[GIT pull] objtool/urgent for 5.19-rc3

From: Thomas Gleixner
Date: Sun Jun 19 2022 - 09:12:59 EST

Linus,

please pull the latest objtool/urgent branch from:

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

up to: 7b6c7a877cc6: x86/ftrace: Remove OBJECT_FILES_NON_STANDARD usage


Build tool updates:

- 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.


Thanks,

tglx

------------------>
Josh Poimboeuf (3):
objtool: Fix obsolete reference to CONFIG_X86_SMAP
faddr2line: Fix overlapping text section failures, the sequel
x86/ftrace: Remove OBJECT_FILES_NON_STANDARD usage


arch/x86/kernel/Makefile | 4 ----
arch/x86/kernel/ftrace_64.S | 11 ++++++++---
include/linux/objtool.h | 6 ++++++
lib/Kconfig.ubsan | 2 +-
scripts/faddr2line | 45 ++++++++++++++++++++++++++++++++-----------
tools/include/linux/objtool.h | 6 ++++++
6 files changed, 55 insertions(+), 19 deletions(-)

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 03364dc40d8d..4c8b6ae802ac 100644
--- a/arch/x86/kernel/Makefile
+++ b/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
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index 4ec13608d3c6..dfeb227de561 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/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
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index 6491fa8fba6d..15b940ec1eac 100644
--- a/include/linux/objtool.h
+++ b/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
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index c4fe15d38b60..a9f7eb047768 100644
--- a/lib/Kconfig.ubsan
+++ b/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
diff --git a/scripts/faddr2line b/scripts/faddr2line
index 0e6268d59883..94ed98dd899f 100755
--- a/scripts/faddr2line
+++ b/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):
diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h
index 6491fa8fba6d..15b940ec1eac 100644
--- a/tools/include/linux/objtool.h
+++ b/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