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-rw-r--r--arch/x86/kernel/i387.c154
1 files changed, 135 insertions, 19 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index eb9ddd8efb82..45723f1fe198 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -21,9 +21,12 @@
# include <asm/sigcontext32.h>
# include <asm/user32.h>
#else
-# define save_i387_ia32 save_i387
-# define restore_i387_ia32 restore_i387
+# define save_i387_xstate_ia32 save_i387_xstate
+# define restore_i387_xstate_ia32 restore_i387_xstate
# define _fpstate_ia32 _fpstate
+# define _xstate_ia32 _xstate
+# define sig_xstate_ia32_size sig_xstate_size
+# define fx_sw_reserved_ia32 fx_sw_reserved
# define user_i387_ia32_struct user_i387_struct
# define user32_fxsr_struct user_fxsr_struct
#endif
@@ -36,6 +39,7 @@
static unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
unsigned int xstate_size;
+unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32);
static struct i387_fxsave_struct fx_scratch __cpuinitdata;
void __cpuinit mxcsr_feature_mask_init(void)
@@ -61,6 +65,11 @@ void __init init_thread_xstate(void)
return;
}
+ if (cpu_has_xsave) {
+ xsave_cntxt_init();
+ return;
+ }
+
if (cpu_has_fxsr)
xstate_size = sizeof(struct i387_fxsave_struct);
#ifdef CONFIG_X86_32
@@ -83,9 +92,19 @@ void __cpuinit fpu_init(void)
write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */
+ /*
+ * Boot processor to setup the FP and extended state context info.
+ */
+ if (!smp_processor_id())
+ init_thread_xstate();
+ xsave_init();
+
mxcsr_feature_mask_init();
/* clean state in init */
- current_thread_info()->status = 0;
+ if (cpu_has_xsave)
+ current_thread_info()->status = TS_XSAVE;
+ else
+ current_thread_info()->status = 0;
clear_used_math();
}
#endif /* CONFIG_X86_64 */
@@ -195,6 +214,13 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
*/
target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
+ /*
+ * update the header bits in the xsave header, indicating the
+ * presence of FP and SSE state.
+ */
+ if (cpu_has_xsave)
+ target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
+
return ret;
}
@@ -395,6 +421,12 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
if (!ret)
convert_to_fxsr(target, &env);
+ /*
+ * update the header bit in the xsave header, indicating the
+ * presence of FP.
+ */
+ if (cpu_has_xsave)
+ target->thread.xstate->xsave.xsave_hdr.xstate_bv |= XSTATE_FP;
return ret;
}
@@ -407,7 +439,6 @@ 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);
fp->status = fp->swd;
if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct)))
return -1;
@@ -421,8 +452,6 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
struct user_i387_ia32_struct env;
int err = 0;
- unlazy_fpu(tsk);
-
convert_from_fxsr(&env, tsk);
if (__copy_to_user(buf, &env, sizeof(env)))
return -1;
@@ -432,16 +461,40 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
if (err)
return -1;
- if (__copy_to_user(&buf->_fxsr_env[0], fx,
- sizeof(struct i387_fxsave_struct)))
+ if (__copy_to_user(&buf->_fxsr_env[0], fx, xstate_size))
return -1;
return 1;
}
-int save_i387_ia32(struct _fpstate_ia32 __user *buf)
+static int save_i387_xsave(void __user *buf)
+{
+ struct _fpstate_ia32 __user *fx = buf;
+ int err = 0;
+
+ if (save_i387_fxsave(fx) < 0)
+ return -1;
+
+ err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved_ia32,
+ sizeof(struct _fpx_sw_bytes));
+ err |= __put_user(FP_XSTATE_MAGIC2,
+ (__u32 __user *) (buf + sig_xstate_ia32_size
+ - FP_XSTATE_MAGIC2_SIZE));
+ if (err)
+ return -1;
+
+ return 1;
+}
+
+int save_i387_xstate_ia32(void __user *buf)
{
+ struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
+ struct task_struct *tsk = current;
+
if (!used_math())
return 0;
+
+ if (!access_ok(VERIFY_WRITE, buf, sig_xstate_ia32_size))
+ return -EACCES;
/*
* This will cause a "finit" to be triggered by the next
* attempted FPU operation by the 'current' process.
