From: John Blackwood Date: Mon, 7 Dec 2015 11:50:34 +0000 (+0000) Subject: arm64: Clear out any singlestep state on a ptrace detach operation X-Git-Tag: firefly_0821_release~3391^2~124 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=c01afb9239eaee84a93e7b0319e3935f55604361;p=firefly-linux-kernel-4.4.55.git 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 [will: added comment to justify why this is in the arch code] Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 1971f491bb90..ff7f13239515 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -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