x86, xsave: reorganization of signal save/restore fpstate code layout

move 64bit routines that saves/restores fpstate in/from user stack from
signal_64.c to xsave.c

restore_i387_xstate() now handles the condition when user passes
NULL fpstate.

Other misc changes for prepartion of xsave/xrstor sigcontext support.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index a05bf0f..c596eab 100644 (file)
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -216,7 +216,7 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
                                   unsigned int *peax)
 {
        unsigned int tmpflags, gs, oldgs, err = 0;
-       struct _fpstate_ia32 __user *buf;
+       void __user *buf;
        u32 tmp;
 
        /* Always make any pending restarted system calls return -EINTR */
@@ -260,26 +260,12 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
 
        err |= __get_user(tmp, &sc->fpstate);
        buf = compat_ptr(tmp);
-       if (buf) {
-               if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
-                       goto badframe;
-               err |= restore_i387_ia32(buf);
-       } else {
-               struct task_struct *me = current;
-
-               if (used_math()) {
-                       clear_fpu(me);
-                       clear_used_math();
-               }
-       }
+       err |= restore_i387_xstate_ia32(buf);
 
        err |= __get_user(tmp, &sc->ax);
        *peax = tmp;
 
        return err;
-
-badframe:
-       return 1;
 }
 
 asmlinkage long sys32_sigreturn(struct pt_regs *regs)
@@ -351,7 +337,7 @@ badframe:
  */
 
 static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,
-                                struct _fpstate_ia32 __user *fpstate,
+                                void __user *fpstate,
                                 struct pt_regs *regs, unsigned int mask)
 {
        int tmp, err = 0;
@@ -382,7 +368,7 @@ static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,
        err |= __put_user((u32)regs->flags, &sc->flags);
        err |= __put_user((u32)regs->sp, &sc->sp_at_signal);
 
-       tmp = save_i387_ia32(fpstate);
+       tmp = save_i387_xstate_ia32(fpstate);
        if (tmp < 0)
                err = -EFAULT;
        else {
@@ -404,7 +390,7 @@ static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,
  */
 static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
                                 size_t frame_size,
-                                struct _fpstate_ia32 **fpstate)
+                                void **fpstate)
 {
        unsigned long sp;
 
@@ -441,7 +427,7 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka,
        struct sigframe __user *frame;
        void __user *restorer;
        int err = 0;
-       struct _fpstate_ia32 __user *fpstate = NULL;
+       void __user *fpstate = NULL;
 
        /* copy_to_user optimizes that into a single 8 byte store */
        static const struct {
@@ -529,7 +515,7 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
        struct rt_sigframe __user *frame;
        void __user *restorer;
        int err = 0;
-       struct _fpstate_ia32 __user *fpstate = NULL;
+       void __user *fpstate = NULL;
 
        /* __copy_to_user optimizes that into a single 8 byte store */
        static const struct {

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 51fb288..7daf3a0 100644 (file)
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -21,9 +21,10 @@
 # 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 user_i387_ia32_struct user_i387_struct
 # define user32_fxsr_struct    user_fxsr_struct
@@ -424,7 +425,6 @@ 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;
@@ -438,8 +438,6 @@ 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;
@@ -455,10 +453,16 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf)
        return 1;
 }
 
-int save_i387_ia32(struct _fpstate_ia32 __user *buf)
+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.
@@ -468,13 +472,15 @@ 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_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)
@@ -502,14 +508,26 @@ static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf)
        return 0;
 }
 
-int restore_i387_ia32(struct _fpstate_ia32 __user *buf)
+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)
@@ -518,13 +536,13 @@ int restore_i387_ia32(struct _fpstate_ia32 __user *buf)
 
        if (HAVE_HWFP) {
                if (cpu_has_fxsr)
-                       err = restore_i387_fxsave(buf);
+                       err = restore_i387_fxsave(fp);
                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();
 

diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index 19a7a56..690cc61 100644 (file)
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -159,28 +159,14 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
        }
 
