diff options
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/entry-common.h | 13 | ||||
| -rw-r--r-- | arch/x86/include/asm/fred.h | 23 | ||||
| -rw-r--r-- | arch/x86/include/asm/msr.h | 25 | ||||
| -rw-r--r-- | arch/x86/include/asm/processor.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/switch_to.h | 6 |
5 files changed, 47 insertions, 23 deletions
diff --git a/arch/x86/include/asm/entry-common.h b/arch/x86/include/asm/entry-common.h index fb2809b20b0a..77d20555e04d 100644 --- a/arch/x86/include/asm/entry-common.h +++ b/arch/x86/include/asm/entry-common.h @@ -8,6 +8,7 @@ #include <asm/nospec-branch.h> #include <asm/io_bitmap.h> #include <asm/fpu/api.h> +#include <asm/fred.h> /* Check that the stack and regs on entry from user mode are sane. */ static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs) @@ -44,8 +45,7 @@ static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs) } #define arch_enter_from_user_mode arch_enter_from_user_mode -static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs, - unsigned long ti_work) +static inline void arch_exit_work(unsigned long ti_work) { if (ti_work & _TIF_USER_RETURN_NOTIFY) fire_user_return_notifiers(); @@ -56,6 +56,15 @@ static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs, fpregs_assert_state_consistent(); if (unlikely(ti_work & _TIF_NEED_FPU_LOAD)) switch_fpu_return(); +} + +static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs, + unsigned long ti_work) +{ + if (IS_ENABLED(CONFIG_X86_DEBUG_FPU) || unlikely(ti_work)) + arch_exit_work(ti_work); + + fred_update_rsp0(); #ifdef CONFIG_COMPAT /* diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index e86c7ba32435..25ca00bd70e8 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -36,6 +36,7 @@ #ifdef CONFIG_X86_FRED #include <linux/kernel.h> +#include <linux/sched/task_stack.h> #include <asm/ptrace.h> @@ -84,13 +85,33 @@ static __always_inline void fred_entry_from_kvm(unsigned int type, unsigned int } void cpu_init_fred_exceptions(void); +void cpu_init_fred_rsps(void); void fred_complete_exception_setup(void); +DECLARE_PER_CPU(unsigned long, fred_rsp0); + +static __always_inline void fred_sync_rsp0(unsigned long rsp0) +{ + __this_cpu_write(fred_rsp0, rsp0); +} + +static __always_inline void fred_update_rsp0(void) +{ + unsigned long rsp0 = (unsigned long) task_stack_page(current) + THREAD_SIZE; + + if (cpu_feature_enabled(X86_FEATURE_FRED) && (__this_cpu_read(fred_rsp0) != rsp0)) { + wrmsrns(MSR_IA32_FRED_RSP0, rsp0); + __this_cpu_write(fred_rsp0, rsp0); + } +} #else /* CONFIG_X86_FRED */ static __always_inline unsigned long fred_event_data(struct pt_regs *regs) { return 0; } static inline void cpu_init_fred_exceptions(void) { } +static inline void cpu_init_fred_rsps(void) { } static inline void fred_complete_exception_setup(void) { } -static __always_inline void fred_entry_from_kvm(unsigned int type, unsigned int vector) { } +static inline void fred_entry_from_kvm(unsigned int type, unsigned int vector) { } +static inline void fred_sync_rsp0(unsigned long rsp0) { } +static inline void fred_update_rsp0(void) { } #endif /* CONFIG_X86_FRED */ #endif /* !__ASSEMBLY__ */ diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index d642037f9ed5..001853541f1e 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -99,19 +99,6 @@ static __always_inline void __wrmsr(unsigned int msr, u32 low, u32 high) : : "c" (msr), "a"(low), "d" (high) : "memory"); } -/* - * WRMSRNS behaves exactly like WRMSR with the only difference being - * that it is not a serializing instruction by default. - */ -static __always_inline void __wrmsrns(u32 msr, u32 low, u32 high) -{ - /* Instruction opcode for WRMSRNS; supported in binutils >= 2.40. */ - asm volatile("1: .byte 0x0f,0x01,0xc6\n" - "2:\n" - _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_WRMSR) - : : "c" (msr), "a"(low), "d" (high)); -} - #define native_rdmsr(msr, val1, val2) \ do { \ u64 __val = __rdmsr((msr)); \ @@ -312,9 +299,19 @@ do { \ #endif /* !CONFIG_PARAVIRT_XXL */ +/* Instruction opcode for WRMSRNS supported in binutils >= 2.40 */ +#define WRMSRNS _ASM_BYTES(0x0f,0x01,0xc6) + +/* Non-serializing WRMSR, when available. Falls back to a serializing WRMSR. */ static __always_inline void wrmsrns(u32 msr, u64 val) { - __wrmsrns(msr, val, val >> 32); + /* + * WRMSR is 2 bytes. WRMSRNS is 3 bytes. Pad WRMSR with a redundant + * DS prefix to avoid a trailing NOP. + */ + asm volatile("1: " ALTERNATIVE("ds wrmsr", WRMSRNS, X86_FEATURE_WRMSRNS) + "2: " _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_WRMSR) + : : "c" (msr), "a" ((u32)val), "d" ((u32)(val >> 32))); } /* diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 775acbdea1a9..4a686f0e5dbf 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -582,7 +582,8 @@ extern void switch_gdt_and_percpu_base(int); extern void load_direct_gdt(int); extern void load_fixmap_gdt(int); extern void cpu_init(void); -extern void cpu_init_exception_handling(void); +extern void cpu_init_exception_handling(bool boot_cpu); +extern void cpu_init_replace_early_idt(void); extern void cr4_init(void); extern void set_task_blockstep(struct task_struct *task, bool on); diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index c3bd0c0758c9..75248546403d 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -70,13 +70,9 @@ static inline void update_task_stack(struct task_struct *task) #ifdef CONFIG_X86_32 this_cpu_write(cpu_tss_rw.x86_tss.sp1, task->thread.sp0); #else - if (cpu_feature_enabled(X86_FEATURE_FRED)) { - /* WRMSRNS is a baseline feature for FRED. */ - wrmsrns(MSR_IA32_FRED_RSP0, (unsigned long)task_stack_page(task) + THREAD_SIZE); - } else if (cpu_feature_enabled(X86_FEATURE_XENPV)) { + if (!cpu_feature_enabled(X86_FEATURE_FRED) && cpu_feature_enabled(X86_FEATURE_XENPV)) /* Xen PV enters the kernel on the thread stack. */ load_sp0(task_top_of_stack(task)); - } #endif } |