[PATCH 13/33] x86/fpu: Remove 'kbuf' parameter from the copy_user_to_xstate() API

From: Ingo Molnar
Date: Sat Sep 23 2017 - 09:05:58 EST


No change in functionality.

Cc: Andy Lutomirski <luto@xxxxxxxxxx>
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: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/fpu/xstate.h | 2 +-
arch/x86/kernel/fpu/regset.c | 2 +-
arch/x86/kernel/fpu/signal.c | 11 ++++-------
arch/x86/kernel/fpu/xstate.c | 19 +++++--------------
4 files changed, 11 insertions(+), 23 deletions(-)

diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index f10889bc0c88..4ceb90740d80 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -51,5 +51,5 @@ int using_compacted_format(void);
int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int offset, unsigned int size);
int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset, unsigned int size);
int copy_kernel_to_xstate(const void *kbuf, struct xregs_state *xsave);
-int copy_user_to_xstate(const void *kbuf, const void __user *ubuf, struct xregs_state *xsave);
+int copy_user_to_xstate(const void __user *ubuf, struct xregs_state *xsave);
#endif
diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c
index 785302c75f38..caf723f31737 100644
--- a/arch/x86/kernel/fpu/regset.c
+++ b/arch/x86/kernel/fpu/regset.c
@@ -138,7 +138,7 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
if (kbuf)
ret = copy_kernel_to_xstate(kbuf, xsave);
else
- ret = copy_user_to_xstate(kbuf, ubuf, xsave);
+ ret = copy_user_to_xstate(ubuf, xsave);
} else {
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
}
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index b1fe9a1fc4e0..2c685b492fd6 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -323,13 +323,10 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
*/
fpu__drop(fpu);

- if (using_compacted_format()) {
- err = copy_user_to_xstate(NULL, buf_fx,
- &fpu->state.xsave);
- } else {
- err = __copy_from_user(&fpu->state.xsave,
- buf_fx, state_size);
- }
+ if (using_compacted_format())
+ err = copy_user_to_xstate(buf_fx, &fpu->state.xsave);
+ else
+ err = __copy_from_user(&fpu->state.xsave, buf_fx, state_size);

if (err || __copy_from_user(&env, buf, sizeof(env))) {
fpstate_init(&fpu->state);
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 71cc8d367fdd..b1f3e4dae2e3 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -1142,8 +1142,7 @@ int copy_kernel_to_xstate(const void *kbuf, struct xregs_state *xsave)
* there we check the CPU has XSAVES and a whole standard-sized buffer
* exists.
*/
-int copy_user_to_xstate(const void *kbuf, const void __user *ubuf,
- struct xregs_state *xsave)
+int copy_user_to_xstate(const void __user *ubuf, struct xregs_state *xsave)
{
unsigned int offset, size;
int i;
@@ -1153,12 +1152,8 @@ int copy_user_to_xstate(const void *kbuf, const void __user *ubuf,
offset = offsetof(struct xregs_state, header);
size = sizeof(xfeatures);

- if (kbuf) {
- memcpy(&xfeatures, kbuf + offset, size);
- } else {
- if (__copy_from_user(&xfeatures, ubuf + offset, size))
- return -EFAULT;
- }
+ if (__copy_from_user(&xfeatures, ubuf + offset, size))
+ return -EFAULT;

/*
* Reject if the user sets any disabled or supervisor features:
@@ -1177,12 +1172,8 @@ int copy_user_to_xstate(const void *kbuf, const void __user *ubuf,
offset = xstate_offsets[i];
size = xstate_sizes[i];

- if (kbuf) {
- memcpy(dst, kbuf + offset, size);
- } else {
- if (__copy_from_user(dst, ubuf + offset, size))
- return -EFAULT;
- }
+ if (__copy_from_user(dst, ubuf + offset, size))
+ return -EFAULT;
}
}

--
2.11.0