Date: Thu, 25 May 2023 20:41:32 GMT From: Christos Margiolis <christos@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 855ade9e722a - main - kinst: be explicit about trampoline placement Message-ID: <202305252041.34PKfWd7086008@gitrepo.freebsd.org>
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The branch main has been updated by christos: URL: https://cgit.FreeBSD.org/src/commit/?id=855ade9e722a5c3f7363f5f78798bdfedadb1005 commit 855ade9e722a5c3f7363f5f78798bdfedadb1005 Author: Christos Margiolis <christos@FreeBSD.org> AuthorDate: 2023-05-25 20:40:46 +0000 Commit: Christos Margiolis <christos@FreeBSD.org> CommitDate: 2023-05-25 20:40:46 +0000 kinst: be explicit about trampoline placement The current implementation and comment was specific to amd64. Even though in the case of kinst's supported architectures (RISC-V and ARM64) VM_MIN_KERNEL_ADDRESS is equal to KERNBASE, it's better to be explicit. Reviewed by: markj Approved by: markj (mentor) Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D40266 --- sys/cddl/dev/kinst/trampoline.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/sys/cddl/dev/kinst/trampoline.c b/sys/cddl/dev/kinst/trampoline.c index 5575503f60fb..75efd022fb20 100644 --- a/sys/cddl/dev/kinst/trampoline.c +++ b/sys/cddl/dev/kinst/trampoline.c @@ -68,15 +68,22 @@ kinst_trampchunk_alloc(void) sx_assert(&kinst_tramp_sx, SX_XLOCKED); +#ifdef __amd64__ /* - * Allocate virtual memory for the trampoline chunk. The returned - * address is saved in "trampaddr". To simplify population of - * trampolines, we follow the amd64 kernel's code model and allocate - * them above KERNBASE, i.e., in the top 2GB of the kernel's virtual - * address space. Trampolines must be executable so max_prot must - * include VM_PROT_EXECUTE. + * To simplify population of trampolines, we follow the amd64 kernel's + * code model and allocate them above KERNBASE, i.e., in the top 2GB of + * the kernel's virtual address space (not the case for other + * platforms). */ trampaddr = KERNBASE; +#else + trampaddr = VM_MIN_KERNEL_ADDRESS; +#endif + /* + * Allocate virtual memory for the trampoline chunk. The returned + * address is saved in "trampaddr". Trampolines must be executable so + * max_prot must include VM_PROT_EXECUTE. + */ error = vm_map_find(kernel_map, NULL, 0, &trampaddr, KINST_TRAMPCHUNK_SIZE, 0, VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL, 0);
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