Linux: Use system call tables during build

Use <arch-syscall.h> instead of <asm/unistd.h> to obtain the system
call numbers.  A few direct includes of <asm/unistd.h> need to be
removed (if the system call numbers are already provided indirectly
by <sysdep.h>) or replaced with <sys/syscall.h>.

Current Linux headers for alpha define the required system call names,
so most of the _NR_* hacks are no longer needed.  For the 32-bit arm
architecture, eliminate the INTERNAL_SYSCALL_ARM macro, now that we
have regular system call names for cacheflush and set_tls.  There are
more such cleanup opportunities for other architectures, but these
cleanups are required to avoid macro redefinition errors during the
build.

For ia64, it is desirable to use <asm/break.h> directly to obtain
the break number for system calls (which is not a system call number
itself).  This requires replacing __BREAK_SYSCALL with
__IA64_BREAK_SYSCALL because the former is defined as an alias in
<asm/unistd.h>, but not in <asm/break.h>.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

21 files changed, 46 insertions, 58 deletions

diff --git a/NEWS b/NEWS
index 7249fcad48..b85989ec3d 100644
--- a/NEWS
+++ b/NEWS
@@ -101,7 +101,8 @@ Deprecated and removed features, and other changes affecting compatibility:
 
 Changes to build and runtime requirements:
 
-  [Add changes to build and runtime requirements here]
+* It is no longer necessary to have recent Linux kernel headers to build
+  working (non-stub) system call wrappers.
 
 Security related changes:
 
diff --git a/sysdeps/ia64/start.S b/sysdeps/ia64/start.S
index dcd2aa0131..18c8962b6e 100644
--- a/sysdeps/ia64/start.S
+++ b/sysdeps/ia64/start.S
@@ -35,7 +35,6 @@
 
 #include <sysdep.h>
 
-#include <asm/unistd.h>
 #include <asm/fpu.h>
 
 /*
diff --git a/sysdeps/microblaze/backtrace_linux.c b/sysdeps/microblaze/backtrace_linux.c
index 9ae5aeded9..49c955b5d6 100644
--- a/sysdeps/microblaze/backtrace_linux.c
+++ b/sysdeps/microblaze/backtrace_linux.c
@@ -20,7 +20,7 @@
 #include <asm/sigcontext.h>
 #include <linux/signal.h>
 #include <asm-generic/ucontext.h>
-#include <asm/unistd.h>
+#include <sys/syscall.h>
 
 int
 _identify_sighandler (unsigned long fp, unsigned long pc,
diff --git a/sysdeps/unix/sysv/linux/alpha/kernel-features.h b/sysdeps/unix/sysv/linux/alpha/kernel-features.h
index 24fd6ca38f..5f003e634a 100644
--- a/sysdeps/unix/sysv/linux/alpha/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/alpha/kernel-features.h
@@ -28,11 +28,6 @@
 # define __ASSUME_STATFS64 0
 #endif
 
-/* Alpha used to define SysV ipc shmat syscall with a different name.  */
-#ifndef __NR_shmat
-# define __NR_shmat __NR_osf_shmat
-#endif
-
 #define __ASSUME_RECV_SYSCALL	1
 #define __ASSUME_SEND_SYSCALL	1
 
diff --git a/sysdeps/unix/sysv/linux/alpha/sysdep.h b/sysdeps/unix/sysv/linux/alpha/sysdep.h
index 81de842644..2458f9860a 100644
--- a/sysdeps/unix/sysv/linux/alpha/sysdep.h
+++ b/sysdeps/unix/sysv/linux/alpha/sysdep.h
@@ -37,31 +37,6 @@
 #undef SYS_ify
 #define SYS_ify(syscall_name)	__NR_##syscall_name
 
