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
This commit is contained in:
Linus Torvalds
2022-01-11 09:23:59 -08:00
4 changed files with 80 additions and 66 deletions

View File

@@ -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(