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e81dc127ef
Mitigating the Intel SKL RSB underflow issue in software requires to track the call depth. That is every CALL and every RET need to be intercepted and additional code injected. The existing retbleed mitigations already include means of redirecting RET to __x86_return_thunk; this can be re-purposed and RET can be redirected to another function doing RET accounting. CALL accounting will use the function padding introduced in prior patches. For each CALL instruction, the destination symbol's padding is rewritten to do the accounting and the CALL instruction is adjusted to call into the padding. This ensures only affected CPUs pay the overhead of this accounting. Unaffected CPUs will leave the padding unused and have their 'JMP __x86_return_thunk' replaced with an actual 'RET' instruction. Objtool has been modified to supply a .call_sites section that lists all the 'CALL' instructions. Additionally the paravirt instruction sites are iterated since they will have been patched from an indirect call to direct calls (or direct instructions in which case it'll be ignored). Module handling and the actual thunk code for SKL will be added in subsequent steps. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111147.470877038@infradead.org
676 lines
18 KiB
ArmAsm
676 lines
18 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* linux/arch/x86/kernel/head_64.S -- start in 32bit and switch to 64bit
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*
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* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
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* Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
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* Copyright (C) 2000 Karsten Keil <kkeil@suse.de>
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* Copyright (C) 2001,2002 Andi Kleen <ak@suse.de>
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* Copyright (C) 2005 Eric Biederman <ebiederm@xmission.com>
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*/
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#include <linux/linkage.h>
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#include <linux/threads.h>
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#include <linux/init.h>
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#include <linux/pgtable.h>
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#include <asm/segment.h>
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#include <asm/page.h>
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#include <asm/msr.h>
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#include <asm/cache.h>
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#include <asm/processor-flags.h>
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#include <asm/percpu.h>
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#include <asm/nops.h>
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#include "../entry/calling.h"
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#include <asm/export.h>
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#include <asm/nospec-branch.h>
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#include <asm/fixmap.h>
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/*
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* We are not able to switch in one step to the final KERNEL ADDRESS SPACE
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* because we need identity-mapped pages.
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*/
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#define l4_index(x) (((x) >> 39) & 511)
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#define pud_index(x) (((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
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L4_PAGE_OFFSET = l4_index(__PAGE_OFFSET_BASE_L4)
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L4_START_KERNEL = l4_index(__START_KERNEL_map)
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L3_START_KERNEL = pud_index(__START_KERNEL_map)
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.text
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__HEAD
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.code64
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SYM_CODE_START_NOALIGN(startup_64)
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UNWIND_HINT_EMPTY
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/*
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* At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
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* and someone has loaded an identity mapped page table
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* for us. These identity mapped page tables map all of the
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* kernel pages and possibly all of memory.
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*
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* %rsi holds a physical pointer to real_mode_data.
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*
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* We come here either directly from a 64bit bootloader, or from
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* arch/x86/boot/compressed/head_64.S.
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*
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* We only come here initially at boot nothing else comes here.
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*
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* Since we may be loaded at an address different from what we were
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* compiled to run at we first fixup the physical addresses in our page
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* tables and then reload them.
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*/
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/* Set up the stack for verify_cpu(), similar to initial_stack below */
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leaq (__end_init_task - FRAME_SIZE)(%rip), %rsp
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leaq _text(%rip), %rdi
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/*
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* initial_gs points to initial fixed_percpu_data struct with storage for
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* the stack protector canary. Global pointer fixups are needed at this
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* stage, so apply them as is done in fixup_pointer(), and initialize %gs
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* such that the canary can be accessed at %gs:40 for subsequent C calls.
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*/
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movl $MSR_GS_BASE, %ecx
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movq initial_gs(%rip), %rax
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movq $_text, %rdx
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subq %rdx, %rax
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addq %rdi, %rax
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movq %rax, %rdx
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shrq $32, %rdx
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wrmsr
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pushq %rsi
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call startup_64_setup_env
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popq %rsi
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#ifdef CONFIG_AMD_MEM_ENCRYPT
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/*
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* Activate SEV/SME memory encryption if supported/enabled. This needs to
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* be done now, since this also includes setup of the SEV-SNP CPUID table,
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* which needs to be done before any CPUID instructions are executed in
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* subsequent code.
