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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Dominik Brodowski <linux@dominikbrodowski.net>,
        Andy Lutomirski <luto@kernel.org>,
        Borislav Petkov <bp@alien8.de>,
        Brian Gerst <brgerst@gmail.com>,
        Denys Vlasenko <dvlasenk@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>, dan.j.williams@intel.com,
        Ingo Molnar <mingo@kernel.org>
Subject: [PATCH 4.14 059/167] x86/entry/64: Merge the POP_C_REGS and POP_EXTRA_REGS macros into a single POP_REGS macro
Date: Wed, 21 Feb 2018 13:47:50 +0100
Message-Id: <20180221124527.747244953@linuxfoundation.org>
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4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dominik Brodowski <linux@dominikbrodowski.net>

commit 502af0d70843c2a9405d7ba1f79b4b0305aaf5f5 upstream.

The two special, opencoded cases for POP_C_REGS can be handled by ASM
macros.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dan.j.williams@intel.com
Link: http://lkml.kernel.org/r/20180211104949.12992-3-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/entry/calling.h  |   15 +++++++++++----
 arch/x86/entry/entry_64.S |   26 ++++----------------------
 2 files changed, 15 insertions(+), 26 deletions(-)

--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -139,25 +139,32 @@ For 32-bit we have the following convent
 	xorq %r15, %r15
 	.endm
 
-	.macro POP_EXTRA_REGS
+	.macro POP_REGS pop_rdi=1 skip_r11rcx=0
 	popq %r15
 	popq %r14
 	popq %r13
 	popq %r12
 	popq %rbp
 	popq %rbx
-	.endm
-
-	.macro POP_C_REGS
+	.if \skip_r11rcx
+	popq %rsi
+	.else
 	popq %r11
+	.endif
 	popq %r10
 	popq %r9
 	popq %r8
 	popq %rax
+	.if \skip_r11rcx
+	popq %rsi
+	.else
 	popq %rcx
+	.endif
 	popq %rdx
 	popq %rsi
+	.if \pop_rdi
 	popq %rdi
+	.endif
 	.endm
 
 	.macro icebp
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -330,15 +330,7 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
 syscall_return_via_sysret:
 	/* rcx and r11 are already restored (see code above) */
 	UNWIND_HINT_EMPTY
-	POP_EXTRA_REGS
-	popq	%rsi	/* skip r11 */
-	popq	%r10
-	popq	%r9
-	popq	%r8
-	popq	%rax
-	popq	%rsi	/* skip rcx */
-	popq	%rdx
-	popq	%rsi
+	POP_REGS pop_rdi=0 skip_r11rcx=1
 
 	/*
 	 * Now all regs are restored except RSP and RDI.
@@ -631,15 +623,7 @@ GLOBAL(swapgs_restore_regs_and_return_to
 	ud2
 1:
 #endif
-	POP_EXTRA_REGS
-	popq	%r11
-	popq	%r10
-	popq	%r9
-	popq	%r8
-	popq	%rax
-	popq	%rcx
-	popq	%rdx
-	popq	%rsi
+	POP_REGS pop_rdi=0
 
 	/*
 	 * The stack is now user RDI, orig_ax, RIP, CS, EFLAGS, RSP, SS.
@@ -697,8 +681,7 @@ GLOBAL(restore_regs_and_return_to_kernel
 	ud2
 1:
 #endif
-	POP_EXTRA_REGS
-	POP_C_REGS
+	POP_REGS
 	addq	$8, %rsp	/* skip regs->orig_ax */
 	INTERRUPT_RETURN
 
@@ -1655,8 +1638,7 @@ end_repeat_nmi:
 nmi_swapgs:
 	SWAPGS_UNSAFE_STACK
 nmi_restore:
-	POP_EXTRA_REGS
-	POP_C_REGS
+	POP_REGS
 
 	/*
 	 * Skip orig_ax and the "outermost" frame to point RSP at the "iret"