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f5963ba7a4
Add a separate bringup IDT for the CPU bringup code that will be used until the kernel switches to the idt_table. There are two reasons for a separate IDT: 1) When the idt_table is set up and the secondary CPUs are booted, it contains entries (e.g. IST entries) which require certain CPU state to be set up. This includes a working TSS (for IST), MSR_GS_BASE (for stack protector) or CR4.FSGSBASE (for paranoid_entry) path. By using a dedicated IDT for early boot this state need not to be set up early. 2) The idt_table is static to idt.c, so any function using/modifying must be in idt.c too. That means that all compiler driven instrumentation like tracing or KASAN is also active in this code. But during early CPU bringup the environment is not set up for this instrumentation to work correctly. To avoid all of these hassles and make early exception handling robust, use a dedicated bringup IDT. The IDT is loaded two times, first on the boot CPU while the kernel is still running on direct mapped addresses, and again later after the switch to kernel addresses has happened. The second IDT load happens on the boot and secondary CPUs. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-34-joro@8bytes.org
155 lines
4 KiB
C
155 lines
4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_SETUP_H
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#define _ASM_X86_SETUP_H
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#include <uapi/asm/setup.h>
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#define COMMAND_LINE_SIZE 2048
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#include <linux/linkage.h>
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#include <asm/page_types.h>
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#ifdef __i386__
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#include <linux/pfn.h>
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/*
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* Reserved space for vmalloc and iomap - defined in asm/page.h
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*/
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#define MAXMEM_PFN PFN_DOWN(MAXMEM)
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#define MAX_NONPAE_PFN (1 << 20)
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#endif /* __i386__ */
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#define PARAM_SIZE 4096 /* sizeof(struct boot_params) */
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#define OLD_CL_MAGIC 0xA33F
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#define OLD_CL_ADDRESS 0x020 /* Relative to real mode data */
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#define NEW_CL_POINTER 0x228 /* Relative to real mode data */
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#ifndef __ASSEMBLY__
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#include <asm/bootparam.h>
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#include <asm/x86_init.h>
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extern u64 relocated_ramdisk;
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/* Interrupt control for vSMPowered x86_64 systems */
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#ifdef CONFIG_X86_64
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void vsmp_init(void);
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#else
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static inline void vsmp_init(void) { }
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#endif
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void setup_bios_corruption_check(void);
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void early_platform_quirks(void);
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extern unsigned long saved_video_mode;
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extern void reserve_standard_io_resources(void);
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extern void i386_reserve_resources(void);
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extern unsigned long __startup_64(unsigned long physaddr, struct boot_params *bp);
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extern unsigned long __startup_secondary_64(void);
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extern void startup_64_setup_env(unsigned long physbase);
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extern int early_make_pgtable(unsigned long address);
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extern void early_setup_idt(void);
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#ifdef CONFIG_X86_INTEL_MID
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extern void x86_intel_mid_early_setup(void);
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#else
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static inline void x86_intel_mid_early_setup(void) { }
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#endif
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#ifdef CONFIG_X86_INTEL_CE
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extern void x86_ce4100_early_setup(void);
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#else
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static inline void x86_ce4100_early_setup(void) { }
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#endif
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#ifndef _SETUP
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#include <asm/espfix.h>
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#include <linux/kernel.h>
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/*
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* This is set up by the setup-routine at boot-time
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*/
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extern struct boot_params boot_params;
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extern char _text[];
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static inline bool kaslr_enabled(void)
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{
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return IS_ENABLED(CONFIG_RANDOMIZE_MEMORY) &&
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!!(boot_params.hdr.loadflags & KASLR_FLAG);
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}
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/*
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* Apply no randomization if KASLR was disabled at boot or if KASAN
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* is enabled. KASAN shadow mappings rely on regions being PGD aligned.
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*/
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static inline bool kaslr_memory_enabled(void)
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{
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return kaslr_enabled() && !IS_ENABLED(CONFIG_KASAN);
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}
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static inline unsigned long kaslr_offset(void)
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{
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return (unsigned long)&_text - __START_KERNEL;
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}
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/*
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* Do NOT EVER look at the BIOS memory size location.
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* It does not work on many machines.
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*/
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#define LOWMEMSIZE() (0x9f000)
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/* exceedingly early brk-like allocator */
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extern unsigned long _brk_end;
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void *extend_brk(size_t size, size_t align);
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/*
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* Reserve space in the brk section. The name must be unique within
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* the file, and somewhat descriptive. The size is in bytes. Must be
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* used at file scope.
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*
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* (This uses a temp function to wrap the asm so we can pass it the
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* size parameter; otherwise we wouldn't be able to. We can't use a
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* "section" attribute on a normal variable because it always ends up
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* being @progbits, which ends up allocating space in the vmlinux
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* executable.)
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*/
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#define RESERVE_BRK(name,sz) \
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static void __section(.discard.text) __used notrace \
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__brk_reservation_fn_##name##__(void) { \
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asm volatile ( \
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".pushsection .brk_reservation,\"aw\",@nobits;" \
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".brk." #name ":" \
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" 1:.skip %c0;" \
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" .size .brk." #name ", . - 1b;" \
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" .popsection" \
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: : "i" (sz)); \
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}
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/* Helper for reserving space for arrays of things */
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#define RESERVE_BRK_ARRAY(type, name, entries) \
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type *name; \
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RESERVE_BRK(name, sizeof(type) * entries)
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extern void probe_roms(void);
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#ifdef __i386__
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asmlinkage void __init i386_start_kernel(void);
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#else
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asmlinkage void __init x86_64_start_kernel(char *real_mode);
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asmlinkage void __init x86_64_start_reservations(char *real_mode_data);
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#endif /* __i386__ */
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#endif /* _SETUP */
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#else
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#define RESERVE_BRK(name,sz) \
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.pushsection .brk_reservation,"aw",@nobits; \
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.brk.name: \
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1: .skip sz; \
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.size .brk.name,.-1b; \
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.popsection
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#endif /* __ASSEMBLY__ */
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#endif /* _ASM_X86_SETUP_H */
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