diff options
Diffstat (limited to 'sys/kern/kern_spawn.c')
| -rw-r--r-- | sys/kern/kern_spawn.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/sys/kern/kern_spawn.c b/sys/kern/kern_spawn.c new file mode 100644 index 0000000..2cddd84 --- /dev/null +++ b/sys/kern/kern_spawn.c @@ -0,0 +1,212 @@ +/* + * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/proc.h> +#include <sys/exec.h> +#include <sys/mman.h> +#include <sys/systm.h> +#include <sys/errno.h> +#include <sys/syslog.h> +#include <sys/syscall.h> +#include <sys/atomic.h> +#include <sys/signal.h> +#include <sys/limits.h> +#include <sys/sched.h> +#include <vm/dynalloc.h> +#include <string.h> + +#define pr_trace(fmt, ...) kprintf("spawn: " fmt, ##__VA_ARGS__) +#define pr_error(...) pr_trace(__VA_ARGS__) + +static volatile size_t nthreads = 0; + +struct spawn_args { + char path[PATH_MAX]; +}; + +static inline void +try_free_data(void *p) +{ + if (p != NULL) { + dynfree(p); + } +} + +static void +spawn_thunk(void) +{ + const char *path; + char pathbuf[PATH_MAX]; + struct proc *cur; + struct execve_args execve_args; + struct spawn_args *args; + char *argv[] = { NULL, NULL }; + char *envp[] = { NULL }; + + cur = this_td(); + args = cur->spawn_data; + path = args->path; + memcpy(pathbuf, path, strlen(path)); + + argv[0] = (char *)pathbuf; + execve_args.pathname = argv[0]; + execve_args.argv = argv; + execve_args.envp = envp; + + path = NULL; + dynfree(args); + execve(cur, &execve_args); + __builtin_unreachable(); +} + +/* + * Spawn a new process + * + * @cur: Parent (current) process. + * @func: Address of start code. + * @p: Data to pass to new process (used for user procs) + * @flags: Spawn flags. + * @newprocp: If not NULL, will contain the new process. + * + * Returns the PID of the child on success, otherwise an + * errno value that is less than zero. + * + * XXX: `p` is only used by sys_spawn and should be set + * to NULL if called in the kernel. + */ +pid_t +spawn(struct proc *cur, void(*func)(void), void *p, int flags, struct proc **newprocp) +{ + struct proc *newproc; + struct mmap_lgdr *mlgdr; + int error; + + newproc = dynalloc(sizeof(*newproc)); + if (newproc == NULL) { + pr_error("could not alloc proc (-ENOMEM)\n"); + try_free_data(p); + return -ENOMEM; + } + + mlgdr = dynalloc(sizeof(*mlgdr)); + if (mlgdr == NULL) { + dynfree(newproc); + try_free_data(p); + pr_error("could not alloc proc mlgdr (-ENOMEM)\n"); + return -ENOMEM; + } + + memset(newproc, 0, sizeof(*newproc)); + error = md_spawn(newproc, cur, (uintptr_t)func); + if (error < 0) { + dynfree(newproc); + dynfree(mlgdr); + try_free_data(p); + pr_error("error initializing proc\n"); + return error; + } + + /* Set proc output if we can */ + if (newprocp != NULL) { + *newprocp = newproc; + } + + if (!ISSET(cur->flags, PROC_LEAFQ)) { + TAILQ_INIT(&cur->leafq); + cur->flags |= PROC_LEAFQ; + } + + /* Add to parent leafq */ + TAILQ_INSERT_TAIL(&cur->leafq, newproc, leaf_link); + atomic_inc_int(&cur->nleaves); + newproc->parent = cur; + newproc->spawn_data = p; + + /* Initialize the mmap ledger */ + mlgdr->nbytes = 0; + RBT_INIT(lgdr_entries, &mlgdr->hd); + newproc->mlgdr = mlgdr; + + newproc->pid = ++nthreads; + signals_init(newproc); + sched_enqueue_td(newproc); + return newproc->pid; +} + +/* + * Get the child of a process by PID. + * + * @cur: Parent process. + * @pid: Child PID. + * + * Returns NULL if no child was found. + */ +struct proc * +get_child(struct proc *cur, pid_t pid) +{ + struct proc *procp; + + TAILQ_FOREACH(procp, &cur->leafq, leaf_link) { + if (procp->pid == pid) { + return procp; + } + } + + return NULL; +} + +/* + * arg0: The file /path/to/executable + * arg1: Optional flags (`flags') + */ +scret_t +sys_spawn(struct syscall_args *scargs) +{ + struct spawn_args *args; + const char *u_path; + struct proc *td; + int flags, error; + + td = this_td(); + flags = scargs->arg1; + u_path = (const char *)scargs->arg0; + + args = dynalloc(sizeof(*args)); + if (args == NULL) { + return -ENOMEM; + } + + error = copyinstr(u_path, args->path, sizeof(args->path)); + if (error < 0) { + dynfree(args); + return error; + } + + return spawn(td, spawn_thunk, args, flags, NULL); +} |