-/* Define some aliases to make automatic syscall generation work
-   properly.  The SYS_* variants are for the benefit of the files in
-   sysdeps/unix.  */
-#define __NR_getpid	__NR_getxpid
-#define __NR_getuid	__NR_getxuid
-#define __NR_getgid	__NR_getxgid
-#define SYS_getpid	__NR_getxpid
-#define SYS_getuid	__NR_getxuid
-#define SYS_getgid	__NR_getxgid
-
-/*
- * Some syscalls no Linux program should know about:
- */
-#define __NR_osf_sigprocmask	 48
-#ifndef __NR_osf_shmat
-# define __NR_osf_shmat		209
-#endif
-#define __NR_osf_getsysinfo	256
-#define __NR_osf_setsysinfo	257
-
-/* Help old kernel headers where particular syscalls are not available.  */
-#ifndef __NR_semtimedop
-# define __NR_semtimedop	423
-#endif
-
 /* This is a kludge to make syscalls.list find these under the names
    pread and pwrite, since some kernel headers define those names
    and some define the *64 names for the same system calls.  */
diff --git a/sysdeps/unix/sysv/linux/arm/dl-machine.h b/sysdeps/unix/sysv/linux/arm/dl-machine.h
index 11b56a62b1..5fc685fdaf 100644
--- a/sysdeps/unix/sysv/linux/arm/dl-machine.h
+++ b/sysdeps/unix/sysv/linux/arm/dl-machine.h
@@ -20,7 +20,7 @@
 
 /* This definition is Linux-specific.  */
 #define CLEAR_CACHE(BEG,END)                                            \
-  INTERNAL_SYSCALL_ARM (cacheflush, , 3, (BEG), (END), 0)
+  INTERNAL_SYSCALL (cacheflush, , 3, (BEG), (END), 0)
 
 #endif
 
diff --git a/sysdeps/unix/sysv/linux/arm/sysdep.h b/sysdeps/unix/sysv/linux/arm/sysdep.h
index 4c2dc2dbb2..2304dad8f3 100644
--- a/sysdeps/unix/sysv/linux/arm/sysdep.h
+++ b/sysdeps/unix/sysv/linux/arm/sysdep.h
@@ -377,10 +377,6 @@ __local_syscall_error:						\
 #define INTERNAL_SYSCALL(name, err, nr, args...)		\
 	INTERNAL_SYSCALL_RAW(SYS_ify(name), err, nr, args)
 
-#undef INTERNAL_SYSCALL_ARM
-#define INTERNAL_SYSCALL_ARM(name, err, nr, args...)		\
-	INTERNAL_SYSCALL_RAW(__ARM_NR_##name, err, nr, args)
-
 #undef INTERNAL_SYSCALL_ERROR_P
 #define INTERNAL_SYSCALL_ERROR_P(val, err) \
   ((unsigned int) (val) >= 0xfffff001u)
diff --git a/sysdeps/unix/sysv/linux/arm/tls.h b/sysdeps/unix/sysv/linux/arm/tls.h
index 3b91f46e3c..18afe244d7 100644
--- a/sysdeps/unix/sysv/linux/arm/tls.h
+++ b/sysdeps/unix/sysv/linux/arm/tls.h
@@ -33,7 +33,7 @@
 # define TLS_INIT_TP(tcbp) \
   ({ INTERNAL_SYSCALL_DECL (err);					\
      long int result_var;						\
-     result_var = INTERNAL_SYSCALL_ARM (set_tls, err, 1, (tcbp));	\
+     result_var = INTERNAL_SYSCALL (set_tls, err, 1, (tcbp));		\
      INTERNAL_SYSCALL_ERROR_P (result_var, err)				\
        ? "unknown error" : NULL; })
 
diff --git a/sysdeps/unix/sysv/linux/hppa/clone.S b/sysdeps/unix/sysv/linux/hppa/clone.S
index e90dd5ed9c..4eda812dd0 100644
--- a/sysdeps/unix/sysv/linux/hppa/clone.S
+++ b/sysdeps/unix/sysv/linux/hppa/clone.S
@@ -20,7 +20,6 @@
 /* clone() is even more special than fork() as it mucks with stacks
    and invokes a function in the right context after its all over.  */
 
-#include <asm/unistd.h>
 #include <sysdep.h>
 #define _ERRNO_H	1
 #include <bits/errno.h>
diff --git a/sysdeps/unix/sysv/linux/ia64/brk.S b/sysdeps/unix/sysv/linux/ia64/brk.S
index f4195c8672..734d3467a7 100644
--- a/sysdeps/unix/sysv/linux/ia64/brk.S
+++ b/sysdeps/unix/sysv/linux/ia64/brk.S
@@ -20,7 +20,6 @@
 
