Objtool changes for v6.13:

- Detect non-relocated text references for more robust
    IBT sealing (Josh Poimboeuf)
 
  - Fix build error when building stripped down
    UAPI headers (HONG Yifan)
 
  - Exclude __tracepoints data from ENDBR checks to fix
    false positives on clang builds (Peter Zijlstra)
 
  - Fix ORC unwind for newly forked tasks (Zheng Yejian)
 
  - Fix readelf related faddr2line regression (Carlos Llamas)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'objtool-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

 - Detect non-relocated text references for more robust
   IBT sealing (Josh Poimboeuf)

 - Fix build error when building stripped down
   UAPI headers (HONG Yifan)

 - Exclude __tracepoints data from ENDBR checks to fix
   false positives on clang builds (Peter Zijlstra)

 - Fix ORC unwind for newly forked tasks (Zheng Yejian)

 - Fix readelf related faddr2line regression (Carlos Llamas)

* tag 'objtool-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Exclude __tracepoints data from ENDBR checks
  Revert "scripts/faddr2line: Check only two symbols when calculating symbol size"
  x86/unwind/orc: Fix unwind for newly forked tasks
  objtool: Also include tools/include/uapi
  objtool: Detect non-relocated text references

arch/x86/kernel/acpi/wakeup_64.S

@@ -87,6 +87,7 @@ SYM_FUNC_START(do_suspend_lowlevel)
 
 	.align 4
 .Lresume_point:
+	ANNOTATE_NOENDBR
 	/* We don't restore %rax, it must be 0 anyway */
 	movq	$saved_context, %rax
 	movq	saved_context_cr4(%rax), %rbx

arch/x86/kernel/head_64.S

@@ -77,6 +77,7 @@ SYM_CODE_START_NOALIGN(startup_64)
 	lretq
 
 .Lon_kernel_cs:
+	ANNOTATE_NOENDBR
 	UNWIND_HINT_END_OF_STACK
 
 #ifdef CONFIG_AMD_MEM_ENCRYPT

arch/x86/kernel/unwind_orc.c

@@ -723,7 +723,7 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task,
 		state->sp = task->thread.sp + sizeof(*frame);
 		state->bp = READ_ONCE_NOCHECK(frame->bp);
 		state->ip = READ_ONCE_NOCHECK(frame->ret_addr);
-		state->signal = (void *)state->ip == ret_from_fork;
+		state->signal = (void *)state->ip == ret_from_fork_asm;
 	}
 
 	if (get_stack_info((unsigned long *)state->sp, state->task,

scripts/faddr2line

@@ -252,7 +252,7 @@ __faddr2line() {
 				found=2
 				break
 			fi
-		done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2 | ${GREP} -A1 --no-group-separator " ${sym_name}$")
+		done < <(echo "${ELF_SYMS}" | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2)
 
 		if [[ $found = 0 ]]; then
 			warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size"

tools/objtool/Makefile

@@ -24,6 +24,7 @@ LIBELF_LIBS  := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lel
 all: $(OBJTOOL)
 
 INCLUDES := -I$(srctree)/tools/include \
+	    -I$(srctree)/tools/include/uapi \
 	    -I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \
 	    -I$(srctree)/tools/arch/$(SRCARCH)/include	\
 	    -I$(srctree)/tools/objtool/include \

tools/objtool/arch/x86/decode.c

@@ -456,10 +456,6 @@ 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;
@@ -467,6 +463,12 @@ 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;
@@ -737,7 +739,10 @@ 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;
 }

tools/objtool/check.c

@@ -4392,58 +4392,12 @@ static bool noendbr_range(struct objtool_file *file, struct instruction *insn)
 	return insn->offset == sym->offset + sym->len;
 }
 
