Based on original work from Serge Hallyn.
Signed-off-by: Nathan Lynch <ntl@xxxxxxxxx>
---
clone_s390x.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 62 insertions(+), 0 deletions(-)
diff --git a/clone_s390x.c b/clone_s390x.c
index dada822..5ed6f15 100644
--- a/clone_s390x.c
+++ b/clone_s390x.c
@@ -70,3 +70,65 @@ int clone_with_pids(int (*fn)(void *), void *child_stack, int flags,
}
#endif /* !defined(__NR_clone_with_pids) */
+
+#include "eclone.h"
+
+#ifndef __NR_eclone
+#define __NR_eclone 332
+#endif
+
+typedef unsigned long long u64;
+
+#define do_eclone(flags, pids, args, sz) \
+( { \
+ register unsigned long int __r1 asm ("1") = (unsigned long int)(__NR_eclone);
+ register unsigned long int __r2 asm ("2") = (unsigned long int)(flags); \
+ register unsigned long int __r3 asm ("3") = (unsigned long int)(args); \
+ register unsigned long int __r4 asm ("4") = (unsigned long int)(sz); \
+ register unsigned long int __r5 asm ("5") = (unsigned long int)(pids); \
+ register long int __result asm ("2"); \
+ __asm__ __volatile__( \
+ " svc 0\n" /* do __NR_eclone syscall */ \
+ " ltgr %%r2,%%r2\n" /* returned 0? */ \
+ " jnz 1f\n" /* if not goto label 1 */ \
+ " lg %%r3,0(%%r15)\n" /* get fnarg off stack into arg 1 */ \
+ " lg %%r2,8(%%r15)\n" /* get fn off stack int r3 basr*/ \
+ " lgr %%r1,%%r15\n" /* tmp store old stack pointer */ \
+ " aghi %%r15,-160\n" /* move the stack */ \
+ " stg %%r1,0(%%r15)\n" /* and save old stack pointer */ \
+ " basr %%r14,%%r3\n" /* call fn(arg) */ \
+ " svc 1\n" /* call exit */ \
+ " 1:\n" \
+ : "=d" (__result) \
+ : "d" (__r1), "0" (__r2), "d" (__r3), "d" (__r4), "d" (__r5) \
+ : "memory"); \
+ __result; \
+} )
+
+int eclone(int (*fn)(void *), void *fn_arg, int clone_flags_low,
+ struct clone_args *clone_args, pid_t *pids)
+{
+ struct clone_args my_args;
+ u64 *child_sp;
+ int rc;
+
+ if (clone_args->child_stack) {
+ child_sp = (void *)(clone_args->child_stack +
+ clone_args->child_stack_size);
+ *--child_sp = (u64)fn_arg;
+ *--child_sp = (u64)fn;
+ } else
+ child_sp = (u64 *)0;
+
+ my_args = *clone_args;
+ my_args.child_stack = (unsigned long)child_sp;
+ my_args.child_stack_size = 0;
+
+ rc = do_eclone(flags, pids, &my_args, sizeof(struct clone_args));
+ if (rc < 0) {
+ errno = rc;
+ rc = -1;
+ }
+
+ return rc;
+}
--
1.6.2.5
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