Commit d9ec1158 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Ingo Molnar
Browse files

x86/boot/64: Use RIP_REL_REF() to assign 'phys_base' 



'phys_base' is assigned from code that executes from a 1:1 mapping so it
cannot use a plain access from C. Replace the use of fixup_pointer()
with RIP_REL_REF(), which is better and simpler.

While at it, move the assignment to before the addition of the SME mask
so there is no need to subtract it again, and drop the unnecessary
addition ('phys_base' is statically initialized to 0x0)

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240221113506.2565718-20-ardb+git@google.com
parent 5da79367

arch/x86/kernel/head64.c

+1 −6
Original line number Diff line number Diff line
@@ -192,6 +192,7 @@ unsigned long __head __startup_64(unsigned long physaddr, 
	 * and the address I am actually running at.

	 */

	load_delta = physaddr - (unsigned long)(_text - __START_KERNEL_map);

	RIP_REL_REF(phys_base) = load_delta;



	/* Is the address not 2M aligned? */

	if (load_delta & ~PMD_MASK)
@@ -301,12 +302,6 @@ unsigned long __head __startup_64(unsigned long physaddr, 
	for (; i < PTRS_PER_PMD; i++)

		pmd[i] &= ~_PAGE_PRESENT;



	/*

	 * Fixup phys_base - remove the memory encryption mask to obtain

	 * the true physical address.

	 */

	*fixup_long(&phys_base, physaddr) += load_delta - sme_get_me_mask();



	return sme_postprocess_startup(bp, pmd);

}