xref: /freebsd/sys/arm64/arm64/elf32_machdep.c (revision da5137ab)
1 /*-
2  * Copyright (c) 2014, 2015 The FreeBSD Foundation.
3  * Copyright (c) 2014, 2017 Andrew Turner.
4  * Copyright (c) 2018 Olivier Houchard
5  * All rights reserved.
6  *
7  * This software was developed by Andrew Turner under
8  * sponsorship from the FreeBSD Foundation.
9  *
10  * Portions of this software were developed by Konstantin Belousov
11  * under sponsorship from the FreeBSD Foundation.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #define	__ELF_WORD_SIZE 32
39 
40 #include <sys/param.h>
41 #include <sys/kernel.h>
42 #include <sys/systm.h>
43 #include <sys/exec.h>
44 #include <sys/imgact.h>
45 #include <sys/linker.h>
46 #include <sys/proc.h>
47 #include <sys/reg.h>
48 #include <sys/sysent.h>
49 #include <sys/imgact_elf.h>
50 #include <sys/syscall.h>
51 #include <sys/signalvar.h>
52 #include <sys/vnode.h>
53 
54 #include <machine/elf.h>
55 #ifdef VFP
56 #include <machine/vfp.h>
57 #endif
58 
59 #include <compat/freebsd32/freebsd32_util.h>
60 
61 #define	FREEBSD32_MINUSER	0x00001000
62 #define	FREEBSD32_MAXUSER	((1ul << 32) - PAGE_SIZE)
63 #define	FREEBSD32_SHAREDPAGE	(FREEBSD32_MAXUSER - PAGE_SIZE)
64 #define	FREEBSD32_USRSTACK	FREEBSD32_SHAREDPAGE
65 
66 extern const char *freebsd32_syscallnames[];
67 
68 extern char aarch32_sigcode[];
69 extern int sz_aarch32_sigcode;
70 
71 static int freebsd32_fetch_syscall_args(struct thread *td);
72 static void freebsd32_setregs(struct thread *td, struct image_params *imgp,
73     u_long stack);
74 static void freebsd32_set_syscall_retval(struct thread *, int);
75 
76 static boolean_t elf32_arm_abi_supported(struct image_params *, int32_t *,
77     uint32_t *);
78 
79 extern void freebsd32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
80 
81 u_long __read_frequently elf32_hwcap;
82 u_long __read_frequently elf32_hwcap2;
83 
84 static struct sysentvec elf32_freebsd_sysvec = {
85 	.sv_size	= SYS_MAXSYSCALL,
86 	.sv_table	= freebsd32_sysent,
87 	.sv_transtrap	= NULL,
88 	.sv_fixup	= elf32_freebsd_fixup,
89 	.sv_sendsig	= freebsd32_sendsig,
90 	.sv_sigcode	= aarch32_sigcode,
91 	.sv_szsigcode	= &sz_aarch32_sigcode,
92 	.sv_name	= "FreeBSD ELF32",
93 	.sv_coredump	= elf32_coredump,
94 	.sv_elf_core_osabi = ELFOSABI_FREEBSD,
95 	.sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
96 	.sv_elf_core_prepare_notes = elf32_prepare_notes,
97 	.sv_imgact_try	= NULL,
98 	.sv_minsigstksz	= MINSIGSTKSZ,
99 	.sv_minuser	= FREEBSD32_MINUSER,
100 	.sv_maxuser	= FREEBSD32_MAXUSER,
101 	.sv_usrstack	= FREEBSD32_USRSTACK,
102 	.sv_psstrings	= FREEBSD32_PS_STRINGS,
103 	.sv_psstringssz	= sizeof(struct freebsd32_ps_strings),
104 	.sv_stackprot	= VM_PROT_READ | VM_PROT_WRITE,
105 	.sv_copyout_auxargs = elf32_freebsd_copyout_auxargs,
106 	.sv_copyout_strings = freebsd32_copyout_strings,
107 	.sv_setregs	= freebsd32_setregs,
108 	.sv_fixlimit	= NULL, // XXX
109 	.sv_maxssiz	= NULL,
110 	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32 | SV_SHP | SV_TIMEKEEP |
111 	    SV_RNG_SEED_VER,
112 	.sv_set_syscall_retval = freebsd32_set_syscall_retval,
113 	.sv_fetch_syscall_args = freebsd32_fetch_syscall_args,
114 	.sv_syscallnames = freebsd32_syscallnames,
115 	.sv_shared_page_base = FREEBSD32_SHAREDPAGE,
116 	.sv_shared_page_len = PAGE_SIZE,
117 	.sv_schedtail	= NULL,
118 	.sv_thread_detach = NULL,
119 	.sv_trap	= NULL,
120 	.sv_hwcap	= &elf32_hwcap,
121 	.sv_hwcap2	= &elf32_hwcap2,
122 	.sv_onexec_old	= exec_onexec_old,
123 	.sv_onexit	= exit_onexit,
124 	.sv_regset_begin = SET_BEGIN(__elfN(regset)),
125 	.sv_regset_end	= SET_LIMIT(__elfN(regset)),
126 };
127 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
128 
129 static Elf32_Brandinfo freebsd32_brand_info = {
130 	.brand		= ELFOSABI_FREEBSD,
131 	.machine	= EM_ARM,
132 	.compat_3_brand	= "FreeBSD",
133 	.emul_path	= NULL,
134 	.interp_path	= "/libexec/ld-elf.so.1",
135 	.sysvec		= &elf32_freebsd_sysvec,
136 	.interp_newpath	= "/libexec/ld-elf32.so.1",
137 	.brand_note	= &elf32_freebsd_brandnote,
138 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
