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From: John Ogness <john.ogness@linutronix.de>
To: Petr Mladek <pmladek@suse.com>
Cc: Andrea Parri <parri.andrea@gmail.com>,
	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	Paul McKenney <paulmck@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
	Steven Rostedt <rostedt@goodmis.org>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH next v3 8/8] scripts/gdb: support printk finalized records
Date: Mon, 31 Aug 2020 03:16:58 +0206	[thread overview]
Message-ID: <20200831011058.6286-9-john.ogness@linutronix.de> (raw)
In-Reply-To: <20200831011058.6286-1-john.ogness@linutronix.de>

With commit ("printk: ringbuffer: add finalization/extension support")
a new state bit for finalized records was added. This not only changed
the bit representation of committed records, but also reduced the size
for record IDs.

Update the gdb scripts to correctly interpret the state variable.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
 Documentation/admin-guide/kdump/gdbmacros.txt | 10 +++++++---
 scripts/gdb/linux/dmesg.py                    | 10 ++++++----
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/Documentation/admin-guide/kdump/gdbmacros.txt b/Documentation/admin-guide/kdump/gdbmacros.txt
index 7adece30237e..bcb78368b381 100644
--- a/Documentation/admin-guide/kdump/gdbmacros.txt
+++ b/Documentation/admin-guide/kdump/gdbmacros.txt
@@ -295,8 +295,11 @@ document dump_record
 end
 
 define dmesg
-	set var $desc_committed = 1UL << ((sizeof(long) * 8) - 1)
-	set var $flags_mask = 3UL << ((sizeof(long) * 8) - 2)
+	# definitions from kernel/printk/printk_ringbuffer.h
+	set var $desc_commit = 1UL << ((sizeof(long) * 8) - 1)
+	set var $desc_final = 1UL << ((sizeof(long) * 8) - 2)
+	set var $desc_reuse = 1UL << ((sizeof(long) * 8) - 3)
+	set var $flags_mask = $desc_commit | $desc_final | $desc_reuse
 	set var $id_mask = ~$flags_mask
 
 	set var $desc_count = 1U << prb->desc_ring.count_bits
@@ -309,7 +312,8 @@ define dmesg
 		set var $desc = &prb->desc_ring.descs[$id % $desc_count]
 
 		# skip non-committed record
-		if (($desc->state_var.counter & $flags_mask) == $desc_committed)
+		# (note that commit+!final records will be displayed)
+		if (($desc->state_var.counter & $desc_commit) == $desc_commit)
 			dump_record $desc $prev_flags
 			set var $prev_flags = $desc->info.flags
 		end
diff --git a/scripts/gdb/linux/dmesg.py b/scripts/gdb/linux/dmesg.py
index 6c6022012ea8..367523c5c270 100644
--- a/scripts/gdb/linux/dmesg.py
+++ b/scripts/gdb/linux/dmesg.py
@@ -79,9 +79,10 @@ class LxDmesg(gdb.Command):
 
         # definitions from kernel/printk/printk_ringbuffer.h
         desc_sv_bits = utils.get_long_type().sizeof * 8
-        desc_committed_mask = 1 << (desc_sv_bits - 1)
-        desc_reuse_mask = 1 << (desc_sv_bits - 2)
-        desc_flags_mask = desc_committed_mask | desc_reuse_mask
+        desc_commit_mask = 1 << (desc_sv_bits - 1)
+        desc_final_mask = 1 << (desc_sv_bits - 2)
+        desc_reuse_mask = 1 << (desc_sv_bits - 3)
+        desc_flags_mask = desc_commit_mask | desc_final_mask | desc_reuse_mask
         desc_id_mask = ~desc_flags_mask
 
         # read in tail and head descriptor ids
@@ -96,8 +97,9 @@ class LxDmesg(gdb.Command):
             desc_off = desc_sz * ind
 
             # skip non-committed record
+            # (note that commit+!final records will be displayed)
             state = utils.read_u64(descs, desc_off + sv_off + counter_off) & desc_flags_mask
-            if state != desc_committed_mask:
+            if state & desc_commit_mask != desc_commit_mask:
                 if did == head_id:
                     break
                 did = (did + 1) & desc_id_mask
-- 
2.20.1


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      parent reply	other threads:[~2020-08-31  1:11 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-31  1:10 [PATCH next v3 0/8] printk: reimplement LOG_CONT handling John Ogness
2020-08-31  1:10 ` [PATCH next v3 1/8] printk: ringbuffer: rename DESC_COMMITTED_MASK flag John Ogness
2020-08-31  1:10 ` [PATCH next v3 2/8] printk: ringbuffer: change representation of reusable John Ogness
2020-08-31  1:10 ` [PATCH next v3 3/8] printk: ringbuffer: relocate get_data() John Ogness
2020-08-31  1:10 ` [PATCH next v3 4/8] printk: ringbuffer: add BLK_DATALESS() macro John Ogness
2020-08-31  1:10 ` [PATCH next v3 5/8] printk: ringbuffer: clear initial reserved fields John Ogness
2020-09-01 14:33   ` Petr Mladek
2020-08-31  1:10 ` [PATCH next v3 6/8] printk: ringbuffer: add finalization/extension support John Ogness
2020-08-31 12:54   ` John Ogness
2020-09-02 10:52   ` state names: vas: " Petr Mladek
2020-09-02 11:20     ` John Ogness
2020-09-02 12:39       ` Petr Mladek
2020-09-02 10:58   ` Petr Mladek
2020-09-02 12:21   ` misc: was: " Petr Mladek
2020-08-31  1:10 ` [PATCH next v3 7/8] printk: reimplement log_cont using record extension John Ogness
2020-09-02 13:38   ` Petr Mladek
2020-08-31  1:10 ` John Ogness [this message]

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