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authorJoerg Roedel <jroedel@suse.de>2020-09-07 15:16:08 +0200
committerBorislav Petkov <bp@suse.de>2020-09-09 11:33:20 +0200
commit520d030852b4c9babfce9a79d8b5320b6b5545e6 (patch)
treeeba2437f1b2a41d21ede8ca9e81e1fb0f7ebd8a5 /arch/x86
parent8940ac9ced8bc1c48c4e28b0784e3234c9d14469 (diff)
downloadlinux-next-520d030852b4c9babfce9a79d8b5320b6b5545e6.tar.gz
x86/smpboot: Load TSS and getcpu GDT entry before loading IDT
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
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/processor.h1
-rw-r--r--arch/x86/kernel/cpu/common.c23
-rw-r--r--arch/x86/kernel/smpboot.c2
3 files changed, 25 insertions, 1 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 97143d87994c..615dd440bed8 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -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)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 81fba4d4a242..beffea22e2af 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1863,6 +1863,29 @@ static inline void tss_setup_io_bitmap(struct tss_struct *tss)
}
/*
+ * 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
* and IDT. We reload them nevertheless, this function acts as a
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index f5ef689dd62a..de776b2e6046 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -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();