| From | Luis Henriques <> | Subject | [PATCH 3.16.y-ckt 031/180] arm64: Clear out any singlestep state on a ptrace detach operation | Date | Wed, 3 Feb 2016 22:30:37 +0000 |
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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
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