Commit 5d770f11 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents 727c3991 7b6c7a87

arch/x86/kernel/Makefile

+0 −4
Original line number Diff line number Diff line
@@ -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

+8 −3
Original line number Diff line number Diff line
@@ -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

+6 −0
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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

+34 −11
Original line number Diff line number Diff line
@@ -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):