From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-kernel@vger.kernel.org
Cc: x86@kernel.org, "Andy Lutomirski" <luto@kernel.org>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
kvm@vger.kernel.org, "Jason A. Donenfeld" <Jason@zx2c4.com>,
"Rik van Riel" <riel@surriel.com>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Sebastian Andrzej Siewior" <bigeasy@linutronix.de>
Subject: [PATCH 07/23] x86/fpu: Remove fpu->initialized usage in copy_fpstate_to_sigframe()
Date: Wed, 7 Nov 2018 20:48:42 +0100 [thread overview]
Message-ID: <20181107194858.9380-8-bigeasy@linutronix.de> (raw)
In-Reply-To: <20181107194858.9380-1-bigeasy@linutronix.de>
Since ->initialized is always true for user tasks and kernel threads
don't get this far, we always save the registers directly to userspace.
Remove check for ->initialized because it is always true and remove the
false condition.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
arch/x86/kernel/fpu/signal.c | 30 ++++++------------------------
1 file changed, 6 insertions(+), 24 deletions(-)
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 5777ee0c32fed..30e65085dc4d9 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -157,7 +157,6 @@ static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf)
int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
{
struct fpu *fpu = ¤t->thread.fpu;
- struct xregs_state *xsave = &fpu->state.xsave;
struct task_struct *tsk = current;
int ia32_fxstate = (buf != buf_fx);
@@ -172,29 +171,12 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
sizeof(struct user_i387_ia32_struct), NULL,
(struct _fpstate_32 __user *) buf) ? -1 : 1;
- if (fpu->initialized || using_compacted_format()) {
- /* Save the live register state to the user directly. */
- if (copy_fpregs_to_sigframe(buf_fx))
- return -1;
- /* Update the thread's fxstate to save the fsave header. */
- if (ia32_fxstate)
- copy_fxregs_to_kernel(fpu);
- } else {
- /*
- * It is a *bug* if kernel uses compacted-format for xsave
- * area and we copy it out directly to a signal frame. It
- * should have been handled above by saving the registers
- * directly.
- */
- if (boot_cpu_has(X86_FEATURE_XSAVES)) {
- WARN_ONCE(1, "x86/fpu: saving compacted-format xsave area to a signal frame!\n");
- return -1;
- }
-
- fpstate_sanitize_xstate(fpu);
- if (__copy_to_user(buf_fx, xsave, fpu_user_xstate_size))
- return -1;
- }
+ /* Save the live register state to the user directly. */
+ if (copy_fpregs_to_sigframe(buf_fx))
+ return -1;
+ /* Update the thread's fxstate to save the fsave header. */
+ if (ia32_fxstate)
+ copy_fxregs_to_kernel(fpu);
/* Save the fsave header for the 32-bit frames. */
if ((ia32_fxstate || !use_fxsr()) && save_fsave_header(tsk, buf))
--
2.19.1
next prev parent reply other threads:[~2018-11-07 19:49 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-07 19:48 [PATCH v4] x86: load FPU registers on return to userland Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 01/23] x86/fpu: Use ULL for shift in xfeature_uncompacted_offset() Sebastian Andrzej Siewior
2018-11-08 11:38 ` Borislav Petkov
2018-11-09 16:56 ` Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 02/23] x86/fpu: Remove fpu->initialized usage in __fpu__restore_sig() Sebastian Andrzej Siewior
2018-11-08 14:57 ` Borislav Petkov
2018-11-09 17:35 ` Sebastian Andrzej Siewior
2018-11-09 18:52 ` Borislav Petkov
2018-11-09 23:25 ` Sebastian Andrzej Siewior
2018-11-12 15:56 ` [PATCH] x86/fpu: Disable BH while while loading FPU registers " Sebastian Andrzej Siewior
2018-11-12 17:48 ` Dave Hansen
2018-11-19 11:41 ` Sebastian Andrzej Siewior
2018-11-19 15:04 ` Dave Hansen
2018-11-19 15:06 ` Sebastian Andrzej Siewior
2018-11-19 15:08 ` Dave Hansen
2018-11-19 15:19 ` Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 03/23] x86/fpu: Remove fpu__restore() Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 04/23] x86/entry/32: Remove asm/math_emu.h include Sebastian Andrzej Siewior
2018-11-08 18:45 ` Andy Lutomirski
2018-11-07 19:48 ` [PATCH 05/23] x86/fpu: Remove preempt_disable() in fpu__clear() Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 06/23] x86/fpu: Always init the `state' " Sebastian Andrzej Siewior
2018-11-07 19:48 ` Sebastian Andrzej Siewior [this message]
2018-11-07 19:48 ` [PATCH 08/23] x86/fpu: Remove fpu->initialized Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 09/23] x86/fpu: Remove user_fpu_begin() Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 10/23] x86/entry: Remove _TIF_ALLWORK_MASK Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 11/23] x86/fpu: Add (__)make_fpregs_active helpers Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 12/23] x86/fpu: Make __raw_xsave_addr() use feature number instead of mask Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 13/23] x86/fpu: Make get_xsave_field_ptr() and get_xsave_addr() " Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 14/23] x86/pkeys: Make init_pkru_value static Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 15/23] x86/fpu: Only write PKRU if it is different from current Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 16/23] x86/pkeys: Don't check if PKRU is zero before writting it Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 17/23] x86/fpu: Eager switch PKRU state Sebastian Andrzej Siewior
2018-11-08 11:12 ` Paolo Bonzini
2018-11-19 18:17 ` Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 18/23] x86/entry: Add TIF_NEED_FPU_LOAD Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 19/23] x86/fpu: Always store the registers in copy_fpstate_to_sigframe() Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 20/23] x86/fpu: Prepare copy_fpstate_to_sigframe() for TIF_NEED_FPU_LOAD Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 21/23] x86/fpu: Update xstate's PKRU value on write_pkru() Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 22/23] x86/fpu: Don't restore the FPU state directly from userland in __fpu__restore_sig() Sebastian Andrzej Siewior
2018-11-08 18:25 ` Andy Lutomirski
2018-11-09 19:09 ` Sebastian Andrzej Siewior
2018-11-07 19:48 ` [PATCH 23/23] x86/fpu: Defer FPU state load until return to userspace Sebastian Andrzej Siewior
2018-11-08 8:33 ` Sebastian Andrzej Siewior
2018-11-12 3:02 ` [PATCH v4] x86: load FPU registers on return to userland Wanpeng Li
2018-11-12 3:26 ` Jason A. Donenfeld
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