Segfault during push!() if using a large struct in 1.10 due to elsize overflow about julia

[vtjnash]

So the constructor should error in v1.10- it seems? We could implement that on the backports branch

[Zentrik]

Can reproduce on 1.9.4 (occurs if you press enter after running above code) and 1.10.2, I don't see it on 1.11-alpha1, 1.11-beta1 or nightly.
It hangs on 1.6, 1.7 and 1.8 on test_vector = Vector{TestStruct5}(). EDIT: Never mind, looks like it takes while but segfaults similarly.

rr trace for 1.10.2 should be here, https://julialang-dumps.s3.amazonaws.com/reports/2024-04-26T09-14-48-Zentrik.tar.zst

[gbaraldi]

This gets fixed in 909bcea, which is the Memory{T} commit, which is not backportable.

[oscardssmith]

Is the issue is that Array used to store the elsize as a UInt16

julia/src/julia.h

Line 192 in bd47eca

uint16_t elsize; // element size including alignment (dim 1 memory stride)

so if you had an array with larger elements it overflows?

[gbaraldi]

Yeah this is gets a elsize of 0 here which causes all kinds of issues.

[oscardssmith]

The ideal fix would be for it to allocate as a ptr array, but that would likely be harder.

[vtjnash]

Also an option. Or backport the layout change. But doesn't seem worthwhile for a previous version only in a particular edge case