diff options
Diffstat (limited to 'arch/x86/include/asm/fpu/xstate.h')
| -rw-r--r-- | arch/x86/include/asm/fpu/xstate.h | 78 |
1 files changed, 57 insertions, 21 deletions
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index 47a92232d595..109dfcc75299 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -6,6 +6,7 @@ #include <linux/types.h> #include <asm/processor.h> +#include <asm/fpu/api.h> #include <asm/user.h> /* Bit 63 of XCR0 is reserved for future expansion */ @@ -34,6 +35,14 @@ XFEATURE_MASK_BNDREGS | \ XFEATURE_MASK_BNDCSR) +/* + * Features which are restored when returning to user space. + * PKRU is not restored on return to user space because PKRU + * is switched eagerly in switch_to() and flush_thread() + */ +#define XFEATURE_MASK_USER_RESTORE \ + (XFEATURE_MASK_USER_SUPPORTED & ~XFEATURE_MASK_PKRU) + /* All currently supported supervisor features */ #define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID) @@ -42,21 +51,21 @@ * and its size may be huge. Saving/restoring such supervisor state components * at each context switch can cause high CPU and space overhead, which should * be avoided. Such supervisor state components should only be saved/restored - * on demand. The on-demand dynamic supervisor features are set in this mask. + * on demand. The on-demand supervisor features are set in this mask. * - * Unlike the existing supported supervisor features, a dynamic supervisor + * Unlike the existing supported supervisor features, an independent supervisor * feature does not allocate a buffer in task->fpu, and the corresponding * supervisor state component cannot be saved/restored at each context switch. * - * To support a dynamic supervisor feature, a developer should follow the + * To support an independent supervisor feature, a developer should follow the * dos and don'ts as below: * - Do dynamically allocate a buffer for the supervisor state component. * - Do manually invoke the XSAVES/XRSTORS instruction to save/restore the * state component to/from the buffer. - * - Don't set the bit corresponding to the dynamic supervisor feature in + * - Don't set the bit corresponding to the independent supervisor feature in * IA32_XSS at run time, since it has been set at boot time. */ -#define XFEATURE_MASK_DYNAMIC (XFEATURE_MASK_LBR) +#define XFEATURE_MASK_INDEPENDENT (XFEATURE_MASK_LBR) /* * Unsupported supervisor features. When a supervisor feature in this mask is @@ -66,7 +75,7 @@ /* All supervisor states including supported and unsupported states. */ #define XFEATURE_MASK_SUPERVISOR_ALL (XFEATURE_MASK_SUPERVISOR_SUPPORTED | \ - XFEATURE_MASK_DYNAMIC | \ + XFEATURE_MASK_INDEPENDENT | \ XFEATURE_MASK_SUPERVISOR_UNSUPPORTED) #ifdef CONFIG_X86_64 @@ -82,17 +91,42 @@ static inline u64 xfeatures_mask_supervisor(void) return xfeatures_mask_all & XFEATURE_MASK_SUPERVISOR_SUPPORTED; } -static inline u64 xfeatures_mask_user(void) +/* + * The xfeatures which are enabled in XCR0 and expected to be in ptrace + * buffers and signal frames. + */ +static inline u64 xfeatures_mask_uabi(void) { return xfeatures_mask_all & XFEATURE_MASK_USER_SUPPORTED; } -static inline u64 xfeatures_mask_dynamic(void) +/* + * The xfeatures which are restored by the kernel when returning to user + * mode. This is not necessarily the same as xfeatures_mask_uabi() as the + * kernel does not manage all XCR0 enabled features via xsave/xrstor as + * some of them have to be switched eagerly on context switch and exec(). + */ +static inline u64 xfeatures_mask_restore_user(void) +{ + return xfeatures_mask_all & XFEATURE_MASK_USER_RESTORE; +} + +/* + * Like xfeatures_mask_restore_user() but additionally restors the + * supported supervisor states. + */ +static inline u64 xfeatures_mask_fpstate(void) +{ + return xfeatures_mask_all & \ + (XFEATURE_MASK_USER_RESTORE | XFEATURE_MASK_SUPERVISOR_SUPPORTED); +} + +static inline u64 xfeatures_mask_independent(void) { if (!boot_cpu_has(X86_FEATURE_ARCH_LBR)) - return XFEATURE_MASK_DYNAMIC & ~XFEATURE_MASK_LBR; + return XFEATURE_MASK_INDEPENDENT & ~XFEATURE_MASK_LBR; - return XFEATURE_MASK_DYNAMIC; + return XFEATURE_MASK_INDEPENDENT; } extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS]; @@ -101,19 +135,21 @@ extern void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask); void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr); -const void *get_xsave_field_ptr(int xfeature_nr); -int using_compacted_format(void); int xfeature_size(int xfeature_nr); -struct membuf; -void copy_xstate_to_kernel(struct membuf to, struct xregs_state *xsave); -int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf); -int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf); -void copy_supervisor_to_kernel(struct xregs_state *xsave); -void copy_dynamic_supervisor_to_kernel(struct xregs_state *xstate, u64 mask); -void copy_kernel_to_dynamic_supervisor(struct xregs_state *xstate, u64 mask); +int copy_uabi_from_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf); +int copy_sigframe_from_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf); +void xsaves(struct xregs_state *xsave, u64 mask); +void xrstors(struct xregs_state *xsave, u64 mask); -/* Validate an xstate header supplied by userspace (ptrace or sigreturn) */ -int validate_user_xstate_header(const struct xstate_header *hdr); +enum xstate_copy_mode { + XSTATE_COPY_FP, + XSTATE_COPY_FX, + XSTATE_COPY_XSAVE, +}; + +struct membuf; +void copy_xstate_to_uabi_buf(struct membuf to, struct task_struct *tsk, + enum xstate_copy_mode mode); #endif |