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authorLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 15:43:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 16:12:40 -0700
commitb30f3ae50cd03ef2ff433a5030fbf88dd8323528 (patch)
treeec140aa507d73eb5f4dfb8d46ccbd9dd80ca84e7
parentb5684b83b1e1579bbbc80e703e990c0cccf5892c (diff)
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x86-64: Clean up 'save/restore_i387()' usage
Suresh Siddha wants to fix a possible FPU leakage in error conditions, but the fact that save/restore_i387() are inlines in a header file makes that harder to do than necessary. So start off with an obvious cleanup. This just moves the x86-64 version of save/restore_i387() out of the header file, and moves it to the only file that it is actually used in: arch/x86/kernel/signal_64.c. So exposing it in a header file was wrong to begin with. [ Side note: I'd like to fix up some of the games we play with the 32-bit version of these functions too, but that's a separate matter. The 32-bit versions are shared - under different names at that! - by both the native x86-32 code and the x86-64 32-bit compatibility code ] Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/x86/kernel/signal_64.c53
-rw-r--r--include/asm-x86/i387.h54
2 files changed, 53 insertions, 54 deletions
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index 47c3d249e63..b45ef8ddd65 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -53,6 +53,59 @@ 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;
+ }
+ return restore_fpu_checking((__force struct i387_fxsave_struct *)buf);
+}
/*
* Do a signal return; undo the signal stack.
diff --git a/include/asm-x86/i387.h b/include/asm-x86/i387.h
index 37672f79dcc..96fa8449ff1 100644
--- a/include/asm-x86/i387.h
+++ b/include/asm-x86/i387.h
@@ -137,60 +137,6 @@ static inline void __save_init_fpu(struct task_struct *tsk)
task_thread_info(tsk)->status &= ~TS_USEDFPU;
}
-/*
- * 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;
- }
- return restore_fpu_checking((__force struct i387_fxsave_struct *)buf);
-}
-
#else /* CONFIG_X86_32 */
extern void finit(void);