[tip:x86/fpu] x86/fpu: Clarify parameter names in the copy_xstate_to_*() methods
From: tip-bot for Ingo Molnar
Date: Tue Sep 26 2017 - 04:32:33 EST
Commit-ID: 56583c9a1400fe1935edd55b24b4fbbc779b59cb
Gitweb: http://git.kernel.org/tip/56583c9a1400fe1935edd55b24b4fbbc779b59cb
Author: Ingo Molnar <mingo@xxxxxxxxxx>
AuthorDate: Sat, 23 Sep 2017 14:59:51 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sun, 24 Sep 2017 13:04:32 +0200
x86/fpu: Clarify parameter names in the copy_xstate_to_*() methods
Right now there's a confusing mixture of 'offset' and 'size' parameters:
- __copy_xstate_to_*() input parameter 'end_pos' not not really an offset,
but the full size of the copy to be performed.
- input parameter 'count' to copy_xstate_to_*() shadows that of
__copy_xstate_to_*()'s 'count' parameter name - but the roles
are different: the first one is the total number of bytes to
be copied, while the second one is a partial copy size.
To unconfuse all this, use a consistent set of parameter names:
- 'size' is the partial copy size within a single xstate component
- 'size_total' is the total copy requested
- 'offset_start' is the requested starting offset.
- 'offset' is the offset within an xstate component.
No change in functionality.
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/20170923130016.21448-9-mingo@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/fpu/xstate.h | 4 ++--
arch/x86/kernel/fpu/xstate.c | 44 +++++++++++++++++++--------------------
2 files changed, 24 insertions(+), 24 deletions(-)
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index e4430b8..fed6617 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -48,8 +48,8 @@ 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(void *kbuf, struct xregs_state *xsave, unsigned int pos, unsigned int count);
-int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int pos, unsigned int count);
+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_user_to_xstate(const void *kbuf, const void __user *ubuf,
struct xregs_state *xsave);
#endif
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 1f50fda..c130835 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -927,15 +927,15 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
static inline int
__copy_xstate_to_kernel(void *kbuf,
const void *data,
- unsigned int pos, unsigned int count, int end_pos)
+ unsigned int offset, unsigned int size, int size_total)
{
- if (!count)
+ if (!size)
return 0;
- if (end_pos < 0 || pos < end_pos) {
- unsigned int copy = end_pos < 0 ? count : min(count, end_pos - pos);
+ if (size_total < 0 || offset < size_total) {
+ unsigned int copy = size_total < 0 ? size : min(size, size_total - offset);
- memcpy(kbuf + pos, data, copy);
+ memcpy(kbuf + offset, data, copy);
}
return 0;
}
@@ -947,7 +947,7 @@ __copy_xstate_to_kernel(void *kbuf,
* 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(void *kbuf, struct xregs_state *xsave, unsigned int pos, unsigned int count)
+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;
@@ -956,7 +956,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int po
/*
* Currently copy_regset_to_user() starts from pos 0:
*/
- if (unlikely(pos != 0))
+ if (unlikely(offset_start != 0))
return -EFAULT;
/*
@@ -972,7 +972,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int po
offset = offsetof(struct xregs_state, header);
size = sizeof(header);
- ret = __copy_xstate_to_kernel(kbuf, &header, offset, size, count);
+ ret = __copy_xstate_to_kernel(kbuf, &header, offset, size, size_total);
if (ret)
return ret;
@@ -986,11 +986,11 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int po
offset = xstate_offsets[i];
size = xstate_sizes[i];
- ret = __copy_xstate_to_kernel(kbuf, src, offset, size, count);
+ ret = __copy_xstate_to_kernel(kbuf, src, offset, size, size_total);
if (ret)
return ret;
- if (offset + size >= count)
+ if (offset + size >= size_total)
break;
}
@@ -1002,7 +1002,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int po
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, count);
+ ret = __copy_xstate_to_kernel(kbuf, xstate_fx_sw_bytes, offset, size, size_total);
if (ret)
return ret;
@@ -1010,15 +1010,15 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int po
}
static inline int
-__copy_xstate_to_user(void __user *ubuf, const void *data, unsigned int pos, unsigned int count, int end_pos)
+__copy_xstate_to_user(void __user *ubuf, const void *data, unsigned int offset, unsigned int size, int size_total)
{
- if (!count)
+ if (!size)
return 0;
- if (end_pos < 0 || pos < end_pos) {
- unsigned int copy = end_pos < 0 ? count : min(count, end_pos - pos);
+ if (size_total < 0 || offset < size_total) {
+ unsigned int copy = size_total < 0 ? size : min(size, size_total - offset);
- if (__copy_to_user(ubuf + pos, data, copy))
+ if (__copy_to_user(ubuf + offset, data, copy))
return -EFAULT;
}
return 0;
@@ -1030,7 +1030,7 @@ __copy_xstate_to_user(void __user *ubuf, const void *data, unsigned int pos, uns
* zero. This is called from xstateregs_get() and there we check the CPU
* has XSAVES.
*/
-int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int pos, unsigned int count)
+int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset_start, unsigned int size_total)
{
unsigned int offset, size;
int ret, i;
@@ -1039,7 +1039,7 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i
/*
* Currently copy_regset_to_user() starts from pos 0:
*/
- if (unlikely(pos != 0))
+ if (unlikely(offset_start != 0))
return -EFAULT;
/*
@@ -1055,7 +1055,7 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i
offset = offsetof(struct xregs_state, header);
size = sizeof(header);
- ret = __copy_xstate_to_user(ubuf, &header, offset, size, count);
+ ret = __copy_xstate_to_user(ubuf, &header, offset, size, size_total);
if (ret)
return ret;
@@ -1069,11 +1069,11 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i
offset = xstate_offsets[i];
size = xstate_sizes[i];
- ret = __copy_xstate_to_user(ubuf, src, offset, size, count);
+ ret = __copy_xstate_to_user(ubuf, src, offset, size, size_total);
if (ret)
return ret;
- if (offset + size >= count)
+ if (offset + size >= size_total)
break;
}
@@ -1085,7 +1085,7 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i
offset = offsetof(struct fxregs_state, sw_reserved);
size = sizeof(xstate_fx_sw_bytes);
- ret = __copy_xstate_to_user(ubuf, xstate_fx_sw_bytes, offset, size, count);
+ ret = __copy_xstate_to_user(ubuf, xstate_fx_sw_bytes, offset, size, size_total);
if (ret)
return ret;