1 files changed, 181 insertions, 38 deletions

diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 2e1caabecb18..f4af82508228 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -16,14 +16,22 @@
 
 #include <asm/orc_types.h>
 #include <objtool/check.h>
+#include <objtool/disas.h>
 #include <objtool/elf.h>
 #include <objtool/arch.h>
 #include <objtool/warn.h>
-#include <objtool/endianness.h>
 #include <objtool/builtin.h>
 #include <arch/elf.h>
 
-int arch_ftrace_match(char *name)
+const char *arch_reg_name[CFI_NUM_REGS] = {
+	"rax", "rcx", "rdx", "rbx",
+	"rsp", "rbp", "rsi", "rdi",
+	"r8",  "r9",  "r10", "r11",
+	"r12", "r13", "r14", "r15",
+	"ra"
+};
+
+int arch_ftrace_match(const char *name)
 {
 	return !strcmp(name, "__fentry__");
 }
@@ -36,7 +44,7 @@ static int is_x86_64(const struct elf *elf)
 	case EM_386:
 		return 0;
 	default:
-		WARN("unexpected ELF machine type %d", elf->ehdr.e_machine);
+		ERROR("unexpected ELF machine type %d", elf->ehdr.e_machine);
 		return -1;
 	}
 }
@@ -68,9 +76,65 @@ bool arch_callee_saved_reg(unsigned char reg)
 	}
 }
 
-unsigned long arch_dest_reloc_offset(int addend)
+/* Undo the effects of __pa_symbol() if necessary */
+static unsigned long phys_to_virt(unsigned long pa)
+{
+	s64 va = pa;
+
+	if (va > 0)
+		va &= ~(0x80000000);
+
+	return va;
+}
+
+s64 arch_insn_adjusted_addend(struct instruction *insn, struct reloc *reloc)
+{
+	s64 addend = reloc_addend(reloc);
+
+	if (arch_pc_relative_reloc(reloc))
+		addend += insn->offset + insn->len - reloc_offset(reloc);
+
+	return phys_to_virt(addend);
+}
+
+static void scan_for_insn(struct section *sec, unsigned long offset,
+			  unsigned long *insn_off, unsigned int *insn_len)
+{
+	unsigned long o = 0;
+	struct insn insn;
+
+	while (1) {
+
+		insn_decode(&insn, sec->data->d_buf + o, sec_size(sec) - o,
+			    INSN_MODE_64);
+
+		if (o + insn.length > offset) {
+			*insn_off = o;
+			*insn_len = insn.length;
+			return;
+		}
+
+		o += insn.length;
+	}
+}
+
+u64 arch_adjusted_addend(struct reloc *reloc)
 {
-	return addend + 4;
+	unsigned int type = reloc_type(reloc);
+	s64 addend = reloc_addend(reloc);
+	unsigned long insn_off;
+	unsigned int insn_len;
+
+	if (type == R_X86_64_PLT32)
+		return addend + 4;
+
+	if (type != R_X86_64_PC32 || !is_text_sec(reloc->sec->base))
+		return addend;
+
+	scan_for_insn(reloc->sec->base, reloc_offset(reloc),
+		      &insn_off, &insn_len);
+
+	return addend + insn_off + insn_len - reloc_offset(reloc);
 }
 
 unsigned long arch_jump_destination(struct instruction *insn)
@@ -125,8 +189,14 @@ bool arch_pc_relative_reloc(struct reloc *reloc)
 #define is_RIP()   ((modrm_rm & 7) == CFI_BP && modrm_mod == 0)
 #define have_SIB() ((modrm_rm & 7) == CFI_SP && mod_is_mem())
 
+/*
+ * Check the ModRM register. If there is a SIB byte then check with
+ * the SIB base register. But if the SIB base is 5 (i.e. CFI_BP) and
+ * ModRM mod is 0 then there is no base register.
+ */
 #define rm_is(reg) (have_SIB() ? \
-		    sib_base == (reg) && sib_index == CFI_SP : \
+		    sib_base == (reg) && sib_index == CFI_SP && \
+		    (sib_base != CFI_BP || modrm_mod != 0) :	\
 		    modrm_rm == (reg))
 
