x86/asm: Introduce push/pop macros which generate CFI_REL_OFFSET and CFI_RESTORE

Sequences:

        pushl_cfi %reg
        CFI_REL_OFFSET reg, 0

and:

        popl_cfi %reg
        CFI_RESTORE reg

happen quite often. This patch adds macros which generate them.

No assembly changes (verified with objdump -dr vmlinux.o).
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1421017655-25561-1-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/2202eb90f175cf45d1b2d1c64dbb5676a8ad07ad.1424989793.git.luto@amacapital.netSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/calling.h

@@ -210,37 +210,23 @@ For 32-bit we have the following conventions - kernel is built with
  */
 
 	.macro SAVE_ALL
-	pushl_cfi %eax
-	CFI_REL_OFFSET eax, 0
-	pushl_cfi %ebp
-	CFI_REL_OFFSET ebp, 0
-	pushl_cfi %edi
-	CFI_REL_OFFSET edi, 0
-	pushl_cfi %esi
-	CFI_REL_OFFSET esi, 0
-	pushl_cfi %edx
-	CFI_REL_OFFSET edx, 0
-	pushl_cfi %ecx
-	CFI_REL_OFFSET ecx, 0
-	pushl_cfi %ebx
-	CFI_REL_OFFSET ebx, 0
+	pushl_cfi_reg eax
+	pushl_cfi_reg ebp
+	pushl_cfi_reg edi
+	pushl_cfi_reg esi
+	pushl_cfi_reg edx
+	pushl_cfi_reg ecx
+	pushl_cfi_reg ebx
 	.endm
 
 	.macro RESTORE_ALL
-	popl_cfi %ebx
-	CFI_RESTORE ebx
-	popl_cfi %ecx
-	CFI_RESTORE ecx
-	popl_cfi %edx
-	CFI_RESTORE edx
-	popl_cfi %esi
-	CFI_RESTORE esi
-	popl_cfi %edi
-	CFI_RESTORE edi
-	popl_cfi %ebp
-	CFI_RESTORE ebp
-	popl_cfi %eax
-	CFI_RESTORE eax
+	popl_cfi_reg ebx
+	popl_cfi_reg ecx
+	popl_cfi_reg edx
+	popl_cfi_reg esi
+	popl_cfi_reg edi
+	popl_cfi_reg ebp
+	popl_cfi_reg eax
 	.endm
 
 #endif /* CONFIG_X86_64 */

arch/x86/include/asm/dwarf2.h

@@ -86,11 +86,23 @@
 	CFI_ADJUST_CFA_OFFSET 8
 	.endm
 
+	.macro pushq_cfi_reg reg
+	pushq %\reg
+	CFI_ADJUST_CFA_OFFSET 8
+	CFI_REL_OFFSET \reg, 0
+	.endm
+
 	.macro popq_cfi reg
 	popq \reg
 	CFI_ADJUST_CFA_OFFSET -8
 	.endm
 
+	.macro popq_cfi_reg reg
+	popq %\reg
+	CFI_ADJUST_CFA_OFFSET -8
+	CFI_RESTORE \reg
+	.endm
+
 	.macro pushfq_cfi
 	pushfq
 	CFI_ADJUST_CFA_OFFSET 8
@@ -116,11 +128,23 @@
 	CFI_ADJUST_CFA_OFFSET 4
 	.endm
 
+	.macro pushl_cfi_reg reg
+	pushl %\reg
+	CFI_ADJUST_CFA_OFFSET 4
+	CFI_REL_OFFSET \reg, 0
+	.endm
+
 	.macro popl_cfi reg
 	popl \reg
 	CFI_ADJUST_CFA_OFFSET -4
 	.endm
 
