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| author | Nick Desaulniers <ndesaulniers@google.com> | 2022-09-19 10:45:47 -0700 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2022-09-24 11:19:19 +0900 |
| commit | 32ef9e5054ec0321b9336058c58ec749e9c6b0fe (patch) | |
| tree | 01c8bb2649848f563a292b9d05be9d5135e24890 | |
| parent | 61f2b7c7497ba96cdde5bbaeb9e07f4c48f41f97 (diff) | |
| download | linux-32ef9e5054ec0321b9336058c58ec749e9c6b0fe.tar.gz | |
Makefile.debug: re-enable debug info for .S files
Alexey reported that the fraction of unknown filename instances in
kallsyms grew from ~0.3% to ~10% recently; Bill and Greg tracked it down
to assembler defined symbols, which regressed as a result of:
commit b8a9092330da ("Kbuild: do not emit debug info for assembly with LLVM_IAS=1")
In that commit, I allude to restoring debug info for assembler defined
symbols in a follow up patch, but it seems I forgot to do so in
commit a66049e2cf0e ("Kbuild: make DWARF version a choice")
Link: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=31bf18645d98b4d3d7357353be840e320649a67d
Fixes: b8a9092330da ("Kbuild: do not emit debug info for assembly with LLVM_IAS=1")
Reported-by: Alexey Alexandrov <aalexand@google.com>
Reported-by: Bill Wendling <morbo@google.com>
Reported-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
| -rw-r--r-- | lib/Kconfig.debug | 4 | ||||
| -rw-r--r-- | scripts/Makefile.debug | 21 |
2 files changed, 14 insertions, 11 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index bcbe60d6c80c..d3e5f36bb01e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -264,8 +264,10 @@ config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT config DEBUG_INFO_DWARF4 bool "Generate DWARF Version 4 debuginfo" select DEBUG_INFO + depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502))) help - Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+. + Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2 + if using clang without clang's integrated assembler, and gdb 7.0+. If you have consumers of DWARF debug info that are not ready for newer revisions of DWARF, you may wish to choose this or have your diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug index 26d6a9d97a20..8cf1cb22dd93 100644 --- a/scripts/Makefile.debug +++ b/scripts/Makefile.debug @@ -1,18 +1,19 @@ -DEBUG_CFLAGS := -g +DEBUG_CFLAGS := +debug-flags-y := -g ifdef CONFIG_DEBUG_INFO_SPLIT DEBUG_CFLAGS += -gsplit-dwarf endif -ifndef CONFIG_AS_IS_LLVM -KBUILD_AFLAGS += -Wa,-gdwarf-2 -endif - -ifndef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT -dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4 -dwarf-version-$(CONFIG_DEBUG_INFO_DWARF5) := 5 -DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y) +debug-flags-$(CONFIG_DEBUG_INFO_DWARF4) += -gdwarf-4 +debug-flags-$(CONFIG_DEBUG_INFO_DWARF5) += -gdwarf-5 +ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_AS_IS_GNU),yy) +# Clang does not pass -g or -gdwarf-* option down to GAS. +# Add -Wa, prefix to explicitly specify the flags. +KBUILD_AFLAGS += $(addprefix -Wa$(comma), $(debug-flags-y)) endif +DEBUG_CFLAGS += $(debug-flags-y) +KBUILD_AFLAGS += $(debug-flags-y) ifdef CONFIG_DEBUG_INFO_REDUCED DEBUG_CFLAGS += -fno-var-tracking @@ -27,5 +28,5 @@ KBUILD_AFLAGS += -gz=zlib KBUILD_LDFLAGS += --compress-debug-sections=zlib endif -KBUILD_CFLAGS += $(DEBUG_CFLAGS) +KBUILD_CFLAGS += $(DEBUG_CFLAGS) export DEBUG_CFLAGS |