From: Ingo Molnar Date: Fri, 24 Apr 2015 08:19:47 +0000 (+0200) Subject: x86/fpu: Rename xsave.header::xstate_bv to 'xfeatures' X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=400e4b209166dcd3e3a155401c57bdc6413bf715;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git x86/fpu: Rename xsave.header::xstate_bv to 'xfeatures' 'xsave.header::xstate_bv' is a misnomer - what does 'bv' stand for? It probably comes from the 'XGETBV' instruction name, but I could not find in the Intel documentation where that abbreviation comes from. It could mean 'bit vector' - or something else? But how about - instead of guessing about a weird name - we named the field in an obvious and descriptive way that tells us exactly what it does? So rename it to 'xfeatures', which is a bitmask of the xfeatures that are fpstate_active in that context structure. Eyesore like: fpu->state->xsave.xsave_hdr.xstate_bv |= XSTATE_FP; is now much more readable: fpu->state->xsave.header.xfeatures |= XSTATE_FP; Which form is not just infinitely more readable, but is also shorter as well. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 3007df99833e..07c6adc02f68 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -261,7 +261,7 @@ static inline int fpu_save_init(struct fpu *fpu) /* * xsave header may indicate the init state of the FP. */ - if (!(fpu->state->xsave.header.xstate_bv & XSTATE_FP)) + if (!(fpu->state->xsave.header.xfeatures & XSTATE_FP)) return 1; } else if (use_fxsr()) { fpu_fxsave(fpu); diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 33c0c7b782db..9bd2cd1a19fd 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -100,7 +100,7 @@ struct bndcsr { } __packed; struct xstate_header { - u64 xstate_bv; + u64 xfeatures; u64 xcomp_bv; u64 reserved[6]; } __attribute__((packed)); diff --git a/arch/x86/include/asm/user.h b/arch/x86/include/asm/user.h index fa042410c42c..59a54e869f15 100644 --- a/arch/x86/include/asm/user.h +++ b/arch/x86/include/asm/user.h @@ -15,7 +15,7 @@ struct user_ymmh_regs { }; struct user_xstate_header { - __u64 xstate_bv; + __u64 xfeatures; __u64 reserved1[2]; __u64 reserved2[5]; }; @@ -41,11 +41,11 @@ struct user_xstate_header { * particular process/thread. * * Also when the user modifies certain state FP/SSE/etc through the - * ptrace interface, they must ensure that the header.xstate_bv + * ptrace interface, they must ensure that the header.xfeatures * bytes[512..519] of the memory layout are updated correspondingly. * i.e., for example when FP state is modified to a non-init state, - * header.xstate_bv's bit 0 must be set to '1', when SSE is modified to - * non-init state, header.xstate_bv's bit 1 must to be set to '1', etc. + * header.xfeatures's bit 0 must be set to '1', when SSE is modified to + * non-init state, header.xfeatures's bit 1 must to be set to '1', etc. */ #define USER_XSTATE_FX_SW_WORDS 6 #define USER_XSTATE_XCR0_WORD 0 diff --git a/arch/x86/include/uapi/asm/sigcontext.h b/arch/x86/include/uapi/asm/sigcontext.h index 7f850f7b5c45..0e8a973de9ee 100644 --- a/arch/x86/include/uapi/asm/sigcontext.h +++ b/arch/x86/include/uapi/asm/sigcontext.h @@ -25,7 +25,7 @@ struct _fpx_sw_bytes { __u32 extended_size; /* total size of the layout referred by * fpstate pointer in the sigcontext. */ - __u64 xstate_bv; + __u64 xfeatures; /* feature bit mask (including fp/sse/extended * state) that is present in the memory * layout. @@ -210,7 +210,7 @@ struct sigcontext { #endif /* !