+	.macro popl_cfi_reg reg
+	popl %\reg
+	CFI_ADJUST_CFA_OFFSET -4
+	CFI_RESTORE \reg
+	.endm
+
 	.macro pushfl_cfi
 	pushfl
 	CFI_ADJUST_CFA_OFFSET 4

arch/x86/kernel/entry_32.S

@@ -1234,20 +1234,13 @@ error_code:
 	/*CFI_REL_OFFSET es, 0*/
 	pushl_cfi %ds
 	/*CFI_REL_OFFSET ds, 0*/
-	pushl_cfi %eax
-	CFI_REL_OFFSET eax, 0
-	pushl_cfi %ebp
-	CFI_REL_OFFSET ebp, 0
-	pushl_cfi %edi
-	CFI_REL_OFFSET edi, 0
-	pushl_cfi %esi
-	CFI_REL_OFFSET esi, 0
-	pushl_cfi %edx
-	CFI_REL_OFFSET edx, 0
-	pushl_cfi %ecx
-	CFI_REL_OFFSET ecx, 0
-	pushl_cfi %ebx
-	CFI_REL_OFFSET ebx, 0
+	pushl_cfi_reg eax
+	pushl_cfi_reg ebp
+	pushl_cfi_reg edi
+	pushl_cfi_reg esi
+	pushl_cfi_reg edx
+	pushl_cfi_reg ecx
+	pushl_cfi_reg ebx
 	cld
 	movl $(__KERNEL_PERCPU), %ecx
 	movl %ecx, %fs

arch/x86/lib/atomic64_cx8_32.S

@@ -13,16 +13,6 @@
 #include <asm/alternative-asm.h>
 #include <asm/dwarf2.h>
 
-.macro SAVE reg
-	pushl_cfi %\reg
-	CFI_REL_OFFSET \reg, 0
-.endm
-
-.macro RESTORE reg
-	popl_cfi %\reg
-	CFI_RESTORE \reg
-.endm
-
 .macro read64 reg
 	movl %ebx, %eax
 	movl %ecx, %edx
@@ -67,10 +57,10 @@ ENDPROC(atomic64_xchg_cx8)
 .macro addsub_return func ins insc
 ENTRY(atomic64_\func\()_return_cx8)
 	CFI_STARTPROC
-	SAVE ebp
-	SAVE ebx
-	SAVE esi
-	SAVE edi
+	pushl_cfi_reg ebp
+	pushl_cfi_reg ebx
+	pushl_cfi_reg esi
+	pushl_cfi_reg edi
 
 	movl %eax, %esi
 	movl %edx, %edi
@@ -89,10 +79,10 @@ ENTRY(atomic64_\func\()_return_cx8)
 10:
 	movl %ebx, %eax
 	movl %ecx, %edx
-	RESTORE edi
-	RESTORE esi
-	RESTORE ebx
-	RESTORE ebp
+	popl_cfi_reg edi
+	popl_cfi_reg esi
+	popl_cfi_reg ebx
+	popl_cfi_reg ebp
 	ret
 	CFI_ENDPROC
 ENDPROC(atomic64_\func\()_return_cx8)
@@ -104,7 +94,7 @@ addsub_return sub sub sbb
 .macro incdec_return func ins insc
 ENTRY(atomic64_\func\()_return_cx8)
 	CFI_STARTPROC
-	SAVE ebx
+	pushl_cfi_reg ebx
 
 	read64 %esi
 1:
@@ -119,7 +109,7 @@ ENTRY(atomic64_\func\()_return_cx8)
 10:
 	movl %ebx, %eax
 	movl %ecx, %edx
-	RESTORE ebx
+	popl_cfi_reg ebx
 	ret
 	CFI_ENDPROC
 ENDPROC(atomic64_\func\()_return_cx8)
@@ -130,7 +120,7 @@ incdec_return dec sub sbb
 
 ENTRY(atomic64_dec_if_positive_cx8)
 	CFI_STARTPROC
-	SAVE ebx
+	pushl_cfi_reg ebx
 
 	read64 %esi
 1:
@@ -146,18 +136,18 @@ ENTRY(atomic64_dec_if_positive_cx8)
 2:
 	movl %ebx, %eax
 	movl %ecx, %edx
-	RESTORE ebx
+	popl_cfi_reg ebx
 	ret
 	CFI_ENDPROC
 ENDPROC(atomic64_dec_if_positive_cx8)
 
