V2 [PATCH 2/2] Add C wrappers for prctl/process_vm_readv/process_vm_writev [BZ #25810]

["H.J. Lu" <hjl.tools@gmail.com>]

On Wed, Apr 29, 2020 at 04:55:43PM +0200, Florian Weimer wrote:
> * H. J. Lu:
> 
> > diff --git a/sysdeps/unix/sysv/linux/prctl.c b/sysdeps/unix/sysv/linux/prctl.c
> > new file mode 100644
> > index 0000000000..e0e5ef4e47
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/prctl.c
> > @@ -0,0 +1,39 @@
> > +/* prctl - Linux specific syscall.
> > +   Copyright (C) 2020 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 <unistd.h>
> > +#include <sysdep.h>
> > +#include <errno.h>
> > +
> > +extern int prctl (int, unsigned long, unsigned long, unsigned long,
> > +		  unsigned long);
> > +hidden_proto (prctl)
> > +extern int __prctl (int, unsigned long, unsigned long, unsigned long,
> > +		    unsigned long);
> > +hidden_proto (__prctl)
> > +
> > +int
> > +__prctl (int option, unsigned long arg2, unsigned long arg3,
> > +	 unsigned long arg4, unsigned long arg5)
> 
> unsigned long int everywhere.

Fixed.

> 
> > +{
> > +  return INLINE_SYSCALL_CALL (prctl, option, arg2, arg3, arg4, arg5);
> > +}
> > +
> > +hidden_def (__prctl)
> > +weak_alias (__prctl, prctl)
> > +hidden_weak (prctl)
> 
> Can't you use libc_hidden_proto in include/sys/prctl.h and
> libc_hidden_proto here?
> 

Since include/sys/prctl.h has

extern int __prctl (int __option, ...);

it can't be used.

> 
> > diff --git a/sysdeps/unix/sysv/linux/process_vm_readv.c b/sysdeps/unix/sysv/linux/process_vm_readv.c
> > new file mode 100644
> > index 0000000000..1e711abe43
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/process_vm_readv.c
> > @@ -0,0 +1,32 @@
> > +/* process_vm_readv - Linux specific syscall.
> > +   Copyright (C) 2020 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 <unistd.h>
> > +#include <sysdep.h>
> > +#include <errno.h>
> > +#include <sys/uio.h>
> > +
> > +ssize_t
> > +process_vm_readv (pid_t pid, const struct iovec *local_iov,
> > +		  unsigned long liovcnt, const struct iovec *remote_iov,
> > +		  unsigned long riovcnt, unsigned long flags)
> > +{
> > +  return INLINE_SYSCALL_CALL (process_vm_readv, pid, local_iov,
> > +			      liovcnt, remote_iov, riovcnt, flags);
> > +}
> 
> Likewise, unsigned long int.

Fixed.
 
> > +
> > diff --git a/sysdeps/unix/sysv/linux/process_vm_writev.c b/sysdeps/unix/sysv/linux/process_vm_writev.c
> > new file mode 100644
> > index 0000000000..e41058750b
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/process_vm_writev.c
> > @@ -0,0 +1,32 @@
> > +/* process_vm_writev - Linux specific syscall.
> > +   Copyright (C) 2020 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 <unistd.h>
> > +#include <sysdep.h>
> > +#include <errno.h>
> > +#include <sys/uio.h>
> > +
> > +ssize_t
> > +process_vm_writev (pid_t pid, const struct iovec *local_iov,
> > +		   unsigned long liovcnt, const struct iovec *remote_iov,
> > +		   unsigned long riovcnt, unsigned long flags)
> > +{
> > +  return INLINE_SYSCALL_CALL (process_vm_writev, pid, local_iov,
> > +			      liovcnt, remote_iov, riovcnt, flags);
> > +}
> 
> Likewise.

Fixed.

> 
> (I trust the indentation is only wrong in the patch, it's okay when
> applied.)
> 

It is due to spaces vs tab.  The indentation is OK.

Ok for master?

Thanks.

H.J.
---
Since the the U marker can only be applied to 2 unsigned long arguments,
add a C wrapper for prctl, process_vm_readv and process_vm_writev syscals
which have more than 2 unsigned long arguments.
---
 sysdeps/unix/sysv/linux/Makefile            |  3 +-
 sysdeps/unix/sysv/linux/prctl.c             | 39 +++++++++++++++++++++
 sysdeps/unix/sysv/linux/process_vm_readv.c  | 33 +++++++++++++++++
 sysdeps/unix/sysv/linux/process_vm_writev.c | 33 +++++++++++++++++
 sysdeps/unix/sysv/linux/syscalls.list       |  3 --
 5 files changed, 107 insertions(+), 4 deletions(-)
 create mode 100644 sysdeps/unix/sysv/linux/prctl.c
 create mode 100644 sysdeps/unix/sysv/linux/process_vm_readv.c
 create mode 100644 sysdeps/unix/sysv/linux/process_vm_writev.c

diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 089a4899d5..1d9a8d3cdb 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -59,7 +59,8 @@ sysdep_routines += adjtimex clone umount umount2 readahead sysctl \
 		   eventfd eventfd_read eventfd_write prlimit \
 		   personality epoll_wait tee vmsplice splice \
 		   open_by_handle_at mlock2 pkey_mprotect pkey_set pkey_get \
-		   timerfd_gettime timerfd_settime
+		   timerfd_gettime timerfd_settime prctl \
+		   process_vm_readv process_vm_writev
 
