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Diffstat (limited to 'arch/x86/kernel/i387.c')
-rw-r--r--arch/x86/kernel/i387.c200
1 files changed, 119 insertions, 81 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index d2e39e69aaf8..db6839b53195 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -5,51 +5,48 @@
* General FPU state handling cleanups
* Gareth Hughes <gareth@valinux.com>, May 2000
*/
-
-#include <linux/sched.h>
#include <linux/module.h>
#include <linux/regset.h>
+#include <linux/sched.h>
+
+#include <asm/sigcontext.h>
#include <asm/processor.h>
-#include <asm/i387.h>
#include <asm/math_emu.h>
-#include <asm/sigcontext.h>
-#include <asm/user.h>
-#include <asm/ptrace.h>
#include <asm/uaccess.h>
+#include <asm/ptrace.h>
+#include <asm/i387.h>
+#include <asm/user.h>
#ifdef CONFIG_X86_64
-
-#include <asm/sigcontext32.h>
-#include <asm/user32.h>
-
+# include <asm/sigcontext32.h>
+# include <asm/user32.h>
#else
-
-#define save_i387_ia32 save_i387
-#define restore_i387_ia32 restore_i387
-
-#define _fpstate_ia32 _fpstate
-#define user_i387_ia32_struct user_i387_struct
-#define user32_fxsr_struct user_fxsr_struct
-
+# define save_i387_ia32 save_i387
+# define restore_i387_ia32 restore_i387
+# define _fpstate_ia32 _fpstate
+# define user_i387_ia32_struct user_i387_struct
+# define user32_fxsr_struct user_fxsr_struct
#endif
#ifdef CONFIG_MATH_EMULATION
-#define HAVE_HWFP (boot_cpu_data.hard_math)
+# define HAVE_HWFP (boot_cpu_data.hard_math)
#else
-#define HAVE_HWFP 1
+# define HAVE_HWFP 1
#endif
-static unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
+static unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
+unsigned int xstate_size;
+static struct i387_fxsave_struct fx_scratch __cpuinitdata;
-void mxcsr_feature_mask_init(void)
+void __cpuinit mxcsr_feature_mask_init(void)
{
unsigned long mask = 0;
+
clts();
if (cpu_has_fxsr) {
- memset(&current->thread.i387.fxsave, 0,
- sizeof(struct i387_fxsave_struct));
- asm volatile("fxsave %0" : : "m" (current->thread.i387.fxsave));
- mask = current->thread.i387.fxsave.mxcsr_mask;
+ memset(&fx_scratch, 0, sizeof(struct i387_fxsave_struct));
+ asm volatile("fxsave %0" : : "m" (fx_scratch));
+ mask = fx_scratch.mxcsr_mask;
if (mask == 0)
mask = 0x0000ffbf;
}
@@ -57,6 +54,16 @@ void mxcsr_feature_mask_init(void)
stts();
}
+void __init init_thread_xstate(void)
+{
+ if (cpu_has_fxsr)
+ xstate_size = sizeof(struct i387_fxsave_struct);
+#ifdef CONFIG_X86_32
+ else
+ xstate_size = sizeof(struct i387_fsave_struct);
+#endif
+}
+
#ifdef CONFIG_X86_64
/*
* Called at bootup to set up the initial FPU state that is later cloned
@@ -65,14 +72,11 @@ void mxcsr_feature_mask_init(void)
void __cpuinit fpu_init(void)
{
unsigned long oldcr0 = read_cr0();
- extern void __bad_fxsave_alignment(void);
- if (offsetof(struct task_struct, thread.i387.fxsave) & 15)
- __bad_fxsave_alignment();
set_in_cr4(X86_CR4_OSFXSR);
set_in_cr4(X86_CR4_OSXMMEXCPT);
- write_cr0(oldcr0 & ~((1UL<<3)|(1UL<<2))); /* clear TS and EM */
+ write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */
mxcsr_feature_mask_init();
/* clean state in init */
@@ -87,32 +91,44 @@ void __cpuinit fpu_init(void)
* value at reset if we support XMM instructions and then
* remeber the current task has used the FPU.
*/
-void init_fpu(struct task_struct *tsk)
+int init_fpu(struct task_struct *tsk)
{
if (tsk_used_math(tsk)) {
if (tsk == current)
unlazy_fpu(tsk);
- return;
+ return 0;
+ }
+
+ /*
+ * Memory allocation at the first usage of the FPU and other state.
