Re: An assertion is triggered in the luaG_runerror()
Sergey Bronnikov <[email protected]> Tue, 26 May 2026 04:27:38 -0700 (PDT)
| Newsgroups | gmane.comp.lang.lua.general |
|---|---|
| Message-ID | <[email protected]> |
Hello,
yet another reproducer, I suppose the root cause is the same.
At least reverting 36c1f6d helps.
cat <<EOF > chunk.lua
xpcall(collectgarbage, function(_, ...)
error('')
end, '')
EOF
How to reproduce:
make MYCFLAGS="-Og -g -Wall -DLUAI_ASSERT -DLUA_USE_APICHECK"
./lua assert.lua
lua: ldebug.c:411: lua_getinfo: Assertion `((((((func)->tt_)) & 0x0F)) ==
(6))' failed.
Aborted (core dumped)
Full backtrace:
(gdb) bt
#0 __pthread_kill_implementation (no_tid=0, signo=6, threadid=<optimized
out>) at ./nptl/pthread_kill.c:44
#1 __pthread_kill_internal (signo=6, threadid=<optimized out>) at
./nptl/pthread_kill.c:78
#2 __GI___pthread_kill (threadid=<optimized out>, signo=signo@entry=6) at
./nptl/pthread_kill.c:89
#3 0x00007ffff7c4527e in __GI_raise (sig=sig@entry=6) at
../sysdeps/posix/raise.c:26
#4 0x00007ffff7c288ff in __GI_abort () at ./stdlib/abort.c:79
#5 0x00007ffff7c2881b in __assert_fail_base (fmt=0x7ffff7dd01e8
"%s%s%s:%u: %s%sAssertion `%s' failed.\n%n",
assertion=assertion@entry=0x555555595548 "((((((func)->tt_)) & 0x0F))
== (6))",
file=file@entry=0x555555591479 "ldebug.c", line=line@entry=411,
function=function@entry=0x55555559b3b8 <__PRETTY_FUNCTION__.16>
"lua_getinfo") at ./assert/assert.c:96
#6 0x00007ffff7c3b517 in __assert_fail (
assertion=assertion@entry=0x555555595548 "((((((func)->tt_)) & 0x0F))
== (6))",
file=file@entry=0x555555591479 "ldebug.c", line=line@entry=411,
function=function@entry=0x55555559b3b8 <__PRETTY_FUNCTION__.16>
"lua_getinfo") at ./assert/assert.c:105
#7 0x0000555555562eb4 in lua_getinfo (L=L@entry=0x5555555af828,
what=what@entry=0x555555592471 "Sl",
ar=ar@entry=0x7fffffffc440) at ldebug.c:411
#8 0x000055555557f4ce in luaL_where (L=L@entry=0x5555555af828,
level=level@entry=1) at lauxlib.c:223
#9 0x0000555555586df7 in luaB_error (L=0x5555555af828) at lbaselib.c:120
#10 0x0000555555564dfd in precallC (L=L@entry=0x5555555af828,
func=0x5555555b5b60, func@entry=0x5555555afa30,
status=<optimized out>, status@entry=1, f=0x555555586da0 <luaB_error>)
at ldo.c:663
#11 0x00005555555653f9 in luaD_precall (L=L@entry=0x5555555af828,
func=0x5555555afa30, nresults=<optimized out>)
at ldo.c:732
#12 0x000055555557dac4 in luaV_execute (L=L@entry=0x5555555af828,
ci=0x5555555b59e0) at lvm.c:1729
#13 0x00005555555655b0 in ccall (L=L@entry=0x5555555af828,
func=0x5555555af9f0, nResults=nResults@entry=1,
inc=inc@entry=65537) at ldo.c:774
#14 0x0000555555565740 in luaD_callnoyield (L=L@entry=0x5555555af828,
func=<optimized out>,
nResults=nResults@entry=1) at ldo.c:792
#15 0x000055555556310b in luaG_errormsg (L=0x5555555af828) at ldebug.c:847
#16 0x0000555555560ddf in lua_error (L=L@entry=0x5555555af828) at
lapi.c:1267
#17 0x000055555557f5c9 in luaL_error (L=L@entry=0x5555555af828,
fmt=fmt@entry=0x555555592552 "bad %s #%d to '%s' (%s)") at lauxlib.c:245
