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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/kernel/machine_kexec_64.c | |
| parent | b38af4721f59d0b564468f623b3e52a638195015 (diff) | |
| download | linux-0-day-74ca317c26a3f8543203b61d262c0ab2e30c384e.tar.gz linux-0-day-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/kernel/machine_kexec_64.c')
| -rw-r--r-- | arch/x86/kernel/machine_kexec_64.c | 11 |
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 8b04018e5d1f0..485981059a40e 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 */ |