From: Mikhail Shishatskiy via Tarantool-patches <tarantool-patches@dev.tarantool.org> To: tarantool-patches@dev.tarantool.org, imun@tarantool.org, skaplun@tarantool.org Subject: [Tarantool-patches] [PATCH luajit] gdb: fix misalignment in lj-stack for LJ_GC64 Date: Wed, 7 Jul 2021 10:10:46 +0300 [thread overview] Message-ID: <20210707071046.649107-1-m.shishatskiy@tarantool.org> (raw) Since commit 58790750b9c4bd4c21d883f109ab552a2e202a15 ('gdb: introduce luajit-gdb extension') when luajit-gdb.py is introduced, Lua stack slots printed by lj-stack command are misaligned, when LJ_GC64 is enabled. The issue is that PADDING variable used for aligning single slots in the output is initialized before LuaJIT build mode is defined in <init> function, so the result was the following: | 0x7ffff7fb0d90:0x7ffff7fb0dc0 [ ] 7 slots: Red zone | 0x7ffff7fb0d88 [ M] | 0x7ffff7fb0cc0:0x7ffff7fb0d80 [ ] 25 slots: Free stack slots | 0x7ffff7fb0cb8 [ T ] | ... In scope of this patch, PADDING initialization is also moved to <init> function right after all commands are loaded. As a result, the output looks as expected: | 0x7ffff7fb0d90:0x7ffff7fb0dc0 [ ] 7 slots: Red zone | 0x7ffff7fb0d88 [ M] | 0x7ffff7fb0cc0:0x7ffff7fb0d80 [ ] 25 slots: Free stack slots | 0x7ffff7fb0cb8 [ T ] | ... Fixes tarantool/tarantool#5876 --- Branch: https://github.com/tarantool/luajit/tree/shishqa/gh-5876 To test changes do the following: | $ gdb -q --args ./luajit -e 'print("QQ")' | Reading symbols from ./luajit... | lj-arch command initialized | lj-tv command initialized | lj-str command initialized | lj-tab command initialized | lj-stack command initialized | lj-state command initialized | lj-gc command initialized | luajit-gdb.py is successfully loaded | (gdb) lj-arch | LJ_64: True, LJ_GC64: True | (gdb) b lj_cf_print | Breakpoint 1 at 0x298b0: file /mnt/WorkDisk/share/dev/__tarantool/lj-tarantool/src/lib_base.c, line 485. | (gdb) r | Starting program: /mnt/WorkDisk/share/dev/__tarantool/lj-tarantool/src/luajit -e print\(\"QQ\"\) | | Breakpoint 1, lj_cf_print (L=0x0) | at /mnt/WorkDisk/share/dev/__tarantool/lj-tarantool/src/lib_base.c:485 | 485 { | (gdb) s | 486 ptrdiff_t i, nargs = L->top - L->base; | (gdb) lj-stack L | 0x7ffff7fa8d90:0x7ffff7fa8dc0 [ ] 7 slots: Red zone | 0x7ffff7fa8d88 [ M] | 0x7ffff7fa8cc0:0x7ffff7fa8d80 [ ] 25 slots: Free stack slots | 0x7ffff7fa8cb8 [ T ] | 0x7ffff7fa8cb0 [ B ] VALUE: string "QQ" @ 0x7ffff7fb1178 | 0x7ffff7fa8ca0:0x7ffff7fa8ca8 [ ] FRAME: [L] delta=2, fast function #29 | 0x7ffff7fa8c90:0x7ffff7fa8c98 [ ] FRAME: [V] delta=2, Lua function @ 0x7ffff7fb1240, 0 upvalues, "=(command line)":0 | 0x7ffff7fa8c80:0x7ffff7fa8c88 [ ] FRAME: [CP] delta=4, Lua function @ 0x7ffff7fb1240, 0 upvalues, "=(command line)":0 | 0x7ffff7fa8c78 [ ] VALUE: C function @ 0x55555555c962 | 0x7ffff7fa8c70 [ ] VALUE: light userdata @ 0x0 | 0x7ffff7fa8c60:0x7ffff7fa8c68 [ ] FRAME: [CP] delta=2, C function @ 0x55555555df1c | 0x7ffff7fa8c58:0x7ffff7fa8c60 [S ] FRAME: dummy L src/luajit-gdb.py | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/src/luajit-gdb.py b/src/luajit-gdb.py index f1fd6230..720d989a 100644 --- a/src/luajit-gdb.py +++ b/src/luajit-gdb.py @@ -160,7 +160,7 @@ LJ_FR2 = None LJ_GCVMASK = ((1 << 47) - 1) -PADDING = ' ' * len(':' + hex((1 << (47 if LJ_GC64 else 32)) - 1)) +PADDING = None # }}} @@ -665,7 +665,7 @@ The command requires no args and dumps current GC stats: )) def init(commands): - global LJ_64, LJ_GC64, LJ_FR2 + global LJ_64, LJ_GC64, LJ_FR2, PADDING # XXX Fragile: though connecting the callback looks like a crap but it # respects both Python 2 and Python 3 (see #4828). @@ -714,6 +714,8 @@ def init(commands): for name, command in commands.items(): command(name) + PADDING = ' ' * len(':' + hex((1 << (47 if LJ_GC64 else 32)) - 1)) + gdb.write('luajit-gdb.py is successfully loaded\n') def load(event=None): -- 2.32.0
next reply other threads:[~2021-07-07 7:12 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-07 7:10 Mikhail Shishatskiy via Tarantool-patches [this message] 2021-07-07 18:35 ` Igor Munkin via Tarantool-patches 2021-07-22 13:35 ` Igor Munkin via Tarantool-patches
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