The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=73a78b5efa737f53c81b37926476757b28888e54
commit 73a78b5efa737f53c81b37926476757b28888e54 Author: Mark Johnston <[email protected]> AuthorDate: 2022-10-14 15:17:12 +0000 Commit: Mark Johnston <[email protected]> CommitDate: 2022-10-14 15:32:47 +0000 kinst: Clarify a comment in the trampoline allocator Fixes: f0bc4ed144fc ("kinst: Initial revision") --- sys/cddl/dev/kinst/trampoline.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/sys/cddl/dev/kinst/trampoline.c b/sys/cddl/dev/kinst/trampoline.c index 094b055f1b14..2749fe7144a2 100644 --- a/sys/cddl/dev/kinst/trampoline.c +++ b/sys/cddl/dev/kinst/trampoline.c @@ -58,10 +58,11 @@ kinst_trampchunk_alloc(void) /* * Allocate virtual memory for the trampoline chunk. The returned - * address is saved in "trampaddr". - * - * Setting "trampaddr" to KERNBASE causes vm_map_find() to return an - * address above KERNBASE, so this satisfies both requirements. + * 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. */ trampaddr = KERNBASE; error = vm_map_find(kernel_map, NULL, 0, &trampaddr,
