Date: Sun, 3 Jan 2021 16:51:15 GMT From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 663de81f852f - main - uma: Avoid unmapping direct-mapped slabs Message-ID: <202101031651.103GpFpH003072@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=663de81f852fccc38006b0172f9337147b65890f commit 663de81f852fccc38006b0172f9337147b65890f Author: Mark Johnston <markj@FreeBSD.org> AuthorDate: 2021-01-03 16:31:00 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2021-01-03 16:50:31 +0000 uma: Avoid unmapping direct-mapped slabs startup_alloc() uses pmap_map() to map slabs used for bootstrapping the VM. pmap_map() may ignore the hint address and simply return a range from the direct map. In this case we must not unmap the range in startup_free(). UMA uses bootstart and bootmem to track the range of KVA into which slabs are mapped if the direct map is not used. Unmap a startup slab only if it was mapped into that range. Reported by: alc Reviewed by: alc, kib Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D27885 --- sys/vm/uma_core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/sys/vm/uma_core.c b/sys/vm/uma_core.c index 39c846effac8..0b6e02861785 100644 --- a/sys/vm/uma_core.c +++ b/sys/vm/uma_core.c @@ -1691,7 +1691,13 @@ startup_free(void *mem, vm_size_t bytes) va = (vm_offset_t)mem; m = PHYS_TO_VM_PAGE(pmap_kextract(va)); - pmap_remove(kernel_pmap, va, va + bytes); + + /* + * startup_alloc() returns direct-mapped slabs on some platforms. Avoid + * unmapping ranges of the direct map. + */ + if (va >= bootstart && va + bytes <= bootmem) + pmap_remove(kernel_pmap, va, va + bytes); for (; bytes != 0; bytes -= PAGE_SIZE, m++) { #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \ defined(__riscv) || defined(__powerpc64__)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202101031651.103GpFpH003072>