printk: move dictionary keys to dev_printk_info

Dictionaries are only used for SUBSYSTEM and DEVICE properties. The
current implementation stores the property names each time they are
used. This requires more space than otherwise necessary. Also,
because the dictionary entries are currently considered optional,
it cannot be relied upon that they are always available, even if the
writer wanted to store them. These issues will increase should new
dictionary properties be introduced.

Rather than storing the subsystem and device properties in the
dict ring, introduce a struct dev_printk_info with separate fields
to store only the property values. Embed this struct within the
struct printk_info to provide guaranteed availability.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/87mu1jl6ne.fsf@jogness.linutronix.de

1 files changed, 33 insertions, 40 deletions

diff --git a/Documentation/admin-guide/kdump/gdbmacros.txt b/Documentation/admin-guide/kdump/gdbmacros.txt
index 94fabb165abf..82aecdcae8a6 100644
--- a/Documentation/admin-guide/kdump/gdbmacros.txt
+++ b/Documentation/admin-guide/kdump/gdbmacros.txt
@@ -172,13 +172,13 @@ end
 
 define dump_record
 	set var $desc = $arg0
-	if ($argc > 1)
-		set var $prev_flags = $arg1
+	set var $info = $arg1
+	if ($argc > 2)
+		set var $prev_flags = $arg2
 	else
 		set var $prev_flags = 0
 	end
 
-	set var $info = &$desc->info
 	set var $prefix = 1
 	set var $newline = 1
 
@@ -237,44 +237,36 @@ define dump_record
 
 	# handle dictionary data
 
-	set var $begin = $desc->dict_blk_lpos.begin % (1U << prb->dict_data_ring.size_bits)
-	set var $next = $desc->dict_blk_lpos.next % (1U << prb->dict_data_ring.size_bits)
-
-	# handle data-less record
-	if ($begin & 1)
-		set var $dict_len = 0
-		set var $dict = ""
-	else
-		# handle wrapping data block
-		if ($begin > $next)
-			set var $begin = 0
-		end
-
-		# skip over descriptor id
-		set var $begin = $begin + sizeof(long)
-
-		# handle truncated message
-		if ($next - $begin < $info->dict_len)
-			set var $dict_len = $next - $begin
-		else
-			set var $dict_len = $info->dict_len
+	set var $dict = &$info->dev_info.subsystem[0]
+	set var $dict_len = sizeof($info->dev_info.subsystem)
+	if ($dict[0] != '\0')
+		printf " SUBSYSTEM="
+		set var $idx = 0
+		while ($idx < $dict_len)
+			set var $c = $dict[$idx]
+			if ($c == '\0')
+				loop_break
+			else
+				if ($c < ' ' || $c >= 127 || $c == '\\')
+					printf "\\x%02x", $c
+				else
+					printf "%c", $c
+				end
+			end
+			set var $idx = $idx + 1
 		end
-
-		set var $dict = &prb->dict_data_ring.data[$begin]
+		printf "\n"
 	end
 
-	if ($dict_len > 0)
+	set var $dict = &$info->dev_info.device[0]
+	set var $dict_len = sizeof($info->dev_info.device)
+	if ($dict[0] != '\0')
+		printf " DEVICE="
 		set var $idx = 0
-		set var $line = 1
 		while ($idx < $dict_len)
-			if ($line)
-				printf " "
-				set var $line = 0
-			end
 			set var $c = $dict[$idx]
 			if ($c == '\0')
-				printf "\n"
-				set var $line = 1
+				loop_break
 			else
 				if ($c < ' ' || $c >= 127 || $c == '\\')
 					printf "\\x%02x", $c
@@ -288,10 +280,10 @@ define dump_record
 	end
 end
 document dump_record
-	Dump a single record. The first parameter is the descriptor
-	sequence number, the second is optional and specifies the
-	previous record's flags, used for properly formatting
-	continued lines.
+	Dump a single record. The first parameter is the descriptor,
+	the second parameter is the info, the third parameter is
+	optional and specifies the previous record's flags, used for
+	properly formatting continued lines.
 end
 
 define dmesg
@@ -311,12 +303,13 @@ define dmesg
 
 	while (1)
 		set var $desc = &prb->desc_ring.descs[$id % $desc_count]
+		set var $info = &prb->desc_ring.infos[$id % $desc_count]
 
 		# skip non-committed record
 		set var $state = 3 & ($desc->state_var.counter >> $desc_flags_shift)
 		if ($state == $desc_committed || $state == $desc_finalized)
-			dump_record $desc $prev_flags
-			set var $prev_flags = $desc->info.flags
+			dump_record $desc $info $prev_flags
+			set var $prev_flags = $info->flags
 		end
 
 		set var $id = ($id + 1) & $id_mask