diff options
| author | Jiri Kosina <jkosina@suse.cz> | 2015-04-27 13:17:19 +0200 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2015-04-29 16:51:33 +0200 |
| commit | 4545c89880138b30a868159bc1b209867b8a5f32 (patch) | |
| tree | 92b5085e5fbecc8946199f976ade079e7e320064 /arch/x86/kernel/machine_kexec_64.c | |
| parent | 9497d7380b9c450830190c75aa43b25c278bb1f9 (diff) | |
x86: introduce kaslr_offset()
Offset that has been chosen for kaslr during kernel decompression can be
easily computed as a difference between _text and __START_KERNEL. We are
already making use of this in dump_kernel_offset() notifier and in
arch_crash_save_vmcoreinfo().
Introduce kaslr_offset() that makes this computation instead of hard-coding
it, so that other kernel code (such as live patching) can make use of it.
Also convert existing users to make use of it.
This patch is equivalent transofrmation without any effects on the resulting
code:
$ diff -u vmlinux.old.asm vmlinux.new.asm
--- vmlinux.old.asm 2015-04-28 17:55:19.520983368 +0200
+++ vmlinux.new.asm 2015-04-28 17:55:24.141206072 +0200
@@ -1,5 +1,5 @@
-vmlinux.old: file format elf64-x86-64
+vmlinux.new: file format elf64-x86-64
Disassembly of section .text:
$
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'arch/x86/kernel/machine_kexec_64.c')
| -rw-r--r-- | arch/x86/kernel/machine_kexec_64.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index 415480d3ea84..e1029633f664 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -25,6 +25,7 @@ #include <asm/io_apic.h> #include <asm/debugreg.h> #include <asm/kexec-bzimage64.h> +#include <asm/setup.h> #ifdef CONFIG_KEXEC_FILE static struct kexec_file_ops *kexec_file_loaders[] = { @@ -334,7 +335,7 @@ void arch_crash_save_vmcoreinfo(void) VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); #endif vmcoreinfo_append_str("KERNELOFFSET=%lx\n", - (unsigned long)&_text - __START_KERNEL); + kaslr_offset()); } /* arch-dependent functionality related to kexec file-based syscall */ |