On Wed, Apr 24, 2024 at 05:53:12PM +0200, Ard Biesheuvel wrote: > From: Ard Biesheuvel <ardb@xxxxxxxxxx> > > The x86 purgatory, which does little more than verify a SHA-256 hash of > the loaded segments, currently uses three different stacks: > - one in .bss that is used to call the purgatory C code > - one in .rodata that is only used to switch to an updated code segment > descriptor in the GDT > - one in .data, which allows it to be prepopulated from the kexec loader > in theory, but this is not actually being taken advantage of. > > Simplify this, by dropping the latter two stacks, as well as the loader > logic that programs RSP. > > Both the stacks in .bss and .data are 4k aligned, but 16 byte alignment > is more than sufficient. > > Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> > --- > arch/x86/include/asm/kexec.h | 1 - > arch/x86/kernel/kexec-bzimage64.c | 8 -------- > arch/x86/purgatory/entry64.S | 8 -------- > arch/x86/purgatory/setup-x86_64.S | 2 +- > arch/x86/purgatory/stack.S | 18 ------------------ This needs a small fix up to build. make[6]: *** No rule to make target 'arch/x86/purgatory/stack.o', needed by 'arch/x86/purgatory/purgatory.ro'. diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index acc09799af2a..2b6b2fb033d6 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 OBJECT_FILES_NON_STANDARD := y -purgatory-y := purgatory.o stack.o setup-x86_$(BITS).o sha256.o entry64.o string.o +purgatory-y := purgatory.o setup-x86_$(BITS).o sha256.o entry64.o string.o targets += $(purgatory-y) PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y)) _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
