Ignat Korchagin <ignat@xxxxxxxxxxxxxx> writes:
Good day!
We have recently started to evaluate Linux 6.6 and noticed that we
cannot disable CONFIG_KEXEC anymore, but keep CONFIG_CRASH_DUMP
enabled. It seems to be related to commit 89cde455 ("kexec:
consolidate kexec and crash options into kernel/Kconfig.kexec"), where
a CONFIG_KEXEC dependency was added to CONFIG_CRASH_DUMP.
In our current kernel (Linux 6.1) we only enable CONFIG_KEXEC_FILE
with enforced signature check to support the kernel crash dumping
functionality and would like to keep CONFIG_KEXEC disabled for
security reasons [1].
I was reading the long commit message, but the reason for adding
CONFIG_KEXEC as a dependency for CONFIG_CRASH_DUMP evaded me. And I
believe from the implementation perspective CONFIG_KEXEC_FILE should
suffice here (as we successfully used it for crashdumps on Linux 6.1).
Is there a reason for adding this dependency or is it just an
oversight? Would some solution of requiring either CONFIG_KEXEC or
CONFIG_KEXEC_FILE work here?
I don't actually see any reason for CRASH_DUMP to depend on KEXEC or
KEXEC_FILE.
None of the old CRASH_DUMP symbols depended on KEXEC AFAICS. Using
something like:
$ git diff 89cde455..95d1fef5 | grep -A 3 "^-.*config CRASH_DUMP"
It's reasonable to want to build a kernel that supports CRASH_DUMP (ie.
can be a dump kernel), but doesn't support kexec and requires a regular
reboot. Though I doubt anyone does that in practice?
cheers
