Date: Thu, 21 Jul 2022 07:01:25 GMT From: Alan Cox <alc@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: dfabdacb279c - main - iommu_gas: Avoid double unmapping on error Message-ID: <202207210701.26L71PTi060155@gitrepo.freebsd.org>
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The branch main has been updated by alc: URL: https://cgit.FreeBSD.org/src/commit/?id=dfabdacb279ca603d008a0e7e952c5c59ac51da4 commit dfabdacb279ca603d008a0e7e952c5c59ac51da4 Author: Alan Cox <alc@FreeBSD.org> AuthorDate: 2022-07-21 06:53:54 +0000 Commit: Alan Cox <alc@FreeBSD.org> CommitDate: 2022-07-21 07:00:46 +0000 iommu_gas: Avoid double unmapping on error In the extremely unlikely case that the iommu_gas_map_region() call in bus_dma_iommu_load_ident() failed, we would attempt to unmap the failed entry twice, first in iommu_gas_map_region(), and a second time in the caller. Once is enough, and twice is problematic because it leads to a second RB_REMOVE call on the same tree node. Like it or not, RB_TREE does not handle that possibility. Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D35869 --- sys/dev/iommu/busdma_iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/dev/iommu/busdma_iommu.c b/sys/dev/iommu/busdma_iommu.c index 10e7476b35eb..67e82fe43e58 100644 --- a/sys/dev/iommu/busdma_iommu.c +++ b/sys/dev/iommu/busdma_iommu.c @@ -1055,7 +1055,7 @@ bus_dma_iommu_load_ident(bus_dma_tag_t dmat, bus_dmamap_t map1, TAILQ_INSERT_TAIL(&map->map_entries, entry, dmamap_link); IOMMU_DMAMAP_UNLOCK(map); } else { - iommu_domain_unload_entry(entry, true); + iommu_gas_free_entry(domain, entry); } for (i = 0; i < atop(length); i++) vm_page_putfake(ma[i]);
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