+ */
+ if (!tsk->thread.xstate) {
+ tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
+ GFP_KERNEL);
+ if (!tsk->thread.xstate)
+ return -ENOMEM;
}
if (cpu_has_fxsr) {
- memset(&tsk->thread.i387.fxsave, 0,
- sizeof(struct i387_fxsave_struct));
- tsk->thread.i387.fxsave.cwd = 0x37f;
+ struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
+
+ memset(fx, 0, xstate_size);
+ fx->cwd = 0x37f;
if (cpu_has_xmm)
- tsk->thread.i387.fxsave.mxcsr = MXCSR_DEFAULT;
+ fx->mxcsr = MXCSR_DEFAULT;
} else {
- memset(&tsk->thread.i387.fsave, 0,
- sizeof(struct i387_fsave_struct));
- tsk->thread.i387.fsave.cwd = 0xffff037fu;
- tsk->thread.i387.fsave.swd = 0xffff0000u;
- tsk->thread.i387.fsave.twd = 0xffffffffu;
- tsk->thread.i387.fsave.fos = 0xffff0000u;
+ struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;
+ memset(fp, 0, xstate_size);
+ fp->cwd = 0xffff037fu;
+ fp->swd = 0xffff0000u;
+ fp->twd = 0xffffffffu;
+ fp->fos = 0xffff0000u;
}
/*
* Only the device not available exception or ptrace can call init_fpu.
*/
set_stopped_child_used_math(tsk);
+ return 0;
}
int fpregs_active(struct task_struct *target, const struct user_regset *regset)
@@ -129,13 +145,17 @@ int xfpregs_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
+ int ret;
+
if (!cpu_has_fxsr)
return -ENODEV;
- init_fpu(target);
+ ret = init_fpu(target);
+ if (ret)
+ return ret;
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
- &target->thread.i387.fxsave, 0, -1);
+ &target->thread.xstate->fxsave, 0, -1);
}
int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
@@ -147,16 +167,19 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
if (!cpu_has_fxsr)
return -ENODEV;
- init_fpu(target);
+ ret = init_fpu(target);
+ if (ret)
+ return ret;
+
set_stopped_child_used_math(target);
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
- &target->thread.i387.fxsave, 0, -1);
+ &target->thread.xstate->fxsave, 0, -1);
/*
* mxcsr reserved bits must be masked to zero for security reasons.
*/
- target->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
+ target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
return ret;
}
@@ -178,6 +201,7 @@ static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
+
return tmp;
}
@@ -232,10 +256,10 @@ static inline u32 twd_fxsr_to_i387(struct i387_fxsave_struct *fxsave)
* FXSR floating point environment conversions.
*/
-static void convert_from_fxsr(struct user_i387_ia32_struct *env,
- struct task_struct *tsk)
+static void
+convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
{
- struct i387_fxsave_struct *fxsave = &tsk->thread.i387.fxsave;
+ struct i387_fxsave_struct *fxsave = &tsk->thread.xstate->fxsave;
struct _fpreg *to = (struct _fpreg *) &env->st_space[0];
struct _fpxreg *from = (struct _fpxreg *) &fxsave->st_space[0];
int i;
@@ -252,10 +276,11 @@ static void convert_from_fxsr(struct user_i387_ia32_struct *env,
* should be actually ds/cs at fpu exception time, but
* that information is not available in 64bit mode.
*/
- asm("mov %%ds,%0" : "=r" (env->fos));
- asm("mov %%cs,%0" : "=r" (env->fcs));
+ asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos));
+ asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs));
} else {
struct pt_regs *regs = task_pt_regs(tsk);
+
env->fos = 0xffff0000 | tsk->thread.ds;
env->fcs = regs->cs;
}
@@ -274,7 +299,7 @@ static void convert_to_fxsr(struct task_struct *tsk,
const struct user_i387_ia32_struct *env)
{
- struct i387_fxsave_struct *fxsave = &tsk->thread.i387.fxsave;
+ struct i387_fxsave_struct *fxsave = &tsk->thread.xstate->fxsave;
struct _fpreg *from = (struct _fpreg *) &env->st_space[0];
struct _fpxreg *to = (struct _fpxreg *) &fxsave->st_space[0];
int i;
@@ -303,15 +328,20 @@ int fpregs_get(struct task_struct *target, const struct user_regset *regset,
void *kbuf, void __user *ubuf)
{
struct user_i387_ia32_struct env;
+ int ret;
if (!HAVE_HWFP)
return fpregs_soft_get(target, regset, pos, count, kbuf, ubuf);
- init_fpu(target);
+ ret = init_fpu(target);
+ if (ret)
+ return ret;
- if (!cpu_has_fxsr)
+ if (!cpu_has_fxsr) {
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
- &target->thread.i387.fsave, 0, -1);
+ &target->thread.xstate->fsave, 0,
+ -1);
+ }
if (kbuf && pos == 0 && count == sizeof(env)) {
