lkml.org 
[lkml]   [2013]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 1/1] Revert "ptrace: PTRACE_DETACH should do flush_ptrace_hw_breakpoint(child)"
This reverts commit fab840fc2d542fabcab903db8e03589a6702ba5f.

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: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
kernel/ptrace.c | 1 -
1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 4041f57..a146ee3 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -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);
/*
--
1.5.5.1



\
 
 \ /
  Last update: 2013-08-06 18:01    [W:0.323 / U:1.412 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site