| Message ID | 20211210000910.3597609-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kees Cook |
| Headers | show |
| Series | Kconfig.debug: Make DEBUG_INFO selectable from a choice | expand |
On Fri, Dec 10, 2021 at 1:09 AM Kees Cook <keescook@chromium.org> wrote: > > Currently it's not possible to enable DEBUG_INFO for an all*config > build, since it is marked as "depends on !COMPILE_TEST". This generally > makes sense because a debug build of an all*config target ends up taking > much longer and the output is much larger. Having this be "default off" > makes sense. However, there are cases where enabling DEBUG_INFO for such > builds is useful for doing treewide A/B comparisons of build options, > etc. > > Make DEBUG_INFO selectable from any of the DWARF version choice options, > with DEBUG_INFO_NONE being the default for COMPILE_TEST. The mutually > exclusive relationship between DWARF5 and BTF must be inverted, but the > result remains the same. Additionally moves DEBUG_KERNEL and DEBUG_MISC > up to the top of the menu because was enabling features _above_ it, > making it weird to navigate menuconfig. > > Suggested-by: Arnd Bergmann <arnd@arndb.de> > Signed-off-by: Kees Cook <keescook@chromium.org> Looks good to me, Reviewed-by: Arnd Bergmann <arnd@arndb.de> One detail: > +choice > + prompt "Debug information" > + depends on DEBUG_KERNEL > + default DEBUG_INFO_NONE if COMPILE_TEST > + default DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT if DEBUG_KERNEL I think this line should be simplified to default DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT since DEBUG_KERNEL is always enabled at this point. You can also consider turning the 'menu' into 'menuconfig DEBUG_KERNEL' and dropping the 'depends on DEBUG_KERNEL' in favor of the implied dependency. Arnd
On Thu, Dec 09, 2021 at 04:09:10PM -0800, Kees Cook wrote: > Currently it's not possible to enable DEBUG_INFO for an all*config > build, since it is marked as "depends on !COMPILE_TEST". This generally > makes sense because a debug build of an all*config target ends up taking > much longer and the output is much larger. Having this be "default off" > makes sense. However, there are cases where enabling DEBUG_INFO for such > builds is useful for doing treewide A/B comparisons of build options, > etc. > > Make DEBUG_INFO selectable from any of the DWARF version choice options, > with DEBUG_INFO_NONE being the default for COMPILE_TEST. The mutually > exclusive relationship between DWARF5 and BTF must be inverted, but the > result remains the same. Additionally moves DEBUG_KERNEL and DEBUG_MISC > up to the top of the menu because was enabling features _above_ it, > making it weird to navigate menuconfig. > > Suggested-by: Arnd Bergmann <arnd@arndb.de> > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> > --- > lib/Kconfig.debug | 142 +++++++++++++++++++++++++--------------------- > 1 file changed, 76 insertions(+), 66 deletions(-) > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 5c12bde10996..70ef47e92681 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -208,20 +208,89 @@ config DEBUG_BUGVERBOSE > > endmenu # "printk and dmesg options" > > +config DEBUG_KERNEL > + bool "Kernel debugging" > + help > + Say Y here if you are developing drivers or trying to debug and > + identify kernel problems. > + > +config DEBUG_MISC > + bool "Miscellaneous debug code" > + default DEBUG_KERNEL > + depends on DEBUG_KERNEL > + help > + Say Y here if you need to enable miscellaneous debug code that should > + be under a more specific debug option but isn't. > + > menu "Compile-time checks and compiler options" > > config DEBUG_INFO > - bool "Compile the kernel with debug info" > - depends on DEBUG_KERNEL && !COMPILE_TEST > + bool > help > - If you say Y here the resulting kernel image will include > - debugging info resulting in a larger kernel image. > + A kernel debug info option other than "None" has been selected > + in the "Debug information" choice below, indicating that debug > + information will be generated for build targets. > + > +choice > + prompt "Debug information" > + depends on DEBUG_KERNEL > + default DEBUG_INFO_NONE if COMPILE_TEST > + default DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT if DEBUG_KERNEL > + help > + Selecting something other than "None" results