-static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn)
+static int __validate_ibt_insn(struct objtool_file *file, struct instruction *insn,
+			       struct instruction *dest)
 {
-	struct instruction *dest;
-	struct reloc *reloc;
-	unsigned long off;
-	int warnings = 0;
-
-	/*
-	 * Looking for function pointer load relocations.  Ignore
-	 * direct/indirect branches:
-	 */
-	switch (insn->type) {
-	case INSN_CALL:
-	case INSN_CALL_DYNAMIC:
-	case INSN_JUMP_CONDITIONAL:
-	case INSN_JUMP_UNCONDITIONAL:
-	case INSN_JUMP_DYNAMIC:
-	case INSN_JUMP_DYNAMIC_CONDITIONAL:
-	case INSN_RETURN:
-	case INSN_NOP:
-		return 0;
-	default:
-		break;
-	}
-
-	for (reloc = insn_reloc(file, insn);
-	     reloc;
-	     reloc = find_reloc_by_dest_range(file->elf, insn->sec,
-					      reloc_offset(reloc) + 1,
-					      (insn->offset + insn->len) - (reloc_offset(reloc) + 1))) {
-
-		/*
-		 * static_call_update() references the trampoline, which
-		 * doesn't have (or need) ENDBR.  Skip warning in that case.
-		 */
-		if (reloc->sym->static_call_tramp)
-			continue;
-
-		off = reloc->sym->offset;
-		if (reloc_type(reloc) == R_X86_64_PC32 ||
-		    reloc_type(reloc) == R_X86_64_PLT32)
-			off += arch_dest_reloc_offset(reloc_addend(reloc));
-		else
-			off += reloc_addend(reloc);
-
-		dest = find_insn(file, reloc->sym->sec, off);
-		if (!dest)
-			continue;
-
 	if (dest->type == INSN_ENDBR) {
 		mark_endbr_used(dest);
-			continue;
+		return 0;
 	}
 
 	if (insn_func(dest) && insn_func(insn) &&
@@ -4463,25 +4417,87 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn
 		 * As such, blanket accept self-references without
 		 * issue.
 		 */
-			continue;
+		return 0;
 	}
 
 	/*
 	 * Accept anything ANNOTATE_NOENDBR.
 	 */
 	if (dest->noendbr)
-			continue;
+		return 0;
 
 	/*
 	 * Accept if this is the instruction after a symbol
 	 * that is (no)endbr -- typical code-range usage.
 	 */
 	if (noendbr_range(file, dest))
-			continue;
+		return 0;
 
 	WARN_INSN(insn, "relocation to !ENDBR: %s", offstr(dest->sec, dest->offset));
+	return 1;
+}
 
-		warnings++;
+static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn)
+{
+	struct instruction *dest;
+	struct reloc *reloc;
+	unsigned long off;
+	int warnings = 0;
+
+	/*
+	 * Looking for function pointer load relocations.  Ignore
+	 * direct/indirect branches:
+	 */
+	switch (insn->type) {
+
+	case INSN_CALL:
+	case INSN_CALL_DYNAMIC:
+	case INSN_JUMP_CONDITIONAL:
+	case INSN_JUMP_UNCONDITIONAL:
+	case INSN_JUMP_DYNAMIC:
+	case INSN_JUMP_DYNAMIC_CONDITIONAL:
+	case INSN_RETURN:
+	case INSN_NOP:
+		return 0;
+
+	case INSN_LEA_RIP:
+		if (!insn_reloc(file, insn)) {
+			/* local function pointer reference without reloc */
+
+			off = arch_jump_destination(insn);
+
+			dest = find_insn(file, insn->sec, off);
+			if (!dest) {
+				WARN_INSN(insn, "corrupt function pointer reference");
+				return 1;
+			}
+
+			return __validate_ibt_insn(file, insn, dest);
+		}
+		break;
+
+	default:
+		break;
+	}
+
+	for (reloc = insn_reloc(file, insn);
+	     reloc;
+	     reloc = find_reloc_by_dest_range(file->elf, insn->sec,
+					      reloc_offset(reloc) + 1,
+					      (insn->offset + insn->len) - (reloc_offset(reloc) + 1))) {
+
+		off = reloc->sym->offset;
+		if (reloc_type(reloc) == R_X86_64_PC32 ||
+		    reloc_type(reloc) == R_X86_64_PLT32)
+			off += arch_dest_reloc_offset(reloc_addend(reloc));
+		else
+			off += reloc_addend(reloc);
+
+		dest = find_insn(file, reloc->sym->sec, off);
+		if (!dest)
+			continue;
+
+		warnings += __validate_ibt_insn(file, insn, dest);
 	}
 
 	return warnings;
@@ -4557,6 +4573,7 @@ static int validate_ibt(struct objtool_file *file)
 		    !strcmp(sec->name, "__jump_table")			||
 		    !strcmp(sec->name, "__mcount_loc")			||
 		    !strcmp(sec->name, ".kcfi_traps")			||
+		    !strcmp(sec->name, "__tracepoints")			||
 		    strstr(sec->name, "__patchable_function_entries"))
 			continue;
 

tools/objtool/include/objtool/arch.h

@@ -28,6 +28,7 @@ enum insn_type {
 	INSN_CLD,
 	INSN_TRAP,
 	INSN_ENDBR,
+	INSN_LEA_RIP,
 	INSN_OTHER,
 };