diff options
| -rw-r--r-- | arch/x86/include/asm/efi.h | 24 | ||||
| -rw-r--r-- | arch/x86/include/asm/fpu/api.h | 12 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 4 | ||||
| -rw-r--r-- | arch/x86/platform/efi/efi_64.c | 4 |
4 files changed, 36 insertions, 8 deletions
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 627347af343a..4d0b126835b8 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -69,17 +69,33 @@ extern unsigned long efi_mixed_mode_stack_pa; #f " called with too many arguments (" #p ">" #n ")"); \ }) +static inline void efi_fpu_begin(void) +{ + /* + * The UEFI calling convention (UEFI spec 2.3.2 and 2.3.4) requires + * that FCW and MXCSR (64-bit) must be initialized prior to calling + * UEFI code. (Oddly the spec does not require that the FPU stack + * be empty.) + */ + kernel_fpu_begin_mask(KFPU_387 | KFPU_MXCSR); +} + +static inline void efi_fpu_end(void) +{ + kernel_fpu_end(); +} + #ifdef CONFIG_X86_32 #define arch_efi_call_virt_setup() \ ({ \ - kernel_fpu_begin(); \ + efi_fpu_begin(); \ firmware_restrict_branch_speculation_start(); \ }) #define arch_efi_call_virt_teardown() \ ({ \ firmware_restrict_branch_speculation_end(); \ - kernel_fpu_end(); \ + efi_fpu_end(); \ }) #define arch_efi_call_virt(p, f, args...) p->f(args) @@ -98,7 +114,7 @@ extern asmlinkage u64 __efi_call(void *fp, ...); #define arch_efi_call_virt_setup() \ ({ \ efi_sync_low_kernel_mappings(); \ - kernel_fpu_begin(); \ + efi_fpu_begin(); \ firmware_restrict_branch_speculation_start(); \ efi_enter_mm(); \ }) @@ -110,7 +126,7 @@ extern asmlinkage u64 __efi_call(void *fp, ...); ({ \ efi_leave_mm(); \ firmware_restrict_branch_speculation_end(); \ - kernel_fpu_end(); \ + efi_fpu_end(); \ }) #ifdef CONFIG_KASAN diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index 67a4f1cb2aac..ed33a14188f6 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -32,7 +32,19 @@ extern void fpregs_mark_activate(void); /* Code that is unaware of kernel_fpu_begin_mask() can use this */ static inline void kernel_fpu_begin(void) { +#ifdef CONFIG_X86_64 + /* + * Any 64-bit code that uses 387 instructions must explicitly request + * KFPU_387. + */ + kernel_fpu_begin_mask(KFPU_MXCSR); +#else + /* + * 32-bit kernel code may use 387 operations as well as SSE2, etc, + * as long as it checks that the CPU has the required capability. + */ kernel_fpu_begin_mask(KFPU_387 | KFPU_MXCSR); +#endif } /* diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 5d8047441a0a..683749b80ae2 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -167,14 +167,14 @@ void fpstate_sanitize_xstate(struct fpu *fpu) fx->fop = 0; fx->rip = 0; fx->rdp = 0; - memset(&fx->st_space[0], 0, 128); + memset(fx->st_space, 0, sizeof(fx->st_space)); } /* * SSE is in init state */ if (!(xfeatures & XFEATURE_MASK_SSE)) - memset(&fx->xmm_space[0], 0, 256); + memset(fx->xmm_space, 0, sizeof(fx->xmm_space)); /* * First two features are FPU and SSE, which above we handled diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index bf85db683af4..1b82d77019b1 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -834,7 +834,7 @@ efi_set_virtual_address_map(unsigned long memory_map_size, virtual_map); efi_enter_mm(); - kernel_fpu_begin(); + efi_fpu_begin(); /* Disable interrupts around EFI calls: */ local_irq_save(flags); @@ -843,7 +843,7 @@ efi_set_virtual_address_map(unsigned long memory_map_size, descriptor_version, virtual_map); local_irq_restore(flags); - kernel_fpu_end(); + efi_fpu_end(); /* grab the virtually remapped EFI runtime services table pointer */ efi.runtime = READ_ONCE(systab->runtime); |