Date: Wed, 19 Feb 2025 14:14:24 GMT From: Olivier Certner <olce@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: e1499bfff8b8 - main - vm_phys_avail_split(): Tolerate split requests at boundaries Message-ID: <202502191414.51JEEOHQ038195@gitrepo.freebsd.org>
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The branch main has been updated by olce: URL: https://cgit.FreeBSD.org/src/commit/?id=e1499bfff8b8c128d7b3d330f95e0c67d7c1fa77 commit e1499bfff8b8c128d7b3d330f95e0c67d7c1fa77 Author: Olivier Certner <olce@FreeBSD.org> AuthorDate: 2024-11-04 17:05:19 +0000 Commit: Olivier Certner <olce@FreeBSD.org> CommitDate: 2025-02-19 14:13:27 +0000 vm_phys_avail_split(): Tolerate split requests at boundaries Previously, such requests would lead to a panic. The only caller so far (vm_phys_early_startup()) actually faces the case where some address can be one of the chunk's boundaries and has to test it by hand. Moreover, a later commit will introduce vm_phys_early_alloc_ex(), which will also have to deal with such boundary cases. Consequently, make this function handle boundaries by not splitting the chunk and returning EJUSTRETURN instead of 0 to distinguish this case from the "was split" result. While here, expand the panic message when the address to split is not in the passed chunk with available details. Reviewed by: markj MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D48630 --- sys/vm/vm_phys.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/sys/vm/vm_phys.c b/sys/vm/vm_phys.c index e2b5a6e21365..82272be1a6c9 100644 --- a/sys/vm/vm_phys.c +++ b/sys/vm/vm_phys.c @@ -1854,7 +1854,13 @@ vm_phys_avail_size(int i) } /* - * Split an entry at the address 'pa'. Return zero on success or errno. + * Split a chunk in phys_avail[] at the address 'pa'. + * + * 'pa' must be within a chunk (slots i and i + 1) or one of its boundaries. + * Returns zero on actual split, in which case the two new chunks occupy slots + * i to i + 3, else EJUSTRETURN if 'pa' was one of the boundaries (and no split + * actually occurred) else ENOSPC if there are not enough slots in phys_avail[] + * to represent the additional chunk caused by the split. */ static int vm_phys_avail_split(vm_paddr_t pa, int i) @@ -1862,8 +1868,12 @@ vm_phys_avail_split(vm_paddr_t pa, int i) int cnt; vm_phys_avail_check(i); - if (pa <= phys_avail[i] || pa >= phys_avail[i + 1]) - panic("vm_phys_avail_split: invalid address"); + if (pa < phys_avail[i] || pa > phys_avail[i + 1]) + panic("%s: Address %#jx not in range at slot %d [%#jx;%#jx].", + __func__, (uintmax_t)pa, i, + (uintmax_t)phys_avail[i], (uintmax_t)phys_avail[i + 1]); + if (pa == phys_avail[i] || pa == phys_avail[i + 1]) + return (EJUSTRETURN); cnt = vm_phys_avail_count(); if (cnt >= PHYS_AVAIL_ENTRIES) return (ENOSPC); @@ -2025,12 +2035,10 @@ vm_phys_early_startup(void) for (i = 0; mem_affinity[i].end != 0; i++) { idx = vm_phys_avail_find(mem_affinity[i].start); - if (idx != -1 && - phys_avail[idx] != mem_affinity[i].start) + if (idx != -1) vm_phys_avail_split(mem_affinity[i].start, idx); idx = vm_phys_avail_find(mem_affinity[i].end); - if (idx != -1 && - phys_avail[idx] != mem_affinity[i].end) + if (idx != -1) vm_phys_avail_split(mem_affinity[i].end, idx); } }
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