#18 0x000055555557fb60 in luaL_argerror (L=L@entry=0x5555555af828,
arg=arg@entry=1,
extramsg=0x5555555b69d8 "invalid option ''") at lauxlib.c:192
#19 0x0000555555580421 in luaL_checkoption (L=L@entry=0x5555555af828,
arg=arg@entry=1,
def=def@entry=0x555555592a78 "collect", lst=lst@entry=0x5555555acdc0
<opts>) at lauxlib.c:374
#20 0x0000555555586ebe in luaB_collectgarbage (L=0x5555555af828) at
lbaselib.c:208
#21 0x0000555555564dfd in precallC (L=L@entry=0x5555555af828,
func=func@entry=0x5555555af9b0,
status=<optimized out>, status@entry=0, f=0x555555586e9b
<luaB_collectgarbage>) at ldo.c:663
#22 0x00005555555653f9 in luaD_precall (L=L@entry=0x5555555af828,
func=func@entry=0x5555555af9b0,
nresults=nresults@entry=-1) at ldo.c:732
#23 0x0000555555565595 in ccall (L=L@entry=0x5555555af828,
func=0x5555555af9b0, nResults=-1,
inc=inc@entry=65537) at ldo.c:772
#24 0x0000555555565740 in luaD_callnoyield (L=L@entry=0x5555555af828,
func=<optimized out>,
nResults=<optimized out>) at ldo.c:792
#25 0x000055555555d843 in f_call (L=L@entry=0x5555555af828,
ud=ud@entry=0x7fffffffcac0) at lapi.c:1071
#26 0x0000555555564118 in luaD_rawrunprotected (L=L@entry=0x5555555af828,
f=f@entry=0x55555555d830 <f_call>,
ud=ud@entry=0x7fffffffcac0) at ldo.c:166
#27 0x0000555555565b70 in luaD_pcall (L=L@entry=0x5555555af828,
func=func@entry=0x55555555d830 <f_call>,
u=u@entry=0x7fffffffcac0, old_top=176, ef=<optimized out>) at ldo.c:1096
#28 0x0000555555560649 in lua_pcallk (L=L@entry=0x5555555af828,
nargs=nargs@entry=1,
nresults=nresults@entry=-1, errfunc=errfunc@entry=2, ctx=ctx@entry=2,
k=k@entry=0x555555586143 <finishpcall>) at lapi.c:1097
#29 0x00005555555861f8 in luaB_xpcall (L=0x5555555af828) at lbaselib.c:497
#30 0x0000555555564dfd in precallC (L=L@entry=0x5555555af828,
func=func@entry=0x5555555af970,
status=<optimized out>, status@entry=1, f=0x555555586184 <luaB_xpcall>)
at ldo.c:663
#31 0x00005555555653f9 in luaD_precall (L=L@entry=0x5555555af828,
func=0x5555555af970, nresults=<optimized out>)
at ldo.c:732
#32 0x000055555557dac4 in luaV_execute (L=L@entry=0x5555555af828,
ci=0x5555555b0bd0) at lvm.c:1729
#33 0x00005555555655b0 in ccall (L=L@entry=0x5555555af828,
func=0x5555555af950, nResults=-1,
inc=inc@entry=65537) at ldo.c:774
#34 0x0000555555565740 in luaD_callnoyield (L=L@entry=0x5555555af828,
func=<optimized out>,
nResults=<optimized out>) at ldo.c:792
#35 0x000055555555d843 in f_call (L=L@entry=0x5555555af828,
ud=ud@entry=0x7fffffffce00) at lapi.c:1071
#36 0x0000555555564118 in luaD_rawrunprotected (L=L@entry=0x5555555af828,
f=f@entry=0x55555555d830 <f_call>,
ud=ud@entry=0x7fffffffce00) at ldo.c:166
#37 0x0000555555565b70 in luaD_pcall (L=L@entry=0x5555555af828,
func=func@entry=0x55555555d830 <f_call>,
u=u@entry=0x7fffffffce00, old_top=80, ef=<optimized out>) at ldo.c:1096
#38 0x0000555555560649 in lua_pcallk (L=L@entry=0x5555555af828,
nargs=nargs@entry=0,
nresults=nresults@entry=-1, errfunc=errfunc@entry=3, ctx=ctx@entry=0,
k=k@entry=0x0) at lapi.c:1097
#39 0x000055555555be46 in docall (L=L@entry=0x5555555af828, narg=0,
