diff mbox

[v1] kdump, vmcoreinfo: report memory sections virtual addresses

Message ID 1471531632-23003-1-git-send-email-thgarnie@google.com
State New, archived
Headers show

Commit Message

Thomas Garnier Aug. 18, 2016, 2:47 p.m. UTC
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(+)

Comments

Baoquan He Aug. 19, 2016, 2:41 a.m. UTC | #1
This makes sense. Makedumpfile need this to parse memory sections.

Ack.

Acked-by: Baoquan He <bhe@redhat.com>

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)

Could it be better to define only one MACRO like VMCOREINFO_
> +#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
Kees Cook Aug. 19, 2016, 6:01 p.m. UTC | #2
On Thu, Aug 18, 2016 at 7:41 PM, Baoquan He <bhe@redhat.com> wrote:
>
> This makes sense. Makedumpfile need this to parse memory sections.

Yup, good addition.

Acked-by: Kees Cook <keescook@chromium.org>

-Kees

>
> Ack.
>
> Acked-by: Baoquan He <bhe@redhat.com>
>
> 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)
>
> Could it be better to define only one MACRO like VMCOREINFO_
>> +#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
diff mbox

Patch

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;