X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Ffork.c;h=8149f3602881db80727310245436c97a661adf2a;hb=b01ef8ffafc5239a871bc24af74f604654e7de2b;hp=b65187f0c74e720281ff6f08b98e3bef19e638c4;hpb=c514720716c7b109ff980f8b3cb93f9af872c91c;p=linux-2.6 diff --git a/kernel/fork.c b/kernel/fork.c index b65187f0c7..8149f36028 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include #include @@ -176,6 +177,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) /* One for us, one for whoever does the "release_task()" (usually parent) */ atomic_set(&tsk->usage,2); + atomic_set(&tsk->fs_excl, 0); return tsk; } @@ -564,24 +566,53 @@ static inline int copy_fs(unsigned long clone_flags, struct task_struct * tsk) return 0; } -static int count_open_files(struct files_struct *files, int size) +static int count_open_files(struct fdtable *fdt) { + int size = fdt->max_fdset; int i; /* Find the last open fd */ for (i = size/(8*sizeof(long)); i > 0; ) { - if (files->open_fds->fds_bits[--i]) + if (fdt->open_fds->fds_bits[--i]) break; } i = (i+1) * 8 * sizeof(long); return i; } +static struct files_struct *alloc_files(void) +{ + struct files_struct *newf; + struct fdtable *fdt; + + newf = kmem_cache_alloc(files_cachep, SLAB_KERNEL); + if (!newf) + goto out; + + atomic_set(&newf->count, 1); + + spin_lock_init(&newf->file_lock); + fdt = &newf->fdtab; + fdt->next_fd = 0; + fdt->max_fds = NR_OPEN_DEFAULT; + fdt->max_fdset = __FD_SETSIZE; + fdt->close_on_exec = &newf->close_on_exec_init; + fdt->open_fds = &newf->open_fds_init; + fdt->fd = &newf->fd_array[0]; + INIT_RCU_HEAD(&fdt->rcu); + fdt->free_files = NULL; + fdt->next = NULL; + rcu_assign_pointer(newf->fdt, fdt); +out: + return newf; +} + static int copy_files(unsigned long clone_flags, struct task_struct * tsk) { struct files_struct *oldf, *newf; struct file **old_fds, **new_fds; int open_files, size, i, error = 0, expand; + struct fdtable *old_fdt, *new_fdt; /* * A background process may not have any files ... @@ -602,35 +633,27 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk) */ tsk->files = NULL; error = -ENOMEM; - newf = kmem_cache_alloc(files_cachep, SLAB_KERNEL); - if (!newf) + newf = alloc_files(); + if (!newf) goto out; - atomic_set(&newf->count, 1); - - spin_lock_init(&newf->file_lock); - newf->next_fd = 0; - newf->max_fds = NR_OPEN_DEFAULT; - newf->max_fdset = __FD_SETSIZE; - newf->close_on_exec = &newf->close_on_exec_init; - newf->open_fds = &newf->open_fds_init; - newf->fd = &newf->fd_array[0]; - spin_lock(&oldf->file_lock); - - open_files = count_open_files(oldf, oldf->max_fdset); + old_fdt = files_fdtable(oldf); + new_fdt = files_fdtable(newf); + size = old_fdt->max_fdset; + open_files = count_open_files(old_fdt); expand = 0; /* * Check whether we need to allocate a larger fd array or fd set. * Note: we're not a clone task, so the open count won't change. */ - if (open_files > newf->max_fdset) { - newf->max_fdset = 0; + if (open_files > new_fdt->max_fdset) { + new_fdt->max_fdset = 0; expand = 1; } - if (open_files > newf->max_fds) { - newf->max_fds = 0; + if (open_files > new_fdt->max_fds) { + new_fdt->max_fds = 0; expand = 1; } @@ -642,14 +665,21 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk) spin_unlock(&newf->file_lock); if (error < 0) goto out_release; + new_fdt = files_fdtable(newf); + /* + * Reacquire the oldf lock and a pointer to its fd table + * who knows it may have a new bigger fd table. We need + * the latest pointer. + */ spin_lock(&oldf->file_lock); + old_fdt = files_fdtable(oldf); } - old_fds = oldf->fd; - new_fds = newf->fd; + old_fds = old_fdt->fd; + new_fds = new_fdt->fd; - memcpy(newf->open_fds->fds_bits, oldf->open_fds->fds_bits, open_files/8); - memcpy(newf->close_on_exec->fds_bits, oldf->close_on_exec->fds_bits, open_files/8); + memcpy(new_fdt->open_fds->fds_bits, old_fdt->open_fds->fds_bits, open_files/8); + memcpy(new_fdt->close_on_exec->fds_bits, old_fdt->close_on_exec->fds_bits, open_files/8); for (i = open_files; i != 0; i--) { struct file *f = *old_fds++; @@ -662,24 +692,24 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk) * is partway through open(). So make sure that this * fd is available to the new process. */ - FD_CLR(open_files - i, newf->open_fds); + FD_CLR(open_files - i, new_fdt->open_fds); } - *new_fds++ = f; + rcu_assign_pointer(*new_fds++, f); } spin_unlock(&oldf->file_lock); /* compute the remainder to be cleared */ - size = (newf->max_fds - open_files) * sizeof(struct file *); + size = (new_fdt->max_fds - open_files) * sizeof(struct file *); /* This is long word aligned thus could use a optimized version */ memset(new_fds, 0, size); - if (newf->max_fdset > open_files) { - int left = (newf->max_fdset-open_files)/8; + if (new_fdt->max_fdset > open_files) { + int left = (new_fdt->max_fdset-open_files)/8; int start = open_files / (8 * sizeof(unsigned long)); - memset(&newf->open_fds->fds_bits[start], 0, left); - memset(&newf->close_on_exec->fds_bits[start], 0, left); + memset(&new_fdt->open_fds->fds_bits[start], 0, left); + memset(&new_fdt->close_on_exec->fds_bits[start], 0, left); } tsk->files = newf; @@ -688,9 +718,9 @@ out: return error; out_release: - free_fdset (newf->close_on_exec, newf->max_fdset); - free_fdset (newf->open_fds, newf->max_fdset); - free_fd_array(newf->fd, newf->max_fds); + free_fdset (new_fdt->close_on_exec, new_fdt->max_fdset); + free_fdset (new_fdt->open_fds, new_fdt->max_fdset); + free_fd_array(new_fdt->fd, new_fdt->max_fds); kmem_cache_free(files_cachep, newf); goto out; } @@ -994,6 +1024,9 @@ static task_t *copy_process(unsigned long clone_flags, * of CLONE_PTRACE. */ clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE); +#ifdef TIF_SYSCALL_EMU + clear_tsk_thread_flag(p, TIF_SYSCALL_EMU); +#endif /* Our parent execution domain becomes current domain These must match for thread signalling to apply */ @@ -1112,6 +1145,9 @@ static task_t *copy_process(unsigned long clone_flags, __get_cpu_var(process_counts)++; } + if (!current->signal->tty && p->signal->tty) + p->signal->tty = NULL; + nr_threads++; total_forks++; write_unlock_irq(&tasklist_lock);