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Date: Tue, 5 May 2015 19:49:36 +0200
From: Ingo Molnar <mingo@...nel.org>
To: linux-kernel@...r.kernel.org
Cc: Andy Lutomirski <luto@...capital.net>,
Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Fenghua Yu <fenghua.yu@...el.com>,
"H. Peter Anvin" <hpa@...or.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Oleg Nesterov <oleg@...hat.com>,
Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 084/208] 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 <bp@...en8.de>
Cc: Andy Lutomirski <luto@...capital.net>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Fenghua Yu <fenghua.yu@...el.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
arch/x86/include/asm/fpu/internal.h | 2 +-
arch/x86/include/asm/fpu/types.h | 2 +-
arch/x86/include/asm/user.h | 8 ++++----
arch/x86/include/uapi/asm/sigcontext.h | 4 ++--
arch/x86/kernel/fpu/core.c | 6 +++---
arch/x86/kernel/fpu/xsave.c | 52 ++++++++++++++++++++++++++--------------------------
arch/x86/kvm/x86.c | 4 ++--
7 files changed, 39 insertions(+), 39 deletions(-)
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 eabf4380366a..c12dd3c0aabb 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;
--
2.1.0
--
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