The branch main has been updated by andrew:
URL:
https://cgit.FreeBSD.org/src/commit/?id=c4e4a7596beb488b4878e9fa2a67cf49e330f78b
commit c4e4a7596beb488b4878e9fa2a67cf49e330f78b
Author: Andrew Turner <and...@freebsd.org>
AuthorDate: 2023-04-05 12:45:19 +0000
Commit: Andrew Turner <and...@freebsd.org>
CommitDate: 2024-02-22 16:27:47 +0000
Add a BTI sysarch
This is used to enable the guard page when an elf binary is built with
BTI instructions.
Reviewed by: markj
Sponsored by: Arm Ltd
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D39453
---
sys/arm64/arm64/sys_machdep.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
sys/arm64/include/sysarch.h | 7 +++++++
2 files changed, 49 insertions(+), 1 deletion(-)
diff --git a/sys/arm64/arm64/sys_machdep.c b/sys/arm64/arm64/sys_machdep.c
index 79546d29e251..eedc57f7c572 100644
--- a/sys/arm64/arm64/sys_machdep.c
+++ b/sys/arm64/arm64/sys_machdep.c
@@ -29,13 +29,54 @@
#include <sys/param.h>
#include <sys/systm.h>
+#include <sys/proc.h>
#include <sys/sysproto.h>
+#include <vm/vm.h>
+#include <vm/pmap.h>
+#include <vm/vm_map.h>
+
#include <machine/sysarch.h>
+#include <machine/vmparam.h>
int
sysarch(struct thread *td, struct sysarch_args *uap)
{
+ struct arm64_guard_page_args gp_args;
+ vm_offset_t eva;
+ int error;
+
+ switch (uap->op) {
+ case ARM64_GUARD_PAGE:
+ error = copyin(uap->parms, &gp_args, sizeof(gp_args));
+ if (error != 0)
+ return (error);
+
+ /* Only accept canonical addresses, no PAC or TBI */
+ if (!ADDR_IS_CANONICAL(gp_args.addr))
+ return (EINVAL);
+
+ eva = gp_args.addr + gp_args.len;
+
+ /* Check for a length overflow */
+ if (gp_args.addr > eva)
+ return (EINVAL);
+
+ /* Check in the correct address space */
+ if (eva >= VM_MAX_USER_ADDRESS)
+ return (EINVAL);
+
+ /* Nothing to do */
+ if (gp_args.len == 0)
+ return (0);
+
+ error = pmap_bti_set(vmspace_pmap(td->td_proc->p_vmspace),
+ trunc_page(gp_args.addr), round_page(eva));
+ break;
+ default:
+ error = EINVAL;
+ break;
+ }
- return (ENOTSUP);
+ return (error);
}
diff --git a/sys/arm64/include/sysarch.h b/sys/arm64/include/sysarch.h
index 2bd45d384743..83094943423a 100644
--- a/sys/arm64/include/sysarch.h
+++ b/sys/arm64/include/sysarch.h
@@ -39,6 +39,13 @@
#ifndef _MACHINE_SYSARCH_H_
#define _MACHINE_SYSARCH_H_
+#define ARM64_GUARD_PAGE 0x100
+
+struct arm64_guard_page_args {
+ __uintptr_t addr;
+ __size_t len;
+};
+
#ifndef _KERNEL
__BEGIN_DECLS
