Messages in this thread | | | Date | Wed, 4 Oct 2023 10:52:23 -0700 | Subject | Re: [PATCH 1/1] kernel/config: Introduce CONFIG_DEBUG_INFO_IKCONFIG | From | Randy Dunlap <> |
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Hi,
On 10/4/23 09:58, 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.
x86_64 allmodconfig is 91 KB gzipped... oh well.
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
> 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. > > Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> > --- > include/asm-generic/vmlinux.lds.h | 3 ++- > kernel/Makefile | 1 + > kernel/configs-debug.S | 18 ++++++++++++++++++ > lib/Kconfig.debug | 14 ++++++++++++++ > 4 files changed, 35 insertions(+), 1 deletion(-) > create mode 100644 kernel/configs-debug.S
-- ~Randy
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