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 at 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 at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/kexec