nres=nres@entry=-1) at lua.c:168
#40 0x000055555555c4e7 in handle_script (L=L@entry=0x5555555af828,
argv=0x7fffffffd2b0) at lua.c:272
#41 0x000055555555cab6 in pmain (L=0x5555555af828) at lua.c:760
#42 0x0000555555564dfd in precallC (L=L@entry=0x5555555af828,
func=func@entry=0x5555555af910,
status=<optimized out>, status@entry=2, f=0x55555555c90d <pmain>) at
ldo.c:663
#43 0x00005555555653f9 in luaD_precall (L=L@entry=0x5555555af828,
func=func@entry=0x5555555af910,
nresults=nresults@entry=1) at ldo.c:732
#44 0x0000555555565595 in ccall (L=L@entry=0x5555555af828,
func=0x5555555af910, nResults=1, inc=inc@entry=65537)
at ldo.c:772
#45 0x0000555555565740 in luaD_callnoyield (L=L@entry=0x5555555af828,
func=<optimized out>,
nResults=<optimized out>) at ldo.c:792
#46 0x000055555555d843 in f_call (L=L@entry=0x5555555af828,
ud=ud@entry=0x7fffffffd120) at lapi.c:1071
#47 0x0000555555564118 in luaD_rawrunprotected (L=L@entry=0x5555555af828,
f=f@entry=0x55555555d830 <f_call>,
ud=ud@entry=0x7fffffffd120) at ldo.c:166
#48 0x0000555555565b70 in luaD_pcall (L=L@entry=0x5555555af828,
func=func@entry=0x55555555d830 <f_call>,
u=u@entry=0x7fffffffd120, old_top=16, ef=<optimized out>) at ldo.c:1096
#49 0x0000555555560649 in lua_pcallk (L=L@entry=0x5555555af828,
nargs=nargs@entry=2, nresults=nresults@entry=1,
errfunc=errfunc@entry=0, ctx=ctx@entry=0, k=k@entry=0x0) at lapi.c:1097
#50 0x000055555555cb5e in main (argc=2, argv=0x7fffffffd2a8) at lua.c:788
(gdb)
Sergey
On Friday, May 15, 2026 at 5:09:04 PM UTC+3 Sergey Bronnikov wrote:
Hello,
the behavior also can be reproduced by the following chunk (select.lua):
```
local function fn()
return function(...)
local n = select("#", ...)
assert(n == 1, tostring(n))
end
end
local f = fn()
f(1)
```
make -j "MYCFLAGS=-DLUAI_ASSERT"
./lua select.lua
./lua: select.lua:4: 0
stack traceback:
[C]: in global 'assert'
select.lua:4: in local 'f'
select.lua:9: in main chunk
[C]: in ?
Reverting the commit 36c1f6d solves the issue.
Sergey
On Tuesday, May 12, 2026 at 10:56:57 PM UTC+3 Roberto Ierusalimschy wrote:
> an assertion is triggered on execution of a Lua chunk below:
>
> ./lua -e "
> > local obj = setmetatable({}, {
> __index = function(l, ...)
> local _ = l > 1
> end
> })
> obj:method();
> > "
> lua: ldebug.c:865: void luaG_runerror(lua_State *, const char *, ...):
> Assertion `(((((&((ci)->func.p)->val)))->tt_) == (((((6) | ((0) << 4))) |
> (1 << 6))))' failed.
> Aborted (core dumped)
Thanks for the feedback. Indeed, the commit 36c1f6d was wrong:
Although OP_VARARGPREP does not need to be preceded by an "OT"
instruction (it is never preceded by any instruction), it does need
a correct L->top to work properly. (The comment in lopcodes.h:420
is misleading.)
-- Roberto
--
You received this message because you are subscribed to the Google Groups "lua-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
To view this discussion visit https://groups.google.com/d/msgid/lua-l/8f2db9d8-3595-4690-92d3-ea9bbbbeda29n%40googlegroups.com.