The program below implements a clone lookalike on IA64. It has been
tested to work properly with CLONE_NEWNS defined as 0 because I didn't
have sufficient privilege to perform a real test. Of course, no real
functionality test has been performed.
The debian/copyright file needs updating; the code snippet from GNU
libc is covered by the LGPL.
Based on the example program, it should be possible to add the
necessary #ifdef __ia64__ hunk to utils/setupns.c (note that there are
actually two files with that name).
#include <stdio.h>
#include <signal.h>
#include <sys/types.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <asm/unistd.h>
#define CLONE_NEWNS 0x00020000 /* Flag to create new namespace */
// The following code has been copied from GNU libc 2.3.2, Debian
// version 2.3.2.ds1-18,, file sysdeps/unix/sysv/linux/ia64/sysdeps.h.
// The __set_errno call has been replaced with an assignment to the
// errno location.
//
// We cannot use __clone2 because it requires a callback and
// automatically invokes _exit in the child. Even if we used longjmp to
// work around this problem, we are still using an internal GNU libc
// interface. The kernel interface used below should be fairly stable.
// BEGIN OF GNU LIBC EXCERPT
#define BREAK_INSN_1(num) "break " #num ";;\n\t"
#define BREAK_INSN(num) BREAK_INSN_1(num)
/* On IA-64 we have stacked registers for passing arguments. The
"out" registers end up being the called function's "in"
registers.
Also, since we have plenty of registers we have two return values
from a syscall. r10 is set to -1 on error, whilst r8 contains the
(non-negative) errno on error or the return value on success.
*/
#undef INLINE_SYSCALL
#define INLINE_SYSCALL(name, nr, args...) \
({ \
register long _r8 asm ("r8"); \
register long _r10 asm ("r10"); \
register long _r15 asm ("r15") = __NR_##name; \
long _retval; \
LOAD_ARGS_##nr (args); \
__asm __volatile (BREAK_INSN (__BREAK_SYSCALL) \
: "=r" (_r8), "=r" (_r10), "=r" (_r15) \
ASM_OUTARGS_##nr \
: "2" (_r15) ASM_ARGS_##nr \
: "memory" ASM_CLOBBERS_##nr); \
_retval = _r8; \
if (_r10 == -1) \
{ \
errno = _retval; \
_retval = -1; \
} \
_retval; })
#define ASM_OUTARGS_0
#define ASM_OUTARGS_1 ASM_OUTARGS_0, "=r" (_out0)
#define ASM_OUTARGS_2 ASM_OUTARGS_1, "=r" (_out1)
#define ASM_OUTARGS_3 ASM_OUTARGS_2, "=r" (_out2)
#define ASM_OUTARGS_4 ASM_OUTARGS_3, "=r" (_out3)
#define ASM_OUTARGS_5 ASM_OUTARGS_4, "=r" (_out4)
#define ASM_OUTARGS_6 ASM_OUTARGS_5, "=r" (_out5)
#define ASM_ARGS_0
#define ASM_ARGS_1 ASM_ARGS_0, "3" (_out0)
#define ASM_ARGS_2 ASM_ARGS_1, "4" (_out1)
#define ASM_ARGS_3 ASM_ARGS_2, "5" (_out2)
#define ASM_ARGS_4 ASM_ARGS_3, "6" (_out3)
#define ASM_ARGS_5 ASM_ARGS_4, "7" (_out4)
#define ASM_ARGS_6 ASM_ARGS_5, "8" (_out5)
#define ASM_CLOBBERS_6 , "out6", "out7", \
/* Non-stacked integer registers, minus r8, r10, r15. */ \
"r2", "r3", "r9", "r11", "r12", "r13", "r14", "r16", "r17", "r18", \
"r19", "r20", "r21", "r22", "r23", "r24", "r25", "r26", "r27", \
"r28", "r29", "r30", "r31", \
/* Predicate registers. */ \
"p6", "p7", "p8", "p9", "p10", "p11", "p12", "p13", "p14", "p15", \
/* Non-rotating fp registers. */ \
"f6", "f7", "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \
/* Branch registers. */ \
"b6", "b7"
#define LOAD_ARGS_0() do { } while (0)
#define LOAD_ARGS_1(out0) \
register long _out0 asm ("out0") = (long) (out0); \
LOAD_ARGS_0 ()
#define LOAD_ARGS_2(out0, out1) \
register long _out1 asm ("out1") = (long) (out1); \
LOAD_ARGS_1 (out0)
#define LOAD_ARGS_3(out0, out1, out2) \
register long _out2 asm ("out2") = (long) (out2); \
LOAD_ARGS_2 (out0, out1)
#define LOAD_ARGS_4(out0, out1, out2, out3) \
register long _out3 asm ("out3") = (long) (out3); \
LOAD_ARGS_3 (out0, out1, out2)
#define LOAD_ARGS_5(out0, out1, out2, out3, out4) \
register long _out4 asm ("out4") = (long) (out4); \
LOAD_ARGS_4 (out0, out1, out2, out3)
#define LOAD_ARGS_6(out0, out1, out2, out3, out4, out5) \
register long _out5 asm ("out5") = (long) (out5); \
LOAD_ARGS_5 (out0, out1, out2, out3, out4)
// END OF GNU LIBC EXCERPT
static inline int
clone (int flags, ...)
{
return INLINE_SYSCALL (clone2, 6, flags, NULL, 0, NULL, NULL, NULL);
}
int
main()
{
errno = 0;
int ret = clone(CLONE_NEWNS|SIGCHLD, 0);
int e = errno;
printf("%d %d(%s) %d %d\n", ret, e, strerror(e), getpid(), getppid());
return 0;
}
--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