        {
-               struct _fpstate __user *buf;
+               void __user *buf;
 
                err |= __get_user(buf, &sc->fpstate);
-               if (buf) {
-                       if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
-                               goto badframe;
-                       err |= restore_i387(buf);
-               } else {
-                       struct task_struct *me = current;
-
-                       if (used_math()) {
-                               clear_fpu(me);
-                               clear_used_math();
-                       }
-               }
+               err |= restore_i387_xstate(buf);
        }
 
        err |= __get_user(*pax, &sc->ax);
        return err;
-
-badframe:
-       return 1;
 }
 
 asmlinkage unsigned long sys_sigreturn(unsigned long __unused)
@@ -262,7 +248,7 @@ badframe:
  * Set up a signal frame.
  */
 static int
-setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
+setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
                 struct pt_regs *regs, unsigned long mask)
 {
        int tmp, err = 0;
@@ -289,7 +275,7 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
        err |= __put_user(regs->sp, &sc->sp_at_signal);
        err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
 
-       tmp = save_i387(fpstate);
+       tmp = save_i387_xstate(fpstate);
        if (tmp < 0)
                err = 1;
        else
@@ -307,7 +293,7 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
  */
 static inline void __user *
 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
-            struct _fpstate **fpstate)
+            void **fpstate)
 {
        unsigned long sp;
 
@@ -356,7 +342,7 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
        void __user *restorer;
        int err = 0;
        int usig;
-       struct _fpstate __user *fpstate = NULL;
+       void __user *fpstate = NULL;
 
        frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
 
@@ -434,7 +420,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
        void __user *restorer;
        int err = 0;
        int usig;
-       struct _fpstate __user *fpstate = NULL;
+       void __user *fpstate = NULL;
 
        frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
 

diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index 0deab8e..ddf6123 100644 (file)
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -53,69 +53,6 @@ sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
        return do_sigaltstack(uss, uoss, regs->sp);
 }
 
-/*
- * Signal frame handlers.
- */
-
-static inline int save_i387(struct _fpstate __user *buf)
-{
-       struct task_struct *tsk = current;
-       int err = 0;
-
-       BUILD_BUG_ON(sizeof(struct user_i387_struct) !=
-                       sizeof(tsk->thread.xstate->fxsave));
-
-       if ((unsigned long)buf % 16)
-               printk("save_i387: bad fpstate %p\n", buf);
-
-       if (!used_math())
-               return 0;
-       clear_used_math(); /* trigger finit */
-       if (task_thread_info(tsk)->status & TS_USEDFPU) {
-               err = save_i387_checking((struct i387_fxsave_struct __user *)
-                                        buf);
-               if (err)
-                       return err;
-               task_thread_info(tsk)->status &= ~TS_USEDFPU;
-               stts();
-       } else {
-               if (__copy_to_user(buf, &tsk->thread.xstate->fxsave,
-                                  sizeof(struct i387_fxsave_struct)))
-                       return -1;
-       }
-       return 1;
-}
-
-/*
- * This restores directly out of user space. Exceptions are handled.
- */
-static inline int restore_i387(struct _fpstate __user *buf)
-{
-       struct task_struct *tsk = current;
-       int err;
-
-       if (!used_math()) {
-               err = init_fpu(tsk);
-               if (err)
-                       return err;
-       }
-
-       if (!(task_thread_info(current)->status & TS_USEDFPU)) {
-               clts();
-               task_thread_info(current)->status |= TS_USEDFPU;
-       }
-       err = restore_fpu_checking((__force struct i387_fxsave_struct *)buf);
-       if (unlikely(err)) {
-               /*
-                * Encountered an error while doing the restore from the
-                * user buffer, clear the fpu state.
-                */
-               clear_fpu(tsk);
-               clear_used_math();
-       }
-       return err;
-}
-
 /*
  * Do a signal return; undo the signal stack.
  */
@@ -160,25 +97,11 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
        {
                struct _fpstate __user * buf;
                err |= __get_user(buf, &sc->fpstate);
-
-               if (buf) {
-                       if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
-                               goto badframe;
-                       err |= restore_i387(buf);
-               } else {
-                       struct task_struct *me = current;
-                       if (used_math()) {
-                               clear_fpu(me);
-                               clear_used_math();
-                       }
-               }
+               err |= restore_i387_xstate(buf);
        }
 
        err |= __get_user(*pax, &sc->ax);
        return err;
-
-badframe:
-       return 1;
 }
 
 asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
@@ -276,7 +199,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                           sigset_t *set, struct pt_regs * regs)
 {
        struct rt_sigframe __user *frame;
-       struct _fpstate __user *fp = NULL; 
+       void __user *fp = NULL;
        int err = 0;
        struct task_struct *me = current;
 
