iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

x86/decompressor: Assign paging related global variables earlier

Browse Source 
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@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230807162720.545787-9-ardb@kernel.org
This commit is contained in:
Ard Biesheuvel 2023-08-07 18:27:05 +02:00 committed by Borislav Petkov (AMD)
parent 8b63cba746
commit 00c6b0978e
2 changed files with 5 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/boot/compressed/misc.h
View File

@ -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: */

14
arch/x86/boot/compressed/pgtable_64.c
View File

@ -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
}