The following commit has been merged into the x86/boot branch of tip:
Commit-ID: 00c6b0978ec182f1a672095930872168b9d5b1e2
Gitweb: https://git.kernel.org/tip/00c6b0978ec182f1a672095930872168b9d5b1e2
Author: Ard Biesheuvel <ardb@xxxxxxxxxx>
AuthorDate: Mon, 07 Aug 2023 18:27:05 +02:00
Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Mon, 07 Aug 2023 20:42:11 +02:00
x86/decompressor: Assign paging related global variables earlier
There is no need to defer the assignment of the paging related global
variables 'pgdir_shift' and 'ptrs_per_p4d' until after the trampoline is
cleaned up, so assign them as soon as it is clear that 5-level paging
will be enabled.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230807162720.545787-9-ardb@xxxxxxxxxx
---
arch/x86/boot/compressed/misc.h | 2 --
arch/x86/boot/compressed/pgtable_64.c | 14 +++++---------
2 files changed, 5 insertions(+), 11 deletions(-)
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 964fe90..cc70d3f 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -179,9 +179,7 @@ static inline int count_immovable_mem_regions(void) { return 0; }
#endif
/* ident_map_64.c */
-#ifdef CONFIG_X86_5LEVEL
extern unsigned int __pgtable_l5_enabled, pgdir_shift, ptrs_per_p4d;
-#endif
extern void kernel_add_identity_map(unsigned long start, unsigned long end);
/* Used by PAGE_KERN* macros: */
diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c
index 2ac12ff..f8092d3 100644
--- a/arch/x86/boot/compressed/pgtable_64.c
+++ b/arch/x86/boot/compressed/pgtable_64.c
@@ -130,6 +130,11 @@ struct paging_config paging_prepare(void *rmode)
native_cpuid_eax(0) >= 7 &&
(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31)))) {
paging_config.l5_required = 1;
+
+ /* Initialize variables for 5-level paging */
+ __pgtable_l5_enabled = 1;
+ pgdir_shift = 48;
+ ptrs_per_p4d = 512;
}
paging_config.trampoline_start = find_trampoline_placement();
@@ -206,13 +211,4 @@ void cleanup_trampoline(void *pgtable)
/* Restore trampoline memory */
memcpy(trampoline_32bit, trampoline_save, TRAMPOLINE_32BIT_SIZE);
-
- /* Initialize variables for 5-level paging */
-#ifdef CONFIG_X86_5LEVEL
- if (__read_cr4() & X86_CR4_LA57) {
- __pgtable_l5_enabled = 1;
- pgdir_shift = 48;
- ptrs_per_p4d = 512;
- }
-#endif
}
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