The following commit has been merged into the x86/boot branch of tip:
Commit-ID: b0fe5fb6095be0f68b570c4cf4cd86b7e70c2e38
Gitweb: https://git.kernel.org/tip/b0fe5fb6095be0f68b570c4cf4cd86b7e70c2e38
Author: Ard Biesheuvel <ardb@xxxxxxxxxx>
AuthorDate: Wed, 21 Feb 2024 12:35:10 +01:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Mon, 26 Feb 2024 12:58:35 +01:00
x86/boot/64: Use RIP_REL_REF() to access early_dynamic_pgts[]
early_dynamic_pgts[] and next_early_pgt are 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>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240221113506.2565718-21-ardb+git@xxxxxxxxxx
---
arch/x86/kernel/head64.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index f98f5b6..2ac9041 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -170,6 +170,7 @@ static unsigned long __head sme_postprocess_startup(struct boot_params *bp, pmdv
unsigned long __head __startup_64(unsigned long physaddr,
struct boot_params *bp)
{
+ pmd_t (*early_pgts)[PTRS_PER_PMD] = RIP_REL_REF(early_dynamic_pgts);
unsigned long load_delta, *p;
unsigned long pgtable_flags;
pgdval_t *pgd;
@@ -179,7 +180,6 @@ unsigned long __head __startup_64(unsigned long physaddr,
pteval_t *mask_ptr;
bool la57;
int i;
- unsigned int *next_pgt_ptr;
la57 = check_la57_support(physaddr);
@@ -231,15 +231,14 @@ unsigned long __head __startup_64(unsigned long physaddr,
* it avoids problems around wraparound.
*/
- next_pgt_ptr = fixup_pointer(&next_early_pgt, physaddr);
- pud = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
- pmd = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++], physaddr);
+ pud = &early_pgts[0]->pmd;
+ pmd = &early_pgts[1]->pmd;
+ RIP_REL_REF(next_early_pgt) = 2;
pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask();
if (la57) {
- p4d = fixup_pointer(early_dynamic_pgts[(*next_pgt_ptr)++],
- physaddr);
+ p4d = &early_pgts[RIP_REL_REF(next_early_pgt)++]->pmd;
i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
pgd[i + 0] = (pgdval_t)p4d + pgtable_flags;
|