Merge tag 'printk-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Remove some twists in the console registration code. It does not
   change the existing behavior except for one corner case. The proper
   default console (with tty binding) will be registered again even when
   it has been removed in the meantime. It is actually a bug fix.
   Anyway, this modified behavior requires some manual interaction.

 - Optimize gdb extension for huge ring buffers.

 - Do not use atomic operations for a local bitmap variable.

 - Update git links in MAINTAINERS.

* tag 'printk-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  MAINTAIERS/printk: Add link to printk git
  MAINTAINERS/vsprintf: Update link to printk git tree
  scripts/gdb: lx-dmesg: read records individually
  printk/console: Clean up boot console handling in register_console()
  printk/console: Remove need_default_console variable
  printk/console: Remove unnecessary need_default_console manipulation
  printk/console: Rename has_preferred_console to need_default_console
  printk/console: Split out code that enables default console
  vsprintf: Use non-atomic bitmap API when applicable

1 files changed, 18 insertions, 17 deletions

diff --git a/scripts/gdb/linux/dmesg.py b/scripts/gdb/linux/dmesg.py
index a92c55bd8de5..d5983cf3db7d 100644
--- a/scripts/gdb/linux/dmesg.py
+++ b/scripts/gdb/linux/dmesg.py
@@ -44,19 +44,17 @@ class LxDmesg(gdb.Command):
         sz = prb_desc_ring_type.get_type().sizeof
         desc_ring = utils.read_memoryview(inf, addr, sz).tobytes()
 
-        # read in descriptor array
+        # read in descriptor count, size, and address
         off = prb_desc_ring_type.get_type()['count_bits'].bitpos // 8
         desc_ring_count = 1 << utils.read_u32(desc_ring, off)
         desc_sz = prb_desc_type.get_type().sizeof
         off = prb_desc_ring_type.get_type()['descs'].bitpos // 8
-        addr = utils.read_ulong(desc_ring, off)
-        descs = utils.read_memoryview(inf, addr, desc_sz * desc_ring_count).tobytes()
+        desc_addr = utils.read_ulong(desc_ring, off)
 
-        # read in info array
+        # read in info size and address
         info_sz = printk_info_type.get_type().sizeof
         off = prb_desc_ring_type.get_type()['infos'].bitpos // 8
-        addr = utils.read_ulong(desc_ring, off)
-        infos = utils.read_memoryview(inf, addr, info_sz * desc_ring_count).tobytes()
+        info_addr = utils.read_ulong(desc_ring, off)
 
         # read in text data ring structure
         off = printk_ringbuffer_type.get_type()['text_data_ring'].bitpos // 8
@@ -64,12 +62,11 @@ class LxDmesg(gdb.Command):
         sz = prb_data_ring_type.get_type().sizeof
         text_data_ring = utils.read_memoryview(inf, addr, sz).tobytes()
 
-        # read in text data
+        # read in text data size and address
         off = prb_data_ring_type.get_type()['size_bits'].bitpos // 8
         text_data_sz = 1 << utils.read_u32(text_data_ring, off)
         off = prb_data_ring_type.get_type()['data'].bitpos // 8
-        addr = utils.read_ulong(text_data_ring, off)
-        text_data = utils.read_memoryview(inf, addr, text_data_sz).tobytes()
+        text_data_addr = utils.read_ulong(text_data_ring, off)
 
         counter_off = atomic_long_type.get_type()['counter'].bitpos // 8
 
@@ -102,17 +99,20 @@ class LxDmesg(gdb.Command):
             desc_off = desc_sz * ind
             info_off = info_sz * ind
 
+            desc = utils.read_memoryview(inf, desc_addr + desc_off, desc_sz).tobytes()
+
             # skip non-committed record
-            state = 3 & (utils.read_u64(descs, desc_off + sv_off +
-                                        counter_off) >> desc_flags_shift)
+            state = 3 & (utils.read_u64(desc, sv_off + counter_off) >> desc_flags_shift)
             if state != desc_committed and state != desc_finalized:
                 if did == head_id:
                     break
                 did = (did + 1) & desc_id_mask
                 continue
 
-            begin = utils.read_ulong(descs, desc_off + begin_off) % text_data_sz
-            end = utils.read_ulong(descs, desc_off + next_off) % text_data_sz
+            begin = utils.read_ulong(desc, begin_off) % text_data_sz
+            end = utils.read_ulong(desc, next_off) % text_data_sz
+
+            info = utils.read_memoryview(inf, info_addr + info_off, info_sz).tobytes()
 
             # handle data-less record
             if begin & 1 == 1:
@@ -125,16 +125,17 @@ class LxDmesg(gdb.Command):
                 # skip over descriptor id
                 text_start = begin + utils.get_long_type().sizeof
 
-                text_len = utils.read_u16(infos, info_off + len_off)
+                text_len = utils.read_u16(info, len_off)
 
                 # handle truncated message
                 if end - text_start < text_len:
                     text_len = end - text_start
 
-                text = text_data[text_start:text_start + text_len].decode(
-                    encoding='utf8', errors='replace')
+                text_data = utils.read_memoryview(inf, text_data_addr + text_start,
+                                                  text_len).tobytes()
+                text = text_data[0:text_len].decode(encoding='utf8', errors='replace')
 
-            time_stamp = utils.read_u64(infos, info_off + ts_off)
+            time_stamp = utils.read_u64(info, ts_off)
 
             for line in text.splitlines():
                 msg = u"[{time:12.6f}] {line}\n".format(