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*/
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movq %rsi, %rdi
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pushq %rsi
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call sme_enable
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popq %rsi
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#endif
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/* Now switch to __KERNEL_CS so IRET works reliably */
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pushq $__KERNEL_CS
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leaq .Lon_kernel_cs(%rip), %rax
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pushq %rax
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lretq
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.Lon_kernel_cs:
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UNWIND_HINT_EMPTY
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/* Sanitize CPU configuration */
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call verify_cpu
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/*
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* Perform pagetable fixups. Additionally, if SME is active, encrypt
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* the kernel and retrieve the modifier (SME encryption mask if SME
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* is active) to be added to the initial pgdir entry that will be
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* programmed into CR3.
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*/
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leaq _text(%rip), %rdi
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pushq %rsi
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call __startup_64
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popq %rsi
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/* Form the CR3 value being sure to include the CR3 modifier */
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addq $(early_top_pgt - __START_KERNEL_map), %rax
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jmp 1f
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SYM_CODE_END(startup_64)
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SYM_CODE_START(secondary_startup_64)
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UNWIND_HINT_EMPTY
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ANNOTATE_NOENDBR
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/*
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* At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
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* and someone has loaded a mapped page table.
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*
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* %rsi holds a physical pointer to real_mode_data.
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*
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* We come here either from startup_64 (using physical addresses)
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* or from trampoline.S (using virtual addresses).
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*
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* Using virtual addresses from trampoline.S removes the need
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* to have any identity mapped pages in the kernel page table
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* after the boot processor executes this code.
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*/
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/* Sanitize CPU configuration */
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call verify_cpu
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/*
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* The secondary_startup_64_no_verify entry point is only used by
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* SEV-ES guests. In those guests the call to verify_cpu() would cause
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* #VC exceptions which can not be handled at this stage of secondary
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* CPU bringup.
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*
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* All non SEV-ES systems, especially Intel systems, need to execute
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* verify_cpu() above to make sure NX is enabled.
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*/
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SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL)
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UNWIND_HINT_EMPTY
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ANNOTATE_NOENDBR
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/*
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* Retrieve the modifier (SME encryption mask if SME is active) to be
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* added to the initial pgdir entry that will be programmed into CR3.
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*/
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#ifdef CONFIG_AMD_MEM_ENCRYPT
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movq sme_me_mask, %rax
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#else
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xorq %rax, %rax
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#endif
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/* Form the CR3 value being sure to include the CR3 modifier */
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addq $(init_top_pgt - __START_KERNEL_map), %rax
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1:
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#ifdef CONFIG_X86_MCE
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/*
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* Preserve CR4.MCE if the kernel will enable #MC support.
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* Clearing MCE may fault in some environments (that also force #MC
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* support). Any machine check that occurs before #MC support is fully
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* configured will crash the system regardless of the CR4.MCE value set
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* here.
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*/
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movq %cr4, %rcx
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andl $X86_CR4_MCE, %ecx
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#else
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movl $0, %ecx
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#endif
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/* Enable PAE mode, PGE and LA57 */
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orl $(X86_CR4_PAE | X86_CR4_PGE), %ecx
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#ifdef CONFIG_X86_5LEVEL
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testl $1, __pgtable_l5_enabled(%rip)
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jz 1f
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orl $X86_CR4_LA57, %ecx
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1:
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#endif
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movq %rcx, %cr4
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/* Setup early boot stage 4-/5-level pagetables. */
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addq phys_base(%rip), %rax
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/*
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* For SEV guests: Verify that the C-bit is correct. A malicious
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* hypervisor could lie about the C-bit position to perform a ROP
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* attack on the guest by writing to the unencrypted stack and wait for
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* the next RET instruction.
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* %rsi carries pointer to realmode data and is callee-clobbered. Save
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* and restore it.
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*/
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pushq %rsi
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movq %rax, %rdi
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call sev_verify_cbit
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popq %rsi
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/*
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* Switch to new page-table
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*
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* For the boot CPU this switches to early_top_pgt which still has the
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* indentity mappings present. The secondary CPUs will switch to the
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* init_top_pgt here, away from the trampoline_pgd and unmap the
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* indentity mapped ranges.
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*/
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movq %rax, %cr3
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/*
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* Do a global TLB flush after the CR3 switch to make sure the TLB
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* entries from the identity mapping are flushed.
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*/
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movq %cr4, %rcx
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movq %rcx, %rax
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xorq $X86_CR4_PGE, %rcx
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movq %rcx, %cr4
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movq %rax, %cr4
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/* Ensure I am executing from virtual addresses */
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movq $1f, %rax
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ANNOTATE_RETPOLINE_SAFE
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jmp *%rax
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1:
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UNWIND_HINT_EMPTY
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ANNOTATE_NOENDBR // above
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/*
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* We must switch to a new descriptor in kernel space for the GDT
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* because soon the kernel won't have access anymore to the userspace
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* addresses where we're currently running on. We have to do that here
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* because in 32bit we couldn't load a 64bit linear address.
