kexec: load and relocate purgatory at kernel load time

Load purgatory code in RAM and relocate it based on the location.
Relocation code has been inspired by module relocation code and purgatory
relocation code in kexec-tools.

Also compute the checksums of loaded kexec segments and store them in
purgatory.

Arch independent code provides this functionality so that arch dependent
bootloaders can make use of it.

Helper functions are provided to get/set symbol values in purgatory which
are used by bootloaders later to set things like stack and entry point of
second kernel etc.

Signed-off-by: Vivek Goyal <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Michael Kerrisk <[email protected]>
Cc: Yinghai Lu <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Matthew Garrett <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Dave Young <[email protected]>
Cc: WANG Chao <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Vivek Goyal 2014-08-08 14:26:04 -07:00 • committed by Linus Torvalds
commit 12db5562e0
12 changed files with 736 additions and 1 deletions

View file

@ -191,6 +191,8 @@ source "kernel/Kconfig.hz"
config KEXEC
bool "kexec system call"
select CRYPTO
select CRYPTO_SHA256
---help---
kexec is a system call that implements the ability to shutdown your
current kernel, and to start another kernel. It is like a reboot