diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/spawni.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/spawni.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/sysdeps/unix/sysv/linux/spawni.c b/sysdeps/unix/sysv/linux/spawni.c index f0d4c62..8d5aefe 100644 --- a/sysdeps/unix/sysv/linux/spawni.c +++ b/sysdeps/unix/sysv/linux/spawni.c @@ -68,6 +68,7 @@ struct posix_spawn_args int xflags; bool use_clone3; int err; + int pidfd; }; /* Older version requires that shell script without shebang definition @@ -309,7 +310,7 @@ fail: /* Spawn a new process executing PATH with the attributes describes in *ATTRP. Before running the process perform the actions described in FILE-ACTIONS. */ static int -__spawnix (pid_t * pid, const char *file, +__spawnix (int *pid, const char *file, const posix_spawn_file_actions_t * file_actions, const posix_spawnattr_t * attrp, char *const argv[], char *const envp[], int xflags, @@ -319,6 +320,17 @@ __spawnix (pid_t * pid, const char *file, struct posix_spawn_args args; int ec; + bool use_pidfd = xflags & SPAWN_XFLAGS_RET_PIDFD; + + /* For CLONE_PIDFD, older kernels might not fail with unsupported flags or + some versions might not support waitid (P_PIDFD). So to avoid the need + to handle the error on the helper process, check for full pidfd + support. + ENOSYS is returned because without proper waitid support, pidfd_spawn + can not be used proporly independently of its arguments. */ + if (use_pidfd && !__clone_pidfd_supported ()) + return ENOSYS; + /* To avoid imposing hard limits on posix_spawn{p} the total number of arguments is first calculated to allocate a mmap to hold all possible values. */ @@ -368,6 +380,7 @@ __spawnix (pid_t * pid, const char *file, args.argv = argv; args.argc = argc; args.envp = envp; + args.pidfd = 0; args.xflags = xflags; internal_signal_block_all (&args.oldmask); @@ -386,13 +399,18 @@ __spawnix (pid_t * pid, const char *file, /* Unsupported flags like CLONE_CLEAR_SIGHAND will be cleared up by __clone_internal_fallback. */ .flags = (set_cgroup ? CLONE_INTO_CGROUP : 0) + | (use_pidfd ? CLONE_PIDFD : 0) | CLONE_CLEAR_SIGHAND | CLONE_VM | CLONE_VFORK, .exit_signal = SIGCHLD, .stack = (uintptr_t) stack, .stack_size = stack_size, - .cgroup = (set_cgroup ? attrp->__cgroup : 0) + .cgroup = (set_cgroup ? attrp->__cgroup : 0), + .pidfd = use_pidfd ? (uintptr_t) &args.pidfd : 0, + /* This is require for clone fallback, where pidfd is returned + on parent_tid. */ + .parent_tid = use_pidfd ? (uintptr_t) &args.pidfd : 0, }; #ifdef HAVE_CLONE3_WRAPPER args.use_clone3 = true; @@ -445,7 +463,7 @@ __spawnix (pid_t * pid, const char *file, __munmap (stack, stack_size); if ((ec == 0) && (pid != NULL)) - *pid = new_pid; + *pid = use_pidfd ? args.pidfd : new_pid; internal_signal_restore_set (&args.oldmask); |