1// SPDX-License-Identifier: GPL-2.0-or-later
2#include <linux/objtool_types.h>
3#include <asm/orc_types.h>
4
5#include <objtool/check.h>
6#include <objtool/orc.h>
7#include <objtool/warn.h>
8#include <objtool/endianness.h>
9
10int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruction *insn)
11{
12	struct cfi_reg *fp = &cfi->regs[CFI_FP];
13	struct cfi_reg *ra = &cfi->regs[CFI_RA];
14
15	memset(orc, 0, sizeof(*orc));
16
17	if (!cfi) {
18		/*
19		 * This is usually either unreachable nops/traps (which don't
20		 * trigger unreachable instruction warnings), or
21		 * STACK_FRAME_NON_STANDARD functions.
22		 */
23		orc->type = ORC_TYPE_UNDEFINED;
24		return 0;
25	}
26
27	switch (cfi->type) {
28	case UNWIND_HINT_TYPE_UNDEFINED:
29		orc->type = ORC_TYPE_UNDEFINED;
30		return 0;
31	case UNWIND_HINT_TYPE_END_OF_STACK:
32		orc->type = ORC_TYPE_END_OF_STACK;
33		return 0;
34	case UNWIND_HINT_TYPE_CALL:
35		orc->type = ORC_TYPE_CALL;
36		break;
37	case UNWIND_HINT_TYPE_REGS:
38		orc->type = ORC_TYPE_REGS;
39		break;
40	case UNWIND_HINT_TYPE_REGS_PARTIAL:
41		orc->type = ORC_TYPE_REGS_PARTIAL;
42		break;
43	default:
44		WARN_INSN(insn, "unknown unwind hint type %d", cfi->type);
45		return -1;
46	}
47
48	orc->signal = cfi->signal;
49
50	switch (cfi->cfa.base) {
51	case CFI_SP:
52		orc->sp_reg = ORC_REG_SP;
53		break;
54	case CFI_FP:
55		orc->sp_reg = ORC_REG_FP;
56		break;
57	default:
58		WARN_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
59		return -1;
60	}
61
62	switch (fp->base) {
63	case CFI_UNDEFINED:
64		orc->fp_reg = ORC_REG_UNDEFINED;
65		orc->fp_offset = 0;
66		break;
67	case CFI_CFA:
68		orc->fp_reg = ORC_REG_PREV_SP;
69		orc->fp_offset = fp->offset;
70		break;
71	case CFI_FP:
72		orc->fp_reg = ORC_REG_FP;
73		break;
74	default:
75		WARN_INSN(insn, "unknown FP base reg %d", fp->base);
76		return -1;
77	}
78
79	switch (ra->base) {
80	case CFI_UNDEFINED:
81		orc->ra_reg = ORC_REG_UNDEFINED;
82		orc->ra_offset = 0;
83		break;
84	case CFI_CFA:
85		orc->ra_reg = ORC_REG_PREV_SP;
86		orc->ra_offset = ra->offset;
87		break;
88	case CFI_FP:
89		orc->ra_reg = ORC_REG_FP;
90		break;
91	default:
92		WARN_INSN(insn, "unknown RA base reg %d", ra->base);
93		return -1;
94	}
95
96	orc->sp_offset = cfi->cfa.offset;
97
98	return 0;
99}
100
101int write_orc_entry(struct elf *elf, struct section *orc_sec,
102		    struct section *ip_sec, unsigned int idx,
103		    struct section *insn_sec, unsigned long insn_off,
104		    struct orc_entry *o)
105{
106	struct orc_entry *orc;
107
108	/* populate ORC data */
109	orc = (struct orc_entry *)orc_sec->data->d_buf + idx;
110	memcpy(orc, o, sizeof(*orc));
111
112	/* populate reloc for ip */
113	if (!elf_init_reloc_text_sym(elf, ip_sec, idx * sizeof(int), idx,
114				     insn_sec, insn_off))
115		return -1;
116
117	return 0;
118}
119
120static const char *reg_name(unsigned int reg)
121{
122	switch (reg) {
123	case ORC_REG_SP:
124		return "sp";
125	case ORC_REG_FP:
126		return "fp";
127	case ORC_REG_PREV_SP:
128		return "prevsp";
129	default:
130		return "?";
131	}
132}
133
134static const char *orc_type_name(unsigned int type)
135{
136	switch (type) {
137	case UNWIND_HINT_TYPE_CALL:
138		return "call";
139	case UNWIND_HINT_TYPE_REGS:
140		return "regs";
141	case UNWIND_HINT_TYPE_REGS_PARTIAL:
142		return "regs (partial)";
143	default:
144		return "?";
145	}
146}
147
148static void print_reg(unsigned int reg, int offset)
149{
150	if (reg == ORC_REG_UNDEFINED)
151		printf(" (und) ");
152	else
153		printf("%s + %3d", reg_name(reg), offset);
154
155}
156
157void orc_print_dump(struct elf *dummy_elf, struct orc_entry *orc, int i)
158{
159	printf("type:%s", orc_type_name(orc[i].type));
160
161	printf(" sp:");
162	print_reg(orc[i].sp_reg, orc[i].sp_offset);
163
164	printf(" fp:");
165	print_reg(orc[i].fp_reg, orc[i].fp_offset);
166
167	printf(" ra:");
168	print_reg(orc[i].ra_reg, orc[i].ra_offset);
169
170	printf(" signal:%d\n", orc[i].signal);
171}
172