xref: /freebsd/sys/arm64/arm64/elf32_machdep.c (revision 19261079)
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/sysent.h>
48 #include <sys/imgact_elf.h>
49 #include <sys/syscall.h>
50 #include <sys/signalvar.h>
51 #include <sys/vnode.h>
52 
53 #include <machine/elf.h>
54 #ifdef VFP
55 #include <machine/vfp.h>
56 #endif
57 
58 #include <compat/freebsd32/freebsd32_util.h>
59 
60 #define	FREEBSD32_MINUSER	0x00001000
61 #define	FREEBSD32_MAXUSER	((1ul << 32) - PAGE_SIZE)
62 #define	FREEBSD32_SHAREDPAGE	(FREEBSD32_MAXUSER - PAGE_SIZE)
63 #define	FREEBSD32_USRSTACK	FREEBSD32_SHAREDPAGE
64 
65 extern const char *freebsd32_syscallnames[];
66 
67 extern char aarch32_sigcode[];
68 extern int sz_aarch32_sigcode;
69 
70 static int freebsd32_fetch_syscall_args(struct thread *td);
71 static void freebsd32_setregs(struct thread *td, struct image_params *imgp,
72     u_long stack);
73 static void freebsd32_set_syscall_retval(struct thread *, int);
74 
75 static boolean_t elf32_arm_abi_supported(struct image_params *, int32_t *,
76     uint32_t *);
77 
78 extern void freebsd32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
79 
80 u_long __read_frequently elf32_hwcap;
81 u_long __read_frequently elf32_hwcap2;
82 
83 static struct sysentvec elf32_freebsd_sysvec = {
84 	.sv_size	= SYS_MAXSYSCALL,
85 	.sv_table	= freebsd32_sysent,
86 	.sv_transtrap	= NULL,
87 	.sv_fixup	= elf32_freebsd_fixup,
88 	.sv_sendsig	= freebsd32_sendsig,
89 	.sv_sigcode	= aarch32_sigcode,
90 	.sv_szsigcode	= &sz_aarch32_sigcode,
91 	.sv_name	= "FreeBSD ELF32",
92 	.sv_coredump	= elf32_coredump,
93 	.sv_elf_core_osabi = ELFOSABI_FREEBSD,
94 	.sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
95 	.sv_elf_core_prepare_notes = elf32_prepare_notes,
96 	.sv_imgact_try	= NULL,
97 	.sv_minsigstksz	= MINSIGSTKSZ,
98 	.sv_minuser	= FREEBSD32_MINUSER,
99 	.sv_maxuser	= FREEBSD32_MAXUSER,
100 	.sv_usrstack	= FREEBSD32_USRSTACK,
101 	.sv_psstrings	= FREEBSD32_PS_STRINGS,
102 	.sv_stackprot	= VM_PROT_READ | VM_PROT_WRITE,
103 	.sv_copyout_auxargs = elf32_freebsd_copyout_auxargs,
104 	.sv_copyout_strings = freebsd32_copyout_strings,
105 	.sv_setregs	= freebsd32_setregs,
106 	.sv_fixlimit	= NULL, // XXX
107 	.sv_maxssiz	= NULL,
108 	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32 | SV_SHP | SV_TIMEKEEP |
109 	    SV_RNG_SEED_VER,
110 	.sv_set_syscall_retval = freebsd32_set_syscall_retval,
111 	.sv_fetch_syscall_args = freebsd32_fetch_syscall_args,
112 	.sv_syscallnames = freebsd32_syscallnames,
113 	.sv_shared_page_base = FREEBSD32_SHAREDPAGE,
114 	.sv_shared_page_len = PAGE_SIZE,
115 	.sv_schedtail	= NULL,
116 	.sv_thread_detach = NULL,
117 	.sv_trap	= NULL,
118 	.sv_hwcap	= &elf32_hwcap,
119 	.sv_hwcap2	= &elf32_hwcap2,
120 	.sv_onexec_old	= exec_onexec_old,
121 	.sv_onexit	= exit_onexit,
122 };
123 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
124 
125 static Elf32_Brandinfo freebsd32_brand_info = {
126 	.brand		= ELFOSABI_FREEBSD,
127 	.machine	= EM_ARM,
128 	.compat_3_brand	= "FreeBSD",
129 	.emul_path	= NULL,
130 	.interp_path	= "/libexec/ld-elf.so.1",
131 	.sysvec		= &elf32_freebsd_sysvec,
132 	.interp_newpath	= "/libexec/ld-elf32.so.1",
133 	.brand_note	= &elf32_freebsd_brandnote,
134 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE,
135 	.header_supported= elf32_arm_abi_supported,
136 };
137 
138 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
139     (sysinit_cfunc_t)elf32_insert_brand_entry, &freebsd32_brand_info);
140 
141 static boolean_t
142 elf32_arm_abi_supported(struct image_params *imgp, int32_t *osrel __unused,
143     uint32_t *fctl0 __unused)
144 {
145 	const Elf32_Ehdr *hdr;
146 