in a kernel image > + that will include debugging info resulting in a larger kernel image. > This adds debug symbols to the kernel and modules (gcc -g), and > is needed if you intend to use kernel crashdump or binary object > tools like crash, kgdb, LKCD, gdb, etc on the kernel. > - Say Y here only if you plan to debug the kernel. > > - If unsure, say N. > + Choose which version of DWARF debug info to emit. If unsure, > + select "Toolchain default". > + > +config DEBUG_INFO_NONE > + bool "Disable debug information" > + help > + Do not build the kernel with debugging information, which will > + result in a faster and smaller build. > + > +config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT > + bool "Rely on the toolchain's implicit default DWARF version" > + select DEBUG_INFO > + help > + The implicit default version of DWARF debug info produced by a > + toolchain changes over time. > + > + This can break consumers of the debug info that haven't upgraded to > + support newer revisions, and prevent testing newer versions, but > + those should be less common scenarios. > + > +config DEBUG_INFO_DWARF4 > + bool "Generate DWARF Version 4 debuginfo" > + select DEBUG_INFO > + help > + Generate DWARF v4 debug info. This requires gcc 4.5+ 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 > + config select this. > + > +config DEBUG_INFO_DWARF5 > + bool "Generate DWARF Version 5 debuginfo" > + select DEBUG_INFO > + depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502))) > + help > + Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc > + 5.0+ accepts the -gdwarf-5 flag but only had partial support for some > + draft features until 7.0), and gdb 8.0+. > + > + Changes to the structure of debug info in Version 5 allow for around > + 15-18% savings in resulting image and debug info section sizes as > + compared to DWARF Version 4. DWARF Version 5 standardizes previous > + extensions such as accelerators for symbol indexing and the format > + for fission (.dwo/.dwp) files. Users may not want to select this > + config if they rely on tooling that has not yet been updated to > + support DWARF Version 5. > + > +endchoice # "Debug information" > > if DEBUG_INFO > > @@ -267,55 +336,11 @@ config DEBUG_INFO_SPLIT > to know about the .dwo files and include them. > Incompatible with older versions of ccache. > > -choice > - prompt "DWARF version" > - help > - Which version of DWARF debug info to emit. > - > -config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT > - bool "Rely on the toolchain's implicit default DWARF version" > - help > - The implicit default version of DWARF debug info produced by a > - toolchain changes over time. > - > - This can break consumers of the debug info that haven't upgraded to > - support newer revisions, and prevent testing newer versions, but > - those should be less common scenarios. > - > - If unsure, say Y. > - > -config DEBUG_INFO_DWARF4 > - bool "Generate DWARF Version 4 debuginfo" > - help > - Generate DWARF v4 debug info. This requires gcc 4.5+ 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 > - config select this. > - > -config DEBUG_INFO_DWARF5 > - bool "Generate DWARF Version 5 debuginfo" > - depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502))) > - depends on !DEBUG_INFO_BTF > - help > - Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc > - 5.0+ accepts the -gdwarf-5 flag but only had partial support for some > - draft features until 7.0), and gdb 8.0+. > - > - Changes to the structure of debug info in Version 5 allow for around > - 15-18% savings in resulting image and debug info section sizes as > - compared to DWARF Version 4. DWARF Version 5 standardizes previous > - extensions such as accelerators for symbol indexing and the format > - for fission (.dwo/.dwp) files. Users may not want to select this > - config if they rely on tooling that has not yet been updated to > - support DWARF Version 5. > - > -endchoice # "DWARF version" > - > config DEBUG_INFO_BTF > bool "Generate BTF typeinfo" > depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED > depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST > + depends on !DEBUG_INFO_DWARF5 > help > Generate deduplicated BTF type information from DWARF debug info. > Turning this on expects presence of pahole tool, which will convert > @@ -584,21 +609,6 @@ source "lib/Kconfig.kcsan" > > endmenu > > -config DEBUG_KERNEL > - bool "Kernel debugging" > - help > - Say Y here if you are developing drivers or trying to debug and > - identify kernel problems. > - > -config DEBUG_MISC > - bool "Miscellaneous debug code" > - default DEBUG_KERNEL > - depends on DEBUG_KERNEL > - help > - Say Y here if you need to enable miscellaneous debug code that should > - be under a more specific debug option but isn't. > - > - > menu "Memory Debugging" > > source "mm/Kconfig.debug" > -- > 2.30.2 >