139 	.header_supported= elf32_arm_abi_supported,
140 };
141 
142 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
143     (sysinit_cfunc_t)elf32_insert_brand_entry, &freebsd32_brand_info);
144 
145 static boolean_t
146 elf32_arm_abi_supported(struct image_params *imgp, int32_t *osrel __unused,
147     uint32_t *fctl0 __unused)
148 {
149 	const Elf32_Ehdr *hdr;
150 
151 	/* Check if we support AArch32 */
152 	if (ID_AA64PFR0_EL0_VAL(READ_SPECIALREG(id_aa64pfr0_el1)) !=
153 	    ID_AA64PFR0_EL0_64_32)
154 		return (FALSE);
155 
156 #define	EF_ARM_EABI_VERSION(x)	(((x) & EF_ARM_EABIMASK) >> 24)
157 #define	EF_ARM_EABI_FREEBSD_MIN	4
158 	hdr = (const Elf32_Ehdr *)imgp->image_header;
159 	if (EF_ARM_EABI_VERSION(hdr->e_flags) < EF_ARM_EABI_FREEBSD_MIN) {
160 		if (bootverbose)
161 			uprintf("Attempting to execute non EABI binary "
162 			    "(rev %d) image %s",
163 			    EF_ARM_EABI_VERSION(hdr->e_flags),
164 			    imgp->args->fname);
165 		return (FALSE);
166         }
167 
168 	return (TRUE);
169 }
170 
171 static int
172 freebsd32_fetch_syscall_args(struct thread *td)
173 {
174 	struct proc *p;
175 	register_t *ap;
176 	struct syscall_args *sa;
177 	int error, i, nap, narg;
178 	unsigned int args[4];
179 
180 	nap = 4;
181 	p = td->td_proc;
182 	ap = td->td_frame->tf_x;
183 	sa = &td->td_sa;
184 
185 	/* r7 is the syscall id */
186 	sa->code = td->td_frame->tf_x[7];
187 	sa->original_code = sa->code;
188 
189 	if (sa->code == SYS_syscall) {
190 		sa->code = *ap++;
191 		nap--;
192 	} else if (sa->code == SYS___syscall) {
193 		sa->code = ap[1];
194 		nap -= 2;
195 		ap += 2;
196 	}
197 
198 	if (sa->code >= p->p_sysent->sv_size)
199 		sa->callp = &p->p_sysent->sv_table[0];
200 	else
201 		sa->callp = &p->p_sysent->sv_table[sa->code];
202 
203 	narg = sa->callp->sy_narg;
204 	for (i = 0; i < nap; i++)
205 		sa->args[i] = ap[i];
206 	if (narg > nap) {
207 		if (narg - nap > nitems(args))
208 			panic("Too many system call arguiments");
209 		error = copyin((void *)td->td_frame->tf_x[13], args,
210 		    (narg - nap) * sizeof(int));
211 		if (error != 0)
212 			return (error);
213 		for (i = 0; i < (narg - nap); i++)
214 			sa->args[i + nap] = args[i];
215 	}
216 
217 	td->td_retval[0] = 0;
218 	td->td_retval[1] = 0;
219 
220 	return (0);
221 }
222 
223 static void
224 freebsd32_set_syscall_retval(struct thread *td, int error)
225 {
226 	struct trapframe *frame;
227 
228 	frame = td->td_frame;
229 	switch (error) {
230 	case 0:
231 		frame->tf_x[0] = td->td_retval[0];
232 		frame->tf_x[1] = td->td_retval[1];
233 		frame->tf_spsr &= ~PSR_C;
234 		break;
235 	case ERESTART:
236 		/*
237 		 * Reconstruct the pc to point at the swi.
238 		 */
239 		if ((frame->tf_spsr & PSR_T) != 0)
240 			frame->tf_elr -= 2; //THUMB_INSN_SIZE;
241 		else
242 			frame->tf_elr -= 4; //INSN_SIZE;
243 		break;
244 	case EJUSTRETURN:
245 		/* nothing to do */
246 		break;
247 	default:
248 		frame->tf_x[0] = error;
249 		frame->tf_spsr |= PSR_C;
250 		break;
251 	}
252 }
253 
254 static void
255 freebsd32_setregs(struct thread *td, struct image_params *imgp,
256    uintptr_t stack)
257 {
258 	struct trapframe *tf = td->td_frame;
259 	struct pcb *pcb = td->td_pcb;
260 
261 	memset(tf, 0, sizeof(struct trapframe));
262 
263 	/*
264 	 * We need to set x0 for init as it doesn't call
265 	 * cpu_set_syscall_retval to copy the value. We also
266 	 * need to set td_retval for the cases where we do.
267 	 */
268 	tf->tf_x[0] = stack;
269 	/* SP_usr is mapped to x13 */
270 	tf->tf_x[13] = stack;
271 	/* LR_usr is mapped to x14 */
272 	tf->tf_x[14] = imgp->entry_addr;
273 	tf->tf_elr = imgp->entry_addr;
274 	tf->tf_spsr = PSR_M_32;
275 	if ((uint32_t)imgp->entry_addr & 1)
276 		tf->tf_spsr |= PSR_T;
277 
278 #ifdef VFP
279 	vfp_reset_state(td, pcb);
280 #endif
281 
282 	/*
283 	 * Clear debug register state. It is not applicable to the new process.
284 	 */
285 	bzero(&pcb->pcb_dbg_regs, sizeof(pcb->pcb_dbg_regs));
286 }
287 
288 void
289 elf32_dump_thread(struct thread *td, void *dst, size_t *off)
290 {
291 }
292