This patch:
1. changes restart to pass the right values to
clone-with-pids.
2. updates the clone_s390x.c to work with the
new kernel.
All tests under cr_tests/ pass with this patch.
Signed-off-by: Serge E. Hallyn <[email protected]>
---
clone_s390x.c | 92 +++++++++++++++++++++++++++++++++++++--------------------
restart.c | 14 +++++----
2 files changed, 68 insertions(+), 38 deletions(-)
diff --git a/clone_s390x.c b/clone_s390x.c
index dada822..71cf52f 100644
--- a/clone_s390x.c
+++ b/clone_s390x.c
@@ -14,6 +14,7 @@
#include <unistd.h>
#include <errno.h>
+#include <string.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include <asm/unistd.h>
@@ -25,48 +26,75 @@
#include <linux/checkpoint.h>
#if defined(__NR_clone_with_pids)
-/* this really belongs to some kernel header ! */
struct pid_set {
int num_pids;
pid_t *pids;
};
-/* (see: http://lkml.indiana.edu/hypermail/linux/kernel/9604.3/0204.html) */
+typedef unsigned long long u64;
+typedef unsigned int u32;
+typedef int pid_t;
+struct clone_args {
+ u64 clone_flags_high;
-#define do_clone_with_pids(stack, flags, ptid, ctid, setp) ({ \
- register unsigned long int __r2 asm ("2") = (unsigned long int)(stack);\
- register unsigned long int __r3 asm ("3") = (unsigned long int)(flags);\
- register unsigned long int __r4 asm ("4") = (unsigned long int)(ptid); \
- register unsigned long int __r5 asm ("5") = (unsigned long int)(ctid); \
- register unsigned long int __r6 asm ("6") = (unsigned long int)(NULL); \
- register unsigned long int __r7 asm ("7") = (unsigned long int)(setp); \
- register unsigned long int __result asm ("2"); \
- __asm__ __volatile__( \
- " lghi %%r1,%7\n" \
- " svc 0\n" \
- : "=d" (__result) \
- : "0" (__r2), "d" (__r3), \
- "d" (__r4), "d" (__r5), "d" (__r6), "d" (__r7), \
- "i" (__NR_clone_with_pids) \
- : "1", "cc", "memory" \
- ); \
- __result; \
- })
+ u64 child_stack_base;
+ u64 child_stack_size;
-int clone_with_pids(int (*fn)(void *), void *child_stack, int flags,
+ u64 parent_tid_ptr;
+ u64 child_tid_ptr;
+
+ u32 nr_pids;
+
+ u32 reserved0;
+ u64 reserved1;
+};
+
+#define do_cwp(flags, pids, args, sz) \
+( { \
+ register unsigned long int __r1 asm ("1") = (unsigned long
int)(__NR_clone_with_pids); \
+ 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_cwp 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 clone_with_pids(int (*fn)(void *), void *child_stack,
+ unsigned long stack_size, unsigned long flags,
struct pid_set *target_pids, void *arg)
{
- long retval;
- retval = do_clone_with_pids(child_stack, flags, NULL, NULL,
- target_pids);
+ struct clone_args clone_args, *ca = &clone_args;
+ u64 *s;
+
+ memset(ca, 0, sizeof(struct clone_args));
+ ca->nr_pids = target_pids->num_pids;
+ ca->child_stack_size = stack_size - 16;
+ ca->child_stack_base = (u64) child_stack;
+ if (child_stack) {
+ s = (u64 *) (ca->child_stack_base + ca->child_stack_size);
+ *--s = (u64) arg;
+ *--s = (u64) fn;
+ ca->child_stack_size -= 16;
+ }
- if (retval < 0) {
- errno = -retval;
- return -1;
- } else if (retval == 0) {
- return fn(arg);
- } else
- return retval;
+ return do_cwp(flags, target_pids->pids, ca,
+ sizeof(struct clone_args));
}
#endif /* !defined(__NR_clone_with_pids) */
diff --git a/restart.c b/restart.c
index 35c54ea..ebc7bf8 100644
--- a/restart.c
+++ b/restart.c
@@ -43,10 +43,12 @@ struct pid_set {
/* (until it's supported by libc) from clone_ARCH.c */
#if defined(__NR_clone_with_pids) && defined(ARCH_HAS_CLONE_WITH_PID)
-extern int clone_with_pids(int (*fn)(void *), void *child_stack, int flags,
+extern int clone_with_pids(int (*fn)(void *), void *child_stack,
+ unsigned long stack_size, int flags,
struct pid_set *target_pids, void *arg);
#else
-static int clone_with_pids(int (*fn)(void *), void *child_stack, int flags,
+static int clone_with_pids(int (*fn)(void *), void *child_stack,
+ unsigned long stack_size, int flags,
struct pid_set *target_pids, void *arg)
{
return clone(fn, child_stack, flags, arg);
@@ -1749,18 +1751,17 @@ static pid_t ckpt_fork_child(struct ckpt_ctx *ctx,
struct task *child)
{
struct pid_set pid_set;
char *stack_region;
- char *stack_start;
unsigned long flags = SIGCHLD;
+ unsigned long stack_size = PTHREAD_STACK_MIN;
pid_t pid = 0;
ckpt_dbg("forking child vpid %d flags %#x\n", child->pid, child->flags);
- stack_region = malloc(PTHREAD_STACK_MIN);
+ stack_region = malloc(stack_size);
if (!stack_region) {
perror("stack malloc");
return -1;
}
- stack_start = stack_region + PTHREAD_STACK_MIN - 1;
pid_set.pids = &pid;
pid_set.num_pids = 1;
@@ -1788,7 +1789,8 @@ static pid_t ckpt_fork_child(struct ckpt_ctx *ctx, struct
task *child)
else
child->real_parent = _getpid();
- pid = clone_with_pids(ckpt_fork_stub, stack_start, flags, &pid_set,
child);
+ pid = clone_with_pids(ckpt_fork_stub, stack_region, stack_size - 16,
+ flags, &pid_set, child);
if (pid < 0) {
perror("clone");
free(stack_region);
--
1.6.1.1
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