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*/
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lgdt early_gdt_descr(%rip)
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/* set up data segments */
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xorl %eax,%eax
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movl %eax,%ds
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movl %eax,%ss
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movl %eax,%es
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/*
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* We don't really need to load %fs or %gs, but load them anyway
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* to kill any stale realmode selectors. This allows execution
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* under VT hardware.
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*/
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movl %eax,%fs
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movl %eax,%gs
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/* Set up %gs.
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*
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* The base of %gs always points to fixed_percpu_data. If the
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* stack protector canary is enabled, it is located at %gs:40.
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* Note that, on SMP, the boot cpu uses init data section until
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* the per cpu areas are set up.
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*/
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movl $MSR_GS_BASE,%ecx
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movl initial_gs(%rip),%eax
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movl initial_gs+4(%rip),%edx
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wrmsr
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/*
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* Setup a boot time stack - Any secondary CPU will have lost its stack
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* by now because the cr3-switch above unmaps the real-mode stack
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*/
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movq initial_stack(%rip), %rsp
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/* Setup and Load IDT */
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pushq %rsi
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call early_setup_idt
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popq %rsi
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/* Check if nx is implemented */
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movl $0x80000001, %eax
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cpuid
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movl %edx,%edi
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/* Setup EFER (Extended Feature Enable Register) */
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movl $MSR_EFER, %ecx
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rdmsr
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/*
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* Preserve current value of EFER for comparison and to skip
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* EFER writes if no change was made (for TDX guest)
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*/
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movl %eax, %edx
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btsl $_EFER_SCE, %eax /* Enable System Call */
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btl $20,%edi /* No Execute supported? */
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jnc 1f
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btsl $_EFER_NX, %eax
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btsq $_PAGE_BIT_NX,early_pmd_flags(%rip)
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/* Avoid writing EFER if no change was made (for TDX guest) */
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1: cmpl %edx, %eax
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je 1f
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xor %edx, %edx
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wrmsr /* Make changes effective */
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1:
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/* Setup cr0 */
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movl $CR0_STATE, %eax
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/* Make changes effective */
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movq %rax, %cr0
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/* zero EFLAGS after setting rsp */
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pushq $0
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popfq
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/* rsi is pointer to real mode structure with interesting info.
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pass it to C */
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movq %rsi, %rdi
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.Ljump_to_C_code:
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/*
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* Jump to run C code and to be on a real kernel address.
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* Since we are running on identity-mapped space we have to jump
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* to the full 64bit address, this is only possible as indirect
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* jump. In addition we need to ensure %cs is set so we make this
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* a far return.
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*
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* Note: do not change to far jump indirect with 64bit offset.
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*
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* AMD does not support far jump indirect with 64bit offset.
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* AMD64 Architecture Programmer's Manual, Volume 3: states only
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* JMP FAR mem16:16 FF /5 Far jump indirect,
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* with the target specified by a far pointer in memory.
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* JMP FAR mem16:32 FF /5 Far jump indirect,
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* with the target specified by a far pointer in memory.
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*
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* Intel64 does support 64bit offset.
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* Software Developer Manual Vol 2: states:
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* FF /5 JMP m16:16 Jump far, absolute indirect,
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* address given in m16:16
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* FF /5 JMP m16:32 Jump far, absolute indirect,
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* address given in m16:32.
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* REX.W + FF /5 JMP m16:64 Jump far, absolute indirect,
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* address given in m16:64.
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*/
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pushq $.Lafter_lret # put return address on stack for unwinder
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xorl %ebp, %ebp # clear frame pointer
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movq initial_code(%rip), %rax
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pushq $__KERNEL_CS # set correct cs
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pushq %rax # target address in negative space
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lretq
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.Lafter_lret:
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ANNOTATE_NOENDBR
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SYM_CODE_END(secondary_startup_64)
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#include "verify_cpu.S"
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#include "sev_verify_cbit.S"
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#ifdef CONFIG_HOTPLUG_CPU
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/*
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* Boot CPU0 entry point. It's called from play_dead(). Everything has been set
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* up already except stack. We just set up stack here. Then call
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* start_secondary() via .Ljump_to_C_code.
