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From: Dominik Brodowski <linux@dominikbrodowski.net>
To: linux-kernel@vger.kernel.org, mingo@kernel.org, x86@kernel.org
Cc: dan.j.williams@intel.com, tglx@linutronix.de, ak@linux.intel.com,
	torvalds@linux-foundation.org, luto@kernel.org
Subject: [PATCH v3 1/7] x86/entry: merge SAVE_C_REGS and SAVE_EXTRA_REGS, remove unused extensions
Date: Sun, 11 Feb 2018 11:49:42 +0100
Message-ID: <20180211104949.12992-2-linux@dominikbrodowski.net> (raw)
In-Reply-To: <20180211104949.12992-1-linux@dominikbrodowski.net>

All current code paths call SAVE_C_REGS and then immediately
SAVE_EXTRA_REGS. Therefore, merge these two macros and order the MOV
sequeneces properly.

While at it, remove the macros to save all except specific registers,
as these macros have been unused for a long time.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/x86/entry/calling.h  | 57 +++++++++++++----------------------------------
 arch/x86/entry/entry_64.S | 12 ++++------
 2 files changed, 19 insertions(+), 50 deletions(-)

diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index f4b129d4af42..8907a6593b42 100644
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -101,49 +101,22 @@ For 32-bit we have the following conventions - kernel is built with
 	addq	$-(15*8), %rsp
 	.endm
 
-	.macro SAVE_C_REGS_HELPER offset=0 rax=1 rcx=1 r8910=1 r11=1
-	.if \r11
-	movq %r11, 6*8+\offset(%rsp)
-	.endif
-	.if \r8910
-	movq %r10, 7*8+\offset(%rsp)
-	movq %r9,  8*8+\offset(%rsp)
-	movq %r8,  9*8+\offset(%rsp)
-	.endif
-	.if \rax
-	movq %rax, 10*8+\offset(%rsp)
-	.endif
-	.if \rcx
-	movq %rcx, 11*8+\offset(%rsp)
-	.endif
-	movq %rdx, 12*8+\offset(%rsp)
-	movq %rsi, 13*8+\offset(%rsp)
+	.macro SAVE_REGS offset=0
 	movq %rdi, 14*8+\offset(%rsp)
-	UNWIND_HINT_REGS offset=\offset extra=0
-	.endm
-	.macro SAVE_C_REGS offset=0
-	SAVE_C_REGS_HELPER \offset, 1, 1, 1, 1
-	.endm
-	.macro SAVE_C_REGS_EXCEPT_RAX_RCX offset=0
-	SAVE_C_REGS_HELPER \offset, 0, 0, 1, 1
-	.endm
-	.macro SAVE_C_REGS_EXCEPT_R891011
-	SAVE_C_REGS_HELPER 0, 1, 1, 0, 0
-	.endm
-	.macro SAVE_C_REGS_EXCEPT_RCX_R891011
-	SAVE_C_REGS_HELPER 0, 1, 0, 0, 0
-	.endm
-	.macro SAVE_C_REGS_EXCEPT_RAX_RCX_R11
-	SAVE_C_REGS_HELPER 0, 0, 0, 1, 0
-	.endm
-
-	.macro SAVE_EXTRA_REGS offset=0
-	movq %r15, 0*8+\offset(%rsp)
-	movq %r14, 1*8+\offset(%rsp)
-	movq %r13, 2*8+\offset(%rsp)
-	movq %r12, 3*8+\offset(%rsp)
-	movq %rbp, 4*8+\offset(%rsp)
+	movq %rsi, 13*8+\offset(%rsp)
+	movq %rdx, 12*8+\offset(%rsp)
+	movq %rcx, 11*8+\offset(%rsp)
+	movq %rax, 10*8+\offset(%rsp)
+	movq %r8,  9*8+\offset(%rsp)
+	movq %r9,  8*8+\offset(%rsp)
+	movq %r10, 7*8+\offset(%rsp)
+	movq %r11, 6*8+\offset(%rsp)
 	movq %rbx, 5*8+\offset(%rsp)
+	movq %rbp, 4*8+\offset(%rsp)
+	movq %r12, 3*8+\offset(%rsp)
+	movq %r13, 2*8+\offset(%rsp)
+	movq %r14, 1*8+\offset(%rsp)
+	movq %r15, 0*8+\offset(%rsp)
 	UNWIND_HINT_REGS offset=\offset
 	.endm
 
@@ -197,7 +170,7 @@ For 32-bit we have the following conventions - kernel is built with
  * is just setting the LSB, which makes it an invalid stack address and is also
  * a signal to the unwinder that it's a pt_regs pointer in disguise.
  *
- * NOTE: This macro must be used *after* SAVE_EXTRA_REGS because it corrupts
+ * NOTE: This macro must be used *after* SAVE_REGS because it corrupts
  * the original rbp.
  */
 .macro ENCODE_FRAME_POINTER ptregs_offset=0
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 9e48002b953b..91e8d84c2496 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -573,8 +573,7 @@ END(irq_entries_start)
 1:
 
