From ff026950e280bc3e9487b41b460fb31bc5b57721 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Thu, 30 Apr 2020 10:42:43 -0700 Subject: [PATCH] Add a C wrapper for prctl [BZ #25896] Add a C wrapper to pass arguments in /* Control process execution. */ extern int prctl (int __option, ...) __THROW; to prctl syscall: extern int prctl (int, unsigned long int, unsigned long int, unsigned long int, unsigned long int); --- include/sys/prctl.h | 1 + sysdeps/unix/sysv/linux/Makefile | 2 +- sysdeps/unix/sysv/linux/prctl.c | 42 +++++++++++++++++++++++++++ sysdeps/unix/sysv/linux/syscalls.list | 1 - 4 files changed, 44 insertions(+), 2 deletions(-) create mode 100644 sysdeps/unix/sysv/linux/prctl.c diff --git a/include/sys/prctl.h b/include/sys/prctl.h index 0920ed642b..d33f3a290e 100644 --- a/include/sys/prctl.h +++ b/include/sys/prctl.h @@ -4,6 +4,7 @@ # ifndef _ISOMAC extern int __prctl (int __option, ...); +libc_hidden_proto (__prctl) # endif /* !_ISOMAC */ #endif diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile index db78eeadd1..0326f92c40 100644 --- a/sysdeps/unix/sysv/linux/Makefile +++ b/sysdeps/unix/sysv/linux/Makefile @@ -59,7 +59,7 @@ 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 diff --git a/sysdeps/unix/sysv/linux/prctl.c b/sysdeps/unix/sysv/linux/prctl.c new file mode 100644 index 0000000000..d5725f14cf --- /dev/null +++ b/sysdeps/unix/sysv/linux/prctl.c @@ -0,0 +1,42 @@ +/* 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 + . */ + +#include +#include +#include + +/* Unconditionally read all potential arguments. This may pass + garbage values to the kernel, but avoids the need for teaching + glibc the argument counts of individual options (including ones + that are added to the kernel in the future). */ + +int +__prctl (int option, ...) +{ + va_list arg; + va_start (arg, option); + unsigned long int arg2 = va_arg (arg, unsigned long int); + unsigned long int arg3 = va_arg (arg, unsigned long int); + unsigned long int arg4 = va_arg (arg, unsigned long int); + unsigned long int arg5 = va_arg (arg, unsigned long int); + va_end (arg); + return INLINE_SYSCALL_CALL (prctl, option, arg2, arg3, arg4, arg5); +} + +libc_hidden_def (__prctl) +weak_alias (__prctl, prctl) diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list index ced77d49fa..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 -- 2.43.5