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    SubjectRe: [PATCH v1] kdump, vmcoreinfo: report memory sections virtual addresses
    On Mon, Aug 29, 2016 at 06:11:37PM +0800, Baoquan He wrote:
    > 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.

    I think we'd better avoid adding arch-specific code in generic code
    if possible, especially in this case, since there is a dedicated interface,
    arch_crash_save_vmcoreinfo().

    -Takahiro AKASHI

    > ---
    > 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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