On Tue, Feb 16, 2016 at 01:57:40PM +0800, Boqun Feng wrote:
> Add two helper functions of irq_context:
>
> task_irq_context(): return the encoded irq_context of the task, the
> return value is encoded in the same as ->irq_context of held_lock.
> Always return 0 if !(CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING)
>
> is_same_irq_context(): compare whether two irq_context are the same.
> Always return true if !(CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING)
>
> These two functions are added for the future use of irq_context by
> LOCKED_ACCESS, because LOCKED_ACCESS needs to get the irq_context value
> of a task when a data access happens rather than when a lock is
> acquired, so it needs another way than getting the value from
> held_lock::irq_context
>
> Signed-off-by: Boqun Feng <[email protected]>
Queued again for review and testing. ;-)
Thanx, Paul
> ---
> kernel/locking/lockdep.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
> index 60ace56..f36df37 100644
> --- a/kernel/locking/lockdep.c
> +++ b/kernel/locking/lockdep.c
> @@ -2839,6 +2839,16 @@ static int mark_irqflags(struct task_struct *curr,
> struct held_lock *hlock)
> return 1;
> }
>
> +static unsigned int task_irq_context(struct task_struct *task)
> +{
> + return 2 * (task->hardirq_context ? 1 : 0) + task->softirq_context;
> +}
> +
> +static bool is_same_irq_context(unsigned int ctx1, unsigned int ctx2)
> +{
> + return ctx1 == ctx2;
> +}
> +
> static int separate_irq_context(struct task_struct *curr,
> struct held_lock *hlock)
> {
> @@ -2847,8 +2857,7 @@ static int separate_irq_context(struct task_struct
> *curr,
> /*
> * Keep track of points where we cross into an interrupt context:
> */
> - hlock->irq_context = 2*(curr->hardirq_context ? 1 : 0) +
> - curr->softirq_context;
> + hlock->irq_context = task_irq_context(curr);
> if (depth) {
> struct held_lock *prev_hlock;
>
> @@ -2880,6 +2889,9 @@ static inline int mark_irqflags(struct task_struct
> *curr,
> return 1;
> }
>
> +#define task_irq_context(task) 0
> +#define is_same_irq_context(ctx1, ctx2) true
> +
> static inline int separate_irq_context(struct task_struct *curr,
> struct held_lock *hlock)
> {
> --
> 2.7.1
>