 ENTRY(atomic64_add_unless_cx8)
 	CFI_STARTPROC
-	SAVE ebp
-	SAVE ebx
+	pushl_cfi_reg ebp
+	pushl_cfi_reg ebx
 /* these just push these two parameters on the stack */
-	SAVE edi
-	SAVE ecx
+	pushl_cfi_reg edi
+	pushl_cfi_reg ecx
 
 	movl %eax, %ebp
 	movl %edx, %edi
@@ -179,8 +169,8 @@ ENTRY(atomic64_add_unless_cx8)
 3:
 	addl $8, %esp
 	CFI_ADJUST_CFA_OFFSET -8
-	RESTORE ebx
-	RESTORE ebp
+	popl_cfi_reg ebx
+	popl_cfi_reg ebp
 	ret
 4:
 	cmpl %edx, 4(%esp)
@@ -192,7 +182,7 @@ ENDPROC(atomic64_add_unless_cx8)
 
 ENTRY(atomic64_inc_not_zero_cx8)
 	CFI_STARTPROC
-	SAVE ebx
+	pushl_cfi_reg ebx
 
 	read64 %esi
 1:
@@ -209,7 +199,7 @@ ENTRY(atomic64_inc_not_zero_cx8)
 
 	movl $1, %eax
 3:
-	RESTORE ebx
+	popl_cfi_reg ebx
 	ret
 	CFI_ENDPROC
 ENDPROC(atomic64_inc_not_zero_cx8)

arch/x86/lib/checksum_32.S

@@ -51,10 +51,8 @@ unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum)
 	   */		
 ENTRY(csum_partial)
 	CFI_STARTPROC
-	pushl_cfi %esi
-	CFI_REL_OFFSET esi, 0
-	pushl_cfi %ebx
-	CFI_REL_OFFSET ebx, 0
+	pushl_cfi_reg esi
+	pushl_cfi_reg ebx
 	movl 20(%esp),%eax	# Function arg: unsigned int sum
 	movl 16(%esp),%ecx	# Function arg: int len
 	movl 12(%esp),%esi	# Function arg: unsigned char *buff
@@ -131,10 +129,8 @@ ENTRY(csum_partial)
 	jz 8f
 	roll $8, %eax
 8:
-	popl_cfi %ebx
-	CFI_RESTORE ebx
-	popl_cfi %esi
-	CFI_RESTORE esi
+	popl_cfi_reg ebx
+	popl_cfi_reg esi
 	ret
 	CFI_ENDPROC
 ENDPROC(csum_partial)
@@ -145,10 +141,8 @@ ENDPROC(csum_partial)
 
 ENTRY(csum_partial)
 	CFI_STARTPROC
-	pushl_cfi %esi
-	CFI_REL_OFFSET esi, 0
-	pushl_cfi %ebx
-	CFI_REL_OFFSET ebx, 0
+	pushl_cfi_reg esi
+	pushl_cfi_reg ebx
 	movl 20(%esp),%eax	# Function arg: unsigned int sum
 	movl 16(%esp),%ecx	# Function arg: int len
 	movl 12(%esp),%esi	# Function arg:	const unsigned char *buf
@@ -255,10 +249,8 @@ ENTRY(csum_partial)
 	jz 90f
 	roll $8, %eax
 90: 
-	popl_cfi %ebx
-	CFI_RESTORE ebx
-	popl_cfi %esi
-	CFI_RESTORE esi
+	popl_cfi_reg ebx
+	popl_cfi_reg esi
 	ret
 	CFI_ENDPROC
 ENDPROC(csum_partial)
@@ -298,12 +290,9 @@ ENTRY(csum_partial_copy_generic)
 	CFI_STARTPROC
 	subl  $4,%esp	
 	CFI_ADJUST_CFA_OFFSET 4
-	pushl_cfi %edi
-	CFI_REL_OFFSET edi, 0
-	pushl_cfi %esi
-	CFI_REL_OFFSET esi, 0
-	pushl_cfi %ebx
-	CFI_REL_OFFSET ebx, 0
+	pushl_cfi_reg edi
+	pushl_cfi_reg esi
+	pushl_cfi_reg ebx
 	movl ARGBASE+16(%esp),%eax	# sum
 	movl ARGBASE+12(%esp),%ecx	# len
 	movl ARGBASE+4(%esp),%esi	# src
@@ -412,12 +401,9 @@ DST(	movb %cl, (%edi)	)
 
