[Closed] Segmentation Fault

[Ensayia]

The attached LOVE file is causing a segfault. It seems to only occur on Linux machines thus far, and I can't reproduce it in Windows. It also won't occur if I run the code from ZeroBrane, with or without debugging enabled.

Use the arrow keys and space, line up three or more gems to clear. It usually happens to me after 2 or 3 gem clears.

I really have no clue what's causing it.

[SneakySnake]

It seems to be a problem with LuaJIT.

I reduced the problem to this:

Code: Select all

local t = {[0] = {}, [1] = {}, [2] = {}, [3] = {}}

for i = 1, 1000 do
    for i = 3,0,-1 do
        t[i].foo = t[i - 1]
    end
end

This crashes both LÖVE and standalone LuaJIT.

[SneakySnake]

Double post for some awkward reason.

[mickeyjm]

It seems to be a problem with LuaJIT.

I reduced the problem to this:

Code: Select all

local t = {[0] = {}, [1] = {}, [2] = {}, [3] = {}}

while true do
    for i = 3,0,-1 do
        t[i].foo = t[i - 1]
    end
end

This crashes both LÖVE and standalone LuaJIT.

You're creating an infinite loop. Of course it is going to crash

[SneakySnake]

You're creating an infinite loop. Of course it is going to crash

An infinite loop in itself won't cause segmentation fault.

[slime]

It might if it runs out of memory, or if there's a bug in the version of LuaJIT you're using (some bugs have been fixed since 2.0.3.)

[SneakySnake]

Okay, to avoid confusion, I changed the infinite loop to a block that repeats 1000 times.
That ought to crash it, but it is in no way enough to cause Lua to run out of memory.

On my system. it runs fine on official Lua interpreter, but crashes with LuaJIT on the 23rd iteration.

or if there's a bug in the version of LuaJIT you're using (some bugs have been fixed since 2.0.3.)

It also crashes with LuaJIT Git master.
I tried to bisect it, but the bug seems to exist ever since v2.0.0-beta10 (versions before that up to initial commit don't build).

[Xgoff]

Okay, to avoid confusion, I changed the infinite loop to a block that repeats 1000 times.
That ought to crash it, but it is in no way enough to cause Lua to run out of memory.

On my system. it runs fine on official Lua interpreter, but crashes with LuaJIT on the 23rd iteration.

or if there's a bug in the version of LuaJIT you're using (some bugs have been fixed since 2.0.3.)

It also crashes with LuaJIT Git master.
I tried to bisect it, but the bug seems to exist ever since v2.0.0-beta10 (versions before that up to initial commit don't build).

yes, crashes for me in both 2.0 and 2.1, but not stock lua

i would definitely report this to mike with your test case

[slime]

Yeah definitely, once you report a bug with a test case he usually fixes it very quickly.

You can also try calling jit.off() before the code to see if it only happens when the code is JIT-compiled.

[SneakySnake]

Yeah definitely, once you report a bug with a test case he usually fixes it very quickly.

You can also try calling jit.off() before the code to see if it only happens when the code is JIT-compiled.

Indeed, it doesn't crash with jit.off().
I reported it to the LuaJIT mailing list.

(why it doesn't have a bug tracker baffles me)