[PATCH 00/15][V4] kexec: A new system call to allow in kernel loading

From: Vivek Goyal
Date: Thu Jun 26 2014 - 16:35:17 EST


Hi,

This is V4 of the patchset. Previous versions were posted here.

V1: https://lkml.org/lkml/2013/11/20/540
V2: https://lkml.org/lkml/2014/1/27/331
V3: https://lkml.org/lkml/2014/6/3/432

Changes since v3:

- Took care of most of the review comments from V3.
- Stopped building purgatory for 32bit.
- If 64bit EFI is not enabled (EFI_64BIT) return error in kernel loading.
- If EFI OLD_MEMMAP is being used, do not do EFI setup and user space is
expected to pass acpi_rsdp=<addr> param and boot second kernel in non
efi mode.
- move machine_kexec.c code into kexec-bzimage64.c
- Renamed kexec-bzimage.c to kexec-bzimage64.c to reflect the fact that
it is only 64bit bzimage loader.

This patch series is generated on top of 3.16.0-rc2.

This patch series does not do kernel signature verification yet. I plan
to post another patch series for that. Now distributions are already signing
PE/COFF bzImage with PKCS7 signature I plan to parse and verify those
signatures.

Primary goal of this patchset is to prepare groundwork so that kernel
image can be signed and signatures be verified during kexec load. This
should help with two things.

- It should allow kexec/kdump on secureboot enabled machines.

- In general it can help even without secureboot. By being able to verify
kernel image signature in kexec, it should help with avoiding module
signing restrictions. Matthew Garret showed how to boot into a custom
kernel, modify first kernel's memory and then jump back to old kernel and
bypass any policy one wants to.

I hope these patches can be queued up for 3.17. Even without signature
verification support, they provide new syscall functionality. But I
wil leave it to maintainers to decide if they want signature verification
support also be ready to merge before they merge this patchset.

Any feedback is welcome.

Thanks
Vivek

Vivek Goyal (15):
bin2c: Move bin2c in scripts/basic
kernel: Build bin2c based on config option CONFIG_BUILD_BIN2C
kexec: rename unusebale_pages to unusable_pages
kexec: Move segment verification code in a separate function
kexec: Use common function for kimage_normal_alloc() and
kimage_crash_alloc()
resource: Provide new functions to walk through resources
kexec: Make kexec_segment user buffer pointer a union
kexec: New syscall kexec_file_load() declaration
kexec: Implementation of new syscall kexec_file_load
purgatory/sha256: Provide implementation of sha256 in purgaotory
context
purgatory: Core purgatory functionality
kexec: Load and Relocate purgatory at kernel load time
kexec-bzImage64: Support for loading bzImage using 64bit entry
kexec: Support for kexec on panic using new system call
kexec: Support kexec/kdump on EFI systems

arch/x86/Kbuild | 4 +
arch/x86/Kconfig | 3 +
arch/x86/Makefile | 8 +
arch/x86/include/asm/crash.h | 9 +
arch/x86/include/asm/kexec-bzimage64.h | 6 +
arch/x86/include/asm/kexec.h | 40 +
arch/x86/kernel/Makefile | 1 +
arch/x86/kernel/crash.c | 563 ++++++++++++++
arch/x86/kernel/kexec-bzimage64.c | 532 +++++++++++++
arch/x86/kernel/machine_kexec_64.c | 228 ++++++
arch/x86/purgatory/Makefile | 30 +
arch/x86/purgatory/entry64.S | 101 +++
arch/x86/purgatory/purgatory.c | 72 ++
arch/x86/purgatory/setup-x86_64.S | 58 ++
arch/x86/purgatory/sha256.c | 283 +++++++
arch/x86/purgatory/sha256.h | 22 +
arch/x86/purgatory/stack.S | 19 +
arch/x86/purgatory/string.c | 13 +
arch/x86/syscalls/syscall_64.tbl | 1 +
drivers/firmware/efi/runtime-map.c | 21 +
include/linux/efi.h | 19 +
include/linux/ioport.h | 6 +
include/linux/kexec.h | 101 ++-
include/linux/syscalls.h | 4 +
include/uapi/linux/kexec.h | 11 +
init/Kconfig | 5 +
kernel/Makefile | 2 +-
kernel/kexec.c | 1322 ++++++++++++++++++++++++++++----
kernel/resource.c | 101 ++-
kernel/sys_ni.c | 1 +
scripts/.gitignore | 1 -
scripts/Makefile | 1 -
scripts/basic/.gitignore | 1 +
scripts/basic/Makefile | 1 +
scripts/basic/bin2c.c | 35 +
scripts/bin2c.c | 36 -
36 files changed, 3463 insertions(+), 198 deletions(-)
create mode 100644 arch/x86/include/asm/crash.h
create mode 100644 arch/x86/include/asm/kexec-bzimage64.h
create mode 100644 arch/x86/kernel/kexec-bzimage64.c
create mode 100644 arch/x86/purgatory/Makefile
create mode 100644 arch/x86/purgatory/entry64.S
create mode 100644 arch/x86/purgatory/purgatory.c
create mode 100644 arch/x86/purgatory/setup-x86_64.S
create mode 100644 arch/x86/purgatory/sha256.c
create mode 100644 arch/x86/purgatory/sha256.h
create mode 100644 arch/x86/purgatory/stack.S
create mode 100644 arch/x86/purgatory/string.c
create mode 100644 scripts/basic/bin2c.c
delete mode 100644 scripts/bin2c.c

--
1.9.0

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