 CFLAGS-gethostid.c = -fexceptions
 CFLAGS-tee.c = -fexceptions -fasynchronous-unwind-tables
diff --git a/sysdeps/unix/sysv/linux/prctl.c b/sysdeps/unix/sysv/linux/prctl.c
new file mode 100644
index 0000000000..6a9c1a8fbf
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/prctl.c
@@ -0,0 +1,39 @@
+/* prctl - Linux specific syscall.
+   Copyright (C) 2020 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 <unistd.h>
+#include <sysdep.h>
+#include <errno.h>
+
+extern int prctl (int, unsigned long int, unsigned long int,
+		  unsigned long int, unsigned long int);
+hidden_proto (prctl)
+extern int __prctl (int, unsigned long int, unsigned long int,
+		    unsigned long int, unsigned long int);
+hidden_proto (__prctl)
+
+int
+__prctl (int option, unsigned long int arg2, unsigned long int arg3,
+	 unsigned long int arg4, unsigned long int arg5)
+{
+  return INLINE_SYSCALL_CALL (prctl, option, arg2, arg3, arg4, arg5);
+}
+
+hidden_def (__prctl)
+weak_alias (__prctl, prctl)
+hidden_weak (prctl)
diff --git a/sysdeps/unix/sysv/linux/process_vm_readv.c b/sysdeps/unix/sysv/linux/process_vm_readv.c
new file mode 100644
index 0000000000..dca826b679
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/process_vm_readv.c
@@ -0,0 +1,33 @@
+/* process_vm_readv - Linux specific syscall.
+   Copyright (C) 2020 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 <unistd.h>
+#include <sysdep.h>
+#include <errno.h>
+#include <sys/uio.h>
+
+ssize_t
+process_vm_readv (pid_t pid, const struct iovec *local_iov,
+		  unsigned long int liovcnt,
+		  const struct iovec *remote_iov,
+		  unsigned long int riovcnt, unsigned long int flags)
+{
+  return INLINE_SYSCALL_CALL (process_vm_readv, pid, local_iov,
+			      liovcnt, remote_iov, riovcnt, flags);
+}
+
diff --git a/sysdeps/unix/sysv/linux/process_vm_writev.c b/sysdeps/unix/sysv/linux/process_vm_writev.c
new file mode 100644
index 0000000000..15748451aa
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/process_vm_writev.c
@@ -0,0 +1,33 @@
+/* process_vm_writev - Linux specific syscall.
+   Copyright (C) 2020 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 <unistd.h>
+#include <sysdep.h>
+#include <errno.h>
+#include <sys/uio.h>
+
+ssize_t
+process_vm_writev (pid_t pid, const struct iovec *local_iov,
+		   unsigned long int liovcnt,
+		   const struct iovec *remote_iov,
+		   unsigned long int riovcnt, unsigned long int flags)
+{
+  return INLINE_SYSCALL_CALL (process_vm_writev, pid, local_iov,
+			      liovcnt, remote_iov, riovcnt, flags);
+}
+
diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
index 5b4e205934..1d8893d1b8 100644
--- a/sysdeps/unix/sysv/linux/syscalls.list
+++ b/sysdeps/unix/sysv/linux/syscalls.list
@@ -43,7 +43,6 @@ nfsservctl	EXTRA	nfsservctl	i:ipp	__compat_nfsservctl	nfsservctl@GLIBC_2.0:GLIBC
 pipe		-	pipe		i:f	__pipe		pipe
 pipe2		-	pipe2		i:fi	__pipe2		pipe2
 pivot_root	EXTRA	pivot_root	i:ss	pivot_root
-prctl		EXTRA	prctl		i:iiiii	__prctl		prctl
 query_module	EXTRA	query_module	i:sipip	__compat_query_module	query_module@GLIBC_2.0:GLIBC_2.23
 quotactl	EXTRA	quotactl	i:isip	quotactl
 remap_file_pages -	remap_file_pages i:pUiUi	__remap_file_pages remap_file_pages
@@ -98,8 +97,6 @@ name_to_handle_at EXTRA	name_to_handle_at i:isppi name_to_handle_at
 
 setns		EXTRA	setns		i:ii	setns
 
-process_vm_readv EXTRA	process_vm_readv i:ipipii process_vm_readv
-process_vm_writev EXTRA	process_vm_writev i:ipipii process_vm_writev
 memfd_create    EXTRA	memfd_create	i:si    memfd_create
 pkey_alloc	EXTRA	pkey_alloc	i:ii	pkey_alloc
 pkey_free	EXTRA	pkey_free	i:i	pkey_free
-- 
2.25.4