 #include <sysdep.h>
 
-#include <asm/unistd.h>
 #include <asm/errno.h>
 
 	.global __curbrk
diff --git a/sysdeps/unix/sysv/linux/ia64/clone2.S b/sysdeps/unix/sysv/linux/ia64/clone2.S
index de6de43706..c8c90e5372 100644
--- a/sysdeps/unix/sysv/linux/ia64/clone2.S
+++ b/sysdeps/unix/sysv/linux/ia64/clone2.S
@@ -58,7 +58,7 @@ ENTRY(__clone2)
 	 */
 	mov r15=SYS_ify (clone2)
 	.save rp, r0
-	break __BREAK_SYSCALL
+	break __IA64_BREAK_SYSCALL
 	.body
 	cmp.eq p6,p0=-1,r10
 	cmp.eq CHILD,PARENT=0,r8 /* Are we the child?   */
@@ -78,7 +78,7 @@ ENTRY(__clone2)
 	mov gp=loc0
 	mov r15=SYS_ify (exit)
 	.save rp, r0
-	break __BREAK_SYSCALL
+	break __IA64_BREAK_SYSCALL
 	ret			/* Not reached.		*/
 PSEUDO_END(__clone2)
 
diff --git a/sysdeps/unix/sysv/linux/ia64/syscall.S b/sysdeps/unix/sysv/linux/ia64/syscall.S
index 14b3be6927..d819f79d4b 100644
--- a/sysdeps/unix/sysv/linux/ia64/syscall.S
+++ b/sysdeps/unix/sysv/linux/ia64/syscall.S
@@ -25,7 +25,7 @@ ENTRY(syscall)
 	   in {out0...out5} like the kernel syscall handler expects.  */
 	alloc r2=ar.pfs,1,0,8,0
 	mov r15=r32		/* syscall number */
-	break __BREAK_SYSCALL
+	break __IA64_BREAK_SYSCALL
 	;;
 	cmp.ne p6,p0=-1,r10	/* r10 = -1 on error */
 (p6)	ret
diff --git a/sysdeps/unix/sysv/linux/ia64/sysdep.S b/sysdeps/unix/sysv/linux/ia64/sysdep.S
index be1aeb2e1c..75fc3d6456 100644
--- a/sysdeps/unix/sysv/linux/ia64/sysdep.S
+++ b/sysdeps/unix/sysv/linux/ia64/sysdep.S
@@ -51,7 +51,7 @@ END(__syscall_error)
 
 ENTRY(__ia64_syscall)
 	mov r15=r37		/* syscall number */
-	break __BREAK_SYSCALL
+	break __IA64_BREAK_SYSCALL
 	cmp.eq p6,p0=-1,r10	/* r10 = -1 on error */
 (p6)	br.cond.spnt.few __syscall_error
 	ret
diff --git a/sysdeps/unix/sysv/linux/ia64/sysdep.h b/sysdeps/unix/sysv/linux/ia64/sysdep.h
index c4aa72a2fc..61f32ca8b4 100644
--- a/sysdeps/unix/sysv/linux/ia64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/ia64/sysdep.h
@@ -25,6 +25,7 @@
 #include <sysdeps/ia64/sysdep.h>
 #include <dl-sysdep.h>
 #include <tls.h>
+#include <asm/break.h>
 
 /* In order to get __set_errno() definition in INLINE_SYSCALL.  */
 #ifndef __ASSEMBLER__
@@ -115,7 +116,7 @@
 
 #define DO_CALL_VIA_BREAK(num)			\
 	mov r15=num;				\
-	break __BREAK_SYSCALL
+	break __IA64_BREAK_SYSCALL
 
