Commit 068e35ee authored Sep 13, 2010 by Matt Helsley Committed by Frederic Weisbecker Sep 17, 2010

hw breakpoints: Fix pid namespace bug

Hardware breakpoints can't be registered within pid namespaces
because tsk->pid is passed rather than the pid in the current
namespace.

(See https://bugzilla.kernel.org/show_bug.cgi?id=17281

 )

This is a quick fix demonstrating the problem but is not the
best method of solving the problem since passing pids internally
is not the best way to avoid pid namespace bugs. Subsequent patches
will show a better solution.

Much thanks to Frederic Weisbecker <fweisbec@gmail.com> for doing
the bulk of the work finding this bug.

Reported-by: Robin Green <greenrd@greenrd.org>
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: 2.6.33-2.6.35 <stable@kernel.org>
LKML-Reference: <f63454af09fb1915717251570423eb9ddd338340.1284407762.git.matthltc@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

parent 89e45aac

kernel/hw_breakpoint.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -433,7 +433,8 @@ register_user_hw_breakpoint(struct perf_event_attr *attr,
		perf_overflow_handler_t triggered,
		struct task_struct *tsk)
		{
		return perf_event_create_kernel_counter(attr, -1, tsk->pid, triggered);
		return perf_event_create_kernel_counter(attr, -1, task_pid_vnr(tsk),
		triggered);
		}
		EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);