Wake up kthreads so that they cycle through kgr_task_safe either by an explicit call to it or implicitly via try_to_freeze. This ensures nobody should use the old version of the code and kgraft core can push everybody to use the new version by switching to the fast path.
Signed-off-by: Jiri Slaby <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Ingo Molnar <[email protected]> --- kernel/kgraft.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/kernel/kgraft.c b/kernel/kgraft.c index ce2f09f3b544..2fe1d922ebac 100644 --- a/kernel/kgraft.c +++ b/kernel/kgraft.c @@ -53,7 +53,7 @@ static void kgr_stub_slow(unsigned long ip, unsigned long parent_ip, { struct kgr_loc_caches *c = ops->private; - if (kgr_task_in_progress(current) && current->mm) { + if (kgr_task_in_progress(current)) { pr_info("kgr: slow stub: calling old code at %lx\n", c->old); kgr_set_regs_ip(regs, c->old + MCOUNT_INSN_SIZE); @@ -71,11 +71,7 @@ static bool kgr_still_patching(void) read_lock(&tasklist_lock); for_each_process(p) { - /* - * TODO - * kernel thread codepaths not supported and silently ignored - */ - if (kgr_task_in_progress(p) && p->mm) { + if (kgr_task_in_progress(p)) { pr_info("pid %d (%s) still in kernel after timeout\n", p->pid, p->comm); failed = true; @@ -123,13 +119,23 @@ static void kgr_work_fn(struct work_struct *work) mutex_unlock(&kgr_in_progress_lock); } -static void kgr_mark_processes(void) +static void kgr_handle_processes(void) { struct task_struct *p; read_lock(&tasklist_lock); - for_each_process(p) + for_each_process(p) { kgr_mark_task_in_progress(p); + + /* wake up kthreads, they will clean the progress flag */ + if (!p->mm) { + /* + * this is incorrect for kthreads waiting still for + * their first wake_up. + */ + wake_up_process(p); + } + } read_unlock(&tasklist_lock); } @@ -274,8 +280,7 @@ static int kgr_patch_code(const struct kgr_patch_fun *patch_fun, bool final) * kgr_start_patching -- the entry for a kgraft patch * @patch: patch to be applied * - * Start patching of code that is neither running in IRQ context nor - * kernel thread. + * Start patching of code that is not running in IRQ context. */ int kgr_start_patching(const struct kgr_patch *patch) { @@ -314,7 +319,7 @@ int kgr_start_patching(const struct kgr_patch *patch) kgr_patch = patch; mutex_unlock(&kgr_in_progress_lock); - kgr_mark_processes(); + kgr_handle_processes(); /* * give everyone time to exit kernel, and check after a while -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