__i386__ */ struct _header { - __u64 xstate_bv; + __u64 xfeatures; __u64 reserved1[2]; __u64 reserved2[5]; }; diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 74189f31f1a2..ae8f26b6b0e5 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -470,7 +470,7 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset, * presence of FP and SSE state. */ if (cpu_has_xsave) - fpu->state->xsave.header.xstate_bv |= XSTATE_FPSSE; + fpu->state->xsave.header.xfeatures |= XSTATE_FPSSE; return ret; } @@ -528,7 +528,7 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, * mxcsr reserved bits must be masked to zero for security reasons. */ xsave->i387.mxcsr &= mxcsr_feature_mask; - xsave->header.xstate_bv &= xfeatures_mask; + xsave->header.xfeatures &= xfeatures_mask; /* * These bits must be zero. */ @@ -740,7 +740,7 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset, * presence of FP. */ if (cpu_has_xsave) - fpu->state->xsave.header.xstate_bv |= XSTATE_FP; + fpu->state->xsave.header.xfeatures |= XSTATE_FP; return ret; } diff --git a/arch/x86/kernel/fpu/xsave.c b/arch/x86/kernel/fpu/xsave.c index 03639fa079b0..467e4635bd29 100644 --- a/arch/x86/kernel/fpu/xsave.c +++ b/arch/x86/kernel/fpu/xsave.c @@ -32,7 +32,7 @@ static unsigned int xfeatures_nr; /* * If a processor implementation discern that a processor state component is * in its initialized state it may modify the corresponding bit in the - * header.xstate_bv as '0', with out modifying the corresponding memory + * header.xfeatures as '0', with out modifying the corresponding memory * layout in the case of xsaveopt. While presenting the xstate information to * the user, we always ensure that the memory layout of a feature will be in * the init state if the corresponding header bit is zero. This is to ensure @@ -43,24 +43,24 @@ void __sanitize_i387_state(struct task_struct *tsk) { struct i387_fxsave_struct *fx = &tsk->thread.fpu.state->fxsave; int feature_bit = 0x2; - u64 xstate_bv; + u64 xfeatures; if (!fx) return; - xstate_bv = tsk->thread.fpu.state->xsave.header.xstate_bv; + xfeatures = tsk->thread.fpu.state->xsave.header.xfeatures; /* * None of the feature bits are in init state. So nothing else * to do for us, as the memory layout is up to date. */ - if ((xstate_bv & xfeatures_mask) == xfeatures_mask) + if ((xfeatures & xfeatures_mask) == xfeatures_mask) return; /* * FP is in init state */ - if (!(xstate_bv & XSTATE_FP)) { + if (!(xfeatures & XSTATE_FP)) { fx->cwd = 0x37f; fx->swd = 0; fx->twd = 0; @@ -73,17 +73,17 @@ void __sanitize_i387_state(struct task_struct *tsk) /* * SSE is in init state */ - if (!(xstate_bv & XSTATE_SSE)) + if (!(xfeatures & XSTATE_SSE)) memset(&fx->xmm_space[0], 0, 256); - xstate_bv = (xfeatures_mask & ~xstate_bv) >> 2; + xfeatures = (xfeatures_mask & ~xfeatures) >> 2; /* * Update all the other memory layouts for which the corresponding * header bit is in the init state. */ - while (xstate_bv) { - if (xstate_bv & 0x1) { + while (xfeatures) { + if (xfeatures & 0x1) { int offset = xstate_offsets[feature_bit]; int size = xstate_sizes[feature_bit]; @@ -92,7 +92,7 @@ void __sanitize_i387_state(struct task_struct *tsk) size); } - xstate_bv >>= 1; + xfeatures >>= 1; feature_bit++; } } @@ -162,7 +162,7 @@ static inline int save_xstate_epilog(void __user *buf, int ia32_frame) { struct xsave_struct __user *x = buf; struct _fpx_sw_bytes *sw_bytes; - u32 xstate_bv; + u32 xfeatures; int err; /* Setup the bytes not touched by the [f]xsave and reserved for SW. */ @@ -175,25 +175,25 @@ static inline int save_xstate_epilog(void __user *buf, int ia32_frame) err |= __put_user(FP_XSTATE_MAGIC2, (__u32 *)(buf + xstate_size)); /* - * Read the xstate_bv which we copied (directly from the cpu or + * Read the xfeatures which we copied (directly from the cpu or * from the state in task struct) to the user buffers. */ - err |= __get_user(xstate_bv, (__u32 *)&x->header.xstate_bv); + err |= __get_user(xfeatures, (__u32 *)&x->header.xfeatures); /* * For legacy compatible, we always set FP/SSE bits in the bit * vector while saving the state