Merge tag 'objtool-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull build tooling updates from Thomas Gleixner:

 - Remove obsolete CONFIG_X86_SMAP reference from objtool

 - Fix overlapping text section failures in faddr2line for real

 - Remove OBJECT_FILES_NON_STANDARD usage from x86 ftrace and replace it
   with finegrained annotations so objtool can validate that code
   correctly.

* tag 'objtool-urgent-2022-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ftrace: Remove OBJECT_FILES_NON_STANDARD usage
  faddr2line: Fix overlapping text section failures, the sequel
  objtool: Fix obsolete reference to CONFIG_X86_SMAP

arch/x86/kernel/Makefile

@@ -36,10 +36,6 @@ KCSAN_SANITIZE := n
 
 OBJECT_FILES_NON_STANDARD_test_nx.o			:= y
 
-ifdef CONFIG_FRAME_POINTER
-OBJECT_FILES_NON_STANDARD_ftrace_$(BITS).o		:= y
-endif
-
 # If instrumentation of this dir is enabled, boot hangs during first second.
 # Probably could be more selective here, but note that files related to irqs,
 # boot, dumpstack/stacktrace, etc are either non-interesting or can lead to

arch/x86/kernel/ftrace_64.S

@@ -175,6 +175,7 @@ SYM_INNER_LABEL(ftrace_caller_end, SYM_L_GLOBAL)
 
 	jmp ftrace_epilogue
 SYM_FUNC_END(ftrace_caller);
+STACK_FRAME_NON_STANDARD_FP(ftrace_caller)
 
 SYM_FUNC_START(ftrace_epilogue)
 /*
@@ -282,6 +283,7 @@ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL)
 	jmp	ftrace_epilogue
 
 SYM_FUNC_END(ftrace_regs_caller)
+STACK_FRAME_NON_STANDARD_FP(ftrace_regs_caller)
 
 
 #else /* ! CONFIG_DYNAMIC_FTRACE */
@@ -311,10 +313,14 @@ trace:
 	jmp ftrace_stub
 SYM_FUNC_END(__fentry__)
 EXPORT_SYMBOL(__fentry__)
+STACK_FRAME_NON_STANDARD_FP(__fentry__)
+
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-SYM_FUNC_START(return_to_handler)
+SYM_CODE_START(return_to_handler)
+	UNWIND_HINT_EMPTY
+	ANNOTATE_NOENDBR
 	subq  $16, %rsp
 
 	/* Save the return values */
@@ -339,7 +345,6 @@ SYM_FUNC_START(return_to_handler)
 	int3
 .Ldo_rop:
 	mov %rdi, (%rsp)
-	UNWIND_HINT_FUNC
 	RET
-SYM_FUNC_END(return_to_handler)
+SYM_CODE_END(return_to_handler)
 #endif

include/linux/objtool.h

@@ -143,6 +143,12 @@ struct unwind_hint {
 	.popsection
 .endm
 
+.macro STACK_FRAME_NON_STANDARD_FP func:req
+#ifdef CONFIG_FRAME_POINTER
+	STACK_FRAME_NON_STANDARD \func
+#endif
+.endm
+
 .macro ANNOTATE_NOENDBR
 .Lhere_\@:
 	.pushsection .discard.noendbr

lib/Kconfig.ubsan

@@ -94,7 +94,7 @@ config UBSAN_UNREACHABLE
 	bool "Perform checking for unreachable code"
 	# objtool already handles unreachable checking and gets angry about
 	# seeing UBSan instrumentation located in unreachable places.
-	depends on !(OBJTOOL && (STACK_VALIDATION || UNWINDER_ORC || X86_SMAP))
+	depends on !(OBJTOOL && (STACK_VALIDATION || UNWINDER_ORC || HAVE_UACCESS_VALIDATION))
 	depends on $(cc-option,-fsanitize=unreachable)
 	help
 	  This option enables -fsanitize=unreachable which checks for control

scripts/faddr2line

@@ -95,17 +95,25 @@ __faddr2line() {
 	local print_warnings=$4
 
 	local sym_name=${func_addr%+*}
-	local offset=${func_addr#*+}
-	offset=${offset%/*}
+	local func_offset=${func_addr#*+}
+	func_offset=${func_offset%/*}
 	local user_size=
+	local file_type
+	local is_vmlinux=0
 	[[ $func_addr =~ "/" ]] && user_size=${func_addr#*/}
 
