Linux-Clone/Clone.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include <sys/errno.h>
#include <sys/mman.h>

#undef _GNU_SOURCE
#define _GNU_SOURCE
#include <sched.h>
#include <unistd.h>
#include <sys/syscall.h>

#ifdef SYS_kcmp
  #include <linux/kcmp.h>
  #define kcmp(pid1,pid2,type,idx1,idx2) \
    syscall (SYS_kcmp, (pid_t)pid1, (pid_t)pid2, \
             (int)type, (unsigned long)idx1, (unsigned long)idx2)
#else
  #define kcmp(pid1,pid2,type,idx1,idx2) \
    (errno = ENOSYS, -1)
#endif

/* from schmorp.h */
static int
s_fileno (SV *fh, int wr)
{
  dTHX;
  SvGETMAGIC (fh);

  if (SvROK (fh))
    {
      fh = SvRV (fh);
      SvGETMAGIC (fh);
    }

  if (SvTYPE (fh) == SVt_PVGV)
    return PerlIO_fileno (wr ? IoOFP (sv_2io (fh)) : IoIFP (sv_2io (fh)));

  if (SvOK (fh) && (SvIV (fh) >= 0) && (SvIV (fh) < 0x7fffffffL))
    return SvIV (fh);

  return -1;
}

static int
clone_cb (void *arg)
{
  dSP;

  PUSHMARK (SP);

  PUTBACK;
  int count = call_sv (sv_2mortal ((SV *)arg), G_SCALAR);
  SPAGAIN;
  int retval = count ? SvIV (POPs) : 0;
  PUTBACK;

  return retval;
}

MODULE = Linux::Clone           PACKAGE = Linux::Clone

PROTOTYPES: ENABLE

BOOT:
  HV *stash = gv_stashpv ("Linux::Clone", 1);

  static const struct {
    const char *name;
    IV iv;
  } *civ, const_iv[] = {
#   define const_iv(name) { # name, (IV)name },
#   ifdef CLONE_FILES
      const_iv (CLONE_FILES)
#   endif
#   ifdef CLONE_FS
      const_iv (CLONE_FS)
#   endif
#   ifdef CLONE_NEWNS
      const_iv (CLONE_NEWNS)
#   endif
#   ifdef CLONE_VM
      const_iv (CLONE_VM)
#   endif
#   ifdef CLONE_THREAD
      const_iv (CLONE_THREAD)
#   endif
#   ifdef CLONE_SIGHAND
      const_iv (CLONE_SIGHAND)
#   endif
#   ifdef CLONE_SYSVSEM
      const_iv (CLONE_SYSVSEM)
#   endif
#   ifdef CLONE_NEWUTS
      const_iv (CLONE_NEWUTS)
#   endif
#   ifdef CLONE_NEWIPC
      const_iv (CLONE_NEWIPC)
#   endif
#   ifdef CLONE_NEWNET
      const_iv (CLONE_NEWNET)
#   endif
#   ifdef CLONE_PTRACE
      const_iv (CLONE_PTRACE)
#   endif
#   ifdef CLONE_VFORK
      const_iv (CLONE_VFORK)
#   endif
#   ifdef CLONE_SETTLS
      const_iv (CLONE_SETTLS)
#   endif
#   ifdef CLONE_PARENT_SETTID
      const_iv (CLONE_PARENT_SETTID)
#   endif
#   ifdef CLONE_CHILD_CLEARTID
      const_iv (CLONE_CHILD_CLEARTID)
#   endif
#   ifdef CLONE_DETACHED
      const_iv (CLONE_DETACHED)
#   endif
#   ifdef CLONE_UNTRACED
      const_iv (CLONE_UNTRACED)
#   endif
#   ifdef CLONE_CHILD_SETTID
      const_iv (CLONE_CHILD_SETTID)
#   endif
#   ifdef CLONE_NEWUSER
      const_iv (CLONE_NEWUSER)
#   endif
#   ifdef CLONE_NEWPID
      const_iv (CLONE_NEWPID)
#   endif
#   ifdef CLONE_IO
      const_iv (CLONE_IO)
#   endif
#   ifdef CLONE_NEWCGROUP
      const_iv (CLONE_NEWCGROUP)
#   endif
#   ifdef SYS_kcmp
      const_iv (KCMP_FILE)
      const_iv (KCMP_VM)
      const_iv (KCMP_FILES)
      const_iv (KCMP_FS)
      const_iv (KCMP_SIGHAND)
      const_iv (KCMP_IO)
      const_iv (KCMP_SYSVSEM)
      const_iv (KCMP_FILE)
#   endif
  };

  for (civ = const_iv + sizeof (const_iv) / sizeof (const_iv [0]); civ > const_iv; civ--)
    newCONSTSUB (stash, (char *)civ[-1].name, newSViv (civ[-1].iv));

int
clone (SV *sub, IV stacksize, int flags, SV *ptid = 0, SV *tls = &PL_sv_undef)
        CODE:
{
        if (!stacksize)
          stacksize = 4 << 20;

        pid_t ptid_;
        char *stack_ptr = mmap (0, stacksize, PROT_EXEC | PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN | MAP_STACK, -1, 0);

