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| author | Vivek Goyal <vgoyal@redhat.com> | 2014-08-29 15:18:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-29 16:28:16 -0700 |
| commit | 74ca317c26a3f8543203b61d262c0ab2e30c384e (patch) | |
| tree | e88c78846c33bd3f86034b2ba16616ea38bb2802 /arch/x86/Kconfig | |
| parent | b38af4721f59d0b564468f623b3e52a638195015 (diff) | |
| download | linux-74ca317c26a3f8543203b61d262c0ab2e30c384e.tar.bz2 | |
kexec: create a new config option CONFIG_KEXEC_FILE for new syscall
Currently new system call kexec_file_load() and all the associated code
compiles if CONFIG_KEXEC=y. But new syscall also compiles purgatory
code which currently uses gcc option -mcmodel=large. This option seems
to be available only gcc 4.4 onwards.
Hiding new functionality behind a new config option will not break
existing users of old gcc. Those who wish to enable new functionality
will require new gcc. Having said that, I am trying to figure out how
can I move away from using -mcmodel=large but that can take a while.
I think there are other advantages of introducing this new config
option. As this option will be enabled only on x86_64, other arches
don't have to compile generic kexec code which will never be used. This
new code selects CRYPTO=y and CRYPTO_SHA256=y. And all other arches had
to do this for CONFIG_KEXEC. Now with introduction of new config
option, we can remove crypto dependency from other arches.
Now CONFIG_KEXEC_FILE is available only on x86_64. So whereever I had
CONFIG_X86_64 defined, I got rid of that.
For CONFIG_KEXEC_FILE, instead of doing select CRYPTO=y, I changed it to
"depends on CRYPTO=y". This should be safer as "select" is not
recursive.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/Kconfig')
| -rw-r--r-- | arch/x86/Kconfig | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5d0bf1aa9dcb..778178f4c7d1 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1585,9 +1585,6 @@ source kernel/Kconfig.hz config KEXEC bool "kexec system call" - select BUILD_BIN2C - select CRYPTO - select CRYPTO_SHA256 ---help--- kexec is a system call that implements the ability to shutdown your current kernel, and to start another kernel. It is like a reboot @@ -1602,9 +1599,22 @@ config KEXEC interface is strongly in flux, so no good recommendation can be made. +config KEXEC_FILE + bool "kexec file based system call" + select BUILD_BIN2C + depends on KEXEC + depends on X86_64 + depends on CRYPTO=y + depends on CRYPTO_SHA256=y + ---help--- + This is new version of kexec system call. This system call is + file based and takes file descriptors as system call argument + for kernel and initramfs as opposed to list of segments as + accepted by previous system call. + config KEXEC_VERIFY_SIG bool "Verify kernel signature during kexec_file_load() syscall" - depends on KEXEC + depends on KEXEC_FILE ---help--- This option makes kernel signature verification mandatory for kexec_file_load() syscall. If kernel is signature can not be |