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| author | Andrew Turner <andrew@FreeBSD.org> | 2023-04-05 12:45:19 +0000 |
|---|---|---|
| committer | Andrew Turner <andrew@FreeBSD.org> | 2024-02-22 16:27:47 +0000 |
| commit | c4e4a7596beb488b4878e9fa2a67cf49e330f78b (patch) | |
| tree | 29c40dde473802dd33439b22d7003a8f1d0c9599 | |
| parent | d3eae160b21f12c769f1e275901ad8ef18901744 (diff) | |
| download | src-c4e4a7596beb488b4878e9fa2a67cf49e330f78b.tar.gz src-c4e4a7596beb488b4878e9fa2a67cf49e330f78b.zip | |
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
| -rw-r--r-- | sys/arm64/arm64/sys_machdep.c | 43 | ||||
| -rw-r--r-- | sys/arm64/include/sysarch.h | 7 |
2 files changed, 49 insertions, 1 deletions
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 |