^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) #
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) # gdb helper commands and functions for Linux kernel debugging
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) # kernel log buffer dump
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) #
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) # Copyright (c) Siemens AG, 2011, 2012
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) # Authors:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) # Jan Kiszka <jan.kiszka@siemens.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) # This work is licensed under the terms of the GNU GPL version 2.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) import gdb
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) import sys
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) from linux import utils
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) printk_info_type = utils.CachedType("struct printk_info")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) prb_data_blk_lpos_type = utils.CachedType("struct prb_data_blk_lpos")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) prb_desc_type = utils.CachedType("struct prb_desc")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) prb_desc_ring_type = utils.CachedType("struct prb_desc_ring")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) prb_data_ring_type = utils.CachedType("struct prb_data_ring")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) printk_ringbuffer_type = utils.CachedType("struct printk_ringbuffer")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) atomic_long_type = utils.CachedType("atomic_long_t")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) class LxDmesg(gdb.Command):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) """Print Linux kernel log buffer."""
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) def __init__(self):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) super(LxDmesg, self).__init__("lx-dmesg", gdb.COMMAND_DATA)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) def invoke(self, arg, from_tty):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) inf = gdb.inferiors()[0]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) # read in prb structure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) prb_addr = int(str(gdb.parse_and_eval("(void *)'printk.c'::prb")).split()[0], 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) sz = printk_ringbuffer_type.get_type().sizeof
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) prb = utils.read_memoryview(inf, prb_addr, sz).tobytes()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) # read in descriptor ring structure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) off = printk_ringbuffer_type.get_type()['desc_ring'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) addr = prb_addr + off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) sz = prb_desc_ring_type.get_type().sizeof
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) desc_ring = utils.read_memoryview(inf, addr, sz).tobytes()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) # read in descriptor array
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) off = prb_desc_ring_type.get_type()['count_bits'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) desc_ring_count = 1 << utils.read_u32(desc_ring, off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) desc_sz = prb_desc_type.get_type().sizeof
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) off = prb_desc_ring_type.get_type()['descs'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) addr = utils.read_ulong(desc_ring, off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) descs = utils.read_memoryview(inf, addr, desc_sz * desc_ring_count).tobytes()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) # read in info array
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) info_sz = printk_info_type.get_type().sizeof
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) off = prb_desc_ring_type.get_type()['infos'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) addr = utils.read_ulong(desc_ring, off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) infos = utils.read_memoryview(inf, addr, info_sz * desc_ring_count).tobytes()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) # read in text data ring structure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) off = printk_ringbuffer_type.get_type()['text_data_ring'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) addr = prb_addr + off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) sz = prb_data_ring_type.get_type().sizeof
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) text_data_ring = utils.read_memoryview(inf, addr, sz).tobytes()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) # read in text data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) off = prb_data_ring_type.get_type()['size_bits'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) text_data_sz = 1 << utils.read_u32(text_data_ring, off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) off = prb_data_ring_type.get_type()['data'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) addr = utils.read_ulong(text_data_ring, off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) text_data = utils.read_memoryview(inf, addr, text_data_sz).tobytes()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) counter_off = atomic_long_type.get_type()['counter'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) sv_off = prb_desc_type.get_type()['state_var'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) off = prb_desc_type.get_type()['text_blk_lpos'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) begin_off = off + (prb_data_blk_lpos_type.get_type()['begin'].bitpos // 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) next_off = off + (prb_data_blk_lpos_type.get_type()['next'].bitpos // 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) ts_off = printk_info_type.get_type()['ts_nsec'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) len_off = printk_info_type.get_type()['text_len'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) # definitions from kernel/printk/printk_ringbuffer.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) desc_committed = 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) desc_finalized = 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) desc_sv_bits = utils.get_long_type().sizeof * 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) desc_flags_shift = desc_sv_bits - 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) desc_flags_mask = 3 << desc_flags_shift
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) desc_id_mask = ~desc_flags_mask
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) # read in tail and head descriptor ids
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) off = prb_desc_ring_type.get_type()['tail_id'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) tail_id = utils.read_u64(desc_ring, off + counter_off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) off = prb_desc_ring_type.get_type()['head_id'].bitpos // 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) head_id = utils.read_u64(desc_ring, off + counter_off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) did = tail_id
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) while True:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) ind = did % desc_ring_count
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) desc_off = desc_sz * ind
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) info_off = info_sz * ind
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) # skip non-committed record
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) state = 3 & (utils.read_u64(descs, desc_off + sv_off +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) counter_off) >> desc_flags_shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) if state != desc_committed and state != desc_finalized:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) if did == head_id:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) break
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) did = (did + 1) & desc_id_mask
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) continue
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) begin = utils.read_ulong(descs, desc_off + begin_off) % text_data_sz
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) end = utils.read_ulong(descs, desc_off + next_off) % text_data_sz
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) # handle data-less record
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) if begin & 1 == 1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) text = ""
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) else:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) # handle wrapping data block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) if begin > end:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) begin = 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) # skip over descriptor id
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) text_start = begin + utils.get_long_type().sizeof
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) text_len = utils.read_u16(infos, info_off + len_off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) # handle truncated message
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) if end - text_start < text_len:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) text_len = end - text_start
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) text = text_data[text_start:text_start + text_len].decode(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) encoding='utf8', errors='replace')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) time_stamp = utils.read_u64(infos, info_off + ts_off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) for line in text.splitlines():
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) msg = u"[{time:12.6f}] {line}\n".format(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) time=time_stamp / 1000000000.0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) line=line)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) # With python2 gdb.write will attempt to convert unicode to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) # ascii and might fail so pass an utf8-encoded str instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) if sys.hexversion < 0x03000000:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) msg = msg.encode(encoding='utf8', errors='replace')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) gdb.write(msg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) if did == head_id:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) break
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) did = (did + 1) & desc_id_mask
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) LxDmesg()
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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