qlop: Properly handle atom_compar_cb when called from qsort #26
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`qsort` passes pointers to elements ("iterators" in C++ lingo) to the
callback, not elements directly.
Hence `l` and `r` in `atom_compar_cb` actually receives `depend_atom**`,
but only when called from `qsort`. The other two call sites
(`tree_pkg_compar` and `pkg_sort_cb`) actually apssed `depend_atom*`.
This leads to type casting confusion and undefined behaviour for any
invocation of `qlop -p`.
First discovered by SEGFAULT-ing with the following invocation:
qlop -p `cat /var/lib/portage/world`
Valgrind and ASAN made triggering the SEGFAULT easier - any invocation
with two or more atoms triggered a NULL dereference.
This commit addresses the above problem:
1. Expect that `atom_compar_cb` is actually called with two
`depend_atom**`.
2. Make `tree_pkg_compar` and `pkg_sort_cb` comply with the above
change, by passing `&al` and `&ar`, instead of `al` and `ar`.
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The coverity failure in CI seems unrelated to my changes. |
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nice catch |
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Mar 29, 2024
Previously, `values_set(merge_averages, avgs)` would allocate `avgs`, then it would be used in `array_for_each(atoms, i, atom)`, but a call to `xarrayfree_int(avgs)` was missing after the loop. Hopefully, this, along with #26, will solve the issues from #19. Signed-off-by: Fabian Groffen <grobian@gentoo.org>
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This pull request resolves an improper call to
qsortwhen invokingqlop -p.On current master it can lead to SEGFAULTs.
Detailed description is in the commit message.
Specific example of the SEGFAULT:
It should be easier to hit the SEGFAULT with atoms that have versions. Or that might have been just my luck.
Not sure what the proper test would look like. Ideally, ASAN would be used in CI, but I see that #19 is still in progress.