 .previous
 
-	popl_cfi %ebx
-	CFI_RESTORE ebx
-	popl_cfi %esi
-	CFI_RESTORE esi
-	popl_cfi %edi
-	CFI_RESTORE edi
+	popl_cfi_reg ebx
+	popl_cfi_reg esi
+	popl_cfi_reg edi
 	popl_cfi %ecx			# equivalent to addl $4,%esp
 	ret	
 	CFI_ENDPROC
@@ -441,12 +427,9 @@ ENDPROC(csum_partial_copy_generic)
 		
 ENTRY(csum_partial_copy_generic)
 	CFI_STARTPROC
-	pushl_cfi %ebx
-	CFI_REL_OFFSET ebx, 0
-	pushl_cfi %edi
-	CFI_REL_OFFSET edi, 0
-	pushl_cfi %esi
-	CFI_REL_OFFSET esi, 0
+	pushl_cfi_reg ebx
+	pushl_cfi_reg edi
+	pushl_cfi_reg esi
 	movl ARGBASE+4(%esp),%esi	#src
 	movl ARGBASE+8(%esp),%edi	#dst	
 	movl ARGBASE+12(%esp),%ecx	#len
@@ -506,12 +489,9 @@ DST(	movb %dl, (%edi)         )
 	jmp  7b			
 .previous				
 
-	popl_cfi %esi
-	CFI_RESTORE esi
-	popl_cfi %edi
-	CFI_RESTORE edi
-	popl_cfi %ebx
-	CFI_RESTORE ebx
+	popl_cfi_reg esi
+	popl_cfi_reg edi
+	popl_cfi_reg ebx
 	ret
 	CFI_ENDPROC
 ENDPROC(csum_partial_copy_generic)

arch/x86/lib/msr-reg.S

@@ -14,8 +14,8 @@
 .macro op_safe_regs op
 ENTRY(\op\()_safe_regs)
 	CFI_STARTPROC
-	pushq_cfi %rbx
-	pushq_cfi %rbp
+	pushq_cfi_reg rbx
+	pushq_cfi_reg rbp
 	movq	%rdi, %r10	/* Save pointer */
 	xorl	%r11d, %r11d	/* Return value */
 	movl    (%rdi), %eax
@@ -35,8 +35,8 @@ ENTRY(\op\()_safe_regs)
 	movl    %ebp, 20(%r10)
 	movl    %esi, 24(%r10)
 	movl    %edi, 28(%r10)
-	popq_cfi %rbp
-	popq_cfi %rbx
+	popq_cfi_reg rbp
+	popq_cfi_reg rbx
 	ret
 3:
 	CFI_RESTORE_STATE
@@ -53,10 +53,10 @@ ENDPROC(\op\()_safe_regs)
 .macro op_safe_regs op
 ENTRY(\op\()_safe_regs)
 	CFI_STARTPROC
-	pushl_cfi %ebx
-	pushl_cfi %ebp
-	pushl_cfi %esi
-	pushl_cfi %edi
+	pushl_cfi_reg ebx
+	pushl_cfi_reg ebp
+	pushl_cfi_reg esi
+	pushl_cfi_reg edi
 	pushl_cfi $0              /* Return value */
 	pushl_cfi %eax
 	movl    4(%eax), %ecx
@@ -80,10 +80,10 @@ ENTRY(\op\()_safe_regs)
 	movl    %esi, 24(%eax)
 	movl    %edi, 28(%eax)
 	popl_cfi %eax
-	popl_cfi %edi
-	popl_cfi %esi
-	popl_cfi %ebp
-	popl_cfi %ebx
+	popl_cfi_reg edi
+	popl_cfi_reg esi
+	popl_cfi_reg ebp
+	popl_cfi_reg ebx
 	ret
 3:
 	CFI_RESTORE_STATE

