[PATCH 10/33] x86/fpu: Simplify __copy_xstate_to_kernel() return values

From: Ingo Molnar
Date: Sat Sep 23 2017 - 09:01:00 EST


__copy_xstate_to_kernel() can only return 0 (because kernel copies cannot fail),
simplify the code throughout.

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/kernel/fpu/xstate.c | 17 +++++------------
1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index b18c5457065a..00c3b41c3cf1 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -924,7 +924,7 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
* This is similar to user_regset_copyout(), but will not add offset to
* the source data pointer or increment pos, count, kbuf, and ubuf.
*/
-static inline int
+static inline void
__copy_xstate_to_kernel(void *kbuf, const void *data,
unsigned int offset, unsigned int size, unsigned int size_total)
{
@@ -933,7 +933,6 @@ __copy_xstate_to_kernel(void *kbuf, const void *data,

memcpy(kbuf + offset, data, copy);
}
- return 0;
}

/*
@@ -946,8 +945,8 @@ __copy_xstate_to_kernel(void *kbuf, const void *data,
int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int offset_start, unsigned int size_total)
{
unsigned int offset, size;
- int ret, i;
struct xstate_header header;
+ int i;

/*
* Currently copy_regset_to_user() starts from pos 0:
@@ -968,9 +967,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int of
offset = offsetof(struct xregs_state, header);
size = sizeof(header);

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

for (i = 0; i < XFEATURE_MAX; i++) {
/*
@@ -986,9 +983,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int of
if (offset + size > size_total)
break;

- ret = __copy_xstate_to_kernel(kbuf, src, offset, size, size_total);
- if (ret)
- return ret;
+ __copy_xstate_to_kernel(kbuf, src, offset, size, size_total);
}

}
@@ -999,9 +994,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int of
offset = offsetof(struct fxregs_state, sw_reserved);
size = sizeof(xstate_fx_sw_bytes);

- ret = __copy_xstate_to_kernel(kbuf, xstate_fx_sw_bytes, offset, size, size_total);
- if (ret)
- return ret;
+ __copy_xstate_to_kernel(kbuf, xstate_fx_sw_bytes, offset, size, size_total);

return 0;
}
--
2.11.0