Hi Bhupesh,
On 8/20/2018 3:45 PM, Bhupesh Sharma wrote:
> Commit 94c97db3fe859ca14d7b38b0ae9ee0ffb83689d2 (arm64: Get
> 'info->page_offset' from PT_LOAD segments to support KASLR boot cases)
> added a method to determine 'info->page_offset' from PT_LOAD segments
> for arm64 platforms.
>
> In this commit we hardcoded the NOT_PADDR_ARM64 macro as
> 0x0000000010a80000UL which was a valid value on
> qualcomm-amberwing boards.
>
> However, I was testing this change on several other arm64 boards
> like apm-mustang, huawei-taishan and hp-moonshot and saw that
> this value can vary on the basic of the "Kernel code" memory range
> placement.
>
> This patch determines the "Kernel code" memory range from
> '/proc/iomem' listing and uses the same to determine the
> NOT_PADDR_ARM64 value, which makes this calculation platform
> independent and this works well on apm-mustang, huawei-taishan,
> qualcomm-amberwing and hp-moonshot platforms.
I don't have any arm64 system for now, but I think that a "Kernel code"
range in /proc/iomem on 2nd kernel will be different from the one on
1st kernel. Does it process /proc/vmcore correctly on 2nd kernel?
If it doesn't, we have to find another way..
This is the condition for x86_64:
if (virt_start != NOT_KV_ADDR ... *1 (0x0)
&& virt_start < __START_KERNEL_map ... *2 (0xffffffff80000000)
&& phys_start != NOT_PADDR) { ... *3 (~0ULL)
These are how we get the appropriate values on x86_64:
# readelf -l vmcore # I got with cp command
...
Type Offset VirtAddr PhysAddr
FileSiz MemSiz Flags Align
NOTE 0x0000000000001000 0x0000000000000000 0x0000000000000000 // PT_NOTE
0x00000000000009c8 0x00000000000009c8 0
LOAD 0x0000000000002000 0xffffffff96c00000 0x000000000f800000 skipped by *2
0x0000000001656000 0x0000000001656000 RWE 0
LOAD 0x0000000001658000 0xffff976b00001000 0x0000000000001000 picked
0x000000000009ec00 0x000000000009ec00 RWE 0
LOAD 0x00000000016f7000 0xffff976b00100000 0x0000000000100000
0x000000002cf00000 0x000000002cf00000 RWE 0
LOAD 0x000000002e5f7000 0xffff976b35000000 0x0000000035000000
0x000000004aff7000 0x000000004aff7000 RWE 0
# readelf -l /proc/kcore
...
Type Offset VirtAddr PhysAddr
FileSiz MemSiz Flags Align
NOTE 0x0000000000000238 0x0000000000000000 0x0000000000000000 // PT_NOTE
0x00000000000011e4 0x0000000000000000 0
LOAD 0x00007fffff602000 0xffffffffff600000 0xffffffffffffffff skipped by *3
0x0000000000800000 0x0000000000800000 RWE 1000
LOAD 0x00007fff96c02000 0xffffffff96c00000 0x000000000f800000 skipped by *2
0x0000000001656000 0x0000000001656000 RWE 1000
LOAD 0x00003228c0002000 0xffffb228c0000000 0xffffffffffffffff skipped by *3
0x00001fffffffffff 0x00001fffffffffff RWE 1000
LOAD 0x00007fffc0002000 0xffffffffc0000000 0xffffffffffffffff skipped by *2
0x000000003f000000 0x000000003f000000 RWE 1000
LOAD 0x0000176b00003000 0xffff976b00001000 0x0000000000001000 picked
0x000000000009e000 0x000000000009e000 RWE 1000
LOAD 0x00006f1880002000 0xffffef1880000000 0xffffffffffffffff
0x0000000000003000 0x0000000000003000 RWE 1000
LOAD 0x0000176b00102000 0xffff976b00100000 0x0000000000100000
0x000000007fef7000 0x000000007fef7000 RWE 1000
LOAD 0x00006f1880006000 0xffffef1880004000 0xffffffffffffffff
0x0000000001ffc000 0x0000000001ffc000 RWE 1000
If a value like NOT_PADDR_ARM64 is needed, can we find the condition
which consists of only static and common values first?