to the user context. This will * enable us capturing any changes(during sigreturn) to * the FP/SSE bits by the legacy applications which don't touch - * xstate_bv in the xsave header. + * xfeatures in the xsave header. * - * xsave aware apps can change the xstate_bv in the xsave + * xsave aware apps can change the xfeatures in the xsave * header as well as change any contents in the memory layout. * xrestore as part of sigreturn will capture all the changes. */ - xstate_bv |= XSTATE_FPSSE; + xfeatures |= XSTATE_FPSSE; - err |= __put_user(xstate_bv, (__u32 *)&x->header.xstate_bv); + err |= __put_user(xfeatures, (__u32 *)&x->header.xfeatures); return err; } @@ -277,7 +277,7 @@ int save_xstate_sig(void __user *buf, void __user *buf_fx, int size) static inline void sanitize_restored_xstate(struct task_struct *tsk, struct user_i387_ia32_struct *ia32_env, - u64 xstate_bv, int fx_only) + u64 xfeatures, int fx_only) { struct xsave_struct *xsave = &tsk->thread.fpu.state->xsave; struct xstate_header *header = &xsave->header; @@ -291,9 +291,9 @@ sanitize_restored_xstate(struct task_struct *tsk, * layout and not enabled by the OS. */ if (fx_only) - header->xstate_bv = XSTATE_FPSSE; + header->xfeatures = XSTATE_FPSSE; else - header->xstate_bv &= (xfeatures_mask & xstate_bv); + header->xfeatures &= (xfeatures_mask & xfeatures); } if (use_fxsr()) { @@ -335,7 +335,7 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size) struct task_struct *tsk = current; struct fpu *fpu = &tsk->thread.fpu; int state_size = xstate_size; - u64 xstate_bv = 0; + u64 xfeatures = 0; int fx_only = 0; ia32_fxstate &= (config_enabled(CONFIG_X86_32) || @@ -369,7 +369,7 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size) fx_only = 1; } else { state_size = fx_sw_user.xstate_size; - xstate_bv = fx_sw_user.xstate_bv; + xfeatures = fx_sw_user.xfeatures; } } @@ -398,7 +398,7 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size) fpstate_init(fpu); err = -1; } else { - sanitize_restored_xstate(tsk, &env, xstate_bv, fx_only); + sanitize_restored_xstate(tsk, &env, xfeatures, fx_only); } fpu->fpstate_active = 1; @@ -415,7 +415,7 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size) * state to the registers directly (with exceptions handled). */ user_fpu_begin(); - if (restore_user_xstate(buf_fx, xstate_bv, fx_only)) { + if (restore_user_xstate(buf_fx, xfeatures, fx_only)) { fpu_reset_state(fpu); return -1; } @@ -441,7 +441,7 @@ static void prepare_fx_sw_frame(void) fx_sw_reserved.magic1 = FP_XSTATE_MAGIC1; fx_sw_reserved.extended_size = size; - fx_sw_reserved.xstate_bv = xfeatures_mask; + fx_sw_reserved.xfeatures = xfeatures_mask; fx_sw_reserved.xstate_size = xstate_size; if (config_enabled(CONFIG_IA32_EMULATION)) { @@ -576,7 +576,7 @@ static void __init setup_init_fpu_buf(void) if (cpu_has_xsaves) { init_xstate_buf->header.xcomp_bv = (u64)1 << 63 | xfeatures_mask; - init_xstate_buf->header.xstate_bv = xfeatures_mask; + init_xstate_buf->header.xfeatures = xfeatures_mask; } /* diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ac24889c8bc3..0b58b9397098 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3197,7 +3197,7 @@ static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu, static void fill_xsave(u8 *dest, struct kvm_vcpu *vcpu) { struct xsave_struct *xsave = &vcpu->arch.guest_fpu.state->xsave; - u64 xstate_bv = xsave->header.xstate_bv; + u64 xstate_bv = xsave->header.xfeatures; u64 valid; /* @@ -3243,7 +3243,7 @@ static void load_xsave(struct kvm_vcpu *vcpu, u8 *src) memcpy(xsave, src, XSAVE_HDR_OFFSET); /* Set XSTATE_BV and possibly XCOMP_BV. */ - xsave->header.xstate_bv = xstate_bv; + xsave->header.xfeatures = xstate_bv; if (cpu_has_xsaves) xsave->header.xcomp_bv = host_xcr0 | XSTATE_COMPACTION_ENABLED;