tree 668bc06caaf9bbac44dcfeb9d6d59abf146dd5d4
parent 333d407393541c078d7c539f3c3907728c5556f7
author Tom de Vries <tdevries@suse.de> 1657905467 +0200
committer Tom de Vries <tdevries@suse.de> 1658408800 +0200

[gdb/symtab] Fix data race in lookup_die_type

Data race between:
...
  Write of size 8 at 0x7b8009b483f8 by main thread:
    #0 read_tag_pointer_type gdb/dwarf2/read.c:16171 (gdb+0x8580b3)
    #1 read_type_die_1 gdb/dwarf2/read.c:21508 (gdb+0x869b69)
    #2 read_type_die gdb/dwarf2/read.c:21474 (gdb+0x869a53)
    #3 lookup_die_type gdb/dwarf2/read.c:21446 (gdb+0x8699ad)
    #4 die_type gdb/dwarf2/read.c:21300 (gdb+0x869286)
    #5 dwarf2_add_field gdb/dwarf2/read.c:13535 (gdb+0x84aabd)
    #6 handle_struct_member_die gdb/dwarf2/read.c:14803 (gdb+0x851ad2)
    #7 process_structure_scope gdb/dwarf2/read.c:14865 (gdb+0x851e70)
    #8 process_die gdb/dwarf2/read.c:8649 (gdb+0x83a048)
    #9 read_file_scope gdb/dwarf2/read.c:9616 (gdb+0x83cb81)
    #10 process_die gdb/dwarf2/read.c:8620 (gdb+0x839f43)
    #11 process_full_comp_unit gdb/dwarf2/read.c:8383 (gdb+0x839509)
    #12 process_queue_item gdb/dwarf2/read.c:7592 (gdb+0x8359f5)
...
and:
...
  Previous read of size 8 at 0x7b8009b483f8 by thread T3:
    #0 dwarf2_cu::addr_type() const gdb/dwarf2/cu.c:99 (gdb+0x7b8d42)
    #1 set_die_type gdb/dwarf2/read.c:23850 (gdb+0x871e4e)
    #2 read_subroutine_type gdb/dwarf2/read.c:16539 (gdb+0x8591c8)
    #3 read_type_die_1 gdb/dwarf2/read.c:21499 (gdb+0x869b15)
    #4 read_type_die gdb/dwarf2/read.c:21474 (gdb+0x869a53)
    #5 lookup_die_type gdb/dwarf2/read.c:21446 (gdb+0x8699ad)
    #6 die_type gdb/dwarf2/read.c:21300 (gdb+0x869286)
    #7 read_tag_pointer_type gdb/dwarf2/read.c:16114 (gdb+0x857d91)
    #8 read_type_die_1 gdb/dwarf2/read.c:21508 (gdb+0x869b69)
    #9 read_type_die gdb/dwarf2/read.c:21474 (gdb+0x869a53)
    #10 lookup_die_type gdb/dwarf2/read.c:21446 (gdb+0x8699ad)
    #11 die_type gdb/dwarf2/read.c:21300 (gdb+0x869286)
    #12 new_symbol gdb/dwarf2/read.c:20742 (gdb+0x8671fe)
    #13 read_variable gdb/dwarf2/read.c:12623 (gdb+0x848823)
    #14 process_die gdb/dwarf2/read.c:8716 (gdb+0x83a28c)
    #15 read_file_scope gdb/dwarf2/read.c:9616 (gdb+0x83cb81)
    #16 process_die gdb/dwarf2/read.c:8620 (gdb+0x839f43)
    #17 process_full_comp_unit gdb/dwarf2/read.c:8383 (gdb+0x839509)
    #18 process_queue_item gdb/dwarf2/read.c:7592 (gdb+0x8359f5)
...

Fix this by adding a lock in lookup_die_type.

Also in read_type_die and set_die_type.

Hmm, we already use another lock in set_die_type.  This needs more work.