It would be better that there is something evidence or data as well.
Thanks,
Kazu
>
> Here are some logs on my huawei-taishan board with kernel version
> 4.18.0-rc8:
>
> The kernel version is not supported.
> The makedumpfile operation may be incomplete.
>
> TYPE PAGES EXCLUDABLE DESCRIPTION
> ----------------------------------------------------------------------
> ZERO 83081 yes Pages filled with zero
> NON_PRI_CACHE 6330 yes Cache pages without private flag
> PRI_CACHE 927 yes Cache pages with private flag
> USER 2659 yes User process pages
> FREE 4053998 yes Free pages
> KERN_DATA 35331 no Dumpable kernel data
>
> page size: 65536
> Total pages on system: 4182326
> Total size on system: 274092916736 Byte
>
> Fixes: 94c97db3fe859ca14d7b38b0ae9ee0ffb83689d2 (arm64: Get
> 'info->page_offset' from PT_LOAD segments to support KASLR boot
> cases)
>
> Signed-off-by: Bhupesh Sharma <bhsharma@xxxxxxxxxx>
> ---
> arch/arm64.c | 26 ++++++++++++++++++++++++--
> makedumpfile.h | 1 -
> 2 files changed, 24 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm64.c b/arch/arm64.c
> index 362609668ea2..e0b30c812124 100644
> --- a/arch/arm64.c
> +++ b/arch/arm64.c
> @@ -303,10 +303,25 @@ get_xen_info_arm64(void)
> return ERROR;
> }
>
> +/* We want to exclude the kernel code mem region while calculating the
> + * info->page_offset for arm64 arch
> + */
> +static struct memory_range kernel_code_mem_range;
> +
> +static int kernel_code_resource_callback(void *data, int nr,
> + char *str,
> + unsigned long base,
> + unsigned long length)
> +{
> + kernel_code_mem_range.start = base;
> + kernel_code_mem_range.end = base + length - 1;
> + return 0;
> +}
> +
> int
> get_versiondep_info_arm64(void)
> {
> - int i;
> + int i, ret;
> unsigned long long phys_start;
> unsigned long long virt_start;
> ulong _stext;
> @@ -333,6 +348,13 @@ get_versiondep_info_arm64(void)
> return FALSE;
> }
>
> + ret = iomem_for_each_line("Kernel code\n",
> + kernel_code_resource_callback, NULL);
> + if (ret != 1) {
> + ERRMSG("Cannot find a proper Kernel code memory range in /proc/iomem\n");
> + return FALSE;
> + }
> +
> if (get_num_pt_loads()) {
> for (i = 0;
> get_pt_load(i, &phys_start, NULL, &virt_start, NULL);
> @@ -340,7 +362,7 @@ get_versiondep_info_arm64(void)
> if (virt_start != NOT_KV_ADDR
> && virt_start < __START_KERNEL_map
> && phys_start != NOT_PADDR
> - && phys_start != NOT_PADDR_ARM64) {
> + && phys_start != kernel_code_mem_range.start) {
> info->page_offset = virt_start - phys_start;
> DEBUG_MSG("info->page_offset: %lx, VA_BITS: %d\n",
> info->page_offset, va_bits);
> diff --git a/makedumpfile.h b/makedumpfile.h
> index 3244d31ae43a..9fefe150829f 100644
> --- a/makedumpfile.h
> +++ b/makedumpfile.h
> @@ -544,7 +544,6 @@ unsigned long get_kvbase_arm64(void);
> #define KVBASE get_kvbase_arm64()
>
> #define __START_KERNEL_map (0xffffffff80000000UL)
> -#define NOT_PADDR_ARM64 (0x0000000010a80000UL)
>
> #endif /* aarch64 */
>
> --
> 2.7.4
>
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