diff options
34 files changed, 955 insertions, 683 deletions
@@ -1302,7 +1302,7 @@ install: sub_make_done := # --------------------------------------------------------------------------- # Tools -ifdef CONFIG_STACK_VALIDATION +ifdef CONFIG_OBJTOOL prepare: tools/objtool endif diff --git a/arch/Kconfig b/arch/Kconfig index 834c9ca8f289..c903f9508eea 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -54,6 +54,7 @@ config JUMP_LABEL bool "Optimize very unlikely/likely branches" depends on HAVE_ARCH_JUMP_LABEL depends on CC_HAS_ASM_GOTO + select OBJTOOL if HAVE_JUMP_LABEL_HACK help This option enables a transparent branch optimization that makes certain almost-always-true or almost-always-false branch @@ -1034,11 +1035,23 @@ config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT depends on MMU select ARCH_HAS_ELF_RANDOMIZE +config HAVE_OBJTOOL + bool + +config HAVE_JUMP_LABEL_HACK + bool + +config HAVE_NOINSTR_HACK + bool + +config HAVE_NOINSTR_VALIDATION + bool + config HAVE_STACK_VALIDATION bool help - Architecture supports the 'objtool check' host tool command, which - performs compile-time stack metadata validation. + Architecture supports objtool compile-time frame pointer rule + validation. config HAVE_RELIABLE_STACKTRACE bool @@ -1308,6 +1321,7 @@ config HAVE_STATIC_CALL config HAVE_STATIC_CALL_INLINE bool depends on HAVE_STATIC_CALL + select OBJTOOL config HAVE_PREEMPT_DYNAMIC bool diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2e8f6fd28e59..762a0b6ab8b6 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -188,7 +188,7 @@ config X86 select HAVE_CONTEXT_TRACKING if X86_64 select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING select HAVE_C_RECORDMCOUNT - select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION + select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL select HAVE_BUILDTIME_MCOUNT_SORT select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_CONTIGUOUS @@ -212,6 +212,7 @@ config X86 select HAVE_IOREMAP_PROT select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 select HAVE_IRQ_TIME_ACCOUNTING + select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL select HAVE_KERNEL_BZIP2 select HAVE_KERNEL_GZIP select HAVE_KERNEL_LZ4 @@ -230,7 +231,10 @@ config X86 select HAVE_MOD_ARCH_SPECIFIC select HAVE_MOVE_PMD select HAVE_MOVE_PUD + select HAVE_NOINSTR_HACK if HAVE_OBJTOOL select HAVE_NMI + select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL + select HAVE_OBJTOOL if X86_64 select HAVE_OPTPROBES select HAVE_PCSPKR_PLATFORM select HAVE_PERF_EVENTS @@ -239,17 +243,17 @@ config X86 select HAVE_PCI select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP - select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT + select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT select HAVE_POSIX_CPU_TIMERS_TASK_WORK select HAVE_REGS_AND_STACK_ACCESS_API - select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION + select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION select HAVE_FUNCTION_ARG_ACCESS_API select HAVE_SETUP_PER_CPU_AREA select HAVE_SOFTIRQ_ON_OWN_STACK select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR - select HAVE_STACK_VALIDATION if X86_64 + select HAVE_STACK_VALIDATION if HAVE_OBJTOOL select HAVE_STATIC_CALL - select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION + select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL select HAVE_PREEMPT_DYNAMIC_CALL select HAVE_RSEQ select HAVE_SYSCALL_TRACEPOINTS @@ -268,7 +272,6 @@ config X86 select RTC_MC146818_LIB select SPARSE_IRQ select SRCU - select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE) select SYSCTL_EXCEPTION_TRACE select THREAD_INFO_IN_TASK select TRACE_IRQFLAGS_SUPPORT @@ -459,6 +462,7 @@ config GOLDFISH config RETPOLINE bool "Avoid speculative indirect branches in kernel" + select OBJTOOL if HAVE_OBJTOOL default y help Compile kernel with the retpoline compiler options to guard against @@ -472,6 +476,7 @@ config CC_HAS_SLS config SLS bool "Mitigate Straight-Line-Speculation" depends on CC_HAS_SLS && X86_64 + select OBJTOOL if HAVE_OBJTOOL default n help Compile the kernel with straight-line-speculation options to guard @@ -1859,9 +1864,10 @@ config CC_HAS_IBT config X86_KERNEL_IBT prompt "Indirect Branch Tracking" bool - depends on X86_64 && CC_HAS_IBT && STACK_VALIDATION + depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f depends on !LD_IS_LLD || LLD_VERSION >= 140000 + select OBJTOOL help Build the kernel with support for Indirect Branch Tracking, a hardware support course-grain forward-edge Control Flow Integrity diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index d3a6f74a94bd..d872a7522e55 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -237,7 +237,7 @@ choice config UNWINDER_ORC bool "ORC unwinder" depends on X86_64 - select STACK_VALIDATION + select OBJTOOL help This option enables the ORC (Oops Rewind Capability) unwinder for unwinding kernel stack traces. It uses a custom data format which is diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index 0449b125d27f..071572e23d3a 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -20,7 +20,7 @@ _ASM_PTR "%c0 + %c1 - .\n\t" \ ".popsection \n\t" -#ifdef CONFIG_STACK_VALIDATION +#ifdef CONFIG_HAVE_JUMP_LABEL_HACK static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { @@ -34,7 +34,7 @@ l_yes: return true; } -#else +#else /* !CONFIG_HAVE_JUMP_LABEL_HACK */ static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch) { @@ -48,7 +48,7 @@ l_yes: return true; } -#endif /* STACK_VALIDATION */ +#endif /* CONFIG_HAVE_JUMP_LABEL_HACK */ static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch) { diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index d374cb3cf024..3c66073e7645 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -338,7 +338,7 @@ next: } } -#if defined(CONFIG_RETPOLINE) && defined(CONFIG_STACK_VALIDATION) +#if defined(CONFIG_RETPOLINE) && defined(CONFIG_OBJTOOL) /* * CALL/JMP *%\reg @@ -507,11 +507,11 @@ void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) } } -#else /* !RETPOLINES || !CONFIG_STACK_VALIDATION */ +#else /* !CONFIG_RETPOLINE || !CONFIG_OBJTOOL */ void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) { } -#endif /* CONFIG_RETPOLINE && CONFIG_STACK_VALIDATION */ +#endif /* CONFIG_RETPOLINE && CONFIG_OBJTOOL */ #ifdef CONFIG_X86_KERNEL_IBT diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 219aa5ddbc73..01ce94b58b42 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -109,7 +109,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, #endif /* Unreachable code */ -#ifdef CONFIG_STACK_VALIDATION +#ifdef CONFIG_OBJTOOL /* * These macros help objtool understand GCC code flow for unreachable code. * The __COUNTER__ based labels are a hack to make each instance of the macros @@ -128,10 +128,10 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, /* Annotate a C jump table to allow objtool to follow the code flow */ #define __annotate_jump_table __section(".rodata..c_jump_table") -#else +#else /* !CONFIG_OBJTOOL */ #define annotate_unreachable() #define __annotate_jump_table -#endif +#endif /* CONFIG_OBJTOOL */ #ifndef unreachable # define unreachable() do { \ diff --git a/include/linux/instrumentation.h b/include/linux/instrumentation.h index 24359b4a9605..bc7babe91b2e 100644 --- a/include/linux/instrumentation.h +++ b/include/linux/instrumentation.h @@ -2,7 +2,7 @@ #ifndef __LINUX_INSTRUMENTATION_H #define __LINUX_INSTRUMENTATION_H -#if defined(CONFIG_DEBUG_ENTRY) && defined(CONFIG_STACK_VALIDATION) +#ifdef CONFIG_NOINSTR_VALIDATION #include <linux/stringify.h> @@ -53,9 +53,9 @@ ".popsection\n\t" : : "i" (c)); \ }) #define instrumentation_end() __instrumentation_end(__COUNTER__) -#else +#else /* !CONFIG_NOINSTR_VALIDATION */ # define instrumentation_begin() do { } while(0) # define instrumentation_end() do { } while(0) -#endif +#endif /* CONFIG_NOINSTR_VALIDATION */ #endif /* __LINUX_INSTRUMENTATION_H */ diff --git a/include/linux/objtool.h b/include/linux/objtool.h index b9c1474a571e..6491fa8fba6d 100644 --- a/include/linux/objtool.h +++ b/include/linux/objtool.h @@ -38,7 +38,7 @@ struct unwind_hint { #define UNWIND_HINT_TYPE_REGS_PARTIAL 2 #define UNWIND_HINT_TYPE_FUNC 3 -#ifdef CONFIG_STACK_VALIDATION +#ifdef CONFIG_OBJTOOL #include <asm/asm.h> @@ -159,7 +159,7 @@ struct unwind_hint { #endif /* __ASSEMBLY__ */ -#else /* !CONFIG_STACK_VALIDATION */ +#else /* !CONFIG_OBJTOOL */ #ifndef __ASSEMBLY__ @@ -181,6 +181,6 @@ struct unwind_hint { .endm #endif -#endif /* CONFIG_STACK_VALIDATION */ +#endif /* CONFIG_OBJTOOL */ #endif /* _LINUX_OBJTOOL_H */ diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index bf5da6c4e999..debbbb083286 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -729,6 +729,7 @@ config FTRACE_MCOUNT_USE_OBJTOOL depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY depends on !FTRACE_MCOUNT_USE_CC depends on FTRACE_MCOUNT_RECORD + select OBJTOOL config FTRACE_MCOUNT_USE_RECORDMCOUNT def_bool y diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 075cd25363ac..55b9acb2f524 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -485,24 +485,25 @@ config FRAME_POINTER larger and slower, but it gives very useful debugging information in case of kernel bugs. (precise oopses/stacktraces/warnings) +config OBJTOOL + bool + config STACK_VALIDATION bool "Compile-time stack metadata validation" - depends on HAVE_STACK_VALIDATION + depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER + select OBJTOOL default n help - Add compile-time checks to validate stack metadata, including frame - pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure - that runtime stack traces are more reliable. - - This