-	if [[ -z $sym_name ]] || [[ -z $offset ]] || [[ $sym_name = $func_addr ]]; then
+	if [[ -z $sym_name ]] || [[ -z $func_offset ]] || [[ $sym_name = $func_addr ]]; then
 		warn "bad func+offset $func_addr"
 		DONE=1
 		return
 	fi
 
+	# vmlinux uses absolute addresses in the section table rather than
+	# section offsets.
+	local file_type=$(${READELF} --file-header $objfile |
+		${AWK} '$1 == "Type:" { print $2; exit }')
+	[[ $file_type = "EXEC" ]] && is_vmlinux=1
+
 	# Go through each of the object's symbols which match the func name.
 	# In rare cases there might be duplicates, in which case we print all
 	# matches.
@@ -114,9 +122,11 @@ __faddr2line() {
 		local sym_addr=0x${fields[1]}
 		local sym_elf_size=${fields[2]}
 		local sym_sec=${fields[6]}
+		local sec_size
+		local sec_name
 
 		# Get the section size:
-		local sec_size=$(${READELF} --section-headers --wide $objfile |
+		sec_size=$(${READELF} --section-headers --wide $objfile |
 			sed 's/\[ /\[/' |
 			${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }')
 
@@ -126,6 +136,17 @@ __faddr2line() {
 			return
 		fi
 
+		# Get the section name:
+		sec_name=$(${READELF} --section-headers --wide $objfile |
+			sed 's/\[ /\[/' |
+			${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print $2; exit }')
+
+		if [[ -z $sec_name ]]; then
+			warn "bad section name: section: $sym_sec"
+			DONE=1
+			return
+		fi
+
 		# Calculate the symbol size.
 		#
 		# Unfortunately we can't use the ELF size, because kallsyms
@@ -174,10 +195,10 @@ __faddr2line() {
 
 		sym_size=0x$(printf %x $sym_size)
 
-		# Calculate the section address from user-supplied offset:
-		local addr=$(($sym_addr + $offset))
+		# Calculate the address from user-supplied offset:
+		local addr=$(($sym_addr + $func_offset))
 		if [[ -z $addr ]] || [[ $addr = 0 ]]; then
-			warn "bad address: $sym_addr + $offset"
+			warn "bad address: $sym_addr + $func_offset"
 			DONE=1
 			return
 		fi
@@ -191,9 +212,9 @@ __faddr2line() {
 		fi
 
 		# Make sure the provided offset is within the symbol's range:
-		if [[ $offset -gt $sym_size ]]; then
+		if [[ $func_offset -gt $sym_size ]]; then
 			[[ $print_warnings = 1 ]] &&
-				echo "skipping $sym_name address at $addr due to size mismatch ($offset > $sym_size)"
+				echo "skipping $sym_name address at $addr due to size mismatch ($func_offset > $sym_size)"
 			continue
 		fi
 
@@ -202,11 +223,13 @@ __faddr2line() {
 		[[ $FIRST = 0 ]] && echo
 		FIRST=0
 
-		echo "$sym_name+$offset/$sym_size:"
+		echo "$sym_name+$func_offset/$sym_size:"
 
 		# Pass section address to addr2line and strip absolute paths
 		# from the output:
-		local output=$(${ADDR2LINE} -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;")
+		local args="--functions --pretty-print --inlines --exe=$objfile"
+		[[ $is_vmlinux = 0 ]] && args="$args --section=$sec_name"
+		local output=$(${ADDR2LINE} $args $addr | sed "s; $dir_prefix\(\./\)*; ;")
 		[[ -z $output ]] && continue
 
 		# Default output (non --list):

tools/include/linux/objtool.h

@@ -143,6 +143,12 @@ struct unwind_hint {
 	.popsection
 .endm
 
+.macro STACK_FRAME_NON_STANDARD_FP func:req
+#ifdef CONFIG_FRAME_POINTER
+	STACK_FRAME_NON_STANDARD \func
+#endif
+.endm
+
 .macro ANNOTATE_NOENDBR
 .Lhere_\@:
 	.pushsection .discard.noendbr