On Thu, Dec 9, 2021 at 4:09 PM Kees Cook <keescook@chromium.org> wrote: > > Currently it's not possible to enable DEBUG_INFO for an all*config > build, since it is marked as "depends on !COMPILE_TEST". This generally Indeed. > makes sense because a debug build of an all*config target ends up taking > much longer and the output is much larger. Having this be "default off" > makes sense. However, there are cases where enabling DEBUG_INFO for such > builds is useful for doing treewide A/B comparisons of build options, > etc. > > Make DEBUG_INFO selectable from any of the DWARF version choice options, > with DEBUG_INFO_NONE being the default for COMPILE_TEST. The mutually > exclusive relationship between DWARF5 and BTF must be inverted, but the > result remains the same. Additionally moves DEBUG_KERNEL and DEBUG_MISC > up to the top of the menu because was enabling features _above_ it, s/was/they were/ Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> > making it weird to navigate menuconfig. > > Suggested-by: Arnd Bergmann <arnd@arndb.de> > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > lib/Kconfig.debug | 142 +++++++++++++++++++++++++--------------------- > 1 file changed, 76 insertions(+), 66 deletions(-) > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 5c12bde10996..70ef47e92681 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -208,20 +208,89 @@ config DEBUG_BUGVERBOSE > > endmenu # "printk and dmesg options" > > +config DEBUG_KERNEL > + bool "Kernel debugging" > + help > + Say Y here if you are developing drivers or trying to debug and > + identify kernel problems. > + > +config DEBUG_MISC > + bool "Miscellaneous debug code" > + default DEBUG_KERNEL > + depends on DEBUG_KERNEL > + help > + Say Y here if you need to enable miscellaneous debug code that should > + be under a more specific debug option but isn't. > + > menu "Compile-time checks and compiler options" > > config DEBUG_INFO > - bool "Compile the kernel with debug info" > - depends on DEBUG_KERNEL && !COMPILE_TEST > + bool > help > - If you say Y here the resulting kernel image will include > - debugging info resulting in a larger kernel image. > + A kernel debug info option other than "None" has been selected > + in the "Debug information" choice below, indicating that debug > + information will be generated for build targets. > + > +choice > + prompt "Debug information" > + depends on DEBUG_KERNEL > + default DEBUG_INFO_NONE if COMPILE_TEST > + default DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT if DEBUG_KERNEL > + help > + Selecting something other than "None" results in a kernel image > + that will include debugging info resulting in a larger kernel image. > This adds debug symbols to the kernel and modules (gcc -g), and > is needed if you intend to use kernel crashdump or binary object > tools like crash, kgdb, LKCD, gdb, etc on the kernel. > - Say Y here only if you plan to debug the kernel. > > - If unsure, say N. > + Choose which version of DWARF debug info to emit. If unsure, > + select "Toolchain default". > + > +config DEBUG_INFO_NONE > + bool "Disable debug information" > + help > + Do not build the kernel with debugging information, which will > + result in a faster and smaller build. > + > +config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT > + bool "Rely on the toolchain's implicit default DWARF version" > + select DEBUG_INFO > + help > + The implicit default version of DWARF debug info produced by a > + toolchain changes over time. > + > + This can break consumers of the debug info that haven't upgraded to > + support newer revisions, and prevent testing newer versions, but > + those should be less common scenarios. > + > +config DEBUG_INFO_DWARF4 > + bool "Generate DWARF Version 4 