is also a prerequisite for generation of ORC unwind data, which - is needed for CONFIG_UNWINDER_ORC. + Validate frame pointer rules at compile-time. This helps ensure that + runtime stack traces are more reliable. For more information, see tools/objtool/Documentation/stack-validation.txt. -config VMLINUX_VALIDATION +config NOINSTR_VALIDATION bool - depends on STACK_VALIDATION && DEBUG_ENTRY + depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY + select OBJTOOL default y config VMLINUX_MAP @@ -2035,10 +2036,11 @@ config KCOV bool "Code coverage for fuzzing" depends on ARCH_HAS_KCOV depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS - depends on !ARCH_WANTS_NO_INSTR || STACK_VALIDATION || \ + depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \ GCC_VERSION >= 120000 || CLANG_VERSION >= 130000 select DEBUG_FS select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC + select OBJTOOL if HAVE_NOINSTR_HACK help KCOV exposes kernel code coverage information in a form suitable for coverage-guided fuzzing (randomized testing). diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan index de022445fbba..47a693c45864 100644 --- a/lib/Kconfig.kcsan +++ b/lib/Kconfig.kcsan @@ -187,7 +187,9 @@ config KCSAN_WEAK_MEMORY # We can either let objtool nop __tsan_func_{entry,exit}() and builtin # atomics instrumentation in .noinstr.text, or use a compiler that can # implement __no_kcsan to really remove all instrumentation. - depends on STACK_VALIDATION || CC_IS_GCC || CLANG_VERSION >= 140000 + depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \ + CC_IS_GCC || CLANG_VERSION >= 140000 + select OBJTOOL if HAVE_NOINSTR_HACK help Enable support for modeling a subset of weak memory, which allows detecting a subset of data races due to missing memory barriers. diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index f3c57ed51838..c4fe15d38b60 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 !STACK_VALIDATION + depends on !(OBJTOOL && (STACK_VALIDATION || UNWINDER_ORC || X86_SMAP)) depends on $(cc-option,-fsanitize=unreachable) help This option enables -fsanitize=unreachable which checks for control diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 3911bfc21702..f89d3fcff39f 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -222,25 +222,29 @@ cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), $(sub_cmd_record_mcount)) endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT -ifdef CONFIG_STACK_VALIDATION +ifdef CONFIG_OBJTOOL objtool := $(objtree)/tools/objtool/objtool objtool_args = \ - $(if $(CONFIG_UNWINDER_ORC),orc generate,check) \ - $(if $(part-of-module), --module) \ - $(if $(CONFIG_X86_KERNEL_IBT), --lto --ibt) \ - $(if $(CONFIG_FRAME_POINTER),, --no-fp) \ - $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) \ + $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \ + $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \ + $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \ + $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \ + $(if $(CONFIG_UNWINDER_ORC), --orc) \ $(if $(CONFIG_RETPOLINE), --retpoline) \ + $(if $(CONFIG_SLS), --sls) \ + $(if $(CONFIG_STACK_VALIDATION), --stackval) \ + $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \ --uaccess \ - $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \ - $(if $(CONFIG_SLS), --sls) + $(if $(linked-object), --link) \ + $(if $(part-of-module), --module) \ + $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@) cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd) -endif # CONFIG_STACK_VALIDATION +endif # CONFIG_OBJTOOL ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),) @@ -303,6 +307,7 @@ quiet_cmd_cc_prelink_modules = LD [M] $@ # modules into native code $(obj)/%.prelink.o: objtool-enabled = y $(obj)/%.prelink.o: part-of-module := y +$(obj)/%.prelink.o: linked-object := y $(obj)/%.prelink.o: $(obj)/%.o FORCE $(call if_changed,cc_prelink_modules) diff --git a/scripts/faddr2line b/scripts/faddr2line index 6c6439f69a72..0e6268d59883 100755 --- a/scripts/faddr2line +++ b/scripts/faddr2line @@ -44,17 +44,6 @@ set -o errexit set -o nounset -READELF="${CROSS_COMPILE:-}readelf" -ADDR2LINE="${CROSS_COMPILE:-}addr2line" -SIZE="${CROSS_COMPILE:-}size" -NM="${CROSS_COMPILE:-}nm" - -command -v awk >/dev/null 2>&1 || die "awk isn't installed" -command -v ${READELF} >/dev/null 2>&1 || die "readelf isn't installed" -command -v ${ADDR2LINE} >/dev/null 2>&1 || die "addr2line isn't installed" -command -v ${SIZE} >/dev/null 2>&1 || die "size isn't installed" -command -v ${NM} >/dev/null 2>&1 || die "nm isn't installed" - usage() { echo "usage: faddr2line [--list] <object file> <func+offset> <func+offset>..." >&2 exit 1 @@ -69,6 +58,14 @@ die() { exit 1 } +READELF="${CROSS_COMPILE:-}readelf" +ADDR2LINE="${CROSS_COMPILE:-}addr2line" +AWK="awk" + +command -v ${AWK} >/dev/null 2>&1 || die "${AWK} isn't installed" +command -v ${READELF} >/dev/null 2>&1 || die "${READELF} isn't installed" +command -v ${ADDR2LINE} >/dev/null 2>&1 || die "${ADDR2LINE} isn't installed" + # Try to figure out the source directory prefix so we can remove it from the # addr2line output. HACK ALERT: This assumes that start_kernel() is in # init/main.c! This only works for vmlinux. Otherwise it falls back to @@ -76,7 +73,7 @@ die() { find_dir_prefix() { local objfile=$1 - local start_kernel_addr=$(${READELF} -sW $objfile | awk '$8 == "start_kernel" {printf "0x%s", $2}') + local start_kernel_addr=$(${READELF} --symbols --wide $objfile | ${AWK} '$8 == "start_kernel" {printf "0x%s", $2}') [[ -z $start_kernel_addr ]] && return local file_line=$(${ADDR2LINE} -e $objfile $start_kernel_addr) @@ -97,86 +94,133 @@ __faddr2line() { local dir_prefix=$3 local print_warnings=$4 - local func=${func_addr%+*} + local sym_name=${func_addr%+*} local offset=${func_addr#*+} offset=${offset%/*} - local size= - [[ $func_addr =~ "/" ]] && size=${func_addr#*/} + local user_size= + [[ $func_addr =~ "/" ]] && user_size=${func_addr#*/} - if [[ -z $func ]] || [[ -z $offset ]] || [[ $func = $func_addr ]]; then + if [[ -z $sym_name ]] || [[ -z $offset ]] || [[ $sym_name = $func_addr ]]; then warn "bad func+offset $func_addr" DONE=1 return fi # Go through each of the object's symbols which match the func name. - # In rare cases there might be duplicates. - file_end=$(${SIZE} -Ax $objfile | awk '$1 == ".text" {print $2}') - while read symbol; do - local fields=($symbol) - local sym_base=0x${fields[0]} - local sym_type=${fields[1]} - local sym_end=${fields[3]} - - # calculate the size - local sym_size=$(($sym_end - $sym_base)) + # In rare cases there might be duplicates, in which case we print all + # matches. + while read line; do + local fields=($line) + local sym_addr=0x${fields[1]} + local sym_elf_size=${fields[2]} + local sym_sec=${fields[6]} + + # Get the section size: + local sec_size=$(${READELF} --section-headers --wide $objfile | + sed 's/\[ /\[/' | + ${AWK} -v sec=$sym_sec '$1 == "[" sec "]" { print "0x" $6; exit }') + + if [[ -z $sec_size ]]; then + warn "bad section size: section: $sym_sec" + DONE=1 + return + fi + + # Calculate the symbol size. + # + # Unfortunately we can't use the ELF size, because kallsyms + # also includes the padding bytes in its size calculation. For + # kallsyms, the size calculation is the distance between the + # symbol and the next symbol in a sorted list. + local sym_size + local cur_sym_addr + local found=0 + while read line; do + local fields=($line) + cur_sym_addr=0x${fields[1]} + local cur_sym_elf_size=${fields[2]} + local cur_sym_name=${fields[7]:-} + + if [[ $cur_sym_addr = $sym_addr ]] && + [[ $cur_sym_elf_size = $sym_elf_size ]] && + [[ $cur_sym_name = $sym_name ]]; then + found=1 + continue + fi + + if [[ $found = 1 ]]; then + sym_size=$(($cur_sym_addr - $sym_addr)) + [[ $sym_size -lt $sym_elf_size ]] && continue; + found=2 + break + fi + done < <(${READELF} --symbols --wide $objfile | ${AWK} -v sec=$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" + DONE=1 + return + fi + + # If nothing was found after the symbol, assume it's the last + # symbol in the section. + [[ $found = 1 ]] && sym_size=$(($sec_size - $sym_addr)) + if [[ -z $sym_size ]] || [[ $sym_size -le 0 ]]; then - warn "bad symbol size: base: $sym_base end: $sym_end" + warn "bad symbol size: sym_addr: $sym_addr cur_sym_addr: $cur_sym_addr" DONE=1 return fi + sym_size=0x$(printf %x $sym_size) - # calculate the address - local addr=$(($sym_base + $offset)) + # Calculate the section address from user-supplied offset: + local addr=$(($sym_addr + $offset)) if [[ -z $addr ]] || [[ $addr = 0 ]]; then - warn "bad address: $sym_base + $offset" + warn "bad address: $sym_addr + $offset" DONE=1 return fi addr=0x$(printf %x $addr) - # weed out non-function symbols - if [[ $sym_type != t ]] && [[ $sym_type != T ]]; then - [[ $print_warnings = 1 ]] && - echo "skipping $func address at $addr due to non-function symbol of type '$sym_type'" - continue - fi - - # if the user provided a size, make sure it matches the symbol's size - if [[ -n $size ]] && [[ $size -ne $sym_size ]]; then + # If the user provided a size, make sure it matches the symbol's size: + if [[ -n $user_size ]] && [[ $user_size -ne $sym_size ]]; then [[ $print_warnings = 1 ]] && - echo "skipping $func address at $addr due to size mismatch ($size != $sym_size)" + echo "skipping $sym_name address at $addr due to size mismatch ($user_size != $sym_size)" continue; fi - # make sure the provided offset is within the symbol's range + # Make sure the provided offset is within the symbol's range: if [[ $offset -gt $sym_size ]]; then [[ $print_warnings = 1 ]] && - echo "skipping $func address at $addr due to size mismatch ($offset > $sym_size)" + echo "skipping $sym_name address at $addr due to size mismatch ($offset > $sym_size)" continue fi - # separate multiple entries with a blank line + # In case of duplicates or multiple addresses specified on the + # cmdline, separate multiple entries with a blank line: [[ $FIRST = 0 ]] && echo FIRST=0 - # pass real address to addr2line - echo "$func+$offset/$sym_size:" - local file_lines=$(${ADDR2LINE} -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;") - [[ -z $file_lines ]] && return + echo "$sym_name+$offset/$sym_size:" + # Pass section address to addr2line and strip absolute paths + # from the output: + local output=$(${ADDR2LINE} -fpie $objfile $addr | sed "s; $dir_prefix\(\./\)*; ;") + [[ -z $output ]] && continue + + # Default output (non --list): if [[ $LIST = 0 ]]; then - echo "$file_lines" | while read -r line + echo "$output" | while read -r line do echo $line done DONE=1; - return + continue fi - # show each line with context - echo "$file_lines" | while read -r line + # For --list, show each line with its corresponding source code: + echo "$output" | while read -r line do echo echo $line @@ -184,12 +228,12 @@ __faddr2line() { n1=$[$n-5] n2=$[$n+5] f=$(echo $line | sed 's/.*at \(.\+\):.*/\1/g') - awk 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f + ${AWK} 'NR>=strtonum("'$n1'") && NR<=strtonum("'$n2'") { if (NR=='$n') printf(">%d<", NR); else printf(" %d ", NR); printf("\t%s\n", $0)}' $f done DONE=1 - done < <(${NM} -n $objfile | awk -v fn=$func -v end=$file_end '$3 == fn { found=1; line=$0; start=$1; next } found == 1 { found=0; print line, "0x"$1 } END {if (found == 1) print line, end; }') + done < <(${READELF} --symbols --wide $objfile | ${AWK} -v fn=$sym_name '$4 == "FUNC" && $8 == fn') } [[ $# -lt 2 ]] && usage diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index e036b0bbb42c..d7f26f02f142 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -108,16 +108,22 @@ objtool_link() local objtoolcmd; local objtoolopt; - if is_enabled CONFIG_STACK_VALIDATION && \ - ( is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT ); then + if ! is_enabled CONFIG_OBJTOOL; then + return; + fi - # Don't perform vmlinux validation unless explicitly requested, - # but run objtool on vmlinux.o now that we have an object file. - if is_enabled CONFIG_UNWINDER_ORC; then - objtoolcmd="orc generate" + if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then + + # For LTO and IBT, objtool doesn't run on individual + # translation units. Run everything on vmlinux instead. + + if is_enabled CONFIG_HAVE_JUMP_LABEL_HACK; then + objtoolopt="${objtoolopt} --hacks=jump_label" fi - objtoolopt="${objtoolopt} --lto" + if is_enabled CONFIG_HAVE_NOINSTR_HACK; then + objtoolopt="${objtoolopt} --hacks=noinstr" + fi if is_enabled CONFIG_X86_KERNEL_IBT; then objtoolopt="${objtoolopt} --ibt" @@ -126,34 +132,44 @@ objtool_link() if is_enabled CONFIG_FTRACE_MCOUNT_USE_OBJTOOL; then objtoolopt="${objtoolopt} --mcount" fi + + if is_enabled CONFIG_UNWINDER_ORC; then + objtoolopt="${objtoolopt} --orc" + fi + + if is_enabled CONFIG_RETPOLINE; then + objtoolopt="${objtoolopt} --retpoline" + fi + + if is_enabled CONFIG_SLS; then + objtoolopt="${objtoolopt} --sls" + fi + + if is_enabled CONFIG_STACK_VALIDATION; then + objtoolopt="${objtoolopt} --stackval" + fi + + if is_enabled CONFIG_HAVE_STATIC_CALL_INLINE; then + objtoolopt="${objtoolopt} --static-call" + fi + + objtoolopt="${objtoolopt} --uaccess" fi - if is_enabled CONFIG_VMLINUX_VALIDATION; then + if is_enabled CONFIG_NOINSTR_VALIDATION; then objtoolopt="${objtoolopt} --noinstr" fi if [ -n "${objtoolopt}" ]; then - if [ -z "${objtoolcmd}" ]; then - objtoolcmd="check" - fi - objtoolopt="${objtoolopt} --vmlinux" - if ! is_enabled CONFIG_FRAME_POINTER; then - objtoolopt="${objtoolopt} --no-fp" - fi + if is_enabled CONFIG_GCOV_KERNEL; then objtoolopt="${objtoolopt} --no-unreachable" fi - if is_enabled CONFIG_RETPOLINE; then - objtoolopt="${objtoolopt} --retpoline" - fi - objtoolopt="${objtoolopt} --uaccess" + objtoolopt="${objtoolopt} --link" - if is_enabled CONFIG_SLS; then - objtoolopt="${objtoolopt} --sls" - fi info OBJTOOL ${1} - tools/objtool/objtool ${objtoolcmd} ${objtoolopt} ${1} + tools/objtool/objtool ${objtoolopt} ${1} fi } diff --git a/scripts/objdump-func b/scripts/objdump-func new file mode 100755 index 000000000000..4eb463dd9f52 --- /dev/null +++ b/scripts/objdump-func @@ -0,0 +1,29 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Disassemble a single function. +# +# usage: objdump-func <file> <func> + +set -o errexit +set -o nounset + +OBJDUMP="${CROSS_COMPILE:-}objdump" + +command -v gawk >/dev/null 2>&1 || die "gawk isn't installed" + +usage() { + echo "usage: objdump-func <file> <func>" >&2 + exit 1 +} + +[[ $# -lt 2 ]] && usage + +OBJ=$1; shift +FUNC=$1; shift + +# Secret feature to allow adding extra objdump args at the end +EXTRA_ARGS=$@ + +# Note this also matches compiler-added suffixes like ".cold", etc +${OBJDUMP} -wdr $EXTRA_ARGS $OBJ | gawk -M -v f=$FUNC '/^$/ { P=0; } $0 ~ "<" f "(\\..*)?>:" { P=1; O=strtonum("0x" $1); } { if (P) { o=strtonum("0x" $1); printf("%04x ", o-O); print $0; } }' diff --git a/scripts/package/builddeb b/scripts/package/builddeb index 91a502bb97e8..67cd420dcf89 100755 --- a/scripts/package/builddeb +++ b/scripts/package/builddeb @@ -67,7 +67,7 @@ deploy_kernel_headers () { ) > debian/hdrsrcfiles { - if is_enabled CONFIG_STACK_VALIDATION; then + if is_enabled CONFIG_OBJTOOL; then echo tools/objtool/objtool fi diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h index b9c1474a571e..6491fa8fba6d 100644 --- a/tools/include/linux/objtool.h +++ b/tools/include/linux/objtool.h @@ -38,7 +38,7 @@ struct unwind_hint { #define UNWIND_HINT_TYPE_REGS_PARTIAL 2 #define UNWIND_HINT_TYPE_FUNC 3 -#ifdef CONFIG_STACK_VALIDATION +#ifdef CONFIG_OBJTOOL #include <asm/asm.h> @@ -159,7 +159,7 @@ struct unwind_hint { #endif /* __ASSEMBLY__ */ -#else /* !CONFIG_STACK_VALIDATION */ +#else /* !CONFIG_OBJTOOL */ #ifndef __ASSEMBLY__ @@ -181,6 +181,6 @@ struct unwind_hint { .endm #endif -#endif /* CONFIG_STACK_VALIDATION */ +#endif /* CONFIG_OBJTOOL */ #endif /* _LINUX_OBJTOOL_H */ diff --git a/tools/lib/subcmd/parse-options.c b/tools/lib/subcmd/parse-options.c index 39ebf6192016..9fa75943f2ed 100644 --- a/tools/lib/subcmd/parse-options.c +++ b/tools/lib/subcmd/parse-options.c @@ -806,9 +806,9 @@ static int option__cmp(const void *va, const void *vb) static struct option *options__order(const struct option *opts) { - int nr_opts = 0, len; + int nr_opts = 0, nr_group = 0, len; const struct option *o = opts; - struct option *ordered; + struct option *opt, *ordered, *group; for (o = opts; o->type != OPTION_END; o++) ++nr_opts; @@ -819,7 +819,18 @@ static struct option *options__order(const struct option *opts) goto out; memcpy(ordered, opts, len); - qsort(ordered, nr_opts, sizeof(*o), option__cmp); + /* sort each option group individually */ + for (opt = group = ordered; opt->type != OPTION_END; opt++) { + if (opt->type == OPTION_GROUP) { + qsort(group, nr_group, sizeof(*opt), option__cmp); + group = opt + 1; + nr_group = 0; + continue; + } + nr_group++; + } + qsort(group, nr_group, sizeof(*opt), option__cmp); + out: return ordered; } diff --git a/tools/objtool/Build b/tools/objtool/Build index b7222d5cc7bc..33f2ee5a46d3 100644 --- a/tools/objtool/Build +++ b/tools/objtool/Build @@ -2,17 +2,15 @@ objtool-y += arch/$(SRCARCH)/ objtool-y += weak.o -objtool-$(SUBCMD_CHECK) += check.o -objtool-$(SUBCMD_CHECK) += special.o -objtool-$(SUBCMD_ORC) += check.o -objtool-$(SUBCMD_ORC) += orc_gen.o -objtool-$(SUBCMD_ORC) += orc_dump.o - +objtool-y += check.o +objtool-y += special.o objtool-y += builtin-check.o -objtool-y += builtin-orc.o objtool-y += elf.o objtool-y += objtool.o +objtool-$(BUILD_ORC) += orc_gen.o +objtool-$(BUILD_ORC) += orc_dump.o + objtool-y += libstring.o objtool-y += libctype.o objtool-y += str_error_r.o diff --git a/tools/objtool/Documentation/stack-validation.txt b/tools/objtool/Documentation/objtool.txt index 30f38fdc0d56..8a671902a187 100644 --- a/tools/objtool/Documentation/stack-validation.txt +++ b/tools/objtool/Documentation/objtool.txt @@ -1,15 +1,103 @@ -Compile-time stack metadata validation -====================================== +Objtool +======= +The kernel CONFIG_OBJTOOL option enables a host tool named 'objtool' +which runs at compile time. It can do various validations and +transformations on .o files. -Overview +Objtool has become an integral part of the x86-64 kernel toolchain. The +kernel depends on it for a variety of security and performance features +(and other types of features as well). + + +Features -------- -The kernel CONFIG_STACK_VALIDATION option enables a host tool named -objtool which runs at compile time. It has a "check" subcommand which -analyzes every .o file and ensures the validity of its stack metadata. -It enforces a set of rules on asm code and C inline assembly code so -that stack traces can be reliable. +Objtool has the following features: + +- Stack unwinding metadata validation -- useful for helping to ensure + stack traces are reliable for live patching + +- ORC unwinder metadata generation -- a faster and more precise + alternative to frame pointer based unwinding + +- Retpoline validation -- ensures that all indirect calls go through + retpoline thunks, for Spectre v2 mitigations + +- Retpoline call site annotation -- annotates all retpoline thunk call + sites, enabling the kernel to patch them inline, to prevent "thunk + funneling" for both security and performance reasons + +- Non-instrumentation validation -- validates non-instrumentable + ("noinstr") code rules, preventing instrumentation in