The branch main has been updated by christos:
URL:
https://cgit.FreeBSD.org/src/commit/?id=855ade9e722a5c3f7363f5f78798bdfedadb1005
commit 855ade9e722a5c3f7363f5f78798bdfedadb1005
Author: Christos Margiolis <chris...@freebsd.org>
AuthorDate: 2023-05-25 20:40:46 +0000
Commit: Christos Margiolis <chris...@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);