 	ALLOC_PT_GPREGS_ON_STACK
-	SAVE_C_REGS
-	SAVE_EXTRA_REGS
+	SAVE_REGS
 	CLEAR_REGS_NOSPEC
 	ENCODE_FRAME_POINTER
 
@@ -1132,8 +1131,7 @@ ENTRY(xen_failsafe_callback)
 	UNWIND_HINT_IRET_REGS
 	pushq	$-1 /* orig_ax = -1 => not a system call */
 	ALLOC_PT_GPREGS_ON_STACK
-	SAVE_C_REGS
-	SAVE_EXTRA_REGS
+	SAVE_REGS
 	CLEAR_REGS_NOSPEC
 	ENCODE_FRAME_POINTER
 	jmp	error_exit
@@ -1178,8 +1176,7 @@ idtentry machine_check		do_mce			has_error_code=0	paranoid=1
 ENTRY(paranoid_entry)
 	UNWIND_HINT_FUNC
 	cld
-	SAVE_C_REGS 8
-	SAVE_EXTRA_REGS 8
+	SAVE_REGS 8
 	CLEAR_REGS_NOSPEC
 	ENCODE_FRAME_POINTER 8
 	movl	$1, %ebx
@@ -1231,8 +1228,7 @@ END(paranoid_exit)
 ENTRY(error_entry)
 	UNWIND_HINT_FUNC
 	cld
-	SAVE_C_REGS 8
-	SAVE_EXTRA_REGS 8
+	SAVE_REGS 8
 	CLEAR_REGS_NOSPEC
 	ENCODE_FRAME_POINTER 8
 	testb	$3, CS+8(%rsp)
-- 
2.16.1

  reply index

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-11 10:49 [PATCH v3 0/7] x86/entry: simplify and unify SAVE/POP_REGS Dominik Brodowski
2018-02-11 10:49 ` Dominik Brodowski [this message]
2018-02-12 10:15   ` [tip:x86/pti] x86/entry/64: Merge SAVE_C_REGS and SAVE_EXTRA_REGS, remove unused extensions tip-bot for Dominik Brodowski
2018-02-13  9:00   ` tip-bot for Dominik Brodowski
2018-02-11 10:49 ` [PATCH v3 2/7] x86/entry: merge POP_C_REGS and POP_EXTRA_REGS Dominik Brodowski
2018-02-12 10:16   ` [tip:x86/pti] x86/entry/64: Merge the POP_C_REGS and POP_EXTRA_REGS macros into a single POP_REGS macro tip-bot for Dominik Brodowski
2018-02-13  9:01   ` tip-bot for Dominik Brodowski
2018-02-11 10:49 ` [PATCH v3 3/7] x86/entry: interleave XOR register clearing with PUSH instructions Dominik Brodowski
2018-02-12 10:16   ` [tip:x86/pti] x86/entry/64: Interleave " tip-bot for Dominik Brodowski
2018-02-13  9:01   ` tip-bot for Dominik Brodowski
2018-02-11 10:49 ` [PATCH v3 4/7] x86/entry: introduce PUSH_AND_CLEAN_REGS Dominik Brodowski
2018-02-12 10:17   ` [tip:x86/pti] x86/entry/64: Introduce the PUSH_AND_CLEAN_REGS macro tip-bot for Dominik Brodowski
2018-02-12 13:29     ` Denys Vlasenko
2018-02-12 13:36       ` David Laight
2018-02-12 13:43         ` Denys Vlasenko
2018-02-12 16:51       ` Linus Torvalds
2018-02-13  9:01   ` tip-bot for Dominik Brodowski
2018-02-11 10:49 ` [PATCH v3 5/7] x86/entry: use PUSH_AND_CLEAN_REGS in more cases Dominik Brodowski
2018-02-12 10:17   ` [tip:x86/pti] x86/entry/64: Use " tip-bot for Dominik Brodowski
2018-02-13  9:02   ` tip-bot for Dominik Brodowski
2018-02-11 10:49 ` [PATCH v3 6/7] x86/entry: get rid of ALLOC_PT_GPREGS_ON_STACK and SAVE_AND_CLEAR_REGS Dominik Brodowski
2018-02-12 10:18   ` [tip:x86/pti] x86/entry/64: Get rid of the ALLOC_PT_GPREGS_ON_STACK and SAVE_AND_CLEAR_REGS macros tip-bot for Dominik Brodowski
2018-02-13  9:02   ` tip-bot for Dominik Brodowski
2018-02-11 10:49 ` [PATCH v3 7/7] x86/entry: indent PUSH_AND_CLEAR_REGS and POP_REGS properly Dominik Brodowski
2018-02-12 10:18   ` [tip:x86/pti] x86/entry/64: Indent " tip-bot for Dominik Brodowski
2018-02-12 20:13     ` [PATCH] x86/entry/64: Remove unused icebp macro Borislav Petkov
2018-02-13  7:36       ` Ingo Molnar
2018-02-13  9:04       ` [tip:x86/pti] x86/entry/64: Remove the unused 'icebp' macro tip-bot for Borislav Petkov
2018-02-13  9:03   ` [tip:x86/pti] x86/entry/64: Indent PUSH_AND_CLEAR_REGS and POP_REGS properly tip-bot for Dominik Brodowski
2018-02-11 10:49 ` [PATCH v3 8/7] TESTING_ONLY x86/entry: reduce static footprint of idtentry Dominik Brodowski
2018-02-12  9:37   ` Ingo Molnar
2018-02-12 19:17     ` Linus Torvalds
2018-02-13 12:41       ` Ingo Molnar

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