orc.c

  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
  9int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruction *insn)
 10{
 11	struct cfi_reg *bp = &cfi->regs[CFI_BP];
 12
 13	memset(orc, 0, sizeof(*orc));
 14
 15	if (!cfi) {
 16		/*
 17		 * This is usually either unreachable nops/traps (which don't
 18		 * trigger unreachable instruction warnings), or
 19		 * STACK_FRAME_NON_STANDARD functions.
 20		 */
 21		orc->type = ORC_TYPE_UNDEFINED;
 22		return 0;
 23	}
 24
 25	switch (cfi->type) {
 26	case UNWIND_HINT_TYPE_UNDEFINED:
 27		orc->type = ORC_TYPE_UNDEFINED;
 28		return 0;
 29	case UNWIND_HINT_TYPE_END_OF_STACK:
 30		orc->type = ORC_TYPE_END_OF_STACK;
 31		return 0;
 32	case UNWIND_HINT_TYPE_CALL:
 33		orc->type = ORC_TYPE_CALL;
 34		break;
 35	case UNWIND_HINT_TYPE_REGS:
 36		orc->type = ORC_TYPE_REGS;
 37		break;
 38	case UNWIND_HINT_TYPE_REGS_PARTIAL:
 39		orc->type = ORC_TYPE_REGS_PARTIAL;
 40		break;
 41	default:
 42		ERROR_INSN(insn, "unknown unwind hint type %d", cfi->type);
 43		return -1;
 44	}
 45
 46	orc->signal = cfi->signal;
 47
 48	switch (cfi->cfa.base) {
 49	case CFI_SP:
 50		orc->sp_reg = ORC_REG_SP;
 51		break;
 52	case CFI_SP_INDIRECT:
 53		orc->sp_reg = ORC_REG_SP_INDIRECT;
 54		break;
 55	case CFI_BP:
 56		orc->sp_reg = ORC_REG_BP;
 57		break;
 58	case CFI_BP_INDIRECT:
 59		orc->sp_reg = ORC_REG_BP_INDIRECT;
 60		break;
 61	case CFI_R10:
 62		orc->sp_reg = ORC_REG_R10;
 63		break;
 64	case CFI_R13:
 65		orc->sp_reg = ORC_REG_R13;
 66		break;
 67	case CFI_DI:
 68		orc->sp_reg = ORC_REG_DI;
 69		break;
 70	case CFI_DX:
 71		orc->sp_reg = ORC_REG_DX;
 72		break;
 73	default:
 74		ERROR_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
 75		return -1;
 76	}
 77
 78	switch (bp->base) {
 79	case CFI_UNDEFINED:
 80		orc->bp_reg = ORC_REG_UNDEFINED;
 81		break;
 82	case CFI_CFA:
 83		orc->bp_reg = ORC_REG_PREV_SP;
 84		break;
 85	case CFI_BP:
 86		orc->bp_reg = ORC_REG_BP;
 87		break;
 88	default:
 89		ERROR_INSN(insn, "unknown BP base reg %d", bp->base);
 90		return -1;
 91	}
 92
 93	orc->sp_offset = cfi->cfa.offset;
 94	orc->bp_offset = bp->offset;
 95
 96	return 0;
 97}
 98
 99int write_orc_entry(struct elf *elf, struct section *orc_sec,
100		    struct section *ip_sec, unsigned int idx,
101		    struct section *insn_sec, unsigned long insn_off,
102		    struct orc_entry *o)
103{
104	struct orc_entry *orc;
105
106	/* populate ORC data */
107	orc = (struct orc_entry *)orc_sec->data->d_buf + idx;
108	memcpy(orc, o, sizeof(*orc));
109	orc->sp_offset = bswap_if_needed(elf, orc->sp_offset);
110	orc->bp_offset = bswap_if_needed(elf, orc->bp_offset);
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_PREV_SP:
124		return "prevsp";
125	case ORC_REG_DX:
126		return "dx";
127	case ORC_REG_DI:
128		return "di";
129	case ORC_REG_BP:
130		return "bp";
131	case ORC_REG_SP:
132		return "sp";
133	case ORC_REG_R10:
134		return "r10";
135	case ORC_REG_R13:
136		return "r13";
137	case ORC_REG_BP_INDIRECT:
138		return "bp(ind)";
139	case ORC_REG_SP_INDIRECT:
140		return "sp(ind)";
141	default:
142		return "?";
143	}
144}
145
146static const char *orc_type_name(unsigned int type)
147{
148	switch (type) {
149	case ORC_TYPE_UNDEFINED:
150		return "(und)";
151	case ORC_TYPE_END_OF_STACK:
152		return "end";
153	case ORC_TYPE_CALL:
154		return "call";
155	case ORC_TYPE_REGS:
156		return "regs";
157	case ORC_TYPE_REGS_PARTIAL:
158		return "regs (partial)";
159	default:
160		return "?";
161	}
162}
163
164static void print_reg(unsigned int reg, int offset)
165{
166	if (reg == ORC_REG_BP_INDIRECT)
167		printf("(bp%+d)", offset);
168	else if (reg == ORC_REG_SP_INDIRECT)
169		printf("(sp)%+d", offset);
170	else if (reg == ORC_REG_UNDEFINED)
171		printf("(und)");
172	else
173		printf("%s%+d", reg_name(reg), offset);
174}
175
176void orc_print_dump(struct elf *dummy_elf, struct orc_entry *orc, int i)
177{
178	printf("type:%s", orc_type_name(orc[i].type));
179
180	printf(" sp:");
181	print_reg(orc[i].sp_reg, bswap_if_needed(dummy_elf, orc[i].sp_offset));
182
183	printf(" bp:");
184	print_reg(orc[i].bp_reg, bswap_if_needed(dummy_elf, orc[i].bp_offset));
185
186	printf(" signal:%d\n", orc[i].signal);
187}