git: e9711ea5e2f5 - stable/13 - iommu_gas: Avoid double unmapping on error
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Date: Mon, 08 Aug 2022 03:22:03 UTC
The branch stable/13 has been updated by dougm: URL: https://cgit.FreeBSD.org/src/commit/?id=e9711ea5e2f5749e0dc6602ae109c786c728d6f5 commit e9711ea5e2f5749e0dc6602ae109c786c728d6f5 Author: Alan Cox <alc@FreeBSD.org> AuthorDate: 2022-07-21 06:53:54 +0000 Commit: Doug Moore <dougm@FreeBSD.org> CommitDate: 2022-08-08 03:16:49 +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 (cherry picked from commit dfabdacb279ca603d008a0e7e952c5c59ac51da4) --- 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 594e685e074a..33549b4af011 100644 --- a/sys/dev/iommu/busdma_iommu.c +++ b/sys/dev/iommu/busdma_iommu.c @@ -1047,7 +1047,7 @@ 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]);