diff options
Diffstat (limited to 'kernel/syscall.c')
| -rw-r--r-- | kernel/syscall.c | 181 |
1 files changed, 178 insertions, 3 deletions
diff --git a/kernel/syscall.c b/kernel/syscall.c index 96d2fcf..44ebfa0 100644 --- a/kernel/syscall.c +++ b/kernel/syscall.c @@ -1,3 +1,5 @@ +#include "comus/fs.h" +#include "lib/kio.h" #include <comus/user.h> #include <comus/cpu.h> #include <comus/syscalls.h> @@ -23,6 +25,16 @@ static struct pcb *pcb; #define stdout 1 #define stderr 2 +static struct file *get_file_ptr(int fd) +{ + // valid index? + if (fd < 3 || fd >= (N_OPEN_FILES + 3)) + return NULL; + + // will be NULL if not open + return pcb->open_files[fd - 3]; +} + __attribute__((noreturn)) static int sys_exit(void) { ARG1(int, status); @@ -36,6 +48,33 @@ __attribute__((noreturn)) static int sys_exit(void) static int sys_waitpid(void) { + ARG1(pid_t, pid); + ARG2(int *, status); + + struct pcb *child; + for (int i = 0; i < N_PROCS; i++) { + child = &ptable[i]; + if (child->state != PROC_STATE_ZOMBIE) + continue; + if (child->parent != pcb) + continue; + + // we found a child! + if (pid && pid != child->pid) + continue; + + // set status + mem_ctx_switch(pcb->memctx); + *status = child->exit_status; + mem_ctx_switch(kernel_mem_ctx); + + // clean up child process + pcb_cleanup(child); + + // return + return child->pid; + } + // arguments are read later // by procs.c pcb->state = PROC_STATE_BLOCKED; @@ -60,6 +99,125 @@ static int sys_fork(void) return 0; } +static int sys_exec(void) +{ + ARG1(const char *, in_filename); + ARG2(const char **, in_args); + + struct file_system *fs; + struct file *file; + char filename[N_FILE_NAME]; + struct pcb save; + + // save data + file = NULL; + save = *pcb; + + // read filename + mem_ctx_switch(pcb->memctx); + memcpy(filename, in_filename, strlen(in_filename) + 1); + mem_ctx_switch(kernel_mem_ctx); + + // get binary + fs = fs_get_root_file_system(); + if (fs == NULL) + goto fail; + if (fs->open(fs, filename, O_RDONLY, &file)) + goto fail; + + // load program + save = *pcb; + if (user_load(pcb, file, in_args, save.memctx)) + goto fail; + file->close(file); + mem_ctx_free(save.memctx); + schedule(pcb); + dispatch(); + +fail: + *pcb = save; + if (file) + file->close(file); + return 1; +} + +static int sys_open(void) +{ + ARG1(const char *, in_filename); + ARG2(int, flags); + + char filename[N_FILE_NAME]; + struct file_system *fs; + struct file **file; + int fd; + + // read filename + mem_ctx_switch(pcb->memctx); + memcpy(filename, in_filename, strlen(in_filename)); + mem_ctx_switch(kernel_mem_ctx); + + // get fd + for (fd = 3; fd < (N_OPEN_FILES + 3); fd++) { + if (pcb->open_files[fd - 3] == NULL) { + file = &pcb->open_files[fd - 3]; + break; + } + } + + // could not find fd + if (fd == (N_OPEN_FILES + 3)) + return -1; + + // open file + fs = fs_get_root_file_system(); + if (fs == NULL) + return -1; + if (fs->open(fs, filename, flags, file)) + return -1; + + // file opened + return fd; +} + +static int sys_close(void) +{ + ARG1(int, fd); + + struct file *file; + file = get_file_ptr(fd); + if (file == NULL) + return 1; + + file->close(file); + return 0; +} + +static int sys_read(void) +{ + ARG1(int, fd); + ARG2(void *, buffer); + ARG3(size_t, nbytes); + + struct file *file; + char *map_buf; + + map_buf = kmapuseraddr(pcb->memctx, buffer, nbytes); + if (map_buf == NULL) + return -1; + + file = get_file_ptr(fd); + if (file == NULL) + goto fail; + + nbytes = file->read(file, map_buf, nbytes); + kunmapaddr(map_buf); + return nbytes; + +fail: + kunmapaddr(map_buf); + return -1; +} + static int sys_write(void) { ARG1(int, fd); @@ -324,17 +482,34 @@ static int sys_ticks(void) return 0; } +static int sys_seek(void) +{ + RET(long int, ret); + ARG1(int, fd); + ARG2(long int, off); + ARG3(int, whence); + + struct file *file; + file = get_file_ptr(fd); + if (file == NULL) + return -1; + + *ret = file->seek(file, off, whence); + return 0; +} + static int (*syscall_tbl[N_SYSCALLS])(void) = { [SYS_exit] = sys_exit, [SYS_waitpid] = sys_waitpid, - [SYS_fork] = sys_fork, [SYS_exec] = NULL, - [SYS_open] = NULL, [SYS_close] = NULL, - [SYS_read] = NULL, [SYS_write] = sys_write, + [SYS_fork] = sys_fork, [SYS_exec] = sys_exec, + [SYS_open] = sys_open, [SYS_close] = sys_close, + [SYS_read] = sys_read, [SYS_write] = sys_write, [SYS_getpid] = sys_getpid, [SYS_getppid] = sys_getppid, [SYS_gettime] = sys_gettime, [SYS_getprio] = sys_getprio, [SYS_setprio] = sys_setprio, [SYS_kill] = sys_kill, [SYS_sleep] = sys_sleep, [SYS_brk] = sys_brk, [SYS_sbrk] = sys_sbrk, [SYS_poweroff] = sys_poweroff, [SYS_drm] = sys_drm, [SYS_ticks] = sys_ticks, + [SYS_seek] = sys_seek, }; void syscall_handler(void) |