arch/x86/lib/rwsem.S

@@ -34,10 +34,10 @@
  */
 
 #define save_common_regs \
-	pushl_cfi %ecx; CFI_REL_OFFSET ecx, 0
+	pushl_cfi_reg ecx
 
 #define restore_common_regs \
-	popl_cfi %ecx; CFI_RESTORE ecx
+	popl_cfi_reg ecx
 
 	/* Avoid uglifying the argument copying x86-64 needs to do. */
 	.macro movq src, dst
@@ -64,22 +64,22 @@
  */
 
 #define save_common_regs \
-	pushq_cfi %rdi; CFI_REL_OFFSET rdi, 0; \
-	pushq_cfi %rsi; CFI_REL_OFFSET rsi, 0; \
-	pushq_cfi %rcx; CFI_REL_OFFSET rcx, 0; \
-	pushq_cfi %r8;  CFI_REL_OFFSET r8,  0; \
-	pushq_cfi %r9;  CFI_REL_OFFSET r9,  0; \
-	pushq_cfi %r10; CFI_REL_OFFSET r10, 0; \
-	pushq_cfi %r11; CFI_REL_OFFSET r11, 0
+	pushq_cfi_reg rdi; \
+	pushq_cfi_reg rsi; \
+	pushq_cfi_reg rcx; \
+	pushq_cfi_reg r8;  \
+	pushq_cfi_reg r9;  \
+	pushq_cfi_reg r10; \
+	pushq_cfi_reg r11
 
 #define restore_common_regs \
-	popq_cfi %r11; CFI_RESTORE r11; \
-	popq_cfi %r10; CFI_RESTORE r10; \
-	popq_cfi %r9;  CFI_RESTORE r9; \
-	popq_cfi %r8;  CFI_RESTORE r8; \
-	popq_cfi %rcx; CFI_RESTORE rcx; \
-	popq_cfi %rsi; CFI_RESTORE rsi; \
-	popq_cfi %rdi; CFI_RESTORE rdi
+	popq_cfi_reg r11; \
+	popq_cfi_reg r10; \
+	popq_cfi_reg r9; \
+	popq_cfi_reg r8; \
+	popq_cfi_reg rcx; \
+	popq_cfi_reg rsi; \
+	popq_cfi_reg rdi
 
 #endif
 
@@ -87,12 +87,10 @@
 ENTRY(call_rwsem_down_read_failed)
 	CFI_STARTPROC
 	save_common_regs
-	__ASM_SIZE(push,_cfi) %__ASM_REG(dx)
-	CFI_REL_OFFSET __ASM_REG(dx), 0
+	__ASM_SIZE(push,_cfi_reg) __ASM_REG(dx)
 	movq %rax,%rdi
 	call rwsem_down_read_failed
-	__ASM_SIZE(pop,_cfi) %__ASM_REG(dx)
-	CFI_RESTORE __ASM_REG(dx)
+	__ASM_SIZE(pop,_cfi_reg) __ASM_REG(dx)
 	restore_common_regs
 	ret
 	CFI_ENDPROC
@@ -124,12 +122,10 @@ ENDPROC(call_rwsem_wake)
 ENTRY(call_rwsem_downgrade_wake)
 	CFI_STARTPROC
 	save_common_regs
-	__ASM_SIZE(push,_cfi) %__ASM_REG(dx)
-	CFI_REL_OFFSET __ASM_REG(dx), 0
+	__ASM_SIZE(push,_cfi_reg) __ASM_REG(dx)
 	movq %rax,%rdi
 	call rwsem_downgrade_wake
-	__ASM_SIZE(pop,_cfi) %__ASM_REG(dx)
-	CFI_RESTORE __ASM_REG(dx)
+	__ASM_SIZE(pop,_cfi_reg) __ASM_REG(dx)
 	restore_common_regs
 	ret
 	CFI_ENDPROC