 #define rm_is_mem(reg)	(mod_is_mem() && !is_RIP() && rm_is(reg))
@@ -167,7 +237,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 	ret = insn_decode(&ins, sec->data->d_buf + offset, maxlen,
 			  x86_64 ? INSN_MODE_64 : INSN_MODE_32);
 	if (ret < 0) {
-		WARN("can't decode instruction at %s:0x%lx", sec->name, offset);
+		ERROR("can't decode instruction at %s:0x%lx", sec->name, offset);
 		return -1;
 	}
 
@@ -291,7 +361,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 		switch (modrm_reg & 7) {
 		case 5:
 			imm = -imm;
-			/* fallthrough */
+			fallthrough;
 		case 0:
 			/* add/sub imm, %rsp */
 			ADD_OP(op) {
@@ -315,7 +385,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			break;
 
 		default:
-			/* WARN ? */
+			/* ERROR ? */
 			break;
 		}
 
@@ -375,7 +445,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			break;
 		}
 
-		/* fallthrough */
+		fallthrough;
 	case 0x88:
 		if (!rex_w)
 			break;
@@ -450,10 +520,6 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 		if (!rex_w)
 			break;
 
-		/* skip RIP relative displacement */
-		if (is_RIP())
-			break;
-
 		/* skip nontrivial SIB */
 		if (have_SIB()) {
 			modrm_rm = sib_base;
@@ -461,6 +527,12 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 				break;
 		}
 
+		/* lea disp(%rip), %dst */
+		if (is_RIP()) {
+			insn->type = INSN_LEA_RIP;
+			break;
+		}
+
 		/* lea disp(%src), %dst */
 		ADD_OP(op) {
 			op->src.offset = ins.displacement.value;
@@ -486,6 +558,12 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 		break;
 
 	case 0x90:
+		if (rex_b) /* XCHG %r8, %rax */
+			break;
+
+		if (prefix == 0xf3) /* REP NOP := PAUSE */
+			break;
+
 		insn->type = INSN_NOP;
 		break;
 
@@ -509,30 +587,44 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 
 		if (op2 == 0x01) {
 
-			if (modrm == 0xca)
-				insn->type = INSN_CLAC;
-			else if (modrm == 0xcb)
-				insn->type = INSN_STAC;
-
+			switch (insn_last_prefix_id(&ins)) {
+			case INAT_PFX_REPE:
+			case INAT_PFX_REPNE:
+				if (modrm == 0xca)
+					/* eretu/erets */
+					insn->type = INSN_SYSRET;
+				break;
+			default:
+				if (modrm == 0xca)
+					insn->type = INSN_CLAC;
+				else if (modrm == 0xcb)
+					insn->type = INSN_STAC;
+				break;
+			}
 		} else if (op2 >= 0x80 && op2 <= 0x8f) {
 
 			insn->type = INSN_JUMP_CONDITIONAL;
 
-		} else if (op2 == 0x05 || op2 == 0x07 || op2 == 0x34 ||
-			   op2 == 0x35) {
+		} else if (op2 == 0x05 || op2 == 0x34) {
 
-			/* sysenter, sysret */
-			insn->type = INSN_CONTEXT_SWITCH;
+			/* syscall, sysenter */
+			insn->type = INSN_SYSCALL;
+
+		} else if (op2 == 0x07 || op2 == 0x35) {
+
+			/* sysret, sysexit */
+			insn->type = INSN_SYSRET;
 
 		} else if (op2 == 0x0b || op2 == 0xb9) {
 
-			/* ud2 */
+			/* ud2, ud1 */
 			insn->type = INSN_BUG;
 
-		} else if (op2 == 0x0d || op2 == 0x1f) {
+		} else if (op2 == 0x1f) {
 
-			/* nopl/nopw */
-			insn->type = INSN_NOP;
+			/* 0f 1f /0 := NOPL */
+			if (modrm_reg == 0)
+				insn->type = INSN_NOP;
 
 		} else if (op2 == 0x1e) {
 
@@ -544,8 +636,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			if (ins.prefixes.nbytes == 1 &&
 			    ins.prefixes.bytes[0] == 0xf2) {
 				/* ENQCMD cannot be used in the kernel. */
-				WARN("ENQCMD instruction at %s:%lx", sec->name,
-				     offset);
+				WARN("ENQCMD instruction at %s:%lx", sec->name, offset);
 			}
 