        #ifndef __hppa
          stack_ptr += stacksize - 16; /* be safe and put the sp at 16 bytes below the end */
        #endif

        RETVAL = -1;
        if (stack_ptr != (void *)-1)
          {
            SV *my_sub = newSVsv (sub);
            
            RETVAL = clone (clone_cb, (void *)stack_ptr, flags, (void *)my_sub, &ptid, SvOK (tls) ? SvPV_nolen (tls) : 0, 0);

            if (ptid) sv_setiv (ptid, (IV)ptid_);

            if ((flags & (CLONE_VM | CLONE_VFORK)) != CLONE_VM)
              {
                int old_errno = errno;
                munmap (stack_ptr, stacksize);
                errno = old_errno;
              }
          }
}
        OUTPUT:
        RETVAL

int
unshare (int flags)

int
setns (SV *fh_or_fd, int nstype = 0)
        C_ARGS: s_fileno (fh_or_fd, 0), nstype

int
pivot_root (SV *new_root, SV *old_root)
        CODE:
        RETVAL = syscall (SYS_pivot_root,
                          (const char *)SvPVbyte_nolen (new_root),
                          (const char *)SvPVbyte_nolen (old_root));
        OUTPUT:
        RETVAL

int
kcmp (IV pid1, IV pid2, IV type, UV idx1 = 0, UV idx2 = 0)

