diff mbox series

docs: gdbmacros: print newest record

Message ID 20221229134339.197627-1-john.ogness@linutronix.de
State New
Headers
Series docs: gdbmacros: print newest record |

Commit Message

John Ogness Dec. 29, 2022, 1:43 p.m. UTC 
  @head_id points to the newest record, but the printing loop
exits when it increments to this value (before printing).

Exit the printing loop after the newest record has been printed.

The python-based function in scripts/gdb/linux/dmesg.py already
does this correctly.

Fixes: e60768311af8 ("scripts/gdb: update for lockless printk ringbuffer")
Cc: stable@vger.kernel.org
Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
 Documentation/admin-guide/kdump/gdbmacros.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)


base-commit: 1b929c02afd37871d5afb9d498426f83432e71c2

Comments

Petr Mladek Jan. 3, 2023, 9:41 a.m. UTC | #1 
On Thu 2022-12-29 14:49:39, John Ogness wrote:
> @head_id points to the newest record, but the printing loop
> exits when it increments to this value (before printing).
> 
> Exit the printing loop after the newest record has been printed.
> 
> The python-based function in scripts/gdb/linux/dmesg.py already
> does this correctly.
> 
> Fixes: e60768311af8 ("scripts/gdb: update for lockless printk ringbuffer")
> Cc: stable@vger.kernel.org
> Signed-off-by: John Ogness <john.ogness@linutronix.de>

Great catch!

Reviewed-by: Petr Mladek <pmladek@suse.com>

Best Regards,
Petr
Petr Mladek Jan. 3, 2023, 9:47 a.m. UTC | #2 
On Thu 2022-12-29 14:49:39, John Ogness wrote:
> @head_id points to the newest record, but the printing loop
> exits when it increments to this value (before printing).
> 
> Exit the printing loop after the newest record has been printed.
> 
> The python-based function in scripts/gdb/linux/dmesg.py already
> does this correctly.
> 
> Fixes: e60768311af8 ("scripts/gdb: update for lockless printk ringbuffer")
> Cc: stable@vger.kernel.org
> Signed-off-by: John Ogness <john.ogness@linutronix.de>

JFYI, the patch has been committed into printk/linux.git,
branch for-6.3.

Best Regards,
Petr
diff mbox series

Patch

diff --git a/Documentation/admin-guide/kdump/gdbmacros.txt b/Documentation/admin-guide/kdump/gdbmacros.txt
index 82aecdcae8a6..030de95e3e6b 100644
--- a/Documentation/admin-guide/kdump/gdbmacros.txt
+++ b/Documentation/admin-guide/kdump/gdbmacros.txt
@@ -312,10 +312,10 @@  define dmesg
 			set var $prev_flags = $info->flags
 		end
 
-		set var $id = ($id + 1) & $id_mask
 		if ($id == $end_id)
 			loop_break
 		end
+		set var $id = ($id + 1) & $id_mask
 	end
 end
 document dmesg