Re: [PATCH v2] livepatch: Replace the fake signal sending with TIF_NOTIFY_SIGNAL infrastructure

[Jiri Kosina]

On Mon, 29 Mar 2021, Miroslav Benes wrote:

> Livepatch sends a fake signal to all remaining blocking tasks of a
> running transition after a set period of time. It uses TIF_SIGPENDING
> flag for the purpose. Commit 12db8b690010 ("entry: Add support for
> TIF_NOTIFY_SIGNAL") added a generic infrastructure to achieve the same.
> Replace our bespoke solution with the generic one.
> 
> Reviewed-by: Jens Axboe 
> Reviewed-by: Petr Mladek 
> Signed-off-by: Miroslav Benes 

Pushed out to livepatching#for-5.13/signal.

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH v2] livepatch: Replace the fake signal sending with TIF_NOTIFY_SIGNAL infrastructure

[Joe Lawrence]

On 3/29/21 9:28 AM, Miroslav Benes wrote:

Livepatch sends a fake signal to all remaining blocking tasks of a
running transition after a set period of time. It uses TIF_SIGPENDING
flag for the purpose. Commit 12db8b690010 ("entry: Add support for
TIF_NOTIFY_SIGNAL") added a generic infrastructure to achieve the same.
Replace our bespoke solution with the generic one.

Reviewed-by: Jens Axboe 
Reviewed-by: Petr Mladek 
Signed-off-by: Miroslav Benes 
---
v2:
- #include from kernel/signal.c removed [Petr]

  kernel/livepatch/transition.c | 5 ++---
  kernel/signal.c   | 4 +---
  2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
index f6310f848f34..3a4beb9395c4 100644
--- a/kernel/livepatch/transition.c
+++ b/kernel/livepatch/transition.c
@@ -9,6 +9,7 @@
  
  #include 

  #include 
+#include 
  #include "core.h"
  #include "patch.h"
  #include "transition.h"
@@ -369,9 +370,7 @@ static void klp_send_signals(void)
 * Send fake signal to all non-kthread tasks which are
 * still not migrated.
 */
-   spin_lock_irq(>sighand->siglock);
-   signal_wake_up(task, 0);
-   spin_unlock_irq(>sighand->siglock);
+   set_notify_signal(task);
}
}
read_unlock(_lock);
diff --git a/kernel/signal.c b/kernel/signal.c
index f2a1b898da29..604290a8ca89 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -43,7 +43,6 @@
  #include 
  #include 
  #include 
-#include 
  #include 
  #include 
  
@@ -181,8 +180,7 @@ void recalc_sigpending_and_wake(struct task_struct *t)
  
  void recalc_sigpending(void)

  {
-   if (!recalc_sigpending_tsk(current) && !freezing(current) &&
-   !klp_patch_pending(current))
+   if (!recalc_sigpending_tsk(current) && !freezing(current))
clear_thread_flag(TIF_SIGPENDING);
  
  }




Looks good to me.  Thanks for checking on this and updating.

Acked-by: Joe Lawrence 

-- Joe

[PATCH v2] livepatch: Replace the fake signal sending with TIF_NOTIFY_SIGNAL infrastructure

[Miroslav Benes]

Livepatch sends a fake signal to all remaining blocking tasks of a
running transition after a set period of time. It uses TIF_SIGPENDING
flag for the purpose. Commit 12db8b690010 ("entry: Add support for
TIF_NOTIFY_SIGNAL") added a generic infrastructure to achieve the same.
Replace our bespoke solution with the generic one.

Reviewed-by: Jens Axboe 
Reviewed-by: Petr Mladek 
Signed-off-by: Miroslav Benes 
---
v2:
- #include from kernel/signal.c removed [Petr]

 kernel/livepatch/transition.c | 5 ++---
 kernel/signal.c   | 4 +---
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c
index f6310f848f34..3a4beb9395c4 100644
--- a/kernel/livepatch/transition.c
+++ b/kernel/livepatch/transition.c
@@ -9,6 +9,7 @@
 
 #include 
 #include 
+#include 
 #include "core.h"
 #include "patch.h"
 #include "transition.h"
@@ -369,9 +370,7 @@ static void klp_send_signals(void)
 * Send fake signal to all non-kthread tasks which are
 * still not migrated.
 */
-   spin_lock_irq(>sighand->siglock);
-   signal_wake_up(task, 0);
-   spin_unlock_irq(>sighand->siglock);
+   set_notify_signal(task);
}
}
read_unlock(_lock);
diff --git a/kernel/signal.c b/kernel/signal.c
index f2a1b898da29..604290a8ca89 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -43,7 +43,6 @@
 #include 
 #include 
 #include 
-#include 
 #include 
 #include 
 
@@ -181,8 +180,7 @@ void recalc_sigpending_and_wake(struct task_struct *t)
 
 void recalc_sigpending(void)
 {
-   if (!recalc_sigpending_tsk(current) && !freezing(current) &&
-   !klp_patch_pending(current))
+   if (!recalc_sigpending_tsk(current) && !freezing(current))
clear_thread_flag(TIF_SIGPENDING);
 
 }
-- 
2.30.2