From 0549a3c02efb350776bc869685a361045efd3a29 Mon Sep 17 00:00:00 2001 From: Thomas Garnier Date: Tue, 11 Oct 2016 13:55:08 -0700 Subject: [PATCH] kdump, vmcoreinfo: report memory sections virtual addresses KASLR memory randomization can randomize the base of the physical memory mapping (PAGE_OFFSET), vmalloc (VMALLOC_START) and vmemmap (VMEMMAP_START). Adding these variables on VMCOREINFO so tools can easily identify the base of each memory section. Link: http://lkml.kernel.org/r/1471531632-23003-1-git-send-email-thgarnie@google.com Signed-off-by: Thomas Garnier Acked-by: Baoquan He Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H . Peter Anvin" Cc: Eric Biederman Cc: Xunlei Pang Cc: HATAYAMA Daisuke Cc: Kees Cook Cc: Eugene Surovegin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/kernel/machine_kexec_64.c | 3 +++ include/linux/kexec.h | 6 ++++++ 2 files changed, 9 insertions(+) diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index 5a294e48b185..8c1f218926d7 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -337,6 +337,9 @@ void arch_crash_save_vmcoreinfo(void) #endif vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); + VMCOREINFO_PAGE_OFFSET(PAGE_OFFSET); + VMCOREINFO_VMALLOC_START(VMALLOC_START); + VMCOREINFO_VMEMMAP_START(VMEMMAP_START); } /* arch-dependent functionality related to kexec file-based syscall */ diff --git a/include/linux/kexec.h b/include/linux/kexec.h index d7437777baaa..406c33dcae13 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -259,6 +259,12 @@ phys_addr_t paddr_vmcoreinfo_note(void); vmcoreinfo_append_str("NUMBER(%s)=%ld\n", #name, (long)name) #define VMCOREINFO_CONFIG(name) \ vmcoreinfo_append_str("CONFIG_%s=y\n", #name) +#define VMCOREINFO_PAGE_OFFSET(value) \ + vmcoreinfo_append_str("PAGE_OFFSET=%lx\n", (unsigned long)value) +#define VMCOREINFO_VMALLOC_START(value) \ + vmcoreinfo_append_str("VMALLOC_START=%lx\n", (unsigned long)value) +#define VMCOREINFO_VMEMMAP_START(value) \ + vmcoreinfo_append_str("VMEMMAP_START=%lx\n", (unsigned long)value) extern struct kimage *kexec_image; extern struct kimage *kexec_crash_image;