@@ -451,13 +504,17 @@ int save_i387_ia32(struct _fpstate_ia32 __user *buf)
if (!HAVE_HWFP) {
return fpregs_soft_get(current, NULL,
0, sizeof(struct user_i387_ia32_struct),
- NULL, buf) ? -1 : 1;
+ NULL, fp) ? -1 : 1;
}
+ unlazy_fpu(tsk);
+
+ if (cpu_has_xsave)
+ return save_i387_xsave(fp);
if (cpu_has_fxsr)
- return save_i387_fxsave(buf);
+ return save_i387_fxsave(fp);
else
- return save_i387_fsave(buf);
+ return save_i387_fsave(fp);
}
static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
@@ -468,14 +525,15 @@ static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
sizeof(struct i387_fsave_struct));
}
-static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf)
+static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf,
+ unsigned int size)
{
struct task_struct *tsk = current;
struct user_i387_ia32_struct env;
int err;
err = __copy_from_user(&tsk->thread.xstate->fxsave, &buf->_fxsr_env[0],
- sizeof(struct i387_fxsave_struct));
+ size);
/* mxcsr reserved bits must be masked to zero for security reasons */
tsk->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask;
if (err || __copy_from_user(&env, buf, sizeof(env)))
@@ -485,14 +543,69 @@ static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf)
return 0;
}
-int restore_i387_ia32(struct _fpstate_ia32 __user *buf)
+static int restore_i387_xsave(void __user *buf)
+{
+ struct _fpx_sw_bytes fx_sw_user;
+ struct _fpstate_ia32 __user *fx_user =
+ ((struct _fpstate_ia32 __user *) buf);
+ struct i387_fxsave_struct __user *fx =
+ (struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0];
+ struct xsave_hdr_struct *xsave_hdr =
+ &current->thread.xstate->xsave.xsave_hdr;
+ u64 mask;
+ int err;
+
+ if (check_for_xstate(fx, buf, &fx_sw_user))
+ goto fx_only;
+
+ mask = fx_sw_user.xstate_bv;
+
+ err = restore_i387_fxsave(buf, fx_sw_user.xstate_size);
+
+ xsave_hdr->xstate_bv &= pcntxt_mask;
+ /*
+ * These bits must be zero.
+ */
+ xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0;
+
+ /*
+ * Init the state that is not present in the memory layout
+ * and enabled by the OS.
+ */
+ mask = ~(pcntxt_mask & ~mask);
+ xsave_hdr->xstate_bv &= mask;
+
+ return err;
+fx_only:
+ /*
+ * Couldn't find the extended state information in the memory
+ * layout. Restore the FP/SSE and init the other extended state
+ * enabled by the OS.
+ */
+ xsave_hdr->xstate_bv = XSTATE_FPSSE;
+ return restore_i387_fxsave(buf, sizeof(struct i387_fxsave_struct));
+}
+
+int restore_i387_xstate_ia32(void __user *buf)
{
int err;
struct task_struct *tsk = current;
+ struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;
if (HAVE_HWFP)
clear_fpu(tsk);
+ if (!buf) {
+ if (used_math()) {
+ clear_fpu(tsk);
+ clear_used_math();
+ }
+
+ return 0;
+ } else
+ if (!access_ok(VERIFY_READ, buf, sig_xstate_ia32_size))
+ return -EACCES;
+
if (!used_math()) {
err = init_fpu(tsk);
if (err)
@@ -500,14 +613,17 @@ int restore_i387_ia32(struct _fpstate_ia32 __user *buf)
}
if (HAVE_HWFP) {
- if (cpu_has_fxsr)
- err = restore_i387_fxsave(buf);
+ if (cpu_has_xsave)
+ err = restore_i387_xsave(buf);
+ else if (cpu_has_fxsr)
+ err = restore_i387_fxsave(fp, sizeof(struct
+ i387_fxsave_struct));
else
- err = restore_i387_fsave(buf);
+ err = restore_i387_fsave(fp);
} else {
err = fpregs_soft_set(current, NULL,
0, sizeof(struct user_i387_ia32_struct),
- NULL, buf) != 0;
+ NULL, fp) != 0;
}
set_used_math();
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 17:57:00 +0100