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*/
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SYM_CODE_START(start_cpu0)
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ANNOTATE_NOENDBR
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UNWIND_HINT_EMPTY
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movq initial_stack(%rip), %rsp
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jmp .Ljump_to_C_code
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SYM_CODE_END(start_cpu0)
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#endif
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#ifdef CONFIG_AMD_MEM_ENCRYPT
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/*
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* VC Exception handler used during early boot when running on kernel
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* addresses, but before the switch to the idt_table can be made.
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* The early_idt_handler_array can't be used here because it calls into a lot
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* of __init code and this handler is also used during CPU offlining/onlining.
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* Therefore this handler ends up in the .text section so that it stays around
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* when .init.text is freed.
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*/
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SYM_CODE_START_NOALIGN(vc_boot_ghcb)
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UNWIND_HINT_IRET_REGS offset=8
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ENDBR
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ANNOTATE_UNRET_END
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/* Build pt_regs */
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PUSH_AND_CLEAR_REGS
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/* Call C handler */
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movq %rsp, %rdi
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movq ORIG_RAX(%rsp), %rsi
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movq initial_vc_handler(%rip), %rax
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ANNOTATE_RETPOLINE_SAFE
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call *%rax
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/* Unwind pt_regs */
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POP_REGS
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/* Remove Error Code */
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addq $8, %rsp
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iretq
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SYM_CODE_END(vc_boot_ghcb)
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#endif
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/* Both SMP bootup and ACPI suspend change these variables */
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__REFDATA
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.balign 8
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SYM_DATA(initial_code, .quad x86_64_start_kernel)
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SYM_DATA(initial_gs, .quad INIT_PER_CPU_VAR(fixed_percpu_data))
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#ifdef CONFIG_AMD_MEM_ENCRYPT
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SYM_DATA(initial_vc_handler, .quad handle_vc_boot_ghcb)
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#endif
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/*
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* The FRAME_SIZE gap is a convention which helps the in-kernel unwinder
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* reliably detect the end of the stack.
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*/
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SYM_DATA(initial_stack, .quad init_thread_union + THREAD_SIZE - FRAME_SIZE)
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__FINITDATA
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__INIT
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SYM_CODE_START(early_idt_handler_array)
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i = 0
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.rept NUM_EXCEPTION_VECTORS
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.if ((EXCEPTION_ERRCODE_MASK >> i) & 1) == 0
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UNWIND_HINT_IRET_REGS
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ENDBR
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pushq $0 # Dummy error code, to make stack frame uniform
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.else
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UNWIND_HINT_IRET_REGS offset=8
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ENDBR
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.endif
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pushq $i # 72(%rsp) Vector number
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jmp early_idt_handler_common
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UNWIND_HINT_IRET_REGS
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i = i + 1
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.fill early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE - ., 1, 0xcc
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.endr
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SYM_CODE_END(early_idt_handler_array)
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ANNOTATE_NOENDBR // early_idt_handler_array[NUM_EXCEPTION_VECTORS]
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SYM_CODE_START_LOCAL(early_idt_handler_common)
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UNWIND_HINT_IRET_REGS offset=16
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ANNOTATE_UNRET_END
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/*
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* The stack is the hardware frame, an error code or zero, and the
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* vector number.
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*/
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cld
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incl early_recursion_flag(%rip)
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/* The vector number is currently in the pt_regs->di slot. */
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pushq %rsi /* pt_regs->si */
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movq 8(%rsp), %rsi /* RSI = vector number */
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movq %rdi, 8(%rsp) /* pt_regs->di = RDI */
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pushq %rdx /* pt_regs->dx */
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pushq %rcx /* pt_regs->cx */
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pushq %rax /* pt_regs->ax */
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pushq %r8 /* pt_regs->r8 */
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pushq %r9 /* pt_regs->r9 */
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pushq %r10 /* pt_regs->r10 */
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pushq %r11 /* pt_regs->r11 */
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pushq %rbx /* pt_regs->bx */
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pushq %rbp /* pt_regs->bp */
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pushq %r12 /* pt_regs->r12 */
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pushq %r13 /* pt_regs->r13 */
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pushq %r14 /* pt_regs->r14 */
|
|
pushq %r15 /* pt_regs->r15 */
|
|
UNWIND_HINT_REGS
|
|
|
|
movq %rsp,%rdi /* RDI = pt_regs; RSI is already trapnr */
|
|
call do_early_exception
|
|
|
|
decl early_recursion_flag(%rip)
|
|
jmp restore_regs_and_return_to_kernel
|
|
SYM_CODE_END(early_idt_handler_common)
|
|
|
|
#ifdef CONFIG_AMD_MEM_ENCRYPT
|
|
/*
|
|
* VC Exception handler used during very early boot. The
|
|
* early_idt_handler_array can't be used because it returns via the
|
|
* paravirtualized INTERRUPT_RETURN and pv-ops don't work that early.
