linuxkpi: Fix assertion in `lkpi_vmf_insert_pfn_prot_locked()`
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Authored by dumbbell on Jul 12 2026, 4:33 PM.

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linuxkpi

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rG8ffe2419e4e7: linuxkpi: Fix assertion in `lkpi_vmf_insert_pfn_prot_locked()`

Summary

Before this change, the assertion would not catch a page index matching the end address, even though the end address of a mapping is outside of that mapping.

While here, add another assertion to catch page indexes outside of the expected range earlier.

Also, pagefaulting an address outside of the mapping range should return VM_FAULT_SIGBUS instead of panicing.

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Event Timeline

dumbbell created this revision.Jul 12 2026, 4:33 PM

Herald added subscribers: emaste, imp. · View Herald TranscriptJul 12 2026, 4:33 PM

dumbbell requested review of this revision.Jul 12 2026, 4:33 PM

dumbbell added a parent revision: D57703: linuxkpi: Define `ULL()`.Jul 12 2026, 4:36 PM

dumbbell added a child revision: D58195: linuxkpi: Update `struct vm_area_struct` when an existing mapping is extended.

emaste added a project: linuxkpi.Mon, Aug 17, 4:59 PM

bz added a subscriber: bz.Sat, Sep 5, 9:16 AM

bz added inline comments.

sys/compat/linuxkpi/common/src/linux_page.c
526	Can this even still happen now that the above addr check is added?

dumbbell marked an inline comment as done.Mon, Sep 7, 5:29 PM

dumbbell added inline comments.

sys/compat/linuxkpi/common/src/linux_page.c
526	No, it shouldn’t. I kept it, just in case we mess something up with the beginning of the function. I can remove it if you prefer, I don’t mind.