[tip:x86/pti] x86/entry: Rename update_sp0 to update_task_stack

[tip-bot for Joerg Roedel]

Commit-ID:  252e1a0526304f0f3f6888fc09e81cb220f957f3
Gitweb:     https://git.kernel.org/tip/252e1a0526304f0f3f6888fc09e81cb220f957f3
Author:     Joerg Roedel <jroedel@xxxxxxx>
AuthorDate: Wed, 18 Jul 2018 11:40:51 +0200
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 20 Jul 2018 01:11:40 +0200

x86/entry: Rename update_sp0 to update_task_stack

The function does not update sp0 anymore but updates makes the task-stack
visible for entry code. This is by either writing it to sp1 or by doing a
hypercall. Rename the function to get rid of the misleading name.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Pavel Machek <pavel@xxxxxx>
Cc: "H . Peter Anvin" <hpa@xxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Jiri Kosina <jkosina@xxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: David Laight <David.Laight@xxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: Eduardo Valentin <eduval@xxxxxxxxxx>
Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: aliguori@xxxxxxxxxx
Cc: daniel.gruss@xxxxxxxxxxxxxx
Cc: hughd@xxxxxxxxxx
Cc: keescook@xxxxxxxxxx
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Waiman Long <llong@xxxxxxxxxx>
Cc: "David H . Gutteridge" <dhgutteridge@xxxxxxxxxxxx>
Cc: joro@xxxxxxxxxx
Link: https://lkml.kernel.org/r/1531906876-13451-15-git-send-email-joro@xxxxxxxxxx

---
 arch/x86/include/asm/switch_to.h | 2 +-
 arch/x86/kernel/process_32.c     | 2 +-
 arch/x86/kernel/process_64.c     | 2 +-
 arch/x86/kernel/vm86_32.c        | 4 ++--
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h
index 8bc2f70b452e..36bd243843d6 100644
--- a/arch/x86/include/asm/switch_to.h
+++ b/arch/x86/include/asm/switch_to.h
@@ -87,7 +87,7 @@ static inline void refresh_sysenter_cs(struct thread_struct *thread)
 #endif
 
 /* This is used when switching tasks or entering/exiting vm86 mode. */
-static inline void update_sp0(struct task_struct *task)
+static inline void update_task_stack(struct task_struct *task)
 {
 	/* sp0 always points to the entry trampoline stack, which is constant: */
 #ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 0ae659de21eb..2924fd447e61 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -285,7 +285,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 	 * current_thread_info().  Refresh the SYSENTER configuration in
 	 * case prev or next is vm86.
 	 */
-	update_sp0(next_p);
+	update_task_stack(next_p);
 	refresh_sysenter_cs(next);
 	this_cpu_write(cpu_current_top_of_stack,
 		       (unsigned long)task_stack_page(next_p) +
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 12bb445fb98d..476e3ddf8890 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -478,7 +478,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 	this_cpu_write(cpu_current_top_of_stack, task_top_of_stack(next_p));
 
 	/* Reload sp0. */
-	update_sp0(next_p);
+	update_task_stack(next_p);
 
 	/*
 	 * Now maybe reload the debug registers and handle I/O bitmaps
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 9d0b5af7db91..1c03e4aa6474 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -149,7 +149,7 @@ void save_v86_state(struct kernel_vm86_regs *regs, int retval)
 	preempt_disable();
 	tsk->thread.sp0 = vm86->saved_sp0;
 	tsk->thread.sysenter_cs = __KERNEL_CS;
-	update_sp0(tsk);
+	update_task_stack(tsk);
 	refresh_sysenter_cs(&tsk->thread);
 	vm86->saved_sp0 = 0;
 	preempt_enable();
@@ -374,7 +374,7 @@ static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus)
 		refresh_sysenter_cs(&tsk->thread);
 	}
 
-	update_sp0(tsk);
+	update_task_stack(tsk);
 	preempt_enable();
 
 	if (vm86->flags & VM86_SCREEN_BITMAP)