|
|
*
|
|
* XXX it does, fix this.
|
|
*
|
|
* This handler will end up in the .init.text section and not be
|
|
* available to boot secondary CPUs.
|
|
*/
|
|
SYM_CODE_START_NOALIGN(vc_no_ghcb)
|
|
UNWIND_HINT_IRET_REGS offset=8
|
|
ENDBR
|
|
|
|
ANNOTATE_UNRET_END
|
|
|
|
/* Build pt_regs */
|
|
PUSH_AND_CLEAR_REGS
|
|
|
|
/* Call C handler */
|
|
movq %rsp, %rdi
|
|
movq ORIG_RAX(%rsp), %rsi
|
|
call do_vc_no_ghcb
|
|
|
|
/* Unwind pt_regs */
|
|
POP_REGS
|
|
|
|
/* Remove Error Code */
|
|
addq $8, %rsp
|
|
|
|
/* Pure iret required here - don't use INTERRUPT_RETURN */
|
|
iretq
|
|
SYM_CODE_END(vc_no_ghcb)
|
|
#endif
|
|
|
|
#define SYM_DATA_START_PAGE_ALIGNED(name) \
|
|
SYM_START(name, SYM_L_GLOBAL, .balign PAGE_SIZE)
|
|
|
|
#ifdef CONFIG_PAGE_TABLE_ISOLATION
|
|
/*
|
|
* Each PGD needs to be 8k long and 8k aligned. We do not
|
|
* ever go out to userspace with these, so we do not
|
|
* strictly *need* the second page, but this allows us to
|
|
* have a single set_pgd() implementation that does not
|
|
* need to worry about whether it has 4k or 8k to work
|
|
* with.
|
|
*
|
|
* This ensures PGDs are 8k long:
|
|
*/
|
|
#define PTI_USER_PGD_FILL 512
|
|
/* This ensures they are 8k-aligned: */
|
|
#define SYM_DATA_START_PTI_ALIGNED(name) \
|
|
SYM_START(name, SYM_L_GLOBAL, .balign 2 * PAGE_SIZE)
|
|
#else
|
|
#define SYM_DATA_START_PTI_ALIGNED(name) \
|
|
SYM_DATA_START_PAGE_ALIGNED(name)
|
|
#define PTI_USER_PGD_FILL 0
|
|
#endif
|
|
|
|
/* Automate the creation of 1 to 1 mapping pmd entries */
|
|
#define PMDS(START, PERM, COUNT) \
|
|
i = 0 ; \
|
|
.rept (COUNT) ; \
|
|
.quad (START) + (i << PMD_SHIFT) + (PERM) ; \
|
|
i = i + 1 ; \
|
|
.endr
|
|
|
|
__INITDATA
|
|
.balign 4
|
|
|
|
SYM_DATA_START_PTI_ALIGNED(early_top_pgt)
|
|
.fill 512,8,0
|
|
.fill PTI_USER_PGD_FILL,8,0
|
|
SYM_DATA_END(early_top_pgt)
|
|
|
|
SYM_DATA_START_PAGE_ALIGNED(early_dynamic_pgts)
|
|
.fill 512*EARLY_DYNAMIC_PAGE_TABLES,8,0
|
|
SYM_DATA_END(early_dynamic_pgts)
|
|
|
|
SYM_DATA(early_recursion_flag, .long 0)
|
|
|
|
.data
|
|
|
|
#if defined(CONFIG_XEN_PV) || defined(CONFIG_PVH)
|
|
SYM_DATA_START_PTI_ALIGNED(init_top_pgt)
|
|
.quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
|
|
.org init_top_pgt + L4_PAGE_OFFSET*8, 0
|
|
.quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
|
|
.org init_top_pgt + L4_START_KERNEL*8, 0
|
|
/* (2^48-(2*1024*1024*1024))/(2^39) = 511 */
|
|
.quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
|
|
.fill PTI_USER_PGD_FILL,8,0
|
|
SYM_DATA_END(init_top_pgt)
|
|
|
|
SYM_DATA_START_PAGE_ALIGNED(level3_ident_pgt)
|
|
.quad level2_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
|
|
.fill 511, 8, 0
|
|
SYM_DATA_END(level3_ident_pgt)
|
|
SYM_DATA_START_PAGE_ALIGNED(level2_ident_pgt)
|
|
/*
|
|
* Since I easily can, map the first 1G.
