diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2024-03-22 10:41:07 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2024-03-24 05:00:36 +0100 |
| commit | 9843231c97267d72be38a0409f5097987bc2cfa4 (patch) | |
| tree | 622dec3c74458613cad8ab43d8e73736075a8657 | |
| parent | 4d0d7e7852752ea56375ac8645f0239e21ca2b50 (diff) | |
| download | lwn-9843231c97267d72be38a0409f5097987bc2cfa4.tar.gz lwn-9843231c97267d72be38a0409f5097987bc2cfa4.zip | |
x86/boot/64: Move 5-level paging global variable assignments back
Commit 63bed9660420 ("x86/startup_64: Defer assignment of 5-level paging
global variables") moved assignment of 5-level global variables to later
in the boot in order to avoid having to use RIP relative addressing in
order to set them. However, when running with 5-level paging and SME
active (mem_encrypt=on), the variables are needed as part of the page
table setup needed to encrypt the kernel (using pgd_none(), p4d_offset(),
etc.). Since the variables haven't been set, the page table manipulation
is done as if 4-level paging is active, causing the system to crash on
boot.
While only a subset of the assignments that were moved need to be set
early, move all of the assignments back into check_la57_support() so that
these assignments aren't spread between two locations. Instead of just
reverting the fix, this uses the new RIP_REL_REF() macro when assigning
the variables.
Fixes: 63bed9660420 ("x86/startup_64: Defer assignment of 5-level paging global variables")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/2ca419f4d0de719926fd82353f6751f717590a86.1711122067.git.thomas.lendacky@amd.com
| -rw-r--r-- | arch/x86/kernel/head64.c | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 7d2eb035b6a3..a817ed0724d1 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -81,6 +81,13 @@ static inline bool check_la57_support(void) if (!(native_read_cr4() & X86_CR4_LA57)) return false; + RIP_REL_REF(__pgtable_l5_enabled) = 1; + RIP_REL_REF(pgdir_shift) = 48; + RIP_REL_REF(ptrs_per_p4d) = 512; + RIP_REL_REF(page_offset_base) = __PAGE_OFFSET_BASE_L5; + RIP_REL_REF(vmalloc_base) = __VMALLOC_BASE_L5; + RIP_REL_REF(vmemmap_base) = __VMEMMAP_BASE_L5; + return true; } @@ -431,15 +438,6 @@ asmlinkage __visible void __init __noreturn x86_64_start_kernel(char * real_mode (__START_KERNEL & PGDIR_MASK))); BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END); - if (check_la57_support()) { - __pgtable_l5_enabled = 1; - pgdir_shift = 48; - ptrs_per_p4d = 512; - page_offset_base = __PAGE_OFFSET_BASE_L5; - vmalloc_base = __VMALLOC_BASE_L5; - vmemmap_base = __VMEMMAP_BASE_L5; - } - cr4_init_shadow(); /* Kill off the identity-map trampoline */ |