debuginfo" > + select DEBUG_INFO > + help > + Generate DWARF v4 debug info. This requires gcc 4.5+ 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 > + config select this. > + > +config DEBUG_INFO_DWARF5 > + bool "Generate DWARF Version 5 debuginfo" > + select DEBUG_INFO > + depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502))) > + help > + Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc > + 5.0+ accepts the -gdwarf-5 flag but only had partial support for some > + draft features until 7.0), and gdb 8.0+. > + > + Changes to the structure of debug info in Version 5 allow for around > + 15-18% savings in resulting image and debug info section sizes as > + compared to DWARF Version 4. DWARF Version 5 standardizes previous > + extensions such as accelerators for symbol indexing and the format > + for fission (.dwo/.dwp) files. Users may not want to select this > + config if they rely on tooling that has not yet been updated to > + support DWARF Version 5. > + > +endchoice # "Debug information" > > if DEBUG_INFO > > @@ -267,55 +336,11 @@ config DEBUG_INFO_SPLIT > to know about the .dwo files and include them. > Incompatible with older versions of ccache. > > -choice > - prompt "DWARF version" > - help > - Which version of DWARF debug info to emit. > - > -config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT > - bool "Rely on the toolchain's implicit default DWARF version" > - help > - The implicit default version of DWARF debug info produced by a > - toolchain changes over time. > - > - This can break consumers of the debug info that haven't upgraded to > - support newer revisions, and prevent testing newer versions, but > - those should be less common scenarios. > - > - If unsure, say Y. > - > -config DEBUG_INFO_DWARF4 > - bool "Generate DWARF Version 4 debuginfo" > - help > - Generate DWARF v4 debug info. This requires gcc 4.5+ 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 > - config select this. > - > -config DEBUG_INFO_DWARF5 > - bool "Generate DWARF Version 5 debuginfo" > - depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502))) > - depends on !DEBUG_INFO_BTF > - help > - Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc > - 5.0+ accepts the -gdwarf-5 flag but only had partial support for some > - draft features until 7.0), and gdb 8.0+. > - > - Changes to the structure of debug info in Version 5 allow for around > - 15-18% savings in resulting image and debug info section sizes as > - compared to DWARF Version 4. DWARF Version 5 standardizes previous > - extensions such as accelerators for symbol indexing and the format > - for fission (.dwo/.dwp) files. Users may not want to select this > - config if they rely on tooling that has not yet been updated to > - support DWARF Version 5. > - > -endchoice # "DWARF version" > - > config DEBUG_INFO_BTF > bool "Generate BTF typeinfo" > depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED > depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST > + depends on !DEBUG_INFO_DWARF5 I did hit a trivial conflict applying this to mainline/next-20211208 against d9847eb8be3d8 ("bpf: Make CONFIG_DEBUG_INFO_BTF depend upon CONFIG_BPF_SYSCALL") > help > Generate deduplicated BTF type information from DWARF debug info. > Turning this on expects presence of pahole tool, which will convert > @@ -584,21 +609,6 @@ source "lib/Kconfig.kcsan" > > endmenu > > -config DEBUG_KERNEL > - bool "Kernel debugging" > - help > - Say Y here if you are developing drivers or trying to debug and > - identify kernel problems. > - > -config DEBUG_MISC > - bool "Miscellaneous debug code" > - default DEBUG_KERNEL > - depends on DEBUG_KERNEL > - help > - Say Y here if you need to enable miscellaneous debug code that should > - be under a more specific debug option but isn't. > - > - > menu "Memory Debugging" > > source "mm/Kconfig.debug" > -- > 2.30.2 >
