git: 8f465f509bc1 - main - {amd64,i386}/SYS.h: add _SYSCALL and _SYSCALL_BODY

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From: Brooks Davis <brooks_at_FreeBSD.org>
Date: Mon, 18 Dec 2023 22:28:59 UTC
The branch main has been updated by brooks:

URL: https://cgit.FreeBSD.org/src/commit/?id=8f465f509bc1b038806963f716263b56004871d3

commit 8f465f509bc1b038806963f716263b56004871d3
Author:     Brooks Davis <brooks@FreeBSD.org>
AuthorDate: 2023-12-18 22:28:42 +0000
Commit:     Brooks Davis <brooks@FreeBSD.org>
CommitDate: 2023-12-18 22:28:42 +0000

    {amd64,i386}/SYS.h: add _SYSCALL and _SYSCALL_BODY
    
    Add a _SYSCALL(name) which calls the SYS_name syscall.  Use it to add a
    _SYSCALL_BODY() macro which invokes the syscall and calls cerror as
    required.  Use the latter to implement PSEUDO() and RSYSCALL().
    
    Reviewed by:    imp, markj
    Sponsored by:   DARPA
    Differential Revision:  https://reviews.freebsd.org/D43059
---
 lib/libc/amd64/SYS.h              | 18 ++++++++++++------
 lib/libc/amd64/gen/rfork_thread.S |  6 ++----
 lib/libc/amd64/sys/getcontext.S   |  3 +--
 lib/libc/amd64/sys/vfork.S        |  3 +--
 lib/libc/i386/SYS.h               | 19 ++++++++++++-------
 lib/libc/i386/gen/rfork_thread.S  |  6 ++----
 lib/libc/i386/sys/getcontext.S    |  3 +--
 lib/libc/i386/sys/syscall.S       |  2 +-
 lib/libc/i386/sys/vfork.S         |  3 +--
 9 files changed, 33 insertions(+), 30 deletions(-)

diff --git a/lib/libc/amd64/SYS.h b/lib/libc/amd64/SYS.h
index 23b4226d942f..2dfca1896fcd 100644
--- a/lib/libc/amd64/SYS.h
+++ b/lib/libc/amd64/SYS.h
@@ -35,17 +35,23 @@
 #include <sys/syscall.h>
 #include <machine/asm.h>
 
+#define	_SYSCALL(name)							\
+			mov $SYS_##name, %eax;				\
+			movq %rcx, %r10;				\
+			syscall
+
+#define	_SYSCALL_BODY(name)						\
+			_SYSCALL(name);					\
+			jb HIDENAME(cerror);				\
+			ret
+
 #define	RSYSCALL(name)	ENTRY(__sys_##name);				\
 			WEAK_REFERENCE(__sys_##name, name);		\
 			WEAK_REFERENCE(__sys_##name, _##name);		\
-			mov $SYS_##name,%eax; KERNCALL;			\
-			jb HIDENAME(cerror); ret;			\
+			_SYSCALL_BODY(name);				\
 			END(__sys_##name)
 
 #define	PSEUDO(name)	ENTRY(__sys_##name);				\
 			WEAK_REFERENCE(__sys_##name, _##name);		\
-			mov $SYS_##name,%eax; KERNCALL;			\
-			jb HIDENAME(cerror); ret;			\
+			_SYSCALL_BODY(name);				\
 			END(__sys_##name)
-
-#define	KERNCALL	movq %rcx, %r10; syscall
diff --git a/lib/libc/amd64/gen/rfork_thread.S b/lib/libc/amd64/gen/rfork_thread.S
index a3c64fad7994..a70551631f1b 100644
--- a/lib/libc/amd64/gen/rfork_thread.S
+++ b/lib/libc/amd64/gen/rfork_thread.S
@@ -51,8 +51,7 @@ ENTRY(rfork_thread)
 	/*
 	 * Prepare and execute the thread creation syscall
 	 */
-	movq	$SYS_rfork, %rax
-	KERNCALL
+	_SYSCALL(rfork)
 	jb 	2f
 
 	/*
@@ -78,8 +77,7 @@ ENTRY(rfork_thread)
 	/*
 	 * Exit system call
 	 */
-	movq	$SYS_exit, %rax
-	KERNCALL
+	_SYSCALL(exit)
 