arch/x86/lib/thunk_32.S

@@ -13,12 +13,9 @@
 	.globl \name
 \name:
 	CFI_STARTPROC
-	pushl_cfi %eax
-	CFI_REL_OFFSET eax, 0
-	pushl_cfi %ecx
-	CFI_REL_OFFSET ecx, 0
-	pushl_cfi %edx
-	CFI_REL_OFFSET edx, 0
+	pushl_cfi_reg eax
+	pushl_cfi_reg ecx
+	pushl_cfi_reg edx
 
 	.if \put_ret_addr_in_eax
 	/* Place EIP in the arg1 */
@@ -26,12 +23,9 @@
 	.endif
 
 	call \func
-	popl_cfi %edx
-	CFI_RESTORE edx
-	popl_cfi %ecx
-	CFI_RESTORE ecx
-	popl_cfi %eax
-	CFI_RESTORE eax
+	popl_cfi_reg edx
+	popl_cfi_reg ecx
+	popl_cfi_reg eax
 	ret
 	CFI_ENDPROC
 	_ASM_NOKPROBE(\name)

arch/x86/lib/thunk_64.S

@@ -17,24 +17,15 @@
 	CFI_STARTPROC
 
 	/* this one pushes 9 elems, the next one would be %rIP */
-	pushq_cfi %rdi
-	CFI_REL_OFFSET rdi, 0
-	pushq_cfi %rsi
-	CFI_REL_OFFSET rsi, 0
-	pushq_cfi %rdx
-	CFI_REL_OFFSET rdx, 0
-	pushq_cfi %rcx
-	CFI_REL_OFFSET rcx, 0
-	pushq_cfi %rax
-	CFI_REL_OFFSET rax, 0
-	pushq_cfi %r8
-	CFI_REL_OFFSET r8, 0
-	pushq_cfi %r9
-	CFI_REL_OFFSET r9, 0
-	pushq_cfi %r10
-	CFI_REL_OFFSET r10, 0
-	pushq_cfi %r11
-	CFI_REL_OFFSET r11, 0
+	pushq_cfi_reg rdi
+	pushq_cfi_reg rsi
+	pushq_cfi_reg rdx
+	pushq_cfi_reg rcx
+	pushq_cfi_reg rax
+	pushq_cfi_reg r8
+	pushq_cfi_reg r9
+	pushq_cfi_reg r10
+	pushq_cfi_reg r11
 
 	.if \put_ret_addr_in_rdi
 	/* 9*8(%rsp) is return addr on stack */
@@ -69,24 +60,15 @@
 	CFI_STARTPROC
 	CFI_ADJUST_CFA_OFFSET 9*8
 restore:
-	popq_cfi %r11
-	CFI_RESTORE r11
-	popq_cfi %r10
-	CFI_RESTORE r10
-	popq_cfi %r9
-	CFI_RESTORE r9
-	popq_cfi %r8
-	CFI_RESTORE r8
-	popq_cfi %rax
-	CFI_RESTORE rax
-	popq_cfi %rcx
-	CFI_RESTORE rcx
-	popq_cfi %rdx
-	CFI_RESTORE rdx
-	popq_cfi %rsi
-	CFI_RESTORE rsi
-	popq_cfi %rdi
-	CFI_RESTORE rdi
+	popq_cfi_reg r11
+	popq_cfi_reg r10
+	popq_cfi_reg r9
+	popq_cfi_reg r8
+	popq_cfi_reg rax
+	popq_cfi_reg rcx
+	popq_cfi_reg rdx
+	popq_cfi_reg rsi
+	popq_cfi_reg rdi
 	ret
 	CFI_ENDPROC
 	_ASM_NOKPROBE(restore)