Build with -Wa,--gsframe-3 flags to generate a .sframe section. This will be used for in-kernel reliable stacktrace in cases where the frame pointer alone is insufficient.
Currently, the sframe format only supports arm64, x86_64 and s390x architectures. Signed-off-by: Weinan Liu <[email protected]> Signed-off-by: Dylan Hatch <[email protected]> Reviewed-by: Prasanna Kumar T S M <[email protected]> --- MAINTAINERS | 1 + Makefile | 8 ++++++++ arch/Kconfig | 7 +++++++ arch/arm64/Kconfig | 1 + arch/arm64/Kconfig.debug | 13 +++++++++++++ arch/arm64/include/asm/unwind_sframe.h | 12 ++++++++++++ arch/arm64/kernel/vdso/Makefile | 2 +- include/asm-generic/vmlinux.lds.h | 15 +++++++++++++++ 8 files changed, 58 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/unwind_sframe.h diff --git a/MAINTAINERS b/MAINTAINERS index cfc7dec88da4..a7d75f9cb5f4 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -27561,6 +27561,7 @@ STACK UNWINDING M: Josh Poimboeuf <[email protected]> M: Steven Rostedt <[email protected]> S: Maintained +F: arch/*/include/asm/unwind_sframe.h F: include/linux/sframe.h F: include/linux/unwind*.h F: kernel/unwind/ diff --git a/Makefile b/Makefile index 2b15f0b4a0cb..e03d09ea6a23 100644 --- a/Makefile +++ b/Makefile @@ -1110,6 +1110,14 @@ endif # Ensure compilers do not transform certain loops into calls to wcslen() KBUILD_CFLAGS += -fno-builtin-wcslen +# build with sframe table +ifdef CONFIG_SFRAME_UNWINDER +CC_FLAGS_SFRAME := -Wa,--gsframe-3 +KBUILD_CFLAGS += $(CC_FLAGS_SFRAME) +KBUILD_AFLAGS += $(CC_FLAGS_SFRAME) +export CC_FLAGS_SFRAME +endif + # change __FILE__ to the relative path to the source directory ifdef building_out_of_srctree KBUILD_CPPFLAGS += -fmacro-prefix-map=$(srcroot)/= diff --git a/arch/Kconfig b/arch/Kconfig index 6695c222c728..c87e489fa978 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -520,6 +520,13 @@ config SFRAME_VALIDATION If unsure, say N. +config ARCH_SUPPORTS_SFRAME_UNWINDER + bool + help + An architecture can select this if it enables the sframe (Simple + Frame) unwinder for unwinding kernel stack traces. It uses unwind + table that is directly generatedby toolchain based on DWARF CFI information. + config HAVE_PERF_REGS bool help diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 38dba5f7e4d2..189bc199ad2e 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -112,6 +112,7 @@ config ARM64 select ARCH_SUPPORTS_SCHED_SMT select ARCH_SUPPORTS_SCHED_CLUSTER select ARCH_SUPPORTS_SCHED_MC + select ARCH_SUPPORTS_SFRAME_UNWINDER select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT select ARCH_WANT_DEFAULT_BPF_JIT diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug index 265c4461031f..df291d64812f 100644 --- a/arch/arm64/Kconfig.debug +++ b/arch/arm64/Kconfig.debug @@ -20,4 +20,17 @@ config ARM64_RELOC_TEST depends on m tristate "Relocation testing module" +config SFRAME_UNWINDER + bool "Sframe unwinder" + depends on AS_SFRAME3 + depends on 64BIT + depends on ARCH_SUPPORTS_SFRAME_UNWINDER + select SFRAME_LOOKUP + help + This option enables the sframe (Simple Frame) unwinder for unwinding + kernel stack traces. It uses unwind table that is directly generated + by toolchain based on DWARF CFI information. In, practice this can + provide more reliable stacktrace results than unwinding with frame + pointers alone. + source "drivers/hwtracing/coresight/Kconfig" diff --git a/arch/arm64/include/asm/unwind_sframe.h b/arch/arm64/include/asm/unwind_sframe.h new file mode 100644 index 000000000000..1682c079e387 --- /dev/null +++ b/arch/arm64/include/asm/unwind_sframe.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_ARM64_UNWIND_SFRAME_H +#define _ASM_ARM64_UNWIND_SFRAME_H + +#ifdef CONFIG_ARM64 + +#define SFRAME_REG_SP 31 +#define SFRAME_REG_FP 29 + +#endif + +#endif /* _ASM_ARM64_UNWIND_SFRAME_H */ diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index 7dec05dd33b7..c60ef921956f 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -38,7 +38,7 @@ ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO CC_FLAGS_REMOVE_VDSO := $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) \ $(RANDSTRUCT_CFLAGS) $(KSTACK_ERASE_CFLAGS) \ $(GCC_PLUGINS_CFLAGS) \ - $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) \ + $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) $(CC_FLAGS_SFRAME) \ -Wmissing-prototypes -Wmissing-declarations CC_FLAGS_ADD_VDSO := -O2 -mcmodel=tiny -fasynchronous-unwind-tables diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 1e1580febe4b..0a5c2f6cc4c0 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -491,6 +491,8 @@ *(.rodata1) \ } \ \ + SFRAME \ + \ /* PCI quirks */ \ .pci_fixup : AT(ADDR(.pci_fixup) - LOAD_OFFSET) { \ BOUNDED_SECTION_PRE_LABEL(.pci_fixup_early, _pci_fixups_early, __start, __end) \ @@ -911,6 +913,19 @@ #define TRACEDATA #endif +#ifdef CONFIG_SFRAME_UNWINDER +#define SFRAME \ + /* sframe */ \ + .sframe : AT(ADDR(.sframe) - LOAD_OFFSET) { \ + __start_sframe_header = .; \ + KEEP(*(.sframe)) \ + KEEP(*(.init.sframe)) \ + __stop_sframe_header = .; \ + } +#else +#define SFRAME +#endif + #ifdef CONFIG_PRINTK_INDEX #define PRINTK_INDEX \ .printk_index : AT(ADDR(.printk_index) - LOAD_OFFSET) { \ -- 2.53.0.1213.gd9a14994de-goog
