[PATCH] kexec: Export memory sections virtual addresses to vmcoreinfo

Baoquan He
2016-10-06T09:35:42Z

KASLR memory randomization can randomize the base of the physical memory
mapping (PAGE_OFFSET), vmalloc (VMALLOC_START) and vmemmap
(VMEMMAP_START). These need be exported to VMCOREINFO so that user space
utility, mainly makedumpfile can use them to identify the base of each
memory section. Here using VMCOREINFO_NUMBER we can reuse the existing
struct number_table in makedumpfile to import data easily.

Since they are related to x86_64 only, put them into
arch_crash_save_vmcoreinfo. And move the exportion of KERNEL_IMAGE_SIZE
together since it's also for x86_64 only.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
arch/x86/kernel/machine_kexec_64.c | 4 ++++
kernel/kexec_core.c | 3 ---
2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 5a294e4..e150dd7 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -337,6 +337,10 @@ void arch_crash_save_vmcoreinfo(void)
#endif
vmcoreinfo_append_str("KERNELOFFSET=%lx\n",
kaslr_offset());
+ VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE);
+ VMCOREINFO_NUMBER(PAGE_OFFSET);
+ VMCOREINFO_NUMBER(VMALLOC_START);
+ VMCOREINFO_NUMBER(VMEMMAP_START);
}

/* arch-dependent functionality related to kexec file-based syscall */
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 5616755..8ad3a29e 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -1467,9 +1467,6 @@ static int __init crash_save_vmcoreinfo_init(void)
#endif
VMCOREINFO_NUMBER(PG_head_mask);
VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
-#ifdef CONFIG_X86
- VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE);
-#endif
#ifdef CONFIG_HUGETLB_PAGE
VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
#endif
--
2.5.5