src/sys/vm/vm_fault.c, branch stable/13

vm_fault: Reset m_needs_zeroing properly

2026-04-13T02:58:16Z

- When allocating a page, we should only consider the PG_ZERO flag when handling the top-level page. - Unconditionally reset the flag when restarting the fault handler. Previously, vm_fault_busy_sleep() would fail to reset it. PR: 294039 Reviewed by: kib Tested by: Peter Much MFC after: 3 days Fixes: cff67bc43df1 ("vm_fault: only rely on PG_ZERO when the page was newly allocated") Differential Revision: https://reviews.freebsd.org/D56234 (cherry picked from commit 04132e01004316ddd0e0cde6ef15b100b7b1844d)

vm_fault: only rely on PG_ZERO when the page was newly allocated

2026-01-26T15:13:36Z

(cherry picked from commit cff67bc43df14d492ccc08ec92fddceadd069953)

sys: Remove $FreeBSD$: one-line .c pattern

2023-08-23T17:43:25Z

Remove /^[\s*]*__FBSDID$"\$FreeBSD\$"$;?\s*\n/ Similar commit in current: (cherry picked from commit 685dc743dc3b)

vm_map: Add a macro to fetch a map entry's split boundary index

2023-08-09T20:48:18Z

The resulting code is a bit more concise. No functional change intended. Reviewed by: alc, dougm, kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D41249 (cherry picked from commit d0e4e53ebd6499d420c19426586eeeafec157150)

vm_fault: move FAULT_* return codes out of range for Mach errors

2023-07-04T03:07:01Z

(cherry picked from commit ef747607ead43552cb3ebb093fadd2c39c56a36d)

vm_fault: Fix a race in vm_fault_soft_fast()

2023-02-27T13:22:33Z

When vm_fault_soft_fast() creates a mapping, it release the VM map lock before unbusying the top-level object. Without the map lock, however, nothing prevents the VM object from being deallocated while still busy. Fix the problem by unbusying the object before releasing the VM map lock. If vm_fault_soft_fast() fails to create a mapping, the VM map lock is not released, so those cases don't need to change. Reported by: syzkaller Reviewed by: kib (previous version) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D38527 (cherry picked from commit d0991948182a1a149ee84f1b9c4d3e30450c8f0b)

vm_pager: add method to veto page allocation

2023-01-20T03:19:29Z

Tested by: pho (cherry picked from commit ec201dddfbddd3a77dd3f3afc9b007d0e13e7ad1)

vm_fault: Shoot down shared mappings in vm_fault_copy_entry()

2022-08-09T19:47:40Z

As in vm_fault_cow(), it's possible, albeit rare, for multiple vm_maps to share a shadow object. When copying a page from a backing object into the shadow, all mappings of the source page must therefore be removed. Otherwise, future operations on the object tree may detect that the source page is fully shadowed and thus can be freed. Approved by: so Security: FreeBSD-SA-22:11.vm Reviewed by: alc, kib Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D35635 (cherry picked from commit 5c50e900ad779fccbf0a230bfb6a68a3e93ccf60)

vm_fault: Fix some nits in vm_fault_copy_entry()

2022-07-25T13:44:45Z

- Correct the description (vm_fault_copy_entry() does not create a shadow object). - Move some initialization and assertions out of the scope of the object locks, when doing so makes sense. - Merge a pair of conditional blocks. - Use __unused when appropriate. No functional change intended. Reviewed by: alc Sponsored by: The FreeBSD Foundation (cherry picked from commit b57be759d079d40aa6ec75207faadce5ae1484a2)

vm_fault: Fix a racy copy of page valid bits

2022-06-29T14:12:34Z

We do not hold the object lock or a page busy lock when copying src_m's validity state. Prior to commit 45d72c7d7fca we marked dst_m as fully valid. Use the source object's read lock to ensure that valid bits are not concurrently cleared. Reviewed by: alc, kib Fixes: 45d72c7d7fca ("vm_fault_copy_entry: accept invalid source pages.") Sponsored by: The FreeBSD Foundation (cherry picked from commit d0443e2b9832f01319bcaaece8102d998bf81f01)