[tip:x86/fpu] x86/fpu: Remove 'ubuf' parameter from the copy_xstate_to_kernel() APIs

From: tip-bot for Ingo Molnar
Date: Tue Sep 26 2017 - 04:29:27 EST


Commit-ID: 4d981cf2d96f29cdfa7d4972c8b377fe7baa9c4c
Gitweb: http://git.kernel.org/tip/4d981cf2d96f29cdfa7d4972c8b377fe7baa9c4c
Author: Ingo Molnar <mingo@xxxxxxxxxx>
AuthorDate: Sat, 23 Sep 2017 14:59:46 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sun, 24 Sep 2017 13:04:31 +0200

x86/fpu: Remove 'ubuf' parameter from the copy_xstate_to_kernel() APIs

The 'ubuf' parameter is unused in the _kernel() side of the API, remove it.

This simplifies the code and makes it easier to think about.

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Eric Biggers <ebiggers3@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@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>
Link: http://lkml.kernel.org/r/20170923130016.21448-4-mingo@xxxxxxxxxx
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/xstate.c | 21 ++++++---------------
3 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index 92dc8ca..c762574 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -48,7 +48,7 @@ void fpu__xstate_clear_all_cpu_caps(void);
void *get_xsave_addr(struct xregs_state *xsave, int xstate);
const void *get_xsave_field_ptr(int xstate_field);
int using_compacted_format(void);
-int copy_xstate_to_kernel(unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf, struct xregs_state *xsave);
+int copy_xstate_to_kernel(unsigned int pos, unsigned int count, void *kbuf, struct xregs_state *xsave);
int copy_xstate_to_user(unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf, struct xregs_state *xsave);
int copy_user_to_xstate(const void *kbuf, const void __user *ubuf,
struct xregs_state *xsave);
diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c
index b6d12d6..34e74ad 100644
--- a/arch/x86/kernel/fpu/regset.c
+++ b/arch/x86/kernel/fpu/regset.c
@@ -93,7 +93,7 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset,

if (using_compacted_format()) {
if (kbuf)
- ret = copy_xstate_to_kernel(pos, count, kbuf, ubuf, xsave);
+ ret = copy_xstate_to_kernel(pos, count, kbuf, xsave);
else
ret = copy_xstate_to_user(pos, count, kbuf, ubuf, xsave);
} else {
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 3856153..71d3bda 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -926,7 +926,7 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
*/
static inline int
__copy_xstate_to_kernel(unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf,
+ void *kbuf,
const void *data, const int start_pos,
const int end_pos)
{
@@ -936,12 +936,7 @@ __copy_xstate_to_kernel(unsigned int pos, unsigned int count,
if (end_pos < 0 || pos < end_pos) {
unsigned int copy = (end_pos < 0 ? count : min(count, end_pos - pos));

- if (kbuf) {
- memcpy(kbuf + pos, data, copy);
- } else {
- if (__copy_to_user(ubuf + pos, data, copy))
- return -EFAULT;
- }
+ memcpy(kbuf + pos, data, copy);
}
return 0;
}
@@ -953,8 +948,7 @@ __copy_xstate_to_kernel(unsigned int pos, unsigned int count,
* It supports partial copy but pos always starts from zero. This is called
* from xstateregs_get() and there we check the CPU has XSAVES.
*/
-int copy_xstate_to_kernel(unsigned int pos, unsigned int count, void *kbuf,
- void __user *ubuf, struct xregs_state *xsave)
+int copy_xstate_to_kernel(unsigned int pos, unsigned int count, void *kbuf, struct xregs_state *xsave)
{
unsigned int offset, size;
int ret, i;
@@ -979,8 +973,7 @@ int copy_xstate_to_kernel(unsigned int pos, unsigned int count, void *kbuf,
offset = offsetof(struct xregs_state, header);
size = sizeof(header);

- ret = __copy_xstate_to_kernel(offset, size, kbuf, ubuf, &header, 0, count);
-
+ ret = __copy_xstate_to_kernel(offset, size, kbuf, &header, 0, count);
if (ret)
return ret;

@@ -994,8 +987,7 @@ int copy_xstate_to_kernel(unsigned int pos, unsigned int count, void *kbuf,
offset = xstate_offsets[i];
size = xstate_sizes[i];

- ret = __copy_xstate_to_kernel(offset, size, kbuf, ubuf, src, 0, count);
-
+ ret = __copy_xstate_to_kernel(offset, size, kbuf, src, 0, count);
if (ret)
return ret;

@@ -1011,8 +1003,7 @@ int copy_xstate_to_kernel(unsigned int pos, unsigned int count, void *kbuf,
offset = offsetof(struct fxregs_state, sw_reserved);
size = sizeof(xstate_fx_sw_bytes);

- ret = __copy_xstate_to_kernel(offset, size, kbuf, ubuf, xstate_fx_sw_bytes, 0, count);
-
+ ret = __copy_xstate_to_kernel(offset, size, kbuf, xstate_fx_sw_bytes, 0, count);
if (ret)
return ret;