Revision:	1.3
Committed:	Thu Nov 2 07:31:16 2017 UTC (8 years, 10 months ago) by root
Branch:	MAIN
CVS Tags:	rel-1_1
Changes since 1.2:	+58 -23 lines
Log Message:	1.1
#	User	Rev	Content
1	root	1.1	#include "EXTERN.h"
2			#include "perl.h"
3			#include "XSUB.h"
4
5			#include <sys/errno.h>
6			#include <sys/mman.h>
7
8			#undef _GNU_SOURCE
9			#define _GNU_SOURCE
10			#include <sched.h>
11	root	1.3	#include <unistd.h>
12			#include <sys/syscall.h>
13
14			#ifdef SYS_kcmp
15			#include <linux/kcmp.h>
16			#define kcmp(pid1,pid2,type,idx1,idx2) \
17			syscall (SYS_kcmp, (pid_t)pid1, (pid_t)pid2, \
18			(int)type, (unsigned long)idx1, (unsigned long)idx2)
19			#else
20			#define kcmp(pid1,pid2,type,idx1,idx2) \
21			(errno = ENOSYS, -1)
22			#endif
23	root	1.1
24	root	1.2	/* from schmorp.h */
25			static int
26			s_fileno (SV *fh, int wr)
27			{
28			dTHX;
29			SvGETMAGIC (fh);
30
31			if (SvROK (fh))
32			{
33			fh = SvRV (fh);
34			SvGETMAGIC (fh);
35			}
36
37			if (SvTYPE (fh) == SVt_PVGV)
38			return PerlIO_fileno (wr ? IoOFP (sv_2io (fh)) : IoIFP (sv_2io (fh)));
39
40			if (SvOK (fh) && (SvIV (fh) >= 0) && (SvIV (fh) < 0x7fffffffL))
41			return SvIV (fh);
42
43			return -1;
44			}
45
46	root	1.1	static int
47			clone_cb (void *arg)
48			{
49			dSP;
50
51			PUSHMARK (SP);
52
53			PUTBACK;
54			int count = call_sv (sv_2mortal ((SV *)arg), G_SCALAR);
55			SPAGAIN;
56			int retval = count ? SvIV (POPs) : 0;
57			PUTBACK;
58
59			return retval;
60			}
61
62			MODULE = Linux::Clone PACKAGE = Linux::Clone
63
64			PROTOTYPES: ENABLE
65
66			BOOT:
67			HV *stash = gv_stashpv ("Linux::Clone", 1);
68
69			static const struct {
70			const char *name;
71			IV iv;
72			} *civ, const_iv[] = {
73	root	1.3	# define const_iv(name) { # name, (IV)name },
74	root	1.1	# ifdef CLONE_FILES
75	root	1.3	const_iv (CLONE_FILES)
76	root	1.1	# endif
77			# ifdef CLONE_FS
78	root	1.3	const_iv (CLONE_FS)
79	root	1.1	# endif
80			# ifdef CLONE_NEWNS
81	root	1.3	const_iv (CLONE_NEWNS)
82	root	1.1	# endif
83			# ifdef CLONE_VM
84	root	1.3	const_iv (CLONE_VM)
85	root	1.1	# endif
86			# ifdef CLONE_THREAD
87	root	1.3	const_iv (CLONE_THREAD)
88	root	1.1	# endif
89			# ifdef CLONE_SIGHAND
90	root	1.3	const_iv (CLONE_SIGHAND)
91	root	1.1	# endif
92			# ifdef CLONE_SYSVSEM
93	root	1.3	const_iv (CLONE_SYSVSEM)
94	root	1.1	# endif
95			# ifdef CLONE_NEWUTS
96	root	1.3	const_iv (CLONE_NEWUTS)
97	root	1.1	# endif
98			# ifdef CLONE_NEWIPC
99	root	1.3	const_iv (CLONE_NEWIPC)
100	root	1.1	# endif
101			# ifdef CLONE_NEWNET
102	root	1.3	const_iv (CLONE_NEWNET)
103	root	1.1	# endif
104			# ifdef CLONE_PTRACE
105	root	1.3	const_iv (CLONE_PTRACE)
106	root	1.1	# endif
107			# ifdef CLONE_VFORK
108	root	1.3	const_iv (CLONE_VFORK)
109	root	1.1	# endif
110			# ifdef CLONE_SETTLS
111	root	1.3	const_iv (CLONE_SETTLS)
112	root	1.1	# endif
113			# ifdef CLONE_PARENT_SETTID
114	root	1.3	const_iv (CLONE_PARENT_SETTID)
115	root	1.1	# endif
116			# ifdef CLONE_CHILD_CLEARTID
117	root	1.3	const_iv (CLONE_CHILD_CLEARTID)
118	root	1.1	# endif
119			# ifdef CLONE_DETACHED
120	root	1.3	const_iv (CLONE_DETACHED)
121	root	1.1	# endif
122			# ifdef CLONE_UNTRACED
123	root	1.3	const_iv (CLONE_UNTRACED)
124	root	1.1	# endif
125			# ifdef CLONE_CHILD_SETTID
126	root	1.3	const_iv (CLONE_CHILD_SETTID)
127	root	1.1	# endif
128			# ifdef CLONE_NEWUSER
129	root	1.3	const_iv (CLONE_NEWUSER)
130	root	1.1	# endif
131			# ifdef CLONE_NEWPID
132	root	1.3	const_iv (CLONE_NEWPID)
133	root	1.1	# endif
134			# ifdef CLONE_IO
135	root	1.3	const_iv (CLONE_IO)
136	root	1.1	# endif
137	root	1.2	# ifdef CLONE_NEWCGROUP
138	root	1.3	const_iv (CLONE_NEWCGROUP)
139			# endif
140			# ifdef SYS_kcmp
141			const_iv (KCMP_FILE)
142			const_iv (KCMP_VM)
143			const_iv (KCMP_FILES)
144			const_iv (KCMP_FS)
145			const_iv (KCMP_SIGHAND)
146			const_iv (KCMP_IO)
147			const_iv (KCMP_SYSVSEM)
148			const_iv (KCMP_FILE)
149	root	1.2	# endif
150	root	1.1	};
151
152			for (civ = const_iv + sizeof (const_iv) / sizeof (const_iv [0]); civ > const_iv; civ--)
153			newCONSTSUB (stash, (char *)civ[-1].name, newSViv (civ[-1].iv));
154
155			int
156			clone (SV sub, IV stacksize, int flags, SV ptid = 0, SV *tls = &PL_sv_undef)
157			CODE:
158			{
159	root	1.2	if (!stacksize)
160	root	1.1	stacksize = 4 << 20;
161
162			pid_t ptid_;
163			char *stack_ptr = mmap (0, stacksize, PROT_EXEC \| PROT_READ \| PROT_WRITE, MAP_PRIVATE \| MAP_ANONYMOUS \| MAP_GROWSDOWN \| MAP_STACK, -1, 0);
164
165			#ifndef __hppa
166			stack_ptr += stacksize - 16; /* be safe and put the sp at 16 bytes below the end */
167			#endif
168
169			RETVAL = -1;
170			if (stack_ptr != (void *)-1)
171			{
172			SV *my_sub = newSVsv (sub);
173
174			RETVAL = clone (clone_cb, (void )stack_ptr, flags, (void )my_sub, &ptid, SvOK (tls) ? SvPV_nolen (tls) : 0, 0);
175
176			if (ptid) sv_setiv (ptid, (IV)ptid_);
177
178			if ((flags & (CLONE_VM \| CLONE_VFORK)) != CLONE_VM)
179			{
180			int old_errno = errno;
181			munmap (stack_ptr, stacksize);
182			errno = old_errno;
183			}
184			}
185			}
186			OUTPUT:
187			RETVAL
188
189	root	1.2	int
190			unshare (int flags)
191
192			int
193			setns (SV *fh_or_fd, int nstype = 0)
194			C_ARGS: s_fileno (fh_or_fd, 0), nstype
195	root	1.3
196			int
197			pivot_root (SV new_root, SV old_root)
198			CODE:
199			RETVAL = syscall (SYS_pivot_root,
200			(const char *)SvPVbyte_nolen (new_root),
201			(const char *)SvPVbyte_nolen (old_root));
202			OUTPUT:
203			RETVAL
204
205			int
206			kcmp (IV pid1, IV pid2, IV type, UV idx1 = 0, UV idx2 = 0)
207