d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

kinst: Clarify a comment in the trampoline allocator

Browse Source 
Fixes:	f0bc4ed144 ("kinst: Initial revision")
This commit is contained in:
Mark Johnston 2022-10-14 11:17:12 -04:00
parent b4e483bdb0
commit 73a78b5efa
1 changed files with 5 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
sys/cddl/dev/kinst/trampoline.c
View File

@ -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,