On Fri, Oct 27, 2023, at 19:17, Stephen Brennan wrote: > The option CONFIG_IKCONFIG allows the gzip compressed kernel > configuration to be included into vmlinux or a module. In these cases, > debuggers can access the config data and use it to adjust their behavior > according to the configuration. However, distributions rarely enable > this, likely because it uses a fair bit of kernel memory which cannot be > swapped out. > > This means that in practice, the kernel configuration is rarely > available to debuggers. > > So, introduce an alternative, CONFIG_DEBUG_INFO_IKCONFIG. This strategy, > which is only available if IKCONFIG is not already built-in, adds a > section ".debug_linux_ikconfig", to the vmlinux ELF. It will be stripped > out of the final images, but will remain in the debuginfo files. So > debuggers which rely on vmlinux debuginfo can have access to the kernel > configuration, without incurring a cost to the kernel at runtime. > > The configuration is enabled whenever DEBUG_INFO=y and IKCONFIG!=y. The > added section is not large compared to debug info sizes. It won't affect > the runtime kernel at all, and this default will ensure that > distributions intending to create useful debuginfo will get this new > addition for kernel debuggers. > > Signed-off-by: Stephen Brennan <stephen.s.brennan@xxxxxxxxxx> > --- > include/asm-generic/vmlinux.lds.h | 3 ++- > kernel/Makefile | 2 ++ > kernel/configs-debug.S | 18 ++++++++++++++++++ > lib/Kconfig.debug | 15 +++++++++++++++ > 4 files changed, 37 insertions(+), 1 deletion(-) > create mode 100644 kernel/configs-debug.S For asm-generic: Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
