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SubjectRe: [PATCH v1] kdump, vmcoreinfo: report memory sections virtual addresses
Hi Thomas,

I used below code and it works. Since using VMCOREINFO_NUMBER can reuse
the existing struct number_table to import the data. It makes change
easier. But the place could be next to KERNEL_IMAGE_SIZE, or as your
patch did, both is fine.

---
kernel/kexec_core.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 5616755..81bde86 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -1469,6 +1469,9 @@ static int __init crash_save_vmcoreinfo_init(void)
VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
#ifdef CONFIG_X86
VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE);
+ VMCOREINFO_NUMBER(PAGE_OFFSET);
+ VMCOREINFO_NUMBER(VMALLOC_START);
+ VMCOREINFO_NUMBER(VMEMMAP_START);
#endif
#ifdef CONFIG_HUGETLB_PAGE
VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
--
2.5.5
On 08/18/16 at 07:47am, Thomas Garnier wrote:
> 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.
>
> Signed-off-by: Thomas Garnier <thgarnie@google.com>
> ---
> Based on next-20160817
> ---
> 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 fc3389f..b1f15a2 100644
> --- a/arch/x86/kernel/machine_kexec_64.c
> +++ b/arch/x86/kernel/machine_kexec_64.c
> @@ -338,6 +338,9 @@ void arch_crash_save_vmcoreinfo(void)
> vmcoreinfo_append_str("KERNELOFFSET=%lx\n",
> kaslr_offset());
> VMCOREINFO_PHYS_BASE(phys_base);
> + 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 d3ae429..cd3874c 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -261,6 +261,12 @@ phys_addr_t paddr_vmcoreinfo_note(void);
> vmcoreinfo_append_str("CONFIG_%s=y\n", #name)
> #define VMCOREINFO_PHYS_BASE(value) \
> vmcoreinfo_append_str("PHYS_BASE=%lx\n", (unsigned long)value)
> +#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;
> --
> 2.8.0.rc3.226.g39d4020
>
>
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec

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