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Fix test flakiness on Linux - #196
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marti4d merged 4 commits intoAug 17, 2026
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schopin-mozilla
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gabrielesvelto
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July 23, 2026 16:03
Building a crash context from the current process and passing it to a writer that dumps *another* process is bound to cause issues. Using stable data, even if invalid, make the tests more predictable -> less flaky.
Up until now, getting a stack pointer to unmapped memory would just silently be ignored and result in an empty stack. This should probably be recorded instead.
If the stack pointer is garbage, it could point to a valid-but-unreadable mapping. Since we already ignore and move on if it points to unmapped memory, let's do the same in this case.
Similarly to stack pointers, garbage IP pointer could potentially point to an unreadable memory mapping rather than just unmapped memory. In that case, let's log and move on.
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marti4d
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Awesome! Glad to see tests got added for this stuff, and thanks for breaking it apart into those 4 commits -- Was much easier to review than the whole thing at once.
I'll merge this in now :)
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Some of our tests build crash contexts for the parent process, to then write the minidump for a child process. Most of the time, the instruction and stack pointers will just point to unmapped memory, which is just silently ignored, but because of ASLR the memory layouts are random and it happens that sometimes they point to mapped but unreadable memory, leading to hard errors.
This branch addresses the issue on both ends: we build a zeroed out crash context (at least we know how it's invalid), and we also use soft errors rather than hard ones to be consistent with the unmapped experience.
FWIW, the unreadable case happens pretty frequently on Android ARM64 for some reason.