147 	/* Check if we support AArch32 */
148 	if (ID_AA64PFR0_EL0_VAL(READ_SPECIALREG(id_aa64pfr0_el1)) !=
149 	    ID_AA64PFR0_EL0_64_32)
150 		return (FALSE);
151 
152 #define	EF_ARM_EABI_VERSION(x)	(((x) & EF_ARM_EABIMASK) >> 24)
153 #define	EF_ARM_EABI_FREEBSD_MIN	4
154 	hdr = (const Elf32_Ehdr *)imgp->image_header;
155 	if (EF_ARM_EABI_VERSION(hdr->e_flags) < EF_ARM_EABI_FREEBSD_MIN) {
156 		if (bootverbose)
157 			uprintf("Attempting to execute non EABI binary "
158 			    "(rev %d) image %s",
159 			    EF_ARM_EABI_VERSION(hdr->e_flags),
160 			    imgp->args->fname);
161 		return (FALSE);
162         }
163 
164 	return (TRUE);
165 }
166 
167 static int
168 freebsd32_fetch_syscall_args(struct thread *td)
169 {
170 	struct proc *p;
171 	register_t *ap;
172 	struct syscall_args *sa;
173 	int error, i, nap, narg;
174 	unsigned int args[4];
175 
176 	nap = 4;
177 	p = td->td_proc;
178 	ap = td->td_frame->tf_x;
179 	sa = &td->td_sa;
180 
181 	/* r7 is the syscall id */
182 	sa->code = td->td_frame->tf_x[7];
183 	sa->original_code = sa->code;
184 
185 	if (sa->code == SYS_syscall) {
186 		sa->code = *ap++;
187 		nap--;
188 	} else if (sa->code == SYS___syscall) {
189 		sa->code = ap[1];
190 		nap -= 2;
191 		ap += 2;
192 	}
193 
194 	if (sa->code >= p->p_sysent->sv_size)
195 		sa->callp = &p->p_sysent->sv_table[0];
196 	else
197 		sa->callp = &p->p_sysent->sv_table[sa->code];
198 
199 	narg = sa->callp->sy_narg;
200 	for (i = 0; i < nap; i++)
201 		sa->args[i] = ap[i];
202 	if (narg > nap) {
203 		if (narg - nap > nitems(args))
204 			panic("Too many system call arguiments");
205 		error = copyin((void *)td->td_frame->tf_x[13], args,
206 		    (narg - nap) * sizeof(int));
207 		for (i = 0; i < (narg - nap); i++)
208 			sa->args[i + nap] = args[i];
209 	}
210 
211 	td->td_retval[0] = 0;
212 	td->td_retval[1] = 0;
213 
214 	return (0);
215 }
216 
217 static void
218 freebsd32_set_syscall_retval(struct thread *td, int error)
219 {
220 	struct trapframe *frame;
221 
222 	frame = td->td_frame;
223 	switch (error) {
224 	case 0:
225 		frame->tf_x[0] = td->td_retval[0];
226 		frame->tf_x[1] = td->td_retval[1];
227 		frame->tf_spsr &= ~PSR_C;
228 		break;
229 	case ERESTART:
230 		/*
231 		 * Reconstruct the pc to point at the swi.
232 		 */
233 		if ((frame->tf_spsr & PSR_T) != 0)
234 			frame->tf_elr -= 2; //THUMB_INSN_SIZE;
235 		else
236 			frame->tf_elr -= 4; //INSN_SIZE;
237 		break;
238 	case EJUSTRETURN:
239 		/* nothing to do */
240 		break;
241 	default:
242 		frame->tf_x[0] = error;
243 		frame->tf_spsr |= PSR_C;
244 		break;
245 	}
246 }
247 
248 static void
249 freebsd32_setregs(struct thread *td, struct image_params *imgp,
250    uintptr_t stack)
251 {
252 	struct trapframe *tf = td->td_frame;
253 	struct pcb *pcb = td->td_pcb;
254 
255 	memset(tf, 0, sizeof(struct trapframe));
256 
257 	/*
258 	 * We need to set x0 for init as it doesn't call
259 	 * cpu_set_syscall_retval to copy the value. We also
260 	 * need to set td_retval for the cases where we do.
261 	 */
262 	tf->tf_x[0] = stack;
263 	/* SP_usr is mapped to x13 */
264 	tf->tf_x[13] = stack;
265 	/* LR_usr is mapped to x14 */
266 	tf->tf_x[14] = imgp->entry_addr;
267 	tf->tf_elr = imgp->entry_addr;
268 	tf->tf_spsr = PSR_M_32;
269 	if ((uint32_t)imgp->entry_addr & 1)
270 		tf->tf_spsr |= PSR_T;
271 
272 #ifdef VFP
273 	vfp_reset_state(td, pcb);
274 #endif
275 
276 	/*
277 	 * Clear debug register state. It is not applicable to the new process.
278 	 */
279 	bzero(&pcb->pcb_dbg_regs, sizeof(pcb->pcb_dbg_regs));
280 }
281 
282 void
283 elf32_dump_thread(struct thread *td, void *dst, size_t *off)
284 {
285 	/* XXX: VFP */
286 }
287