 		} else if (op2 == 0xa0 || op2 == 0xa8) {
@@ -629,7 +720,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			if (disp->sym->type == STT_SECTION)
 				func = find_symbol_by_offset(disp->sym->sec, reloc_addend(disp));
 			if (!func) {
-				WARN("no func for pv_ops[]");
+				ERROR("no func for pv_ops[]");
 				return -1;
 			}
 
@@ -656,11 +747,15 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			break;
 		}
 
-		/* fallthrough */
+		fallthrough;
 
 	case 0xca: /* retf */
 	case 0xcb: /* retf */
-		insn->type = INSN_CONTEXT_SWITCH;
+		insn->type = INSN_SYSRET;
+		break;
+
+	case 0xd6: /* udb */
+		insn->type = INSN_BUG;
 		break;
 
 	case 0xe0: /* loopne */
@@ -705,7 +800,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 		} else if (modrm_reg == 5) {
 
 			/* jmpf */
-			insn->type = INSN_CONTEXT_SWITCH;
+			insn->type = INSN_SYSRET;
 
 		} else if (modrm_reg == 6) {
 
@@ -722,7 +817,10 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 		break;
 	}
 
-	insn->immediate = ins.immediate.nbytes ? ins.immediate.value : 0;
+	if (ins.immediate.nbytes)
+		insn->immediate = ins.immediate.value;
+	else if (ins.displacement.nbytes)
+		insn->immediate = ins.displacement.value;
 
 	return 0;
 }
@@ -756,7 +854,7 @@ const char *arch_nop_insn(int len)
 	};
 
 	if (len < 1 || len > 5) {
-		WARN("invalid NOP size: %d\n", len);
+		ERROR("invalid NOP size: %d\n", len);
 		return NULL;
 	}
 
@@ -776,7 +874,7 @@ const char *arch_ret_insn(int len)
 	};
 
 	if (len < 1 || len > 5) {
-		WARN("invalid RET size: %d\n", len);
+		ERROR("invalid RET size: %d\n", len);
 		return NULL;
 	}
 
@@ -819,10 +917,55 @@ int arch_decode_hint_reg(u8 sp_reg, int *base)
 
 bool arch_is_retpoline(struct symbol *sym)
 {
-	return !strncmp(sym->name, "__x86_indirect_", 15);
+	return !strncmp(sym->name, "__x86_indirect_", 15) ||
+	       !strncmp(sym->name, "__pi___x86_indirect_", 20);
 }
 
 bool arch_is_rethunk(struct symbol *sym)
 {
-	return !strcmp(sym->name, "__x86_return_thunk");
+	return !strcmp(sym->name, "__x86_return_thunk") ||
+	       !strcmp(sym->name, "__pi___x86_return_thunk");
 }
+
+bool arch_is_embedded_insn(struct symbol *sym)
+{
+	return !strcmp(sym->name, "retbleed_return_thunk") ||
+	       !strcmp(sym->name, "srso_alias_safe_ret") ||
+	       !strcmp(sym->name, "srso_safe_ret");
+}
+
+unsigned int arch_reloc_size(struct reloc *reloc)
+{
+	switch (reloc_type(reloc)) {
+	case R_X86_64_32:
+	case R_X86_64_32S:
+	case R_X86_64_PC32:
+	case R_X86_64_PLT32:
+		return 4;
+	default:
+		return 8;
+	}
+}
+
+bool arch_absolute_reloc(struct elf *elf, struct reloc *reloc)
+{
+	switch (reloc_type(reloc)) {
+	case R_X86_64_32:
+	case R_X86_64_32S:
+	case R_X86_64_64:
+		return true;
+	default:
+		return false;
+	}
+}
+
+#ifdef DISAS
+
+int arch_disas_info_init(struct disassemble_info *dinfo)
+{
+	return disas_info_init(dinfo, bfd_arch_i386,
+			       bfd_mach_i386_i386, bfd_mach_x86_64,
+			       "att");
+}
+
+#endif /* DISAS */