On Tue, Aug 15, 2017 at 05:09:26PM +0800, Miles Chen wrote:

After the kernel ASLR, the module virtual address is moved to
[module_alloc_base, module_alloc_base + MODULES_VSIZE).
However, the MODULES_VADDR is still defined as a constant and functions
like is_vmalloc_or_module_addr() and dump function will not able to
use correct module range information.

Use module_alloc_base to define MODULES_VADDR. I tested the patch under
three different conditions:
1.CONFIG_RANDOMIZE_BASE=y, seed=0, CONFIG_KASAN=n
2.CONFIG_RANDOMIZE_BASE=y, seed=0x2304909023333333, CONFIG_KASAN=n
3.CONFIG_RANDOMIZE_BASE=y, seed=0x2304909023333333, CONFIG_KASAN=y

test log:

1.CONFIG_RANDOMIZE_BASE=y, seed=0, CONFIG_KASAN=n

[    0.000000] Virtual kernel memory layout:
[    0.000000]     modules : 0xffffff8000550000 - 0xffffff8008550000   (   128 MB)

Minor nit: but it might be worth putting this after the vmalloc line in
the case where they overlap.

[    0.000000]     vmalloc : 0xffffff8008000000 - 0xffffffbebfff0000   (   250 GB)
[    0.000000]       .text : 0xffffff8008080000 - 0xffffff8008550000   (  4928 KB)
[    0.000000]     .rodata : 0xffffff8008550000 - 0xffffff80086a0000   (  1344 KB)
[    0.000000]       .init : 0xffffff80086a0000 - 0xffffff8008a30000   (  3648 KB)
[    0.000000]       .data : 0xffffff8008a30000 - 0xffffff8008ab9200   (   549 KB)
[    0.000000]        .bss : 0xffffff8008ab9200 - 0xffffff8008b0b238   (   329 KB)
[    0.000000]     fixed   : 0xffffffbefe7fd000 - 0xffffffbefec00000   (  4108 KB)
[    0.000000]     PCI I/O : 0xffffffbefee00000 - 0xffffffbeffe00000   (    16 MB)
[    0.000000]     vmemmap : 0xffffffbf00000000 - 0xffffffc000000000   (     4 GB maximum)
[    0.000000]               0xffffffbf00000000 - 0xffffffbf02000000   (    32 MB actual)
[    0.000000]     memory  : 0xffffffc000000000 - 0xffffffc080000000   (  2048 MB)

\# cat kernel_page_tables
---[ Modules start ]---
---[ Modules end ]---

I still reckon we should just omit talking about the modules area at all
for the cases where they're mapped entirely within vmalloc here.

Will