Wake up kthreads so that they cycle through kgr_task_safe either by explicit call to it or implicitly via kthread_should_stop. 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: Steven Rostedt <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Ingo Molnar <[email protected]> --- arch/x86/include/asm/kgr.h | 2 +- kernel/kgr.c | 25 +++++++++++++++---------- 2 files changed, 16 insertions(+), 11 deletions(-) diff --git a/arch/x86/include/asm/kgr.h b/arch/x86/include/asm/kgr.h index 172f7b966bb5..49daa46243fc 100644 --- a/arch/x86/include/asm/kgr.h +++ b/arch/x86/include/asm/kgr.h @@ -13,7 +13,7 @@ static void _new_function ##_stub_slow (unsigned long ip, unsigned long parent_i { \ struct kgr_loc_caches *c = ops->private; \ \ - if (task_thread_info(current)->kgr_in_progress && current->mm) {\ + if (task_thread_info(current)->kgr_in_progress) { \ pr_info("kgr: slow stub: calling old code at %lx\n", \ c->old); \ regs->ip = c->old + MCOUNT_INSN_SIZE; \ diff --git a/kernel/kgr.c b/kernel/kgr.c index 5e9a07faddb9..ea63e857a78a 100644 --- a/kernel/kgr.c +++ b/kernel/kgr.c @@ -42,11 +42,7 @@ static bool kgr_still_patching(void) read_lock(&tasklist_lock); for_each_process(p) { - /* - * TODO - * kernel thread codepaths not supported and silently ignored - */ - if (task_thread_info(p)->kgr_in_progress && p->mm) { + if (task_thread_info(p)->kgr_in_progress) { pr_info("pid %d (%s) still in kernel after timeout\n", p->pid, p->comm); failed = true; @@ -94,13 +90,23 @@ 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) { task_thread_info(p)->kgr_in_progress = true; + + /* 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); } @@ -237,8 +243,7 @@ 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) { @@ -276,7 +281,7 @@ 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 -- 1.9.2 -- 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/