convert_from_fxsr(kbuf, target);
@@ -319,6 +349,7 @@ int fpregs_get(struct task_struct *target, const struct user_regset *regset,
}
convert_from_fxsr(&env, target);
+
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &env, 0, -1);
}
@@ -332,12 +363,16 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
if (!HAVE_HWFP)
return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);
- init_fpu(target);
+ ret = init_fpu(target);
+ if (ret)
+ return ret;
+
set_stopped_child_used_math(target);
- if (!cpu_has_fxsr)
+ if (!cpu_has_fxsr) {
return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
- &target->thread.i387.fsave, 0, -1);
+ &target->thread.xstate->fsave, 0, -1);
+ }
if (pos > 0 || count < sizeof(env))
convert_from_fxsr(&env, target);
@@ -356,11 +391,11 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf)
{
struct task_struct *tsk = current;
+ struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;
unlazy_fpu(tsk);
- tsk->thread.i387.fsave.status = tsk->thread.i387.fsave.swd;
- if (__copy_to_user(buf, &tsk->thread.i387.fsave,
- sizeof(struct i387_fsave_struct)))
+ fp->status = fp->swd;
+ if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct)))
return -1;
return 1;
}
@@ -368,6 +403,7 @@ static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf)
static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
{
struct task_struct *tsk = current;
+ struct i387_fxsave_struct *fx = &tsk->thread.xstate->fxsave;
struct user_i387_ia32_struct env;
int err = 0;
@@ -377,12 +413,12 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
if (__copy_to_user(buf, &env, sizeof(env)))
return -1;
- err |= __put_user(tsk->thread.i387.fxsave.swd, &buf->status);
+ err |= __put_user(fx->swd, &buf->status);
err |= __put_user(X86_FXSR_MAGIC, &buf->magic);
if (err)
return -1;
- if (__copy_to_user(&buf->_fxsr_env[0], &tsk->thread.i387.fxsave,
+ if (__copy_to_user(&buf->_fxsr_env[0], fx,
sizeof(struct i387_fxsave_struct)))
return -1;
return 1;
@@ -392,46 +428,48 @@ int save_i387_ia32(struct _fpstate_ia32 __user *buf)
{
if (!used_math())
return 0;
-
- /* This will cause a "finit" to be triggered by the next
+ /*
+ * This will cause a "finit" to be triggered by the next
* attempted FPU operation by the 'current' process.
*/
clear_used_math();
- if (HAVE_HWFP) {
- if (cpu_has_fxsr) {
- return save_i387_fxsave(buf);
- } else {
- return save_i387_fsave(buf);
- }
- } else {
+ if (!HAVE_HWFP) {
return fpregs_soft_get(current, NULL,
0, sizeof(struct user_i387_ia32_struct),
NULL, buf) ? -1 : 1;
}
+
+ if (cpu_has_fxsr)
+ return save_i387_fxsave(buf);
+ else
+ return save_i387_fsave(buf);
}
static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
{
struct task_struct *tsk = current;
+
clear_fpu(tsk);
- return __copy_from_user(&tsk->thread.i387.fsave, buf,
+ return __copy_from_user(&tsk->thread.xstate->fsave, buf,
sizeof(struct i387_fsave_struct));
}
static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf)
{
- int err;
struct task_struct *tsk = current;
struct user_i387_ia32_struct env;
+ int err;
+
clear_fpu(tsk);
- err = __copy_from_user(&tsk->thread.i387.fxsave, &buf->_fxsr_env[0],
+ err = __copy_from_user(&tsk->thread.xstate->fxsave, &buf->_fxsr_env[0],
sizeof(struct i387_fxsave_struct));
/* mxcsr reserved bits must be masked to zero for security reasons */
- tsk->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
+ tsk->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
if (err || __copy_from_user(&env, buf, sizeof(env)))
return 1;
convert_to_fxsr(tsk, &env);
+
return 0;
}
@@ -440,17 +478,17 @@ int restore_i387_ia32(struct _fpstate_ia32 __user *buf)
int err;
if (HAVE_HWFP) {
- if (cpu_has_fxsr) {
+ if (cpu_has_fxsr)
err = restore_i387_fxsave(buf);
- } else {
+ else
err = restore_i387_fsave(buf);
- }
} else {
err = fpregs_soft_set(current, NULL,
0, sizeof(struct user_i387_ia32_struct),
NULL, buf) != 0;
}
set_used_math();
+
return err;
}
@@ -463,8 +501,8 @@ int restore_i387_ia32(struct _fpstate_ia32 __user *buf)
*/
int dump_fpu(struct pt_regs *regs, struct user_i387_struct *fpu)
{
- int fpvalid;
struct task_struct *tsk = current;
+ int fpvalid;
fpvalid = !!used_math();
if (fpvalid)
generated by cgit (git 2.34.1) at 2024-07-02 06:09:40 +0000