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vm_phys_enq_range: no alignment assert for npages==0

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Do not assume that when vm_phys_enq_range is passed npages==0 that the
vm_page argument is valid in any way, much less that it has a
page-aligned address. Just don't look at it. Assert nothing about it.

Reported by:	karels
Differential Revision:	https://reviews.freebsd.org/D41317
This commit is contained in:
Doug Moore 2023-08-04 13:41:59 -05:00
parent a0e20c0ded
commit ccdb28275d
1 changed files with 5 additions and 3 deletions
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8
sys/vm/vm_phys.c
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@ -690,15 +690,17 @@ vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl, int order,
* term fragmentation by promoting contemporaneous allocation and (hopefully)
* deallocation.
*
* The physical page m's buddy must not be free.
* If npages is zero, this function does nothing and ignores the physical page
* parameter m. Otherwise, the physical page m's buddy must not be free.
*/
static vm_page_t
vm_phys_enq_range(vm_page_t m, u_int npages, struct vm_freelist *fl, int tail)
{
int order;
KASSERT(((VM_PAGE_TO_PHYS(m) + npages * PAGE_SIZE) &
((PAGE_SIZE << fls(npages / 2)) - 1)) == 0,
KASSERT(npages == 0 ||
((VM_PAGE_TO_PHYS(m) + npages * PAGE_SIZE) &
((PAGE_SIZE << (fls(npages) - 1)) - 1)) == 0,
("vm_phys_enq_range: page %p and npages %u are misaligned",
m, npages));
while (npages > 0) {