Re: [PATCH v9 0/8] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory

[Chao Fan <fanc.fnst@cn.fujitsu.com>]

On Thu, Oct 18, 2018 at 11:59:58AM +0800, Baoquan He wrote:
>On 10/17/18 at 06:20pm, Chao Fan wrote:
>> In the earliest time, I tried to dig ACPI tabls to solve this problem.
>> But I didn't splite the code in 'compressed/' and ACPI code, so the patch
>> is hard to follow so refused by community.
>> Somebody suggest to add a kernel parameter to specify the
>> immovable memory so that limit kaslr in these regions. Then I make
>> a new patchset. After several versions, Ingo gave a suggestion:
>> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1634024.html
>> Follow Ingo's suggestion, imitate the ACPI code to parse the acpi
>> tables, so that the kaslr can get necessary memory information in
>> ACPI tables.
>> I think ACPI code is an independent part, so imitate the codes
>> and functions to 'compressed/' directory, so that kaslr won't
>> influence the initialization of ACPI.
>> 
>> PATCH 1/3 Add acpitb.c to provide functions to parse ACPI code.
>> PATCH 2/3 If CONFIG_MEMORY_HOTREMOVE enabled, walk all nodes and
>>           store the information of immovable memory regions.
>> PATCH 3/3 According to the immovable memory regions, filter the
>>           immovable regions which KASLR can choose.
>
>Chao, seems you didn't update above accordingly.

oops, sorry for that.

Thanks,
Chao Fan

>
>> 
>> v1->v2:
>>  -  Simplify some code.
>> Follow Baoquan He's suggestion:
>>  - Reuse the head file of acpi code.
>> 
>> v2->v3:
>>  - Test in more conditions, so remove the 'RFC' tag.
>>  - Change some comments.
>> 
>> v3->v4:
>> Follow Thomas Gleixner's suggetsion:
>>  - Put the whole efi related function into #define CONFIG_EFI and return
>>    false in the other stub.
>>  - Simplify two functions in head file.
>> 
>> v4->v5:
>> Follow Dou Liyang's suggestion:
>>  - Add more comments about some functions based on kernel code.
>>  - Change some typo in comments.
>>  - Clean useless variable.
>>  - Add check for the boundary of array.
>>  - Add check for 'movable_node' parameter
>> 
>> v5->v6:
>> Follow Baoquan He's suggestion:
>>  - Change some log.
>>  - Add the check for acpi_rsdp
>>  - Change some code logical to make code clear
>> 
>> v6->v7:
>> Follow Rafael's suggestion:
>>  - Add more comments and patch log.
>> Follow test robot's suggestion:
>>  - Add "static" tag for function
>> 
>> v7-v8:
>> Follow Kees Cook's suggestion:
>>  - Use mem_overlaps() to check memory region.
>>  - Use #ifdef in the definition of function.
>> 
>> v8-v9:
>> Follow Boris' suggetion:
>>  - Change code style.
>>  - Splite PATCH 1/3 to more path.
>>  - Introduce some new function
>>  - Use existing function to rework some code
>> Follow Masayoshi's suggetion:
>>  - Make code more readable
>> 
>> Any comments will be welcome.
>> 
>> 
>> Chao Fan (8):
>>   x86/boot: Introduce cmdline_find_option_arg()to detect if option=arg
>>     in cmdline
>>   x86/boot: Copy kstrtoull() to compressed period
>>   x86/boot: Add efi_get_rsdp_addr() to dig out RSDP from EFI table
>>   x86/boot: Add bios_get_rsdp_addr() to search RSDP in memory
>>   x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdlien from kexec
>>   x86/boot: Dig out SRAT table from RSDP and find immovable memory
>>   x86/boot/KASLR: Walk srat tables to filter immovable memory
>>   x86/boot/KASLR: Limit kaslr to choosing the immovable memory
>> 
>>  arch/x86/boot/compressed/Makefile  |   4 +
>>  arch/x86/boot/compressed/acpitb.c  | 354 +++++++++++++++++++++++++++++
>>  arch/x86/boot/compressed/cmdline.c |  15 ++
>>  arch/x86/boot/compressed/kaslr.c   |  77 ++++++-
>>  arch/x86/boot/compressed/misc.c    |  88 +++++++
>>  arch/x86/boot/compressed/misc.h    |  15 ++
>>  6 files changed, 542 insertions(+), 11 deletions(-)
>>  create mode 100644 arch/x86/boot/compressed/acpitb.c
>> 
>> -- 
>> 2.17.2
>> 
>> 
>> 
>
>