Commit c01afb92 authored Dec 07, 2015 by John Blackwood Committed by Greg Kroah-Hartman Jan 31, 2016

arm64: Clear out any singlestep state on a ptrace detach operation



commit 5db4fd8c52810bd9740c1240ebf89223b171aa70 upstream.

Make sure to clear out any ptrace singlestep state when a ptrace(2)
PTRACE_DETACH call is made on arm64 systems.

Otherwise, the previously ptraced task will die off with a SIGTRAP
signal if the debugger just previously singlestepped the ptraced task.

Signed-off-by: John Blackwood <john.blackwood@ccur.com>
[will: added comment to justify why this is in the arch code]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent e268f848

arch/arm64/kernel/ptrace.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -58,6 +58,12 @@
		*/
		void ptrace_disable(struct task_struct *child)
		{
		/*
		* This would be better off in core code, but PTRACE_DETACH has
		* grown its fair share of arch-specific worts and changing it
		* is likely to cause regressions on obscure architectures.
		*/
		user_disable_single_step(child);
		}

		#ifdef CONFIG_HAVE_HW_BREAKPOINT