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Commit 35114fcb authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
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Revert "ptrace: PTRACE_DETACH should do flush_ptrace_hw_breakpoint(child)" 



This reverts commit fab840fc.

This commit even has the test-case to prove that the tracee
can be killed by SIGTRAP if the debugger does not remove the
breakpoints before PTRACE_DETACH.

However, this is exactly what wineserver deliberately does,
set_thread_context() calls PTRACE_ATTACH + PTRACE_DETACH just
for PTRACE_POKEUSER(DR*) in between.

So we should revert this fix and document that PTRACE_DETACH
should keep the breakpoints.

Reported-by: default avatarFelipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1853a65e

kernel/ptrace.c

+0 −1
Original line number Diff line number Diff line
@@ -469,7 +469,6 @@ static int ptrace_detach(struct task_struct *child, unsigned int data) 
	/* Architecture-specific hardware disable .. */

	ptrace_disable(child);

	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);

	flush_ptrace_hw_breakpoint(child);



	write_lock_irq(&tasklist_lock);

	/*