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

Baoquan He
2018-10-18T03:59:58Z

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.

>
> 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
>
>
>