 #ifdef IA64_USE_NEW_STUB
 # ifdef SHARED
@@ -229,7 +230,7 @@
     register long _r15 asm ("r15") = name;			\
     long _retval;						\
     LOAD_REGS_##nr						\
-    __asm __volatile (BREAK_INSN (__BREAK_SYSCALL)		\
+    __asm __volatile (BREAK_INSN (__IA64_BREAK_SYSCALL)		\
 		      : "=r" (_r8), "=r" (_r10), "=r" (_r15)	\
 			ASM_OUTARGS_##nr			\
 		      : "2" (_r15) ASM_ARGS_##nr		\
diff --git a/sysdeps/unix/sysv/linux/include/sys/syscall.h b/sysdeps/unix/sysv/linux/include/sys/syscall.h
new file mode 100644
index 0000000000..9611ca4481
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/include/sys/syscall.h
@@ -0,0 +1,29 @@
+/* Wrapper header for <sys/syscall.h>.  Linux version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SYSCALL_H
+
+#ifdef _ISOMAC
+# include <sysdeps/unix/sysv/linux/sys/syscall.h>
+#else /* !_ISOMAC */
+/* Use the built-in system call list, not <asm/unistd.h>, which may
+   not list all the system call numbers we need.  */
+# define _SYSCALL_H
+# include <arch-syscall.h>
+#endif /* !_ISOMAC */
+
+#endif /* _SYSCALL_H */
diff --git a/sysdeps/unix/sysv/linux/mips/vfork.S b/sysdeps/unix/sysv/linux/mips/vfork.S
index 1c08f222da..ba3c64ae1e 100644
--- a/sysdeps/unix/sysv/linux/mips/vfork.S
+++ b/sysdeps/unix/sysv/linux/mips/vfork.S
@@ -19,7 +19,6 @@
 
 #include <sys/asm.h>
 #include <sysdep.h>
-#include <asm/unistd.h>
 #include <sgidefs.h>
 #include <tls.h>
 
diff --git a/sysdeps/unix/sysv/linux/nios2/sysdep.h b/sysdeps/unix/sysv/linux/nios2/sysdep.h
index 82a126b697..b02730bd23 100644
--- a/sysdeps/unix/sysv/linux/nios2/sysdep.h
+++ b/sysdeps/unix/sysv/linux/nios2/sysdep.h
@@ -19,7 +19,6 @@
 #ifndef _LINUX_NIOS2_SYSDEP_H
 #define _LINUX_NIOS2_SYSDEP_H 1
 
-#include <asm/unistd.h>
 #include <sysdeps/unix/sysdep.h>
 #include <sysdeps/nios2/sysdep.h>
 #include <sysdeps/unix/sysv/linux/generic/sysdep.h>
diff --git a/sysdeps/unix/sysv/linux/riscv/flush-icache.c b/sysdeps/unix/sysv/linux/riscv/flush-icache.c
index ef41725f6f..f1565ab2dd 100644
--- a/sysdeps/unix/sysv/linux/riscv/flush-icache.c
+++ b/sysdeps/unix/sysv/linux/riscv/flush-icache.c
@@ -26,6 +26,7 @@
 #else
 # include <asm/unistd.h>
 #endif
+#include <sys/syscall.h>
 
 typedef int (*func_type) (void *, void *, unsigned long int);
 
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S
index 94ce7aef28..a6a797f30d 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S
@@ -20,7 +20,6 @@
    and invokes a function in the right context after its all over.  */
 
 #include <asm/errno.h>
-#include <asm/unistd.h>
 #include <tcb-offsets.h>
 #include <sysdep.h>
 
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S
index 177ef93ef0..de5e054d84 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S
@@ -20,7 +20,6 @@
    and invokes a function in the right context after its all over.  */
 
 #include <asm/errno.h>
-#include <asm/unistd.h>
 #include <tcb-offsets.h>
 #include <sysdep.h>
 
diff --git a/sysdeps/unix/sysv/linux/sys/syscall.h b/sysdeps/unix/sysv/linux/sys/syscall.h
index 2a42f5be2e..aa89a74e6b 100644
--- a/sysdeps/unix/sysv/linux/sys/syscall.h
+++ b/sysdeps/unix/sysv/linux/sys/syscall.h
@@ -23,12 +23,9 @@
    from the kernel sources.  */
 #include <asm/unistd.h>
 
-#ifndef _LIBC
-/* The Linux kernel header file defines macros `__NR_<name>', but some
-   programs expect the traditional form `SYS_<name>'.  So in building libc
-   we scan the kernel's list and produce <bits/syscall.h> with macros for
-   all the `SYS_' names.  */
-# include <bits/syscall.h>
-#endif
+/* The Linux kernel header file defines macros __NR_*, but some
+   programs expect the traditional form SYS_*.  <bits/syscall.h>
+   defines SYS_* macros for __NR_* macros of known names.  */
+#include <bits/syscall.h>
 
 #endif