arm: Add the clone3 wrapper

It follows the internal signature:

  extern int clone3 (struct clone_args *__cl_args, size_t __size,
		    int (*__func) (void *__arg), void *__arg);

Checked on arm-linux-gnueabihf.

diff --git a/sysdeps/unix/sysv/linux/arm/clone3.S b/sysdeps/unix/sysv/linux/arm/clone3.S
new file mode 100644 (file)
index 0000000..f236d18
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arm/clone3.S
@@ -0,0 +1,80 @@
+/* The clone3 syscall wrapper.  Linux/arm version.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+#define _ERRNO_H       1
+#include <bits/errno.h>
+
+/* The userland implementation is:
+   int clone3 (struct clone_args *cl_args, size_t size,
+               int (*func)(void *arg), void *arg);
+
+   the kernel entry is:
+   int clone3 (struct clone_args *cl_args, size_t size);
+
+   The parameters are passed in registers from userland:
+   r0: cl_args
+   r1: size
+   r2: func
+   r3: arg  */
+
+        .text
+ENTRY(__clone3)
+       /* Sanity check args.  */
+       cmp     r0, #0
+       ite     ne
+       cmpne   r1, #0
+       moveq   r0, #-EINVAL
+       beq     PLTJMP(syscall_error)
+
+       /* Do the syscall, the kernel expects:
+          r7: system call number:
+          r0: cl_args
+          r1: size  */
+       push    { r7 }
+       cfi_adjust_cfa_offset (4)
+       cfi_rel_offset (r7, 0)
+       ldr     r7, =SYS_ify(clone3)
+       swi     0x0
+       cfi_endproc
+
+       cmp     r0, #0
+       beq     1f
+       pop     {r7}
+       blt     PLTJMP(C_SYMBOL_NAME(__syscall_error))
+       RETINSTR(, lr)
+
+       cfi_startproc
+PSEUDO_END (__clone3)
+
+1:
+       .fnstart
+       .cantunwind
+       mov     r0, r3
+       mov     ip, r2
+       BLX (ip)
+
+       /* And we are done, passing the return value through r0.  */
+       ldr     r7, =SYS_ify(exit)
+       swi     0x0
+
+       .fnend
+
+libc_hidden_def (__clone3)
+weak_alias (__clone3, clone3)

diff --git a/sysdeps/unix/sysv/linux/arm/sysdep.h b/sysdeps/unix/sysv/linux/arm/sysdep.h
index 2f32188..57fc5f1 100644 (file)
--- a/sysdeps/unix/sysv/linux/arm/sysdep.h
+++ b/sysdeps/unix/sysv/linux/arm/sysdep.h
@@ -362,6 +362,7 @@ __local_syscall_error:                                              \
 #define HAVE_CLOCK_GETTIME_VSYSCALL    "__vdso_clock_gettime"
 #define HAVE_CLOCK_GETTIME64_VSYSCALL  "__vdso_clock_gettime64"
 #define HAVE_GETTIMEOFDAY_VSYSCALL     "__vdso_gettimeofday"
+#define HAVE_CLONE3_WRAPPER            1
 
 #define LOAD_ARGS_0()
 #define ASM_ARGS_0