low-level C + entry code + +- Static call annotation -- annotates static call sites, enabling the + kernel to implement inline static calls, a faster alternative to some + indirect branches + +- Uaccess validation -- validates uaccess rules for a proper + implementation of Supervisor Mode Access Protection (SMAP) + +- Straight Line Speculation validation -- validates certain SLS + mitigations + +- Indirect Branch Tracking validation -- validates Intel CET IBT rules + to ensure that all functions referenced by function pointers have + corresponding ENDBR instructions + +- Indirect Branch Tracking annotation -- annotates unused ENDBR + instruction sites, enabling the kernel to "seal" them (replace them + with NOPs) to further harden IBT + +- Function entry annotation -- annotates function entries, enabling + kernel function tracing + +- Other toolchain hacks which will go unmentioned at this time... + +Each feature can be enabled individually or in combination using the +objtool cmdline. + + +Objects +------- + +Typically, objtool runs on every translation unit (TU, aka ".o file") in +the kernel. If a TU is part of a kernel module, the '--module' option +is added. + +However: + +- If noinstr validation is enabled, it also runs on vmlinux.o, with all + options removed and '--noinstr' added. + +- If IBT or LTO is enabled, it doesn't run on TUs at all. Instead it + runs on vmlinux.o and linked modules, with all options. + +In summary: + + A) Legacy mode: + TU: objtool [--module] <options> + vmlinux: N/A + module: N/A + + B) CONFIG_NOINSTR_VALIDATION=y && !(CONFIG_X86_KERNEL_IBT=y || CONFIG_LTO=y): + TU: objtool [--module] <options> // no --noinstr + vmlinux: objtool --noinstr // other options removed + module: N/A + + C) CONFIG_X86_KERNEL_IBT=y || CONFIG_LTO=y: + TU: N/A + vmlinux: objtool --noinstr <options> + module: objtool --module --noinstr <options> + + +Stack validation +---------------- + +Objtool's stack validation feature analyzes every .o file and ensures +the validity of its stack metadata. It enforces a set of rules on asm +code and C inline assembly code so that stack traces can be reliable. For each function, it recursively follows all possible code paths and validates the correct frame pointer state at each instruction. @@ -20,14 +108,6 @@ alternative execution paths to a given instruction (or set of instructions). Similarly, it knows how to follow switch statements, for which gcc sometimes uses jump tables. -(Objtool also has an 'orc generate' subcommand which generates debuginfo -for the ORC unwinder. See Documentation/x86/orc-unwinder.rst in the -kernel tree for more details.) - - -Why do we need stack metadata validation? ------------------------------------------ - Here are some of the benefits of validating stack metadata: a) More reliable stack traces for frame pointer enabled kernels @@ -113,9 +193,6 @@ c) Higher live patching compatibility rate For more details, see the livepatch documentation in the Linux kernel source tree at Documentation/livepatch/livepatch.rst. -Rules ------ - To achieve the validation, objtool enforces the following rules: 1. Each callable function must be annotated as such with the ELF @@ -177,7 +254,8 @@ Another possible cause for errors in C code is if the Makefile removes -fno-omit-frame-pointer or adds -fomit-frame-pointer to the gcc options. Here are some examples of common warnings reported by objtool, what -they mean, and suggestions for how to fix them. +they mean, and suggestions for how to fix them. When in doubt, ping +the objtool maintainers. 1. file.o: warning: objtool: func()+0x128: call without frame pointer save/setup @@ -358,3 +436,7 @@ ignore it: OBJECT_FILES_NON_STANDARD := y to the Makefile. + +NOTE: OBJECT_FILES_NON_STANDARD doesn't work for link time validation of +vmlinux.o or a linked module. So it should only be used for files which +aren't linked into vmlinux or a module. diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile index 0dbd397f319d..e66d717c245d 100644 --- a/tools/objtool/Makefile +++ b/tools/objtool/Makefile @@ -39,15 +39,13 @@ CFLAGS += $(if $(elfshdr),,-DLIBELF_USE_DEPRECATED) AWK = awk -SUBCMD_CHECK := n -SUBCMD_ORC := n +BUILD_ORC := n ifeq ($(SRCARCH),x86) - SUBCMD_CHECK := y - SUBCMD_ORC := y + BUILD_ORC := y endif -export SUBCMD_CHECK SUBCMD_ORC +export BUILD_ORC export srctree OUTPUT CFLAGS SRCARCH AWK include $(srctree)/tools/build/Makefile.include @@ -65,7 +63,7 @@ $(LIBSUBCMD): fixdep FORCE clean: $(call QUIET_CLEAN, objtool) $(RM) $(OBJTOOL) $(Q)find $(OUTPUT) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete - $(Q)$(RM) $(OUTPUT)arch/x86/inat-tables.c $(OUTPUT)fixdep + $(Q)$(RM) $(OUTPUT)arch/x86/lib/inat-tables.c $(OUTPUT)fixdep $(LIBSUBCMD) FORCE: diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 943cb41cddf7..8b990a52aada 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -581,7 +581,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec break; case 0xc7: /* mov imm, r/m */ - if (!noinstr) + if (!opts.noinstr) break; if (insn.length == 3+4+4 && !strncmp(sec->name, ".init.text", 10)) { diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c index e707d9bcd161..7c97b7391279 100644 --- a/tools/objtool/arch/x86/special.c +++ b/tools/objtool/arch/x86/special.c @@ -20,7 +20,7 @@ void arch_handle_alternative(unsigned short feature, struct special_alt *alt) * find paths that see the STAC but take the NOP instead of * CLAC and the other way around. */ - if (uaccess) + if (opts.uaccess) alt->skip_orig = true; else alt->skip_alt = true; diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index fc6975ab8b06..f4c3a5091737 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -3,28 +3,21 @@ * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com> */ -/* - * objtool check: - * - * This command analyzes every .o file and ensures the validity of its stack - * trace metadata. It enforces a set of rules on asm code and C inline - * assembly code so that stack traces can be reliable. - * - * For more information, see tools/objtool/Documentation/stack-validation.txt. - */ - #include <subcmd/parse-options.h> #include <string.h> #include <stdlib.h> #include <objtool/builtin.h> #include <objtool/objtool.h> -bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, - lto, vmlinux, mcount, noinstr, backup, sls, dryrun, - ibt; +#define ERROR(format, ...) \ + fprintf(stderr, \ + "error: objtool: " format "\n", \ + ##__VA_ARGS__) + +struct opts opts; static const char * const check_usage[] = { - "objtool check [<options>] file.o", + "objtool <actions> [<options>] file.o", NULL, }; @@ -33,22 +26,64 @@ static const char * const env_usage[] = { NULL, }; +static int parse_dump(const struct option *opt, const char *str, int unset) +{ + if (!str || !strcmp(str, "orc")) { + opts.dump_orc = true; + return 0; + } + + return -1; +} + +static int parse_hacks(const struct option *opt, const char *str, int unset) +{ + bool found = false; + + /* + * Use strstr() as a lazy method of checking for comma-separated + * options. + * + * No string provided == enable all options. + */ + + if (!str || strstr(str, "jump_label")) { + opts.hack_jump_label = true; + found = true; + } + + if (!str || strstr(str, "noinstr")) { + opts.hack_noinstr = true; + found = true; + } + + return found ? 0 : -1; +} + const struct option check_options[] = { - OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"), - OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"), - OPT_BOOLEAN('r', "retpoline", &retpoline, "Validate retpoline assumptions"), - OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"), - OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"), - OPT_BOOLEAN('a', "uaccess", &uaccess, "enable uaccess checking"), - OPT_BOOLEAN('s', "stats", &stats, "print statistics"), - OPT_BOOLEAN(0, "lto", <o, "whole-archive like runs"), - OPT_BOOLEAN('n', "noinstr", &noinstr, "noinstr validation for vmlinux.o"), - OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"), - OPT_BOOLEAN('M', "mcount", &mcount, "generate __mcount_loc"), - OPT_BOOLEAN('B', "backup", &backup, "create .orig files before modification"), - OPT_BOOLEAN('S', "sls", &sls, "validate straight-line-speculation"), - OPT_BOOLEAN(0, "dry-run", &dryrun, "don't write the modifications"), - OPT_BOOLEAN(0, "ibt", &ibt, "validate ENDBR placement"), + OPT_GROUP("Actions:"), + OPT_CALLBACK_OPTARG('h', "hacks", NULL, NULL, "jump_label,noinstr", "patch toolchain bugs/limitations", parse_hacks), + OPT_BOOLEAN('i', "ibt", &opts.ibt, "validate and annotate IBT"), + OPT_BOOLEAN('m', "mcount", &opts.mcount, "annotate mcount/fentry calls for ftrace"), + OPT_BOOLEAN('n', "noinstr", &opts.noinstr, "validate noinstr rules"), + OPT_BOOLEAN('o', "orc", &opts.orc, "generate ORC metadata"), + OPT_BOOLEAN('r', "retpoline", &opts.retpoline, "validate and annotate retpoline usage"), + OPT_BOOLEAN('l', "sls", &opts.sls, "validate straight-line-speculation mitigations"), + OPT_BOOLEAN('s', "stackval", &opts.stackval, "validate frame pointer rules"), + OPT_BOOLEAN('t', "static-call", &opts.static_call, "annotate static calls"), + OPT_BOOLEAN('u', "uaccess", &opts.uaccess, "validate uaccess rules for SMAP"), + OPT_CALLBACK_OPTARG(0, "dump", NULL, NULL, "orc", "dump metadata", parse_dump), + + OPT_GROUP("Options:"), + OPT_BOOLEAN(0, "backtrace", &opts.backtrace, "unwind on error"), + OPT_BOOLEAN(0, "backup", &opts.backup, "create .orig files before modification"), + OPT_BOOLEAN(0, "dry-run", &opts.dryrun, "don't write modifications"), + OPT_BOOLEAN(0, "link", &opts.link, "object is a linked object"), + OPT_BOOLEAN(0, "module", &opts.module, "object is part of a kernel module"), + OPT_BOOLEAN(0, "no-unreachable", &opts.no_unreachable, "skip 