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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 05/22] x86/fpu: Remove fpu->initialized usage in copy_fpstate_to_sigframe()
Date: Wed,  9 Jan 2019 12:47:27 +0100	[thread overview]
Message-ID: <20190109114744.10936-6-bigeasy@linutronix.de> (raw)
In-Reply-To: <20190109114744.10936-1-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 c0cdcb9b7de5a..c136a4327659d 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 = &current->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))
-- 
2.20.1


  parent reply	other threads:[~2019-01-09 11:49 UTC|newest]

Thread overview: 91+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-09 11:47 [PATCH v6] x86: load FPU registers on return to userland Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 01/22] x86/fpu: Remove fpu->initialized usage in __fpu__restore_sig() Sebastian Andrzej Siewior
2019-01-14 16:24   ` Borislav Petkov
2019-02-05 10:08     ` Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 02/22] x86/fpu: Remove fpu__restore() Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 03/22] x86/fpu: Remove preempt_disable() in fpu__clear() Sebastian Andrzej Siewior
2019-01-14 18:55   ` Borislav Petkov
2019-01-09 11:47 ` [PATCH 04/22] x86/fpu: Always init the `state' " Sebastian Andrzej Siewior
2019-01-14 19:32   ` Borislav Petkov
2019-01-09 11:47 ` Sebastian Andrzej Siewior [this message]
2019-01-16 19:36   ` [PATCH 05/22] x86/fpu: Remove fpu->initialized usage in copy_fpstate_to_sigframe() Borislav Petkov
2019-01-16 22:40     ` Sebastian Andrzej Siewior
2019-01-17 12:22       ` Borislav Petkov
2019-01-18 21:14         ` Sebastian Andrzej Siewior
2019-01-18 21:17           ` Dave Hansen
2019-01-18 21:37             ` Sebastian Andrzej Siewior
2019-01-18 21:43               ` Dave Hansen
2019-01-21 11:21             ` Oleg Nesterov
2019-01-22 13:40               ` Borislav Petkov
2019-01-22 16:15                 ` Oleg Nesterov
2019-01-22 17:00                   ` Borislav Petkov
2019-02-05 11:34                     ` Sebastian Andrzej Siewior
2019-02-05 11:17               ` Sebastian Andrzej Siewior
2019-02-26 16:38                 ` Oleg Nesterov
2019-03-08 18:12                   ` Sebastian Andrzej Siewior
2019-02-05 14:37         ` [PATCH 05/22 v2] " Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 06/22] x86/fpu: Don't save fxregs for ia32 frames " Sebastian Andrzej Siewior
2019-01-24 11:17   ` Borislav Petkov
2019-02-05 16:43     ` [PATCH 06/22 v2] x86/fpu: Don't save fxregs for ia32 frames in Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 07/22] x86/fpu: Remove fpu->initialized Sebastian Andrzej Siewior
2019-01-24 13:34   ` Borislav Petkov
2019-02-05 18:03     ` Sebastian Andrzej Siewior
2019-02-06 14:01       ` Borislav Petkov
2019-02-07 10:13         ` Sebastian Andrzej Siewior
2019-02-07 10:37           ` Borislav Petkov
2019-02-05 18:06     ` [PATCH 07/22 v2] " Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 08/22] x86/fpu: Remove user_fpu_begin() Sebastian Andrzej Siewior
2019-01-25 15:18   ` Borislav Petkov
2019-02-05 18:16     ` Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 09/22] x86/fpu: Add (__)make_fpregs_active helpers Sebastian Andrzej Siewior
2019-01-28 18:23   ` Borislav Petkov
2019-02-07 10:43     ` Sebastian Andrzej Siewior
2019-02-13  9:30       ` Borislav Petkov
2019-02-14 14:51         ` Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 10/22] x86/fpu: Make __raw_xsave_addr() use feature number instead of mask Sebastian Andrzej Siewior
2019-01-28 18:30   ` Borislav Petkov
2019-01-09 11:47 ` [PATCH 11/22] x86/fpu: Make get_xsave_field_ptr() and get_xsave_addr() " Sebastian Andrzej Siewior
2019-01-28 18:49   ` Borislav Petkov
2019-02-07 11:13     ` Sebastian Andrzej Siewior
2019-02-13  9:31       ` Borislav Petkov
2019-01-09 11:47 ` [PATCH 12/22] x86/fpu: Only write PKRU if it is different from current Sebastian Andrzej Siewior
2019-01-23 18:09   ` Dave Hansen
2019-02-07 11:27     ` Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 13/22] x86/pkeys: Don't check if PKRU is zero before writting it Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 14/22] x86/fpu: Eager switch PKRU state Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 15/22] x86/entry: Add TIF_NEED_FPU_LOAD Sebastian Andrzej Siewior
2019-01-30 11:55   ` Borislav Petkov
2019-02-07 11:49     ` Sebastian Andrzej Siewior
2019-02-13  9:35       ` Borislav Petkov
2019-02-14 15:28         ` Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 16/22] x86/fpu: Always store the registers in copy_fpstate_to_sigframe() Sebastian Andrzej Siewior
2019-01-30 11:43   ` Borislav Petkov
2019-02-07 13:28     ` Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 17/22] x86/fpu: Prepare copy_fpstate_to_sigframe() for TIF_NEED_FPU_LOAD Sebastian Andrzej Siewior
2019-01-30 11:56   ` Borislav Petkov
2019-01-30 12:28     ` Sebastian Andrzej Siewior
2019-01-30 12:53       ` Borislav Petkov
2019-02-07 14:10         ` Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 18/22] x86/fpu: Update xstate's PKRU value on write_pkru() Sebastian Andrzej Siewior
2019-01-23 17:28   ` Dave Hansen
2019-01-09 11:47 ` [PATCH 19/22] x86/fpu: Inline copy_user_to_fpregs_zeroing() Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 20/22] x86/fpu: Let __fpu__restore_sig() restore the !32bit+fxsr frame from kernel memory Sebastian Andrzej Siewior
2019-01-30 21:29   ` Borislav Petkov
2019-01-09 11:47 ` [PATCH 21/22] x86/fpu: Merge the two code paths in __fpu__restore_sig() Sebastian Andrzej Siewior
2019-01-09 11:47 ` [PATCH 22/22] x86/fpu: Defer FPU state load until return to userspace Sebastian Andrzej Siewior
2019-01-31  9:16   ` Borislav Petkov
2019-01-15 12:44 ` [PATCH v6] x86: load FPU registers on return to userland David Laight
2019-01-15 13:15   ` 'Sebastian Andrzej Siewior'
2019-01-15 14:33     ` David Laight
2019-01-15 19:46   ` Dave Hansen
2019-01-15 20:26     ` Andy Lutomirski
2019-01-15 20:54       ` Dave Hansen
2019-01-15 21:11         ` Andy Lutomirski
2019-01-16 10:31           ` David Laight
2019-01-16 10:18       ` David Laight
2019-01-30 11:35 ` Borislav Petkov
2019-01-30 12:06   ` Sebastian Andrzej Siewior
2019-01-30 12:27     ` Borislav Petkov
2019-02-08 13:12       ` Sebastian Andrzej Siewior
2019-02-13 15:54         ` Sebastian Andrzej Siewior
2019-02-21 11:49 [PATCH v7] " Sebastian Andrzej Siewior
2019-02-21 11:50 ` [PATCH 05/22] x86/fpu: Remove fpu->initialized usage in copy_fpstate_to_sigframe() Sebastian Andrzej Siewior

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