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
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -216,7 +216,7 @@
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 @@
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 @@
*/
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 @@
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 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 @@
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 @@
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
--- 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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -159,28 +159,14 @@
}
{
- 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 @@
* 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 @@
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 @@
*/
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 @@
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 @@
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
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -54,69 +54,6 @@
}
/*
- * 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.
*/
static int
@@ -160,25 +97,11 @@
{
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 @@
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 @@
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
--- 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.
*/