'unreachable instruction' warnings"), + OPT_BOOLEAN(0, "sec-address", &opts.sec_address, "print section addresses in warnings"), + OPT_BOOLEAN(0, "stats", &opts.stats, "print statistics"), + OPT_END(), }; @@ -79,7 +114,59 @@ int cmd_parse_options(int argc, const char **argv, const char * const usage[]) return argc; } -int cmd_check(int argc, const char **argv) +static bool opts_valid(void) +{ + if (opts.hack_jump_label || + opts.hack_noinstr || + opts.ibt || + opts.mcount || + opts.noinstr || + opts.orc || + opts.retpoline || + opts.sls || + opts.stackval || + opts.static_call || + opts.uaccess) { + if (opts.dump_orc) { + ERROR("--dump can't be combined with other options"); + return false; + } + + return true; + } + + if (opts.dump_orc) + return true; + + ERROR("At least one command required"); + return false; +} + +static bool link_opts_valid(struct objtool_file *file) +{ + if (opts.link) + return true; + + if (has_multiple_files(file->elf)) { + ERROR("Linked object detected, forcing --link"); + opts.link = true; + return true; + } + + if (opts.noinstr) { + ERROR("--noinstr requires --link"); + return false; + } + + if (opts.ibt) { + ERROR("--ibt requires --link"); + return false; + } + + return true; +} + +int objtool_run(int argc, const char **argv) { const char *objname; struct objtool_file *file; @@ -88,10 +175,19 @@ int cmd_check(int argc, const char **argv) argc = cmd_parse_options(argc, argv, check_usage); objname = argv[0]; + if (!opts_valid()) + return 1; + + if (opts.dump_orc) + return orc_dump(objname); + file = objtool_open_read(objname); if (!file) return 1; + if (!link_opts_valid(file)) + return 1; + ret = check(file); if (ret) return ret; diff --git a/tools/objtool/builtin-orc.c b/tools/objtool/builtin-orc.c deleted file mode 100644 index 17f8b9307738..000000000000 --- a/tools/objtool/builtin-orc.c +++ /dev/null @@ -1,73 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com> - */ - -/* - * objtool orc: - * - * This command analyzes a .o file and adds .orc_unwind and .orc_unwind_ip - * sections to it, which is used by the in-kernel ORC unwinder. - * - * This command is a superset of "objtool check". - */ - -#include <string.h> -#include <objtool/builtin.h> -#include <objtool/objtool.h> - -static const char *orc_usage[] = { - "objtool orc generate [<options>] file.o", - "objtool orc dump file.o", - NULL, -}; - -int cmd_orc(int argc, const char **argv) -{ - const char *objname; - - argc--; argv++; - if (argc <= 0) - usage_with_options(orc_usage, check_options); - - if (!strncmp(argv[0], "gen", 3)) { - struct objtool_file *file; - int ret; - - argc = cmd_parse_options(argc, argv, orc_usage); - objname = argv[0]; - - file = objtool_open_read(objname); - if (!file) - return 1; - - ret = check(file); - if (ret) - return ret; - - if (list_empty(&file->insn_list)) - return 0; - - ret = orc_create(file); - if (ret) - return ret; - - if (!file->elf->changed) - return 0; - - return elf_write(file->elf); - } - - if (!strcmp(argv[0], "dump")) { - if (argc != 2) - usage_with_options(orc_usage, check_options); - - objname = argv[1]; - - return orc_dump(objname); - } - - usage_with_options(orc_usage, check_options); - - return 0; -} diff --git a/tools/objtool/check.c b/tools/objtool/check.c index ca5b74603008..190b2f6e360a 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -5,6 +5,7 @@ #include <string.h> #include <stdlib.h> +#include <inttypes.h> #include <sys/mman.h> #include <arch/elf.h> @@ -263,7 +264,8 @@ static void init_cfi_state(struct cfi_state *cfi) cfi->drap_offset = -1; } -static void init_insn_state(struct insn_state *state, struct section *sec) +static void init_insn_state(struct objtool_file *file, struct insn_state *state, + struct section *sec) { memset(state, 0, sizeof(*state)); init_cfi_state(&state->cfi); @@ -273,7 +275,7 @@ static void init_insn_state(struct insn_state *state, struct section *sec) * not correctly determine insn->call_dest->sec (external symbols do * not have a section). */ - if (vmlinux && noinstr && sec) + if (opts.link && opts.noinstr && sec) state->noinstr = sec->noinstr; } @@ -339,7 +341,7 @@ static void *cfi_hash_alloc(unsigned long size) if (cfi_hash == (void *)-1L) { WARN("mmap fail cfi_hash"); cfi_hash = NULL; - } else if (stats) { + } else if (opts.stats) { printf("cfi_bits: %d\n", cfi_bits); } @@ -434,7 +436,7 @@ static int decode_instructions(struct objtool_file *file) } } - if (stats) + if (opts.stats) printf("nr_insns: %lu\n", nr_insns); return 0; @@ -497,7 +499,7 @@ static int init_pv_ops(struct objtool_file *file) struct symbol *sym; int idx, nr; - if (!noinstr) + if (!opts.noinstr) return 0; file->pv_ops = NULL; @@ -560,12 +562,12 @@ static int add_dead_ends(struct objtool_file *file) else if (reloc->addend == reloc->sym->sec->sh.sh_size) { insn = find_last_insn(file, reloc->sym->sec); if (!insn) { - WARN("can't find unreachable insn at %s+0x%lx", + WARN("can't find unreachable insn at %s+0x%" PRIx64, reloc->sym->sec->name, reloc->addend); return -1; } } else { - WARN("can't find unreachable insn at %s+0x%lx", + WARN("can't find unreachable insn at %s+0x%" PRIx64, reloc->sym->sec->name, reloc->addend); return -1; } @@ -595,12 +597,12 @@ reachable: else if (reloc->addend == reloc->sym->sec->sh.sh_size) { insn = find_last_insn(file, reloc->sym->sec); if (!insn) { - WARN("can't find reachable insn at %s+0x%lx", + WARN("can't find reachable insn at %s+0x%" PRIx64, reloc->sym->sec->name, reloc->addend); return -1; } } else { - WARN("can't find reachable insn at %s+0x%lx", + WARN("can't find reachable insn at %s+0x%" PRIx64, reloc->sym->sec->name, reloc->addend); return -1; } @@ -668,7 +670,7 @@ static int create_static_call_sections(struct objtool_file *file) key_sym = find_symbol_by_name(file->elf, tmp); if (!key_sym) { - if (!module) { + if (!opts.module) { WARN("static_call: can't find static_call_key symbol: %s", tmp); return -1; } @@ -761,7 +763,7 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file) list_for_each_entry(insn, &file->endbr_list, call_node) idx++; - if (stats) { + if (opts.stats) { printf("ibt: ENDBR at function start: %d\n", file->nr_endbr); printf("ibt: ENDBR inside functions: %d\n", file->nr_endbr_int); printf("ibt: superfluous ENDBR: %d\n", idx); @@ -1028,7 +1030,7 @@ static void add_uaccess_safe(struct objtool_file *file) struct symbol *func; const char **name; - if (!uaccess) + if (!opts.uaccess) return; for (name = uaccess_safe_builtin; *name; name++) { @@ -1144,7 +1146,7 @@ static void annotate_call_site(struct objtool_file *file, * attribute so they need a little help, NOP out any such calls from * noinstr text. */ - if (insn->sec->noinstr && sym->profiling_func) { + if (opts.hack_noinstr && insn->sec->noinstr && sym->profiling_func) { if (reloc) { reloc->type = R_NONE; elf_write_reloc(file->elf, reloc); @@ -1170,7 +1172,7 @@ static void annotate_call_site(struct objtool_file *file, return; } - if (mcount && sym->fentry) { + if (opts.mcount && sym->fentry) { if (sibling) WARN_FUNC("Tail call to __fentry__ !?!?", insn->sec, insn->offset); @@ -1256,7 +1258,7 @@ static bool is_first_func_insn(struct objtool_file *file, struct instruction *in if (insn->offset == insn->func->offset) return true; - if (ibt) { + if (opts.ibt) { struct instruction *prev = prev_insn_same_sym(file, insn); if (prev && prev->type == INSN_ENDBR && @@ -1592,7 +1594,7 @@ static int handle_jump_alt(struct objtool_file *file, return -1; } - if (special_alt->key_addend & 2) { + if (opts.hack_jump_label && special_alt->key_addend & 2) { struct reloc *reloc = insn_reloc(file, orig_insn); if (reloc) { @@ -1699,7 +1701,7 @@ static int add_special_section_alts(struct objtool_file *file) free(special_alt); } - if (stats) { + if (opts.stats) { printf("jl\\\tNOP\tJMP\n"); printf("short:\t%ld\t%ld\n", file->jl_nop_short, file->jl_short); printf("long:\t%ld\t%ld\n", file->jl_nop_long, file->jl_long); @@ -1945,7 +1947,7 @@ static int read_unwind_hints(struct objtool_file *file) insn->hint = true; - if (ibt && hint->type == UNWIND_HINT_TYPE_REGS_PARTIAL) { + if (opts.ibt && hint->type == UNWIND_HINT_TYPE_REGS_PARTIAL) { struct symbol *sym = find_symbol_by_offset(insn->sec, insn->offset); if (sym && sym->bind == STB_GLOBAL && @@ -2806,7 +2808,7 @@ static int update_cfi_state(struct instruction *insn, } /* detect when asm code uses rbp as a scratch register */ - if (!no_fp && insn->func && op->src.reg == CFI_BP && + if (opts.stackval && insn->func && op->src.reg == CFI_BP && cfa->base != CFI_BP) cfi->bp_scratch = true; break; @@ -3182,114 +3184,6 @@ static struct instruction *next_insn_to_validate(struct objtool_file *file, return next_insn_same_sec(file, insn); } -static struct instruction * -validate_ibt_reloc(struct objtool_file *file, struct reloc *reloc) -{ - struct instruction *dest; - struct section *sec; - unsigned long off; - - sec = reloc->sym->sec; - off = reloc->sym->offset; - - if ((reloc->sec->base->sh.sh_flags & SHF_EXECINSTR) && - (reloc->type == R_X86_64_PC32 || reloc->type == R_X86_64_PLT32)) - off += arch_dest_reloc_offset(reloc->addend); - else - off += reloc->addend; - - dest = find_insn(file, sec, off); - if (!dest) - return NULL; - - if (dest->type == INSN_ENDBR) { - if (!list_empty(&dest->call_node)) - list_del_init(&dest->call_node); - - return NULL; - } - - if (reloc->sym->static_call_tramp) - return NULL; - - return dest; -} - -static void warn_noendbr(const char *msg, struct section *sec, unsigned long offset, - struct instruction *dest) -{ - WARN_FUNC("%srelocation to !ENDBR: %s", sec, offset, msg, - offstr(dest->sec, dest->offset)); -} - -static void validate_ibt_dest(struct objtool_file *file, struct instruction *insn, - struct instruction *dest) -{ - if (dest->func && dest->func == insn->func) { - /* - * Anything from->to self is either _THIS_IP_ or IRET-to-self. - * - * There is no sane way to annotate _THIS_IP_ since the compiler treats the - * relocation as a constant and is happy to fold in offsets, skewing any - * annotation we do, leading to vast amounts of false-positives. - * - * There's also compiler generated _THIS_IP_ through KCOV and - * such which we have no hope of annotating. - * - * As such, blanket accept self-references without issue. - */ - return; - } - - if (dest->noendbr) - return; - - warn_noendbr("", insn->sec, insn->offset, dest); -} - -static void validate_ibt_insn(struct objtool_file *file, struct instruction *insn) -{ - struct instruction *dest; - struct reloc *reloc; - - 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: - /* - * We're looking for code references setting up indirect code - * flow. As such, ignore direct code flow and the actual - * dynamic branches. - */ - return; - - case INSN_NOP: - /* - * handle_group_alt() will create INSN_NOP instruction that - * don't belong to any section, ignore all NOP since they won't - * carry a (useful) relocation anyway. - */ - return; - - default: - break; - } - - for (reloc = insn_reloc(file, insn); - reloc; - reloc = find_reloc_by_dest_range(file->elf, insn->sec, - reloc->offset + 1, - (insn->offset + insn->len) - (reloc->offset + 1))) { - dest = validate_ibt_reloc(file, reloc); - if (dest) - validate_ibt_dest(file, insn, dest); - } -} - /* * Follow the branch starting at the given instruction, and recursively follow * any other branches (jumps). Meanwhile, track the frame pointer state at @@ -3363,7 +3257,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, ret = validate_branch(file, func, alt->insn, state); if (ret) { - if (backtrace) + if (opts.backtrace) BT_FUNC("(alt)", insn); return ret; } @@ -3379,11 +3273,6 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, switch (insn->type) { case INSN_RETURN: - if (sls && !insn->retpoline_safe && - next_insn && next_insn->type != INSN_TRAP) { - WARN_FUNC("missing int3 after ret", - insn->sec, insn->offset); - } return validate_return(func, insn, &state); case INSN_CALL: @@ -3392,7 +3281,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, if (ret) return ret; - if (!no_fp && func && !is_fentry_call(insn) && + if (opts.stackval && func && !is_fentry_call(insn) && !has_valid_stack_frame(&state)) { WARN_FUNC("call without frame pointer save/setup", sec, insn->offset); @@ -3415,7 +3304,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, ret = validate_branch(file, func, insn->jump_dest, state); if (ret) { - if (backtrace) + if (opts.backtrace) BT_FUNC("(branch)", insn); return ret; } @@ -3427,13 +3316,6 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, break; case INSN_JUMP_DYNAMIC: - if (sls && !insn->retpoline_safe && - next_insn && next_insn->type != INSN_TRAP) { - WARN_FUNC("missing int3 after indirect jump", - insn->sec, insn->offset); - } - - /* fallthrough */ case INSN_JUMP_DYNAMIC_CONDITIONAL: if (is_sibling_call(insn)) { ret = validate_sibling_call(file, insn, &state); @@ -3499,9 +3381,6 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, break; } - if (ibt) - validate_ibt_insn(file, insn); - if (insn->dead_end) return 0; @@ -3528,7 +3407,7 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec) if (!file->hints) return 0; - init_insn_state(&state, sec); + init_insn_state(file, &state, sec); if (sec) { insn = find_insn(file, sec, 0); @@ -3541,7 +3420,7 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec) while (&insn->list != &file->insn_list && (!sec || insn->sec == sec)) { if (insn->hint && !insn->visited && !insn->ignore) { ret = validate_branch(file, insn->func, insn, state); - if (ret && backtrace) + if (ret && opts.backtrace) BT_FUNC("<=== (hint)", insn); warnings += ret; } @@ -3571,7 +3450,7 @@ static int validate_retpoline(struct objtool_file *file) * loaded late, they very much do need retpoline in their * .init.text */ - if (!strcmp(insn->sec->name, ".init.text") && !module) + if (!strcmp(insn->sec->name, ".init.text") && !opts.module) continue; WARN_FUNC("indirect %s found in RETPOLINE build", @@ -3614,14 +3493,14 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio return true; /* - * Whole archive runs might encounder dead code from weak symbols. + * Whole archive runs might encounter dead code from weak symbols. * This is where the linker will have dropped the weak symbol in * favour of a regular symbol, but leaves the code in place. * * In this case we'll find a piece of code (whole function) that is not * covered by a !section symbol. Ignore them. */ - if (!insn->func && lto) { + if (opts.link && !insn->func) { int size = find_symbol_hole_containing(insn->sec, insn->offset); unsigned long end = insn->offset + size; @@ -3728,7 +3607,7 @@ static int validate_symbol(struct objtool_file *file, struct section *sec, state->uaccess = sym->uaccess_safe; ret = validate_branch(file, insn->func, insn, *state); - if (ret && backtrace) + if (ret && opts.backtrace) BT_FUNC("<=== (sym)", insn); return ret; } @@ -3743,7 +3622,7 @@ static int validate_section(struct objtool_file *file, struct section *sec) if (func->type != STT_FUNC) continue; - init_insn_state(&state, sec); + init_insn_state(file, &state, sec); set_func_state(&state.cfi); warnings += validate_symbol(file, sec, func, &state); @@ -3752,7 +3631,7 @@ static int validate_section(struct objtool_file *file, struct section *sec) return warnings; } -static int validate_vmlinux_functions(struct objtool_file *file) +static int validate_noinstr_sections(struct objtool_file *file) { struct section *sec; int warnings = 0; @@ -3787,48 +3666,208 @@ static int validate_functions(struct objtool_file *file) return warnings; } +static void mark_endbr_used(struct instruction *insn) +{ + if (!list_empty(&insn->call_node)) + list_del_init(&insn->call_node); +} + +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; + default: + break; + } + + for (reloc = insn_reloc(file, insn); + reloc; + reloc = find_reloc_by_dest_range(file->elf, insn->sec, + reloc->offset + 1, + (insn->offset + insn->len) - (reloc->offset + 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 == R_X86_64_PC32 || reloc->type == R_X86_64_PLT32) + off += arch_dest_reloc_offset(reloc->addend); + else + off += reloc->addend; + + dest = find_insn(file, reloc->sym->sec, off); + if (!dest) + continue; + + if (dest->type == INSN_ENDBR) { + mark_endbr_used(dest); + continue; + } + + if (dest->func && dest->func == insn->func) { + /* + * Anything from->to self is either _THIS_IP_ or + * IRET-to-self. + * + * There is no sane way to annotate _THIS_IP_ since the + * compiler treats the relocation as a constant and is + * happy to fold in offsets, skewing any annotation we + * do, leading to vast amounts of false-positives. + * + * There's also compiler generated _THIS_IP_ through + * KCOV and such which we have no hope of annotating. + * + * As such, blanket accept self-references without + * issue. + */ + continue; + } + + if (dest->noendbr) + continue; + + WARN_FUNC("relocation to !ENDBR: %s", + insn->sec, insn->offset, + offstr(dest->sec, dest->offset)); + + warnings++; + } + + return warnings; +} + +static int validate_ibt_data_reloc(struct objtool_file *file, + struct reloc *reloc) +{ + struct instruction *dest; + + dest = find_insn(file, reloc->sym->sec, + reloc->sym->offset + reloc->addend); + if (!dest) + return 0; + + if (dest->type == INSN_ENDBR) { + mark_endbr_used(dest); + return 0; + } + + if (dest->noendbr) + return 0; + + WARN_FUNC("data relocation to !ENDBR: %s", + reloc->sec->base, reloc->offset, + offstr(dest->sec, dest->offset)); + + return 1; +} + +/* + * Validate IBT rules and remove used ENDBR instructions from the seal list. + * Unused ENDBR instructions will be annotated for sealing (i.e., replaced with + * NOPs) later, in create_ibt_endbr_seal_sections(). + */ static int validate_ibt(struct objtool_file *file) { struct section *sec; struct reloc *reloc; + struct instruction *insn; + int warnings = 0; + + for_each_insn(file, insn) + warnings += validate_ibt_insn(file, insn); for_each_sec(file, sec) { - bool is_data; - /* already done in validate_branch() */ + /* Already done by validate_ibt_insn() */ if (sec->sh.sh_flags & SHF_EXECINSTR) continue; if (!sec->reloc) continue; - if (!strncmp(sec->name, ".orc", 4)) + /* + * These sections can reference text addresses, but not with + * the intent to indirect branch to them. + */ + if (!strncmp(sec->name, ".discard", 8) || + !strncmp(sec->name, ".debug", 6) || + !strcmp(sec->name, ".altinstructions") || + !strcmp(sec->name, ".ibt_endbr_seal") || + !strcmp(sec->name, ".orc_unwind_ip") || + !strcmp(sec->name, ".parainstructions") || + !strcmp(sec->name, ".retpoline_sites") || + !strcmp(sec->name, ".smp_locks") || + !strcmp(sec->name, ".static_call_sites") || + !strcmp(sec->name, "_error_injection_whitelist") || + !strcmp(sec->name, "_kprobe_blacklist") || + !strcmp(sec->name, "__bug_table") || + !strcmp(sec->name, "__ex_table") || + !strcmp(sec->name, "__jump_table") || + !strcmp(sec->name, "__mcount_loc") || + !strcmp(sec->name, "__tracepoints")) continue; - if (!strncmp(sec->name, ".discard", 8)) - continue; + list_for_each_entry(reloc, &sec->reloc->reloc_list, list) + warnings += validate_ibt_data_reloc(file, reloc); + } - if (!strncmp(sec->name, ".debug", 6)) - continue; + return warnings; +} - if (!strcmp(sec->name, "_error_injection_whitelist")) - continue; +static int validate_sls(struct objtool_file *file) +{ + struct instruction *insn, *next_insn; + int warnings = 0; - if (!strcmp(sec->name, "_kprobe_blacklist")) - continue; + for_each_insn(file, insn) { + next_insn = next_insn_same_sec(file, insn); - is_data = strstr(sec->name, ".data") || strstr(sec->name, ".rodata"); + if (insn->retpoline_safe) + continue; - list_for_each_entry(reloc, &sec->reloc->reloc_list, list) { - struct instruction *dest; + switch (insn->type) { + case INSN_RETURN: + if (!next_insn || next_insn->type != INSN_TRAP) { + WARN_FUNC("missing int3 after ret", + insn->sec, insn->offset); + warnings++; + } - dest = validate_ibt_reloc(file, reloc); - if (is_data && dest && !dest->noendbr) - warn_noendbr("data ", sec, reloc->offset, dest); + break; + case INSN_JUMP_DYNAMIC: + if (!next_insn || next_insn->type != INSN_TRAP) { + WARN_FUNC("missing int3 after indirect jump", + insn->sec, insn->offset); + warnings++; + } + break; + default: + break; } } - return 0; + return warnings; } static int validate_reachable_instructions(struct objtool_file *file) @@ -3853,16 +3892,6 @@ int check(struct objtool_file *file) { int ret, warnings = 0; - if (lto && !