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Diffstat (limited to 'tools/objtool/arch/x86/decode.c')
-rw-r--r--tools/objtool/arch/x86/decode.c167
1 files changed, 142 insertions, 25 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index fe1362c34564..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)
{
- return addend + 4;
+ 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)
+{
+ 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)
@@ -173,7 +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;
}
@@ -321,7 +385,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
break;
default:
- /* WARN ? */
+ /* ERROR ? */
break;
}
@@ -494,6 +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;
@@ -522,7 +592,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
case INAT_PFX_REPNE:
if (modrm == 0xca)
/* eretu/erets */
- insn->type = INSN_CONTEXT_SWITCH;
+ insn->type = INSN_SYSRET;
break;
default:
if (modrm == 0xca)
@@ -535,21 +605,26 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
insn->type = INSN_JUMP_CONDITIONAL;
- } else if (op2 == 0x05 || op2 == 0x07 || op2 == 0x34 ||
- op2 == 0x35) {
+ } else if (op2 == 0x05 || op2 == 0x34) {
+
+ /* syscall, sysenter */
+ insn->type = INSN_SYSCALL;
- /* sysenter, sysret */
- insn->type = INSN_CONTEXT_SWITCH;
+ } 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) {
@@ -561,8 +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) {
@@ -646,7 +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;
}
@@ -677,7 +751,11 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
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 */
@@ -722,7 +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) {
@@ -776,7 +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;
}
@@ -796,7 +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;
}
@@ -839,16 +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 */