s390: 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 s390x-linux-gnu and s390-linux-gnu.

diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/clone3.S b/sysdeps/unix/sysv/linux/s390/s390-32/clone3.S
new file mode 100644 (file)
index 0000000..bbe75ce
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/clone3.S
@@ -0,0 +1,78 @@
+/* The clone3 syscall wrapper.  Linux/s390x 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:
+   r2: cl_args
+   r3: size
+   r4: func
+   r5: arg  */
+
+        .text
+ENTRY(__clone3)
+       /* Sanity check args.  */
+       ltr     %r2, %r2
+       je      error
+       ltr     %r4, %r4
+       je      error
+
+       /* Do the system call, the kernel expects:
+          r1: system call number
+          r2: cl_args
+          r3: size  */
+       lhi     %r1, SYS_ify(clone3)
+       svc     0
+       ltr     %r2,%r2                 /* check return code */
+       jz      thread_start
+       jm      SYSCALL_ERROR_LABEL
+       br      %r14
+error:
+       lhi     %r2,-EINVAL
+       j       SYSCALL_ERROR_LABEL
+PSEUDO_END (__clone3)
+
+       .align 16
+       .type thread_start, %function
+thread_start:
+       cfi_startproc
+       /* Mark r14 as undefined in order to stop unwinding here.  */
+       cfi_undefined (r14)
+
+       /* func is in gpr 4, arg in gpr 5.  */
+       lr      %r2, %r5
+       ahi     %r15, -96
+       xc      0(4,%r15),0(%r15)
+       basr    %r14, %r4
+
+       DO_CALL (exit, 1)
+       cfi_endproc
+       ASM_SIZE_DIRECTIVE (thread_start)
+
+libc_hidden_def (__clone3)
+weak_alias (__clone3, clone3)

diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S b/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S
new file mode 100644 (file)
index 0000000..62800f8
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/clone3.S
@@ -0,0 +1,78 @@
+/* The clone3 syscall wrapper.  Linux/s390x 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:
+   r2: cl_args
+   r3: size
+   r4: func
+   r5: arg  */
+
+        .text
+ENTRY(__clone3)
+       /* Sanity check args.  */
+       ltgr    %r2, %r2
+       je      error
+       ltgr    %r4, %r4
+       je      error
+
+       /* Do the system call, the kernel expects:
+          r1: system call number
+          r2: cl_args
+          r3: size  */
+       lghi    %r1, SYS_ify(clone3)
+       svc     0
+       ltgr    %r2,%r2                 /* check return code */
+       jz      thread_start
+       jgm     SYSCALL_ERROR_LABEL
+       br      %r14
+error:
+       lghi    %r2,-EINVAL
+       jg      SYSCALL_ERROR_LABEL
+PSEUDO_END (__clone3)
+
+       .align 16
+       .type thread_start, %function
+thread_start:
+       cfi_startproc
+       /* Mark r14 as undefined in order to stop unwinding here.  */
+       cfi_undefined (r14)
+
+       /* func is in gpr 4, arg in gpr 5.  */
+       lgr     %r2, %r5
+       aghi    %r15, -160
+       xc      0(8,%r15),0(%r15)
+       basr    %r14, %r4
+
+       DO_CALL (exit, 1)
+       cfi_endproc
+       ASM_SIZE_DIRECTIVE (thread_start)
+
+libc_hidden_def (__clone3)
+weak_alias (__clone3, clone3)

diff --git a/sysdeps/unix/sysv/linux/s390/sysdep.h b/sysdeps/unix/sysv/linux/s390/sysdep.h
index 3bde8ba19c4d0d9815f663b078dcf0bd3f75c1aa..b2621630f0f2d1f15046d2cca60e3dd25a5e4071 100644 (file)
--- a/sysdeps/unix/sysv/linux/s390/sysdep.h
+++ b/sysdeps/unix/sysv/linux/s390/sysdep.h
@@ -79,4 +79,5 @@
 #define HAVE_GETTIMEOFDAY_VSYSCALL     "__kernel_gettimeofday"
 #define HAVE_GETCPU_VSYSCALL           "__kernel_getcpu"
 
+#define HAVE_CLONE3_WRAPPER            1
 #endif