git: 5d4545a2270e - main - arm64 pmap: Release PTP reference on leaf ptpage allocation failure

The branch main has been updated by bnovkov:

URL: https://cgit.FreeBSD.org/src/commit/?id=5d4545a2270e9d6c37c0a580c010c579ccdfa129

commit 5d4545a2270e9d6c37c0a580c010c579ccdfa129
Author:     Bojan Novković <bnovkov@FreeBSD.org>
AuthorDate: 2024-06-13 15:59:29 +0000
Commit:     Bojan Novković <bnovkov@FreeBSD.org>
CommitDate: 2024-06-16 16:19:26 +0000

    arm64 pmap: Release PTP reference on leaf ptpage allocation failure
    
    808f5ac fixed an edge case invloving mlock() and superpage creation
    by creating and inserting a leaf pagetable page for mlock'd superpages.
    However, the code does not properly release the reference to the
    pagetable page in the error handling path.
    This commit fixes the issue by adding calls to 'pmap_abort_ptp'
    in the error handling path.
    
    Reported by: alc
    Approved by: markj (mentor)
    Fixes: 808f5ac
    Differential Revision:  https://reviews.freebsd.org/D45578
---
 sys/arm64/arm64/pmap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
index 7b30b2a6ae37..e8991ae706f9 100644
--- a/sys/arm64/arm64/pmap.c
+++ b/sys/arm64/arm64/pmap.c
@@ -5545,12 +5545,14 @@ pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t new_l2, u_int flags,
 	if ((new_l2 & ATTR_SW_WIRED) != 0 && pmap != kernel_pmap) {
 		uwptpg = vm_page_alloc_noobj(VM_ALLOC_WIRED);
 		if (uwptpg == NULL) {
+			pmap_abort_ptp(pmap, va, l2pg);
 			return (KERN_RESOURCE_SHORTAGE);
 		}
 		uwptpg->pindex = pmap_l2_pindex(va);
 		if (pmap_insert_pt_page(pmap, uwptpg, true, false)) {
 			vm_page_unwire_noq(uwptpg);
 			vm_page_free(uwptpg);
+			pmap_abort_ptp(pmap, va, l2pg);
 			return (KERN_RESOURCE_SHORTAGE);
 		}
 		pmap_resident_count_inc(pmap, 1);