@@ -288,7 +211,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
                        goto give_sigsegv;
 
-               if (save_i387(fp) < 0) 
+               if (save_i387_xstate(fp) < 0)
                        err |= -1; 
        } else
                frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;

diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index 7ad169e..608e72d 100644 (file)
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -12,6 +12,85 @@
  */
 unsigned int pcntxt_hmask, pcntxt_lmask;
 
+#ifdef CONFIG_X86_64
+/*
+ * Signal frame handlers.
+ */
+
+int save_i387_xstate(void __user *buf)
+{
+       struct task_struct *tsk = current;
+       int err = 0;
+
+       if (!access_ok(VERIFY_WRITE, buf, sig_xstate_size))
+               return -EACCES;
+
+       BUILD_BUG_ON(sizeof(struct user_i387_struct) !=
+                       sizeof(tsk->thread.xstate->fxsave));
+
+       if ((unsigned long)buf % 16)
+               printk("save_i387_xstate: bad fpstate %p\n", buf);
+
+       if (!used_math())
+               return 0;
+       clear_used_math(); /* trigger finit */
+       if (task_thread_info(tsk)->status & TS_USEDFPU) {
+               err = save_i387_checking((struct i387_fxsave_struct __user *)
+                                        buf);
+               if (err)
+                       return err;
+               task_thread_info(tsk)->status &= ~TS_USEDFPU;
+               stts();
+       } else {
+               if (__copy_to_user(buf, &tsk->thread.xstate->fxsave,
+                                  xstate_size))
+                       return -1;
+       }
+       return 1;
+}
+
+/*
+ * This restores directly out of user space. Exceptions are handled.
+ */
+int restore_i387_xstate(void __user *buf)
+{
+       struct task_struct *tsk = current;
+       int err;
+
+       if (!buf) {
+               if (used_math()) {
+                       clear_fpu(tsk);
+                       clear_used_math();
+               }
+
+               return 0;
+       } else
+               if (!access_ok(VERIFY_READ, buf, sig_xstate_size))
+                       return -EACCES;
+
+       if (!used_math()) {
+               err = init_fpu(tsk);
+               if (err)
+                       return err;
+       }
+
+       if (!(task_thread_info(current)->status & TS_USEDFPU)) {
+               clts();
+               task_thread_info(current)->status |= TS_USEDFPU;
+       }
+       err = fxrstor_checking((__force struct i387_fxsave_struct *)buf);
+       if (unlikely(err)) {
+               /*
+                * Encountered an error while doing the restore from the
+                * user buffer, clear the fpu state.
+                */
+               clear_fpu(tsk);
+               clear_used_math();
+       }
+       return err;
+}
+#endif
+
 /*
  * Represents init state for the supported extended state.
  */

diff --git a/include/asm-x86/i387.h b/include/asm-x86/i387.h
index 36dca8d..dc3745e 100644 (file)
--- a/include/asm-x86/i387.h
+++ b/include/asm-x86/i387.h
@@ -34,8 +34,9 @@ extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set;
 #ifdef CONFIG_IA32_EMULATION
 extern unsigned int sig_xstate_ia32_size;
 struct _fpstate_ia32;
-extern int save_i387_ia32(struct _fpstate_ia32 __user *buf);
-extern int restore_i387_ia32(struct _fpstate_ia32 __user *buf);
+struct _xstate_ia32;
+extern int save_i387_xstate_ia32(void __user *buf);
+extern int restore_i387_xstate_ia32(void __user *buf);
 #endif
 
 #define X87_FSW_ES (1 << 7)    /* Exception Summary */
@@ -249,13 +250,13 @@ end:
        task_thread_info(tsk)->status &= ~TS_USEDFPU;
 }
 
+#endif /* CONFIG_X86_64 */
+
 /*
  * Signal frame handlers...
  */
-extern int save_i387(struct _fpstate __user *buf);
-extern int restore_i387(struct _fpstate __user *buf);
-
-#endif /* CONFIG_X86_64 */
+extern int save_i387_xstate(void __user *buf);
+extern int restore_i387_xstate(void __user *buf);
 
 static inline void __unlazy_fpu(struct task_struct *tsk)
 {