diff options
Diffstat (limited to 'sys/arm64/arm64/undefined.c')
| -rw-r--r-- | sys/arm64/arm64/undefined.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/sys/arm64/arm64/undefined.c b/sys/arm64/arm64/undefined.c new file mode 100644 index 000000000000..2cdb5f9a97fb --- /dev/null +++ b/sys/arm64/arm64/undefined.c @@ -0,0 +1,177 @@ +/*- + * Copyright (c) 2017 Andrew Turner + * All rights reserved. + * + * This software was developed by SRI International and the University of + * Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237 + * ("CTSRD"), as part of the DARPA CRASH research programme. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/malloc.h> +#include <sys/proc.h> +#include <sys/queue.h> +#include <sys/signal.h> +#include <sys/signalvar.h> +#include <sys/sysent.h> + +#include <machine/frame.h> +#include <machine/undefined.h> +#include <machine/vmparam.h> + +MALLOC_DEFINE(M_UNDEF, "undefhandler", "Undefined instruction handler data"); + +struct undef_handler { + LIST_ENTRY(undef_handler) uh_link; + undef_handler_t uh_handler; +}; + +/* + * Create two undefined instruction handler lists, one for userspace, one for + * the kernel. This allows us to handle instructions that will trap + */ +LIST_HEAD(, undef_handler) undef_handlers[2]; + +/* + * Work around a bug in QEMU prior to 2.5.1 where reading unknown ID + * registers would raise an exception when they should return 0. + */ +static int +id_aa64mmfr2_handler(vm_offset_t va, uint32_t insn, struct trapframe *frame, + uint32_t esr) +{ + int reg; + +#define MRS_ID_AA64MMFR2_EL0_MASK (MRS_MASK | 0x000fffe0) +#define MRS_ID_AA64MMFR2_EL0_VALUE (MRS_VALUE | 0x00080740) + + /* mrs xn, id_aa64mfr2_el1 */ + if ((insn & MRS_ID_AA64MMFR2_EL0_MASK) == MRS_ID_AA64MMFR2_EL0_VALUE) { + reg = MRS_REGISTER(insn); + + frame->tf_elr += INSN_SIZE; + if (reg < nitems(frame->tf_x)) { + frame->tf_x[reg] = 0; + } else if (reg == 30) { + frame->tf_lr = 0; + } + /* If reg is 32 then write to xzr, i.e. do nothing */ + + return (1); + } + return (0); +} + +#ifdef COMPAT_FREEBSD32 +/* arm32 GDB breakpoints */ +#define GDB_BREAKPOINT 0xe6000011 +#define GDB5_BREAKPOINT 0xe7ffdefe +static int +gdb_trapper(vm_offset_t va, uint32_t insn, struct trapframe *frame, + uint32_t esr) +{ + struct thread *td = curthread; + + if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) { + if (SV_PROC_FLAG(td->td_proc, SV_ILP32) && + va < VM_MAXUSER_ADDRESS) { + ksiginfo_t ksi; + + ksiginfo_init_trap(&ksi); + ksi.ksi_signo = SIGTRAP; + ksi.ksi_code = TRAP_TRACE; + ksi.ksi_addr = (void *)va; + trapsignal(td, &ksi); + return 1; + } + } + return 0; +} +#endif + +void +undef_init(void) +{ + + LIST_INIT(&undef_handlers[0]); + LIST_INIT(&undef_handlers[1]); + + install_undef_handler(false, id_aa64mmfr2_handler); +#ifdef COMPAT_FREEBSD32 + install_undef_handler(true, gdb_trapper); +#endif +} + +void * +install_undef_handler(bool user, undef_handler_t func) +{ + struct undef_handler *uh; + + uh = malloc(sizeof(*uh), M_UNDEF, M_WAITOK); + uh->uh_handler = func; + LIST_INSERT_HEAD(&undef_handlers[user ? 0 : 1], uh, uh_link); + + return (uh); +} + +void +remove_undef_handler(void *handle) +{ + struct undef_handler *uh; + + uh = handle; + LIST_REMOVE(uh, uh_link); + free(handle, M_UNDEF); +} + +int +undef_insn(u_int el, struct trapframe *frame) +{ + struct undef_handler *uh; + uint32_t insn; + int ret; + + KASSERT(el < 2, ("Invalid exception level %u", el)); + + if (el == 0) { + ret = fueword32((uint32_t *)frame->tf_elr, &insn); + if (ret != 0) + panic("Unable to read userspace faulting instruction"); + } else { + insn = *(uint32_t *)frame->tf_elr; + } + + LIST_FOREACH(uh, &undef_handlers[el], uh_link) { + ret = uh->uh_handler(frame->tf_elr, insn, frame, frame->tf_esr); + if (ret) + return (1); + } + + return (0); +} |