From dd0a88b94744053653a032149ba7d6eb1f392021 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Fri, 15 Mar 2024 19:54:43 -0400 Subject: kernel: Add basic file descriptor support Signed-off-by: Ian Moffett --- sys/kern/kern_filedesc.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++ sys/kern/kern_sched.c | 11 +++++ 2 files changed, 134 insertions(+) create mode 100644 sys/kern/kern_filedesc.c (limited to 'sys/kern') diff --git a/sys/kern/kern_filedesc.c b/sys/kern/kern_filedesc.c new file mode 100644 index 0000000..a943714 --- /dev/null +++ b/sys/kern/kern_filedesc.c @@ -0,0 +1,123 @@ +/* + * Copyright (c) 2023-2024 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 +#include +#include +#include +#include +#include + +/* + * Allocate a file descriptor. + * + * @td: Thread to allocate from, NULL for current thread. + */ +struct filedesc * +fd_alloc(struct proc *td) +{ + struct filedesc *fd; + + if (td == NULL) { + td = this_td(); + __assert(td != NULL); + } + + for (size_t i = 0; i < PROC_MAX_FDS; ++i) { + if (td->fds[i] != NULL) { + continue; + } + + fd = dynalloc(sizeof(struct filedesc)); + memset(fd, 0, sizeof(struct filedesc)); + + if (fd == NULL) { + return NULL; + } + + fd->fdno = i; + td->fds[i] = fd; + return fd; + } + + return NULL; +} + +/* + * Fetch a file descriptor from a file descriptor + * number. + * + * @td: Thread to fetch from, NULL for current thread. + * @fdno: File descriptor to fetch + */ +struct filedesc * +fd_from_fdnum(const struct proc *td, int fdno) +{ + if (td == NULL) { + td = this_td(); + __assert(td != NULL); + } + + if (fdno < 0 || fdno > PROC_MAX_FDS) { + return NULL; + } + + for (size_t i = 0; i < PROC_MAX_FDS; ++i) { + if (i == fdno && td->fds[i] != NULL) { + return td->fds[i]; + } + } + + return NULL; +} + +/* + * Close a file descriptor from its fd number. + * + * @td: Thread to fetch from, NULL for current thread. + * @fdno: File descriptor number to close. + */ +void +fd_close_fdnum(struct proc *td, int fdno) +{ + struct filedesc *fd; + + if (td == NULL) { + td = this_td(); + __assert(td != NULL); + } + + fd = fd_from_fdnum(td, fdno); + if (fd == NULL) { + return; + } + + dynfree(fd); + td->fds[fdno] = NULL; +} diff --git a/sys/kern/kern_sched.c b/sys/kern/kern_sched.c index bd59e41..77aab54 100644 --- a/sys/kern/kern_sched.c +++ b/sys/kern/kern_sched.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include @@ -268,6 +269,11 @@ sched_create_td(uintptr_t rip, char *argvp[], char *envp[], struct auxval auxv, td->is_user = is_user; processor_init_pcb(td); + /* Allocate standard file descriptors */ + __assert(fd_alloc(td) != NULL); /* STDIN */ + __assert(fd_alloc(td) != NULL); /* STDOUT */ + __assert(fd_alloc(td) != NULL); /* STDERR */ + /* Setup trapframe */ if (!is_user) { init_frame(tf, rip, (uintptr_t)stack); @@ -294,6 +300,11 @@ sched_destroy_td(struct proc *td) dynfree((void *)td->stack_base); } + /* Close all of the file descriptors */ + for (size_t i = 0; i < PROC_MAX_FDS; ++i) { + fd_close_fdnum(td, i); + } + pmap_free_vas(vm_get_ctx(), td->addrsp); dynfree(td); } -- cgit v1.2.3