lkml.org 
[lkml]   [2016]   [Feb]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3.16.y-ckt 031/180] arm64: Clear out any singlestep state on a ptrace detach operation
Date
3.16.7-ckt24 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: John Blackwood <john.blackwood@ccur.com>

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: Luis Henriques <luis.henriques@canonical.com>
---
arch/arm64/kernel/ptrace.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 167c5edecad4..d2b9a3f7457d 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -55,6 +55,12 @@
*/
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
\
 
 \ /
  Last update: 2016-02-04 01:41    [W:0.357 / U:0.744 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site