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authorVivek Goyal <vgoyal@redhat.com>2014-08-29 15:18:46 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-29 16:28:16 -0700
commit74ca317c26a3f8543203b61d262c0ab2e30c384e (patch)
treee88c78846c33bd3f86034b2ba16616ea38bb2802 /arch/x86/kernel/machine_kexec_64.c
parentb38af4721f59d0b564468f623b3e52a638195015 (diff)
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/kernel/machine_kexec_64.c')
-rw-r--r--arch/x86/kernel/machine_kexec_64.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 8b04018e5d1f..485981059a40 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -25,9 +25,11 @@
#include <asm/debugreg.h>
#include <asm/kexec-bzimage64.h>
+#ifdef CONFIG_KEXEC_FILE
static struct kexec_file_ops *kexec_file_loaders[] = {
&kexec_bzImage64_ops,
};
+#endif
static void free_transition_pgtable(struct kimage *image)
{
@@ -178,6 +180,7 @@ static void load_segments(void)
);
}
+#ifdef CONFIG_KEXEC_FILE
/* Update purgatory as needed after various image segments have been prepared */
static int arch_update_purgatory(struct kimage *image)
{
@@ -209,6 +212,12 @@ static int arch_update_purgatory(struct kimage *image)
return ret;
}
+#else /* !CONFIG_KEXEC_FILE */
+static inline int arch_update_purgatory(struct kimage *image)
+{
+ return 0;
+}
+#endif /* CONFIG_KEXEC_FILE */
int machine_kexec_prepare(struct kimage *image)
{
@@ -329,6 +338,7 @@ void arch_crash_save_vmcoreinfo(void)
/* arch-dependent functionality related to kexec file-based syscall */
+#ifdef CONFIG_KEXEC_FILE
int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
unsigned long buf_len)
{
@@ -522,3 +532,4 @@ overflow:
(int)ELF64_R_TYPE(rel[i].r_info), value);
return -ENOEXEC;
}
+#endif /* CONFIG_KEXEC_FILE */