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

From: Baoquan He <bhe@redhat.com>
To: kexec@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: tglx@linutronix.de, akpm@linux-foundation.org, mingo@redhat.com,
	hpa@zytor.com, ebiederm@xmission.com, dyoung@redhat.com,
	tonli@redhat.com, keescook@chromium.org,
	takahiro.akashi@linaro.org, thgarnie@google.com,
	ats-kumagai@wm.jp.nec.com, Baoquan He <bhe@redhat.com>
Subject: [PATCH] kexec: Export memory sections virtual addresses to vmcoreinfo
Date: Thu,  6 Oct 2016 16:46:01 +0800	[thread overview]
Message-ID: <1475743561-23912-1-git-send-email-bhe@redhat.com> (raw)

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
