From: Oleg Nesterov <oleg@redhat.com>
To: Tavis Ormandy <taviso@google.com>, Borislav Petkov <bp@alien8.de>,
Ingo Molnar <mingo@kernel.org>
Cc: Rik van Riel <riel@redhat.com>,
Andy Lutomirski <luto@amacapital.net>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] x86/regsets: change xstateregs_get/set to use ->xsave.i387 rather than ->fxsave
Date: Mon, 2 Mar 2015 19:32:37 +0100 [thread overview]
Message-ID: <20150302183237.GB23085@redhat.com> (raw)
In-Reply-To: <20150302183210.GA23085@redhat.com>
Cosmetic. xstateregs_get() and xstateregs_set() abuse ->fxsave to access
xsave->i387.sw_reserved. This is correct, ->fxsave and xsave->i387 share
the same memory, but imho this looks confusing.
And we can make this code more readable if we add "struct xsave_struct *"
local.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
arch/x86/kernel/i387.c | 25 +++++++++----------------
1 files changed, 9 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 8e070a6..4b12df8 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -339,6 +339,7 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
+ struct xsave_struct *xsave = &target->thread.fpu.state->xsave;
int ret;
if (!cpu_has_xsave)
@@ -353,14 +354,12 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset,
* memory layout in the thread struct, so that we can copy the entire
* xstateregs to the user using one user_regset_copyout().
*/
- memcpy(&target->thread.fpu.state->fxsave.sw_reserved,
- xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes));
-
+ memcpy(&xsave->i387.sw_reserved,
+ xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes));
/*
* Copy the xstate memory layout.
*/
- ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
- &target->thread.fpu.state->xsave, 0, -1);
+ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
return ret;
}
@@ -368,8 +367,8 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
+ struct xsave_struct *xsave = &target->thread.fpu.state->xsave;
int ret;
- struct xsave_hdr_struct *xsave_hdr;
if (!cpu_has_xsave)
return -ENODEV;
@@ -378,22 +377,16 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
if (ret)
return ret;
- ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
- &target->thread.fpu.state->xsave, 0, -1);
-
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
/*
* mxcsr reserved bits must be masked to zero for security reasons.
*/
- target->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask;
-
- xsave_hdr = &target->thread.fpu.state->xsave.xsave_hdr;
-
- xsave_hdr->xstate_bv &= pcntxt_mask;
+ xsave->i387.mxcsr &= mxcsr_feature_mask;
+ xsave->xsave_hdr.xstate_bv &= pcntxt_mask;
/*
* These bits must be zero.
*/
- memset(xsave_hdr->reserved, 0, 48);
-
+ memset(&xsave->xsave_hdr.reserved, 0, 48);
return ret;
}
--
1.5.5.1
next prev parent reply other threads:[~2015-03-02 18:34 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAJ_zFkJkHpU4Y8wrrZjO0VnhzUVqJfyrLmNfRsBRT29bgbDSHg@mail.gmail.com>
[not found] ` <20150301184650.GA12758@redhat.com>
[not found] ` <20150301185943.GA14318@redhat.com>
[not found] ` <20150302174818.GA16886@redhat.com>
2015-03-02 18:32 ` [PATCH 0/2] x86/fpu: minor cleanups Oleg Nesterov
2015-03-02 18:32 ` Oleg Nesterov [this message]
2015-03-03 19:23 ` [PATCH 1/2] x86/regsets: change xstateregs_get/set to use ->xsave.i387 rather than ->fxsave Rik van Riel
2015-03-04 10:30 ` Borislav Petkov
2015-03-10 10:08 ` [tip:x86/fpu] x86/fpu: Change xstateregs_get()/set() to use -> xsave.i387 " tip-bot for Oleg Nesterov
2015-03-02 18:32 ` [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths Oleg Nesterov
2015-03-03 22:01 ` Rik van Riel
2015-03-04 11:38 ` Borislav Petkov
2015-03-10 10:08 ` [tip:x86/fpu] x86/fpu: Factor out memset(xstate, 0) in fpu_finit( ) paths tip-bot for Oleg Nesterov
2015-03-09 18:08 [GIT PULL] x86/fpu cleanups Borislav Petkov
2015-03-10 6:06 ` [PATCH 1/2] x86/fpu: Change xstateregs_get()/set() to use ->xsave.i387 rather than ->fxsave Borislav Petkov
2015-03-10 6:06 ` [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths Borislav Petkov
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