[PATCH v5 04/16] x86/startup_64: Use RIP_REL_REF() to access __supported_pte_mask

From: Ard Biesheuvel
Date: Wed Feb 21 2024 - 06:37:28 EST


From: Ard Biesheuvel <ardb@xxxxxxxxxx>

__supported_pte_mask is accessed 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.

Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/x86/kernel/head64.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 2ac904110f6a..e2573ddae32f 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -177,7 +177,6 @@ unsigned long __head __startup_64(unsigned long physaddr,
p4dval_t *p4d;
pudval_t *pud;
pmdval_t *pmd, pmd_entry;
- pteval_t *mask_ptr;
bool la57;
int i;

@@ -259,8 +258,7 @@ unsigned long __head __startup_64(unsigned long physaddr,

pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
/* Filter out unsupported __PAGE_KERNEL_* bits: */
- mask_ptr = fixup_pointer(&__supported_pte_mask, physaddr);
- pmd_entry &= *mask_ptr;
+ pmd_entry &= RIP_REL_REF(__supported_pte_mask);
pmd_entry += sme_get_me_mask();
pmd_entry += physaddr;

--
2.44.0.rc0.258.g7320e95886-goog