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authorVivek Goyal <vgoyal@redhat.com>2014-08-30 02:18:46 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-30 03:28:16 +0400
commit74ca317c26a3f8543203b61d262c0ab2e30c384e (patch)
treee88c78846c33bd3f86034b2ba16616ea38bb2802 /arch/x86/Kconfig
parentb38af4721f59d0b564468f623b3e52a638195015 (diff)
downloadlinux-74ca317c26a3f8543203b61d262c0ab2e30c384e.tar.xz
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/Kconfig18
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