7 @@ static void do_signal(struct pt_regs *regs) 
	/* If there's no signal to deliver, we just restore the saved mask.  */

	restore_saved_sigmask();



	if (current->ptrace & PT_SINGLESTEP)

	if (test_thread_flag(TIF_SINGLESTEP))

		task_pt_regs(current)->icountlevel = 1;

	return;

}

include/linux/ptrace.h

+0 −6
Original line number Diff line number Diff line
@@ -40,12 +40,6 @@ extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, 
#define PT_EXITKILL		(PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT)

#define PT_SUSPEND_SECCOMP	(PTRACE_O_SUSPEND_SECCOMP << PT_OPT_FLAG_SHIFT)



/* single stepping state bits (used on ARM and PA-RISC) */

#define PT_SINGLESTEP_BIT	31

#define PT_SINGLESTEP		(1<<PT_SINGLESTEP_BIT)

#define PT_BLOCKSTEP_BIT	30

#define PT_BLOCKSTEP		(1<<PT_BLOCKSTEP_BIT)



extern long arch_ptrace(struct task_struct *child, long request,

			unsigned long addr, unsigned long data);

extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);