ed8cae8ba0
This patch introduces the new syscall pipe2 which is like pipe but it also
takes an additional parameter which takes a flag value. This patch implements
the handling of O_CLOEXEC for the flag. I did not add support for the new
syscall for the architectures which have a special sys_pipe implementation. I
think the maintainers of those archs have the chance to go with the unified
implementation but that's up to them.
The implementation introduces do_pipe_flags. I did that instead of changing
all callers of do_pipe because some of the callers are written in assembler.
I would probably screw up changing the assembly code. To avoid breaking code
do_pipe is now a small wrapper around do_pipe_flags. Once all callers are
changed over to do_pipe_flags the old do_pipe function can be removed.
The following test must be adjusted for architectures other than x86 and
x86-64 and in case the syscall numbers changed.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/syscall.h>
#ifndef __NR_pipe2
# ifdef __x86_64__
# define __NR_pipe2 293
# elif defined __i386__
# define __NR_pipe2 331
# else
# error "need __NR_pipe2"
# endif
#endif
int
main (void)
{
int fd[2];
if (syscall (__NR_pipe2, fd, 0) != 0)
{
puts ("pipe2(0) failed");
return 1;
}
for (int i = 0; i < 2; ++i)
{
int coe = fcntl (fd[i], F_GETFD);
if (coe == -1)
{
puts ("fcntl failed");
return 1;
}
if (coe & FD_CLOEXEC)
{
printf ("pipe2(0) set close-on-exit for fd[%d]\n", i);
return 1;
}
}
close (fd[0]);
close (fd[1]);
if (syscall (__NR_pipe2, fd, O_CLOEXEC) != 0)
{
puts ("pipe2(O_CLOEXEC) failed");
return 1;
}
for (int i = 0; i < 2; ++i)
{
int coe = fcntl (fd[i], F_GETFD);
if (coe == -1)
{
puts ("fcntl failed");
return 1;
}
if ((coe & FD_CLOEXEC) == 0)
{
printf ("pipe2(O_CLOEXEC) does not set close-on-exit for fd[%d]\n", i);
return 1;
}
}
close (fd[0]);
close (fd[1]);
puts ("OK");
return 0;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
84 lines
2.2 KiB
C
84 lines
2.2 KiB
C
#include <linux/errno.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/sem.h>
|
|
#include <linux/msg.h>
|
|
#include <linux/shm.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/mman.h>
|
|
#include <linux/file.h>
|
|
#include <linux/utsname.h>
|
|
#include <linux/module.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/ipc.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/unistd.h>
|
|
|
|
/*
|
|
* sys_pipe() is the normal C calling standard for creating
|
|
* a pipe. It's not the way Unix traditionally does this, though.
|
|
*/
|
|
asmlinkage int sys_pipe(unsigned long r4, unsigned long r5,
|
|
unsigned long r6, unsigned long r7,
|
|
struct pt_regs __regs)
|
|
{
|
|
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
|
|
int fd[2];
|
|
int error;
|
|
|
|
error = do_pipe_flags(fd, 0);
|
|
if (!error) {
|
|
regs->regs[1] = fd[1];
|
|
return fd[0];
|
|
}
|
|
return error;
|
|
}
|
|
|
|
asmlinkage ssize_t sys_pread_wrapper(unsigned int fd, char * buf,
|
|
size_t count, long dummy, loff_t pos)
|
|
{
|
|
return sys_pread64(fd, buf, count, pos);
|
|
}
|
|
|
|
asmlinkage ssize_t sys_pwrite_wrapper(unsigned int fd, const char * buf,
|
|
size_t count, long dummy, loff_t pos)
|
|
{
|
|
return sys_pwrite64(fd, buf, count, pos);
|
|
}
|
|
|
|
asmlinkage int sys_fadvise64_64_wrapper(int fd, u32 offset0, u32 offset1,
|
|
u32 len0, u32 len1, int advice)
|
|
{
|
|
#ifdef __LITTLE_ENDIAN__
|
|
return sys_fadvise64_64(fd, (u64)offset1 << 32 | offset0,
|
|
(u64)len1 << 32 | len0, advice);
|
|
#else
|
|
return sys_fadvise64_64(fd, (u64)offset0 << 32 | offset1,
|
|
(u64)len0 << 32 | len1, advice);
|
|
#endif
|
|
}
|
|
|
|
#if defined(CONFIG_CPU_SH2) || defined(CONFIG_CPU_SH2A)
|
|
#define SYSCALL_ARG3 "trapa #0x23"
|
|
#else
|
|
#define SYSCALL_ARG3 "trapa #0x13"
|
|
#endif
|
|
|
|
/*
|
|
* Do a system call from kernel instead of calling sys_execve so we
|
|
* end up with proper pt_regs.
|
|
*/
|
|
int kernel_execve(const char *filename, char *const argv[], char *const envp[])
|
|
{
|
|
register long __sc0 __asm__ ("r3") = __NR_execve;
|
|
register long __sc4 __asm__ ("r4") = (long) filename;
|
|
register long __sc5 __asm__ ("r5") = (long) argv;
|
|
register long __sc6 __asm__ ("r6") = (long) envp;
|
|
__asm__ __volatile__ (SYSCALL_ARG3 : "=z" (__sc0)
|
|
: "0" (__sc0), "r" (__sc4), "r" (__sc5), "r" (__sc6)
|
|
: "memory");
|
|
return __sc0;
|
|
}
|