|
|
* Don't set NX because code runs from these pages.
|
|
*
|
|
* Note: This sets _PAGE_GLOBAL despite whether
|
|
* the CPU supports it or it is enabled. But,
|
|
* the CPU should ignore the bit.
|
|
*/
|
|
PMDS(0, __PAGE_KERNEL_IDENT_LARGE_EXEC, PTRS_PER_PMD)
|
|
SYM_DATA_END(level2_ident_pgt)
|
|
#else
|
|
SYM_DATA_START_PTI_ALIGNED(init_top_pgt)
|
|
.fill 512,8,0
|
|
.fill PTI_USER_PGD_FILL,8,0
|
|
SYM_DATA_END(init_top_pgt)
|
|
#endif
|
|
|
|
#ifdef CONFIG_X86_5LEVEL
|
|
SYM_DATA_START_PAGE_ALIGNED(level4_kernel_pgt)
|
|
.fill 511,8,0
|
|
.quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
|
|
SYM_DATA_END(level4_kernel_pgt)
|
|
#endif
|
|
|
|
SYM_DATA_START_PAGE_ALIGNED(level3_kernel_pgt)
|
|
.fill L3_START_KERNEL,8,0
|
|
/* (2^48-(2*1024*1024*1024)-((2^39)*511))/(2^30) = 510 */
|
|
.quad level2_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
|
|
.quad level2_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
|
|
SYM_DATA_END(level3_kernel_pgt)
|
|
|
|
SYM_DATA_START_PAGE_ALIGNED(level2_kernel_pgt)
|
|
/*
|
|
* Kernel high mapping.
|
|
*
|
|
* The kernel code+data+bss must be located below KERNEL_IMAGE_SIZE in
|
|
* virtual address space, which is 1 GiB if RANDOMIZE_BASE is enabled,
|
|
* 512 MiB otherwise.
|
|
*
|
|
* (NOTE: after that starts the module area, see MODULES_VADDR.)
|
|
*
|
|
* This table is eventually used by the kernel during normal runtime.
|
|
* Care must be taken to clear out undesired bits later, like _PAGE_RW
|
|
* or _PAGE_GLOBAL in some cases.
|
|
*/
|
|
PMDS(0, __PAGE_KERNEL_LARGE_EXEC, KERNEL_IMAGE_SIZE/PMD_SIZE)
|
|
SYM_DATA_END(level2_kernel_pgt)
|
|
|
|
SYM_DATA_START_PAGE_ALIGNED(level2_fixmap_pgt)
|
|
.fill (512 - 4 - FIXMAP_PMD_NUM),8,0
|
|
pgtno = 0
|
|
.rept (FIXMAP_PMD_NUM)
|
|
.quad level1_fixmap_pgt + (pgtno << PAGE_SHIFT) - __START_KERNEL_map \
|
|
+ _PAGE_TABLE_NOENC;
|
|
pgtno = pgtno + 1
|
|
.endr
|
|
/* 6 MB reserved space + a 2MB hole */
|
|
.fill 4,8,0
|
|
SYM_DATA_END(level2_fixmap_pgt)
|
|
|
|
SYM_DATA_START_PAGE_ALIGNED(level1_fixmap_pgt)
|
|
.rept (FIXMAP_PMD_NUM)
|
|
.fill 512,8,0
|
|
.endr
|
|
SYM_DATA_END(level1_fixmap_pgt)
|
|
|
|
#undef PMDS
|
|
|
|
.data
|
|
.align 16
|
|
|
|
SYM_DATA(early_gdt_descr, .word GDT_ENTRIES*8-1)
|
|
SYM_DATA_LOCAL(early_gdt_descr_base, .quad INIT_PER_CPU_VAR(gdt_page))
|
|
|
|
.align 16
|
|
/* This must match the first entry in level2_kernel_pgt */
|
|
SYM_DATA(phys_base, .quad 0x0)
|
|
EXPORT_SYMBOL(phys_base)
|
|
|
|
#include "../../x86/xen/xen-head.S"
|
|
|
|
__PAGE_ALIGNED_BSS
|
|
SYM_DATA_START_PAGE_ALIGNED(empty_zero_page)
|
|
.skip PAGE_SIZE
|
|
SYM_DATA_END(empty_zero_page)
|
|
EXPORT_SYMBOL(empty_zero_page)
|
|
|