[PATCH 182/208] x86/fpu: Move the signal frame handling code closer to each other

From: Ingo Molnar
Date: Tue May 05 2015 - 13:59:46 EST


Consolidate more signal frame related functions:

text data bss dec filename
14108070 2575280 1634304 18317654 vmlinux.before
14107944 2575344 1634304 18317592 vmlinux.after

Also, while moving it, rename alloc_mathframe() to fpu__alloc_mathframe().

Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/ia32/ia32_signal.c | 2 +-
arch/x86/include/asm/fpu/internal.h | 38 ++++----------------------------------
arch/x86/kernel/fpu/xstate.c | 39 ++++++++++++++++++++++++++++++++++++++-
arch/x86/kernel/signal.c | 4 ++--
4 files changed, 45 insertions(+), 38 deletions(-)

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index de81ddf3b0b2..54605eb1631f 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -325,7 +325,7 @@ static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
if (fpu->fpstate_active) {
unsigned long fx_aligned, math_size;

- sp = alloc_mathframe(sp, 1, &fx_aligned, &math_size);
+ sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size);
*fpstate = (struct _fpstate_ia32 __user *) sp;
if (copy_fpstate_to_sigframe(*fpstate, (void __user *)fx_aligned,
math_size) < 0)
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index d6cfbdafbab2..34fbf95bbe14 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -53,6 +53,7 @@ extern int dump_fpu(struct pt_regs *, struct user_i387_struct *);
*/
extern void fpu__save(struct fpu *fpu);
extern void fpu__restore(void);
+extern int fpu__restore_sig(void __user *buf, int ia32_frame);
extern void fpu__drop(struct fpu *fpu);
extern int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu);
extern void fpu__reset(struct fpu *fpu);
@@ -497,25 +498,6 @@ static inline void switch_fpu_finish(struct fpu *new_fpu, fpu_switch_t fpu_switc
* Signal frame handlers...
*/
extern int copy_fpstate_to_sigframe(void __user *buf, void __user *fx, int size);
-extern int __fpu__restore_sig(void __user *buf, void __user *fx, int size);
-
-static inline int xstate_sigframe_size(void)
-{
- return use_xsave() ? xstate_size + FP_XSTATE_MAGIC2_SIZE : xstate_size;
-}
-
-static inline int fpu__restore_sig(void __user *buf, int ia32_frame)
-{
- void __user *buf_fx = buf;
- int size = xstate_sigframe_size();
-
- if (ia32_frame && use_fxsr()) {
- buf_fx = buf + sizeof(struct i387_fsave_struct);
- size += sizeof(struct i387_fsave_struct);
- }
-
- return __fpu__restore_sig(buf, buf_fx, size);
-}

/*
* Needs to be preemption-safe.
@@ -565,20 +547,8 @@ static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk)
}
}

-static inline unsigned long
-alloc_mathframe(unsigned long sp, int ia32_frame, unsigned long *buf_fx,
- unsigned long *size)
-{
- unsigned long frame_size = xstate_sigframe_size();
-
- *buf_fx = sp = round_down(sp - frame_size, 64);
- if (ia32_frame && use_fxsr()) {
- frame_size += sizeof(struct i387_fsave_struct);
- sp -= sizeof(struct i387_fsave_struct);
- }
-
- *size = frame_size;
- return sp;
-}
+unsigned long
+fpu__alloc_mathframe(unsigned long sp, int ia32_frame,
+ unsigned long *buf_fx, unsigned long *size);

#endif /* _ASM_X86_FPU_INTERNAL_H */
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index ea514d6a34e8..810f080fadf3 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -388,7 +388,7 @@ static inline int restore_user_xstate(void __user *buf, u64 xbv, int fx_only)
return frstor_user(buf);
}

-int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
+static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
{
int ia32_fxstate = (buf != buf_fx);
struct task_struct *tsk = current;
@@ -482,6 +482,43 @@ int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
return 0;
}

+static inline int xstate_sigframe_size(void)
+{
+ return use_xsave() ? xstate_size + FP_XSTATE_MAGIC2_SIZE : xstate_size;
+}
+
+/*
+ * Restore FPU state from a sigframe:
+ */
+int fpu__restore_sig(void __user *buf, int ia32_frame)
+{
+ void __user *buf_fx = buf;
+ int size = xstate_sigframe_size();
+
+ if (ia32_frame && use_fxsr()) {
+ buf_fx = buf + sizeof(struct i387_fsave_struct);
+ size += sizeof(struct i387_fsave_struct);
+ }
+
+ return __fpu__restore_sig(buf, buf_fx, size);
+}
+
+unsigned long
+fpu__alloc_mathframe(unsigned long sp, int ia32_frame,
+ unsigned long *buf_fx, unsigned long *size)
+{
+ unsigned long frame_size = xstate_sigframe_size();
+
+ *buf_fx = sp = round_down(sp - frame_size, 64);
+ if (ia32_frame && use_fxsr()) {
+ frame_size += sizeof(struct i387_fsave_struct);
+ sp -= sizeof(struct i387_fsave_struct);
+ }
+
+ *size = frame_size;
+
+ return sp;
+}
/*
* Prepare the SW reserved portion of the fxsave memory layout, indicating
* the presence of the extended state information in the memory layout
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 7416fa86f3c7..9554ca69a84e 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -219,8 +219,8 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
}

if (fpu->fpstate_active) {
- sp = alloc_mathframe(sp, config_enabled(CONFIG_X86_32),
- &buf_fx, &math_size);
+ sp = fpu__alloc_mathframe(sp, config_enabled(CONFIG_X86_32),
+ &buf_fx, &math_size);
*fpstate = (void __user *)sp;
}

--
2.1.0

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