(vmlinux || module)) { - fprintf(stderr, "--lto requires: --vmlinux or --module\n"); - return 1; - } - - if (ibt && !lto) { - fprintf(stderr, "--ibt requires: --lto\n"); - return 1; - } - arch_initial_func_cfi_state(&initial_func_cfi); init_cfi_state(&init_cfi); init_cfi_state(&func_cfi); @@ -3883,73 +3912,89 @@ int check(struct objtool_file *file) if (list_empty(&file->insn_list)) goto out; - if (vmlinux && !lto) { - ret = validate_vmlinux_functions(file); + if (opts.retpoline) { + ret = validate_retpoline(file); if (ret < 0) - goto out; - + return ret; warnings += ret; - goto out; } - if (retpoline) { - ret = validate_retpoline(file); + if (opts.stackval || opts.orc || opts.uaccess) { + ret = validate_functions(file); if (ret < 0) - return ret; + goto out; warnings += ret; - } - ret = validate_functions(file); - if (ret < 0) - goto out; - warnings += ret; + ret = validate_unwind_hints(file, NULL); + if (ret < 0) + goto out; + warnings += ret; - ret = validate_unwind_hints(file, NULL); - if (ret < 0) - goto out; - warnings += ret; + if (!warnings) { + ret = validate_reachable_instructions(file); + if (ret < 0) + goto out; + warnings += ret; + } - if (ibt) { + } else if (opts.noinstr) { + ret = validate_noinstr_sections(file); + if (ret < 0) + goto out; + warnings += ret; + } + + if (opts.ibt) { ret = validate_ibt(file); if (ret < 0) goto out; warnings += ret; } - if (!warnings) { - ret = validate_reachable_instructions(file); + if (opts.sls) { + ret = validate_sls(file); if (ret < 0) goto out; warnings += ret; } - ret = create_static_call_sections(file); - if (ret < 0) - goto out; - warnings += ret; + if (opts.static_call) { + ret = create_static_call_sections(file); + if (ret < 0) + goto out; + warnings += ret; + } - if (retpoline) { + if (opts.retpoline) { ret = create_retpoline_sites_sections(file); if (ret < 0) goto out; warnings += ret; } - if (mcount) { + if (opts.mcount) { ret = create_mcount_loc_sections(file); if (ret < 0) goto out; warnings += ret; } - if (ibt) { + if (opts.ibt) { ret = create_ibt_endbr_seal_sections(file); if (ret < 0) goto out; warnings += ret; } - if (stats) { + if (opts.orc && !list_empty(&file->insn_list)) { + ret = orc_create(file); + if (ret < 0) + goto out; + warnings += ret; + } + + + if (opts.stats) { printf("nr_insns_visited: %ld\n", nr_insns_visited); printf("nr_cfi: %ld\n", nr_cfi); printf("nr_cfi_reused: %ld\n", nr_cfi_reused); diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index ebf2ba5755c1..c25e957c1e52 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -355,7 +355,7 @@ static int read_sections(struct elf *elf) elf_hash_add(section_name, &sec->name_hash, str_hash(sec->name)); } - if (stats) { + if (opts.stats) { printf("nr_sections: %lu\n", (unsigned long)sections_nr); printf("section_bits: %d\n", elf->section_bits); } @@ -374,9 +374,15 @@ static void elf_add_symbol(struct elf *elf, struct symbol *sym) struct list_head *entry; struct rb_node *pnode; + INIT_LIST_HEAD(&sym->pv_target); + sym->alias = sym; + sym->type = GELF_ST_TYPE(sym->sym.st_info); sym->bind = GELF_ST_BIND(sym->sym.st_info); + if (sym->type == STT_FILE) + elf->num_files++; + sym->offset = sym->sym.st_value; sym->len = sym->sym.st_size; @@ -435,8 +441,6 @@ static int read_symbols(struct elf *elf) return -1; } memset(sym, 0, sizeof(*sym)); - INIT_LIST_HEAD(&sym->pv_target); - sym->alias = sym; sym->idx = i; @@ -475,7 +479,7 @@ static int read_symbols(struct elf *elf) elf_add_symbol(elf, sym); } - if (stats) { + if (opts.stats) { printf("nr_symbols: %lu\n", (unsigned long)symbols_nr); printf("symbol_bits: %d\n", elf->symbol_bits); } @@ -546,7 +550,7 @@ static struct section *elf_create_reloc_section(struct elf *elf, int reltype); int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, - unsigned int type, struct symbol *sym, long addend) + unsigned int type, struct symbol *sym, s64 addend) { struct reloc *reloc; @@ -600,24 +604,21 @@ static void elf_dirty_reloc_sym(struct elf *elf, struct symbol *sym) } /* - * Move the first global symbol, as per sh_info, into a new, higher symbol - * index. This fees up the shndx for a new local symbol. + * The libelf API is terrible; gelf_update_sym*() takes a data block relative + * index value, *NOT* the symbol index. As such, iterate the data blocks and + * adjust index until it fits. + * + * If no data block is found, allow adding a new data block provided the index + * is only one past the end. */ -static int elf_move_global_symbol(struct elf *elf, struct section *symtab, - struct section *symtab_shndx) +static int elf_update_symbol(struct elf *elf, struct section *symtab, + struct section *symtab_shndx, struct symbol *sym) { - Elf_Data *data, *shndx_data = NULL; - Elf32_Word first_non_local; - struct symbol *sym; - Elf_Scn *s; - - first_non_local = symtab->sh.sh_info; - - sym = find_symbol_by_index(elf, first_non_local); - if (!sym) { - WARN("no non-local symbols !?"); - return first_non_local; - } + Elf32_Word shndx = sym->sec ? sym->sec->idx : SHN_UNDEF; + Elf_Data *symtab_data = NULL, *shndx_data = NULL; + Elf64_Xword entsize = symtab->sh.sh_entsize; + int max_idx, idx = sym->idx; + Elf_Scn *s, *t = NULL; s = elf_getscn(elf->elf, symtab->idx); if (!s) { @@ -625,79 +626,124 @@ static int elf_move_global_symbol(struct elf *elf, struct section *symtab, return -1; } - data = elf_newdata(s); - if (!data) { - WARN_ELF("elf_newdata"); - return -1; + if (symtab_shndx) { + t = elf_getscn(elf->elf, symtab_shndx->idx); + if (!t) { + WARN_ELF("elf_getscn"); + return -1; + } } - data->d_buf = &sym->sym; - data->d_size = sizeof(sym->sym); - data->d_align = 1; - data->d_type = ELF_T_SYM; + for (;;) { + /* get next data descriptor for the relevant sections */ + symtab_data = elf_getdata(s, symtab_data); + if (t) + shndx_data = elf_getdata(t, shndx_data); - sym->idx = symtab->sh.sh_size / sizeof(sym->sym); - elf_dirty_reloc_sym(elf, sym); + /* end-of-list */ + if (!symtab_data) { + void *buf; - symtab->sh.sh_info += 1; - symtab->sh.sh_size += data->d_size; - symtab->changed = true; + if (idx) { + /* we don't do holes in symbol tables */ + WARN("index out of range"); + return -1; + } - if (symtab_shndx) { - s = elf_getscn(elf->elf, symtab_shndx->idx); - if (!s) { - WARN_ELF("elf_getscn"); + /* if @idx == 0, it's the next contiguous entry, create it */ + symtab_data = elf_newdata(s); + if (t) + shndx_data = elf_newdata(t); + + buf = calloc(1, entsize); + if (!buf) { + WARN("malloc"); + return -1; + } + + symtab_data->d_buf = buf; + symtab_data->d_size = entsize; + symtab_data->d_align = 1; + symtab_data->d_type = ELF_T_SYM; + + symtab->sh.sh_size += entsize; + symtab->changed = true; + + if (t) { + shndx_data->d_buf = &sym->sec->idx; + shndx_data->d_size = sizeof(Elf32_Word); + shndx_data->d_align = sizeof(Elf32_Word); + shndx_data->d_type = ELF_T_WORD; + + symtab_shndx->sh.sh_size += sizeof(Elf32_Word); + symtab_shndx->changed = true; + } + + break; + } + + /* empty blocks should not happen */ + if (!symtab_data->d_size) { + WARN("zero size data"); return -1; } - shndx_data = elf_newdata(s); + /* is this the right block? */ + max_idx = symtab_data->d_size / entsize; + if (idx < max_idx) + break; + + /* adjust index and try again */ + idx -= max_idx; + } + + /* something went side-ways */ + if (idx < 0) { + WARN("negative index"); + return -1; + } + + /* setup extended section index magic and write the symbol */ + if (shndx >= SHN_UNDEF && shndx < SHN_LORESERVE) { + sym->sym.st_shndx = shndx; + if (!shndx_data) + shndx = 0; + } else { + sym->sym.st_shndx = SHN_XINDEX; if (!shndx_data) { - WARN_ELF("elf_newshndx_data"); + WARN("no .symtab_shndx"); return -1; } + } - shndx_data->d_buf = &sym->sec->idx; - shndx_data->d_size = sizeof(Elf32_Word); - shndx_data->d_align = 4; - shndx_data->d_type = ELF_T_WORD; - - symtab_shndx->sh.sh_size += 4; - symtab_shndx->changed = true; + if (!gelf_update_symshndx(symtab_data, shndx_data, idx, &sym->sym, shndx)) { + WARN_ELF("gelf_update_symshndx"); + return -1; } - return first_non_local; + return 0; } static struct symbol * elf_create_section_symbol(struct elf *elf, struct section *sec) { struct section *symtab, *symtab_shndx; - Elf_Data *shndx_data = NULL; - struct symbol *sym; - Elf32_Word shndx; + Elf32_Word first_non_local, new_idx; + struct symbol *sym, *old; symtab = find_section_by_name(elf, ".symtab"); if (symtab) { symtab_shndx = find_section_by_name(elf, ".symtab_shndx"); - if (symtab_shndx) - shndx_data = symtab_shndx->data; } else { WARN("no .symtab"); return NULL; } - sym = malloc(sizeof(*sym)); + sym = calloc(1, sizeof(*sym)); if (!sym) { perror("malloc"); return NULL; } - memset(sym, 0, sizeof(*sym)); - - sym->idx = elf_move_global_symbol(elf, symtab, symtab_shndx); - if (sym->idx < 0) { - WARN("elf_move_global_symbol"); - return NULL; - } sym->name = sec->name; sym->sec = sec; @@ -707,24 +753,41 @@ elf_create_section_symbol(struct elf *elf, struct section *sec) // st_other 0 // st_value 0 // st_size 0 - shndx = sec->idx; - if (shndx >= SHN_UNDEF && shndx < SHN_LORESERVE) { - sym->sym.st_shndx = shndx; - if (!shndx_data) - shndx = 0; - } else { - sym->sym.st_shndx = SHN_XINDEX; - if (!shndx_data) { - WARN("no .symtab_shndx"); + + /* + * Move the first global symbol, as per sh_info, into a new, higher + * symbol index. This fees up a spot for a new local symbol. + */ + first_non_local = symtab->sh.sh_info; + new_idx = symtab->sh.sh_size / symtab->sh.sh_entsize; + old = find_symbol_by_index(elf, first_non_local); + if (old) { + old->idx = new_idx; + + hlist_del(&old->hash); + elf_hash_add(symbol, &old->hash, old->idx); + + elf_dirty_reloc_sym(elf, old); + + if (elf_update_symbol(elf, symtab, symtab_shndx, old)) { + WARN("elf_update_symbol move"); return NULL; } + + new_idx = first_non_local; } - if (!gelf_update_symshndx(symtab->data, shndx_data, sym->idx, &sym->sym, shndx)) { - WARN_ELF("gelf_update_symshndx"); + sym->idx = new_idx; + if (elf_update_symbol(elf, symtab, symtab_shndx, sym)) { + WARN("elf_update_symbol"); return NULL; } + /* + * Either way, we added a LOCAL symbol. + */ + symtab->sh.sh_info += 1; + elf_add_symbol(elf, sym); return sym; @@ -843,7 +906,7 @@ static int read_relocs(struct elf *elf) tot_reloc += nr_reloc; } - if (stats) { + if (opts.stats) { printf("max_reloc: %lu\n", max_reloc); printf("tot_reloc: %lu\n", tot_reloc); printf("reloc_bits: %d\n", elf->reloc_bits); @@ -1222,7 +1285,7 @@ int elf_write(struct elf *elf) struct section *sec; Elf_Scn *s; - if (dryrun) + if (opts.dryrun) return 0; /* Update changed relocation sections and section headers: */ diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h index c39dbfaef6dc..280ea18b7f2b 100644 --- a/tools/objtool/include/objtool/builtin.h +++ b/tools/objtool/include/objtool/builtin.h @@ -8,13 +8,37 @@ #include <subcmd/parse-options.h> extern const struct option check_options[]; -extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, - lto, vmlinux, mcount, noinstr, backup, sls, dryrun, - ibt; + +struct opts { + /* actions: */ + bool dump_orc; + bool hack_jump_label; + bool hack_noinstr; + bool ibt; + bool mcount; + bool noinstr; + bool orc; + bool retpoline; + bool sls; + bool stackval; + bool static_call; + bool uaccess; + + /* options: */ + bool backtrace; + bool backup; + bool dryrun; + bool link; + bool module; + bool no_unreachable; + bool sec_address; + bool stats; +}; + +extern struct opts opts; extern int cmd_parse_options(int argc, const char **argv, const char * const usage[]); -extern int cmd_check(int argc, const char **argv); -extern int cmd_orc(int argc, const char **argv); +extern int objtool_run(int argc, const char **argv); #endif /* _BUILTIN_H */ diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 9b36802ed86f..adebfbc2b518 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -73,7 +73,7 @@ struct reloc { struct symbol *sym; unsigned long offset; unsigned int type; - long addend; + s64 addend; int idx; bool jump_table_start; }; @@ -86,7 +86,7 @@ struct elf { int fd; bool changed; char *name; - unsigned int text_size; + unsigned int text_size, num_files; struct list_head sections; int symbol_bits; @@ -131,11 +131,21 @@ static inline u32 reloc_hash(struct reloc *reloc) return sec_offset_hash(reloc->sec, reloc->offset); } +/* + * Try to see if it's a whole archive (vmlinux.o or module). + * + * Note this will miss the case where a module only has one source file. + */ +static inline bool has_multiple_files(struct elf *elf) +{ + return elf->num_files > 1; +} + struct elf *elf_open_read(const char *name, int flags); struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr); int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, - unsigned int type, struct symbol *sym, long addend); + unsigned int type, struct symbol *sym, s64 addend); int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, unsigned long offset, unsigned int type, struct section *insn_sec, unsigned long insn_off); diff --git a/tools/objtool/include/objtool/warn.h b/tools/objtool/include/objtool/warn.h index 802cfda0a6f6..a3e79ae75f2e 100644 --- a/tools/objtool/include/objtool/warn.h +++ b/tools/objtool/include/objtool/warn.h @@ -11,34 +11,33 @@ #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> +#include <objtool/builtin.h> #include <objtool/elf.h> extern const char *objname; static inline char *offstr(struct section *sec, unsigned long offset) { - struct symbol *func; - char *name, *str; - unsigned long name_off; + bool is_text = (sec->sh.sh_flags & SHF_EXECINSTR); + struct symbol *sym = NULL; + char *str; + int len; - func = find_func_containing(sec, offset); - if (!func) - func = find_symbol_containing(sec, offset); - if (func) { - name = func->name; - name_off = offset - func->offset; + if (is_text) + sym = find_func_containing(sec, offset); + if (!sym) + sym = find_symbol_containing(sec, offset); + + if (sym) { + str = malloc(strlen(sym->name) + strlen(sec->name) + 40); + len = sprintf(str, "%s+0x%lx", sym->name, offset - sym->offset); + if (opts.sec_address) + sprintf(str+len, " (%s+0x%lx)", sec->name, offset); } else { - name = sec->name; - name_off = offset; + str = malloc(strlen(sec->name) + 20); + sprintf(str, "%s+0x%lx", sec->name, offset); } - str = malloc(strlen(name) + 20); - - if (func) - sprintf(str, "%s()+0x%lx", name, name_off); - else - sprintf(str, "%s+0x%lx", name, name_off); - return str; } diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c index 843ff3c2f28e..512669ce064c 100644 --- a/tools/objtool/objtool.c +++ b/tools/objtool/objtool.c @@ -3,16 +3,6 @@ * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com> */ -/* - * objtool: - * - * The 'check' subcmd analyzes every .o file and ensures the validity of its - * stack trace metadata. It enforces a set of rules on asm code and C inline - * assembly code so that stack traces can be reliable. - * - * For more information, see tools/objtool/Documentation/stack-validation.txt. - */ - #include <stdio.h> #include <stdbool.h> #include <string.h> @@ -26,20 +16,6 @@ #include <objtool/objtool.h> #include <objtool/warn.h> -struct cmd_struct { - const char *name; - int (*fn)(int, const char **); - const char *help; -}; - -static const char objtool_usage_string[] = - "objtool COMMAND [ARGS]"; - -static struct cmd_struct objtool_cmds[] = { - {"check", cmd_check, "Perform stack metadata validation on an object file" }, - {"orc", cmd_orc, "Generate in-place ORC unwind tables for an object file" }, -}; - bool help; const char *objname; @@ -118,7 +94,7 @@ struct objtool_file *objtool_open_read(const char *_objname) if (!file.elf) return NULL; - if (backup && !objtool_create_backup(objname)) { + if (opts.backup && !objtool_create_backup(objname)) { WARN("can't create backup file"); return NULL; } @@ -129,7 +105,7 @@ struct objtool_file *objtool_open_read(const char *_objname) INIT_LIST_HEAD(&file.static_call_list); INIT_LIST_HEAD(&file.mcount_loc_list); INIT_LIST_HEAD(&file.endbr_list); - file.ignore_unreachables = no_unreachable; + file.ignore_unreachables = opts.no_unreachable; file.hints = false; return &file; @@ -137,7 +113,7 @@ struct objtool_file *objtool_open_read(const char *_objname) void objtool_pv_add(struct objtool_file *f, int idx, struct symbol *func) { - if (!noinstr) + if (!opts.noinstr) return; if (!f->pv_ops) { @@ -161,70 +137,6 @@ void objtool_pv_add(struct objtool_file *f, int idx, struct symbol *func) f->pv_ops[idx].clean = false; } -static void cmd_usage(void) -{ - unsigned int i, longest = 0; - - printf("\n usage: %s\n\n", objtool_usage_string); - - for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) { - if (longest < strlen(objtool_cmds[i].name)) - longest = strlen(objtool_cmds[i].name); - } - - puts(" Commands:"); - for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) { - printf(" %-*s ", longest, objtool_cmds[i].name); - puts(objtool_cmds[i].help); - } - - printf("\n"); - - if (!help) - exit(129); - exit(0); -} - -static void handle_options(int *argc, const char ***argv) -{ - while (*argc > 0) { - const char *cmd = (*argv)[0]; - - if (cmd[0] != '-') - break; - - if (!strcmp(cmd, "--help") || !strcmp(cmd, "-h")) { - help = true; - break; - } else { - fprintf(stderr, "Unknown option: %s\n", cmd); - cmd_usage(); - } - - (*argv)++; - (*argc)--; - } -} - -static void handle_internal_command(int argc, const char **argv) -{ - const char *cmd = argv[0]; - unsigned int i, ret; - - for (i = 0; i < ARRAY_SIZE(objtool_cmds); i++) { - struct cmd_struct *p = objtool_cmds+i; - - if (strcmp(p->name, cmd)) - continue; - - ret = p->fn(argc, argv); - - exit(ret); - } - - cmd_usage(); -} - int main(int argc, const char **argv) { static const char *UNUSED = "OBJTOOL_NOT_IMPLEMENTED"; @@ -233,14 +145,7 @@ int main(int argc, const char **argv) exec_cmd_init("objtool", UNUSED, UNUSED, UNUSED); pager_init(UNUSED); - argv++; - argc--; - handle_options(&argc, &argv); - - if (!argc || help) - cmd_usage(); - - handle_internal_command(argc, argv); + objtool_run(argc, argv); return 0; } diff --git a/tools/objtool/weak.c b/tools/objtool/weak.c index 8314e824db4a..d83f607733b0 100644 --- a/tools/objtool/weak.c +++ b/tools/objtool/weak.c @@ -15,17 +15,12 @@ return ENOSYS; \ }) -int __weak check(struct objtool_file *file) -{ - UNSUPPORTED("check subcommand"); -} - int __weak orc_dump(const char *_objname) { - UNSUPPORTED("orc"); + UNSUPPORTED("ORC"); } int __weak orc_create(struct objtool_file *file) { - UNSUPPORTED("orc"); + UNSUPPORTED("ORC"); } |