On Fri, Dec 10, 2021 at 6:40 PM Arnd Bergmann <arnd@arndb.de> wrote: > > On Fri, Dec 10, 2021 at 1:09 AM Kees Cook <keescook@chromium.org> wrote: > > > > Currently it's not possible to enable DEBUG_INFO for an all*config > > build, since it is marked as "depends on !COMPILE_TEST". This generally > > makes sense because a debug build of an all*config target ends up taking > > much longer and the output is much larger. Having this be "default off" > > makes sense. However, there are cases where enabling DEBUG_INFO for such > > builds is useful for doing treewide A/B comparisons of build options, > > etc. > > > > Make DEBUG_INFO selectable from any of the DWARF version choice options, > > with DEBUG_INFO_NONE being the default for COMPILE_TEST. The mutually > > exclusive relationship between DWARF5 and BTF must be inverted, but the > > result remains the same. Additionally moves DEBUG_KERNEL and DEBUG_MISC > > up to the top of the menu because was enabling features _above_ it, > > making it weird to navigate menuconfig. > > > > Suggested-by: Arnd Bergmann <arnd@arndb.de> > > Signed-off-by: Kees Cook <keescook@chromium.org> > > Looks good to me, > > Reviewed-by: Arnd Bergmann <arnd@arndb.de> > > One detail: > > > +choice > > + prompt "Debug information" > > + depends on DEBUG_KERNEL > > + default DEBUG_INFO_NONE if COMPILE_TEST > > + default DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT if DEBUG_KERNEL > > I think this line should be simplified to > > default DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT Indeed. It can be simplified into: default DEBUG_INFO_NONE if COMPILE_TEST default DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT The first entry of the choice is the default. So, it can be further simplified to: default DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT if !COMPILE_TEST Another way is to move DEBUG_INFO_NONE to the last entry of the choice, then default DEBUG_INFO_NONE if COMPILE_TEST > since DEBUG_KERNEL is always enabled at this point. You can also consider > turning the 'menu' into 'menuconfig DEBUG_KERNEL' and dropping the 'depends > on DEBUG_KERNEL' in favor of the implied dependency. > > Arnd
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 5c12bde10996..70ef47e92681 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -208,20 +208,89 @@ config DEBUG_BUGVERBOSE endmenu # "printk and dmesg options" +config DEBUG_KERNEL + bool "Kernel debugging" + help + Say Y here if you are developing drivers or trying to debug and + identify kernel problems. + +config DEBUG_MISC + bool "Miscellaneous debug code" + default DEBUG_KERNEL + depends on DEBUG_KERNEL + help + Say Y here if you need to enable miscellaneous debug code that should + be under a more specific debug option but isn't. + menu "Compile-time checks and compiler options" config DEBUG_INFO - bool "Compile the kernel with debug info" - depends on DEBUG_KERNEL && !COMPILE_TEST + bool help - If you say Y here the resulting kernel image will include - debugging info resulting in a larger kernel image. + A kernel debug info option other than "None" has been selected + in the "Debug information" choice below, indicating that debug + information will be generated for build targets. + +choice + prompt "Debug information" + depends on DEBUG_KERNEL + default DEBUG_INFO_NONE if COMPILE_TEST + default DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT if DEBUG_KERNEL + help + Selecting something other than "None" results in a kernel image + that will include debugging info resulting in a larger kernel image. This adds debug symbols to the kernel and modules (gcc -g), and is needed if you intend to use kernel crashdump or binary object tools like crash, kgdb, LKCD, gdb, etc on the kernel. - Say Y here only if you plan to debug the kernel. - If unsure, say N. + Choose which version of DWARF debug info to emit. If unsure, + select "Toolchain default". + +config DEBUG_INFO_NONE + bool "Disable debug information" + help + Do not build the kernel with debugging information, which will + result in a faster and smaller build. + +config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT + bool "Rely on the toolchain's implicit default DWARF version" + select DEBUG_INFO + help + The implicit default version of DWARF debug info produced by a + toolchain changes over time. + + This can break consumers of the debug info that haven't upgraded to + support newer revisions, and prevent testing newer versions, but + those should be less common scenarios. + +config DEBUG_INFO_DWARF4 + bool "Generate DWARF Version 4 debuginfo" + select DEBUG_INFO + help + Generate DWARF v4 debug info. This requires gcc 4.5+ 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 + config select this. + +config DEBUG_INFO_DWARF5 + bool "Generate DWARF Version 5 debuginfo" + select DEBUG_INFO + depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502))) + help + Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc + 5.0+ accepts the -gdwarf-5 flag but only had partial support for some + draft features until 7.0), and gdb 8.0+. + + Changes to the structure of debug info in Version 5 allow for around + 15-18% savings in resulting image and debug info section sizes as + compared to DWARF Version 4. DWARF Version 5 standardizes previous + extensions such as accelerators for symbol indexing and the format + for fission (.dwo/.dwp) files. Users may not want to select this + config if they rely on tooling that has not yet been updated to + support DWARF Version 5. + +endchoice # "Debug information" if DEBUG_INFO @@ -267,55 +336,11 @@ config DEBUG_INFO_SPLIT to know about the .dwo files and include them. Incompatible with older versions of ccache. -choice - prompt "DWARF version" - help - Which version of DWARF debug info to emit. - -config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT - bool "Rely on the toolchain's implicit default DWARF version" - help - The implicit default version of DWARF debug info produced by a - toolchain changes over time. - - This can break consumers of the debug info that haven't upgraded to - support newer revisions, and prevent testing newer versions, but - those should be less common scenarios. - - If unsure, say Y. - -config DEBUG_INFO_DWARF4 - bool "Generate DWARF Version 4 debuginfo" - help - Generate DWARF v4 debug info. This requires gcc 4.5+ 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 - config select this. - -config DEBUG_INFO_DWARF5 - bool "Generate DWARF Version 5 debuginfo" - depends on !CC_IS_CLANG || (CC_IS_CLANG && (AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502))) - depends on !DEBUG_INFO_BTF - help - Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc - 5.0+ accepts the -gdwarf-5 flag but only had partial support for some - draft features until 7.0), and gdb 8.0+. - - Changes to the structure of debug info in Version 5 allow for around - 15-18% savings in resulting image and debug info section sizes as - compared to DWARF Version 4. DWARF Version 5 standardizes previous - extensions such as accelerators for symbol indexing and the format - for fission (.dwo/.dwp) files. Users may not want to select this - config if they rely on tooling that has not yet been updated to - support DWARF Version 5. - -endchoice # "DWARF version" - config DEBUG_INFO_BTF bool "Generate BTF typeinfo" depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST + depends on !DEBUG_INFO_DWARF5 help Generate deduplicated BTF type information from DWARF debug info. Turning this on expects presence of pahole tool, which will convert @@ -584,21 +609,6 @@ source "lib/Kconfig.kcsan" endmenu -config DEBUG_KERNEL - bool "Kernel debugging" - help - Say Y here if you are developing drivers or trying to debug and - identify kernel problems. - -config DEBUG_MISC - bool "Miscellaneous debug code" - default DEBUG_KERNEL - depends on DEBUG_KERNEL - help - Say Y here if you need to enable miscellaneous debug code that should - be under a more specific debug option but isn't. - - menu "Memory Debugging" source "mm/Kconfig.debug"
Currently it's not possible to enable DEBUG_INFO for an all*config build, since it is marked as "depends on !COMPILE_TEST". This generally makes sense because a debug build of an all*config target ends up taking much longer and the output is much larger. Having this be "default off" makes sense. However, there are cases where enabling DEBUG_INFO for such builds is useful for doing treewide A/B comparisons of build options, etc. Make DEBUG_INFO selectable from any of the DWARF version choice options, with DEBUG_INFO_NONE being the default for COMPILE_TEST. The mutually exclusive relationship between DWARF5 and BTF must be inverted, but the result remains the same. Additionally moves DEBUG_KERNEL and DEBUG_MISC up to the top of the menu because was enabling features _above_ it, making it weird to navigate menuconfig. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Kees Cook <keescook@chromium.org> --- lib/Kconfig.debug | 142 +++++++++++++++++++++++++--------------------- 1 file changed, 76 insertions(+), 66 deletions(-)