 	/*
 	 * Branch here if the thread creation fails:
diff --git a/lib/libc/amd64/sys/getcontext.S b/lib/libc/amd64/sys/getcontext.S
index 6860a3cf9bef..c3a856c879f8 100644
--- a/lib/libc/amd64/sys/getcontext.S
+++ b/lib/libc/amd64/sys/getcontext.S
@@ -36,8 +36,7 @@
 	WEAK_REFERENCE(__sys_getcontext, getcontext)
 ENTRY(__sys_getcontext)
 	movq	(%rsp),%rsi	/* save getcontext return address */
-	mov	$SYS_getcontext,%rax
-	KERNCALL
+	_SYSCALL(getcontext)
 	jb	HIDENAME(cerror)
 	addq	$8,%rsp		/* remove stale (setcontext) return address */
 	jmp	*%rsi		/* restore return address */
diff --git a/lib/libc/amd64/sys/vfork.S b/lib/libc/amd64/sys/vfork.S
index 3714a742bc15..e3c5f701dcff 100644
--- a/lib/libc/amd64/sys/vfork.S
+++ b/lib/libc/amd64/sys/vfork.S
@@ -37,8 +37,7 @@
 	WEAK_REFERENCE(__sys_vfork, vfork)
 ENTRY(__sys_vfork)
 	popq	%rsi		/* fetch return address (%rsi preserved) */
-	mov	$SYS_vfork,%rax
-	KERNCALL
+	_SYSCALL(vfork)
 	jb	1f
 	jmp	*%rsi
 1:
diff --git a/lib/libc/i386/SYS.h b/lib/libc/i386/SYS.h
index 24b0060372f8..292b705f80f2 100644
--- a/lib/libc/i386/SYS.h
+++ b/lib/libc/i386/SYS.h
@@ -35,17 +35,22 @@
 #include <sys/syscall.h>
 #include <machine/asm.h>
 
+#define	_SYSCALL(name)							\
+			mov $SYS_##name, %eax;				\
+			int $0x80
+
+#define _SYSCALL_BODY(name)						\
+			_SYSCALL(name);					\
+			jb HIDENAME(cerror);				\
+			ret
+
 #define	RSYSCALL(name)	ENTRY(__sys_##name);				\
 			WEAK_REFERENCE(__sys_##name, name);		\
 			WEAK_REFERENCE(__sys_##name, _##name);		\
-			mov $SYS_##name,%eax; KERNCALL;			\
-			jb HIDENAME(cerror);				\
-			ret; END(__sys_##name)
+			_SYSCALL_BODY(name);				\
+			END(__sys_##name)
 
 #define	PSEUDO(name)	ENTRY(__sys_##name);				\
 			WEAK_REFERENCE(__sys_##name, _##name);		\
-			mov $SYS_##name,%eax; KERNCALL;			\
-			jb HIDENAME(cerror); ret;			\
+			_SYSCALL_BODY(name);				\
 			END(__sys_##name)
-
-#define KERNCALL	int $0x80
diff --git a/lib/libc/i386/gen/rfork_thread.S b/lib/libc/i386/gen/rfork_thread.S
index e4d3b904d523..b37f16c930e8 100644
--- a/lib/libc/i386/gen/rfork_thread.S
+++ b/lib/libc/i386/gen/rfork_thread.S
@@ -64,8 +64,7 @@ ENTRY(rfork_thread)
 	 */
 	pushl	8(%ebp)
 	pushl	$0
-	movl	$SYS_rfork, %eax
-	KERNCALL
+	_SYSCALL(rfork)
 	jb 	2f
 
 	/*
@@ -96,8 +95,7 @@ ENTRY(rfork_thread)
 	 */
 	pushl	%eax
 	pushl	$0
-	movl	$SYS_exit, %eax
-	KERNCALL
+	_SYSCALL(exit)
 
 	/*
 	 * Branch here if the thread creation fails:
diff --git a/lib/libc/i386/sys/getcontext.S b/lib/libc/i386/sys/getcontext.S
index 8baf0caf18fd..d6b5dcd58669 100644
--- a/lib/libc/i386/sys/getcontext.S
+++ b/lib/libc/i386/sys/getcontext.S
@@ -36,8 +36,7 @@
 	WEAK_REFERENCE(__sys_getcontext, getcontext)
 ENTRY(__sys_getcontext)
 	movl	(%esp),%ecx	/* save getcontext return address */
-	mov	$SYS_getcontext,%eax
-	KERNCALL
+	_SYSCALL(getcontext)
 	jb	HIDENAME(cerror)
 	addl	$4,%esp		/* remove stale (setcontext) return address */
 	jmp	*%ecx		/* restore return address */
diff --git a/lib/libc/i386/sys/syscall.S b/lib/libc/i386/sys/syscall.S
index 6e9f8e587258..9eaf193c1d7a 100644
--- a/lib/libc/i386/sys/syscall.S
+++ b/lib/libc/i386/sys/syscall.S
@@ -37,7 +37,7 @@ ENTRY(syscall)
 	pop	%ecx	/* rta */
 	pop	%eax	/* syscall number */
 	push	%ecx
-	KERNCALL
+	int	$0x80
 	push	%ecx	/* need to push a word to keep stack frame intact
 			   upon return; the word must be the return address. */
 	jb	HIDENAME(cerror)
diff --git a/lib/libc/i386/sys/vfork.S b/lib/libc/i386/sys/vfork.S
index b96f3d18c950..3399b8b752de 100644
--- a/lib/libc/i386/sys/vfork.S
+++ b/lib/libc/i386/sys/vfork.S
@@ -37,8 +37,7 @@
 	WEAK_REFERENCE(__sys_vfork, vfork)
 ENTRY(__sys_vfork)
 	popl	%ecx		/* my rta into ecx */
-	mov	$SYS_vfork,%eax
-	KERNCALL
+	_SYSCALL(vfork)
 	jb	1f
 	jmp	*%ecx
 1: