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x86/smpboot: Load TSS and getcpu GDT entry before loading IDT

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The IDT on 64-bit contains vectors which use paranoid_entry() and/or IST
stacks. To make these vectors work, the TSS and the getcpu GDT entry need
to be set up before the IDT is loaded.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-68-joro@8bytes.org
This commit is contained in:
Joerg Roedel 2020-09-07 15:16:08 +02:00 committed by Borislav Petkov
parent 8940ac9ced
commit 520d030852
3 changed files with 25 additions and 1 deletions
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1
arch/x86/include/asm/processor.h
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@ -696,6 +696,7 @@ extern void load_direct_gdt(int);
extern void load_fixmap_gdt(int);
extern void load_percpu_segment(int);
extern void cpu_init(void);
extern void cpu_init_exception_handling(void);
extern void cr4_init(void);
static inline unsigned long get_debugctlmsr(void)

23
arch/x86/kernel/cpu/common.c
View File

@ -1862,6 +1862,29 @@ static inline void tss_setup_io_bitmap(struct tss_struct *tss)
#endif
}
/*
* Setup everything needed to handle exceptions from the IDT, including the IST
* exceptions which use paranoid_entry().
*/
void cpu_init_exception_handling(void)
{
struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw);
int cpu = raw_smp_processor_id();
/* paranoid_entry() gets the CPU number from the GDT */
setup_getcpu(cpu);
/* IST vectors need TSS to be set up. */
tss_setup_ist(tss);
tss_setup_io_bitmap(tss);
set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
load_TR_desc();
/* Finally load the IDT */
load_current_idt();
}
/*
* cpu_init() initializes state that is per-CPU. Some data is already
* initialized (naturally) in the bootstrap process, such as the GDT

2
arch/x86/kernel/smpboot.c
View File

@ -227,7 +227,7 @@ static void notrace start_secondary(void *unused)
load_cr3(swapper_pg_dir);
__flush_tlb_all();
#endif
load_current_idt();
cpu_init_exception_handling();
cpu_init();
x86_cpuinit.early_percpu_clock_init();
preempt_disable();