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| author | Brian Gerst <brgerst@gmail.com> | 2024-02-26 23:05:44 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2024-02-28 11:02:16 +0100 |
| commit | 11e36b0f7c2150a6453872b79555767b43c846d0 (patch) | |
| tree | 0493b027909783638eef78ed5b28f5fd67b722b5 /arch | |
| parent | x86/boot/64: Use RIP_REL_REF() to access early_top_pgt[] (diff) | |
| download | linux-11e36b0f7c2150a6453872b79555767b43c846d0.tar.xz linux-11e36b0f7c2150a6453872b79555767b43c846d0.zip | |
x86/boot/64: Load the final kernel GDT during early boot directly, remove startup_gdt[]
Instead of loading a duplicate GDT just for early boot, load the kernel
GDT from its physical address.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20240226220544.70769-1-brgerst@gmail.com
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/desc.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/head64.c | 13 |
2 files changed, 3 insertions, 11 deletions
diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h index ab97b22ac04a..52c015017990 100644 --- a/arch/x86/include/asm/desc.h +++ b/arch/x86/include/asm/desc.h @@ -46,6 +46,7 @@ struct gdt_page { } __attribute__((aligned(PAGE_SIZE))); DECLARE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page); +DECLARE_INIT_PER_CPU(gdt_page); /* Provide the original GDT */ static inline struct desc_struct *get_cpu_gdt_rw(unsigned int cpu) diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 72351c3121a6..fd77a266f29d 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -68,15 +68,6 @@ unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE_L4; EXPORT_SYMBOL(vmemmap_base); #endif -/* - * GDT used on the boot CPU before switching to virtual addresses. - */ -static struct desc_struct startup_gdt[GDT_ENTRIES] __initdata = { - [GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(DESC_CODE32, 0, 0xfffff), - [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(DESC_CODE64, 0, 0xfffff), - [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(DESC_DATA64, 0, 0xfffff), -}; - #ifdef CONFIG_X86_5LEVEL static void __head *fixup_pointer(void *ptr, unsigned long physaddr) { @@ -589,8 +580,8 @@ void __head startup_64_setup_gdt_idt(void) void *handler = NULL; struct desc_ptr startup_gdt_descr = { - .address = (unsigned long)&RIP_REL_REF(startup_gdt), - .size = sizeof(startup_gdt) - 1, + .address = (unsigned long)&RIP_REL_REF(init_per_cpu_var(gdt_page.gdt)), + .size = GDT_SIZE - 1, }; /* Load GDT */ |