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From: "Chang S. Bae" <chang.seok.bae@intel.com>
To: Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andy Lutomirski <luto@kernel.org>,
	"H . Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Markus T Metzger <markus.t.metzger@intel.com>,
	Ravi Shankar <ravi.v.shankar@intel.com>,
	"Chang S . Bae" <chang.seok.bae@intel.com>,
	LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH v6 5/8] x86/fsgsbase/64: Factor out load FS/GS segments from __switch_to()
Date: Tue, 18 Sep 2018 16:08:56 -0700	[thread overview]
Message-ID: <1537312139-5580-6-git-send-email-chang.seok.bae@intel.com> (raw)
In-Reply-To: <1537312139-5580-1-git-send-email-chang.seok.bae@intel.com>

Instead of open coding the calls to load_seg_legacy(), add
x86_fsgsbase_load() to load FS/GS segments.  When FSGSBASE is
enabled, the new helper will be updated.

Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
---
 arch/x86/kernel/process_64.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 710f639..31b4755 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -285,6 +285,15 @@ static __always_inline void load_seg_legacy(unsigned short prev_index,
 	}
 }
 
+static __always_inline void x86_fsgsbase_load(struct thread_struct *prev,
+					      struct thread_struct *next)
+{
+	load_seg_legacy(prev->fsindex, prev->fsbase,
+			next->fsindex, next->fsbase, FS);
+	load_seg_legacy(prev->gsindex, prev->gsbase,
+			next->gsindex, next->gsbase, GS);
+}
+
 static unsigned long x86_fsgsbase_read_task(struct task_struct *task,
 					    unsigned short selector)
 {
@@ -595,10 +604,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 	if (unlikely(next->ds | prev->ds))
 		loadsegment(ds, next->ds);
 
-	load_seg_legacy(prev->fsindex, prev->fsbase,
-			next->fsindex, next->fsbase, FS);
-	load_seg_legacy(prev->gsindex, prev->gsbase,
-			next->gsindex, next->gsbase, GS);
+	x86_fsgsbase_load(prev, next);
 
 	switch_fpu_finish(next_fpu, cpu);
 
-- 
2.7.4


  parent reply	other threads:[~2018-09-18 23:10 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-18 23:08 [PATCH v6 0/8] x86: infrastructure to enable FSGSBASE Chang S. Bae
2018-09-18 23:08 ` [PATCH v6 1/8] x86/arch_prctl/64: Make ptrace read FS/GS base accurately Chang S. Bae
2018-10-08  9:54   ` [tip:x86/asm] x86/fsgsbase/64: Fix ptrace() to read the " tip-bot for Andy Lutomirski
2018-10-08  9:59   ` [tip:x86/asm] x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick tip-bot for Ingo Molnar
2018-10-08  9:59   ` [tip:x86/asm] x86/fsgsbase/64: Clean up various details tip-bot for Ingo Molnar
2018-09-18 23:08 ` [PATCH v6 2/8] x86/fsgsbase/64: Introduce FS/GS base helper functions Chang S. Bae
2018-10-08  9:55   ` [tip:x86/asm] " tip-bot for Chang S. Bae
2018-10-24 19:01   ` [regression in -rc1] Re: [PATCH v6 2/8] " Andy Lutomirski
2018-10-24 19:13     ` Bae, Chang Seok
2018-10-24 19:22       ` Andy Lutomirski
2018-10-24 19:29         ` Bae, Chang Seok
2018-10-24 19:43           ` Andy Lutomirski
2018-10-24 22:50             ` Bae, Chang Seok
2018-10-25 22:37     ` Andy Lutomirski
2018-09-18 23:08 ` [PATCH v6 3/8] x86/fsgsbase/64: Make ptrace use correct FS/GS base helpers Chang S. Bae
2018-10-08  9:56   ` [tip:x86/asm] x86/fsgsbase/64: Make ptrace use the new " tip-bot for Chang S. Bae
2018-09-18 23:08 ` [PATCH v6 4/8] x86/fsgsbase/64: Use FS/GS base helpers in core dump Chang S. Bae
2018-10-08  9:56   ` [tip:x86/asm] x86/fsgsbase/64: Convert the ELF core dump code to the new FSGSBASE helpers tip-bot for Chang S. Bae
2018-09-18 23:08 ` Chang S. Bae [this message]
2018-10-08  9:57   ` [tip:x86/asm] x86/fsgsbase/64: Factor out FS/GS segment loading from __switch_to() tip-bot for Chang S. Bae
2018-09-18 23:08 ` [PATCH v6 6/8] x86/segments/64: Rename PER_CPU segment to CPU_NUMBER Chang S. Bae
2018-10-08  9:57   ` [tip:x86/asm] x86/segments/64: Rename the GDT PER_CPU entry " tip-bot for Chang S. Bae
2018-09-18 23:08 ` [PATCH v6 7/8] x86/vdso: Introduce helper functions for CPU and node number Chang S. Bae
2018-10-08  9:58   ` [tip:x86/asm] " tip-bot for Chang S. Bae
2018-09-18 23:08 ` [PATCH v6 8/8] x86/vdso: Move out the CPU initialization Chang S. Bae
2018-10-08  8:36   ` Ingo Molnar
2018-10-08  9:58   ` [tip:x86/asm] x86/vdso: Initialize the CPU/node NR segment descriptor earlier tip-bot for Chang S. Bae

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