Off-by-one error: the stack address passed to clone/clone_with_pids must be within the region allocated. (Also, arithmetic on void * is a gcc extension; change the relevant variables to char *).
Signed-off-by: Nathan Lynch <[email protected]> --- mktree.c | 15 ++++++++------- 1 files changed, 8 insertions(+), 7 deletions(-) diff --git a/mktree.c b/mktree.c index 63be82d..2d8d796 100644 --- a/mktree.c +++ b/mktree.c @@ -1367,18 +1367,19 @@ int ckpt_fork_stub(void *data) static pid_t ckpt_fork_child(struct ckpt_ctx *ctx, struct task *child) { struct target_pid_set pid_set; - void *stack = NULL; + char *stack_region; + char *stack_start; unsigned long flags = SIGCHLD; pid_t pid = 0; ckpt_dbg("forking child vpid %d flags %#x\n", child->pid, child->flags); - stack = malloc(PTHREAD_STACK_MIN); - if (!stack) { + stack_region = malloc(PTHREAD_STACK_MIN); + if (!stack_region) { perror("stack malloc"); return -1; } - stack += PTHREAD_STACK_MIN; + stack_start = stack_region + PTHREAD_STACK_MIN - 1; pid_set.target_pids = &pid; pid_set.num_pids = 1; @@ -1406,15 +1407,15 @@ 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, flags, &pid_set, child); + pid = clone_with_pids(ckpt_fork_stub, stack_start, flags, &pid_set, child); if (pid < 0) { perror("clone"); - free(stack - PTHREAD_STACK_MIN); + free(stack_region); return -1; } if (!(child->flags & TASK_THREAD)) - free(stack - PTHREAD_STACK_MIN); + free(stack_region); ckpt_dbg("forked child vpid %d (asked %d)\n", pid, child->pid); return pid; -- 1.6.0.6 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
