VFS/LibC: Create ftruncate function and corresponding syscall and libc implementation

Previously this function was only used for shared memory region created
by shm_open because I was lazy. Now exists for all files.

14 files changed, 56 insertions, 47 deletions

diff --git a/Makefile b/Makefile
index 32b521f..1a77824 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 CC="./sysroot/bin/i686-sb-gcc"
 AS="./sysroot/bin/i686-sb-as"
-OBJ = arch/i386/boot.o init/kernel.o cpu/gdt.o cpu/reload_gdt.o cpu/idt.o cpu/io.o libc/stdio/print.o drivers/keyboard.o log.o drivers/pit.o libc/string/memcpy.o libc/string/strlen.o libc/string/memcmp.o drivers/ata.o libc/string/memset.o cpu/syscall.o  read_eip.o libc/exit/assert.o process.o cpu/int_syscall.o libc/string/strcpy.o arch/i386/mmu.o kmalloc.o fs/ext2.o fs/vfs.o fs/devfs.o cpu/spinlock.o random.o libc/string/strcmp.o crypto/ChaCha20/chacha20.o crypto/SHA1/sha1.o fs/tmpfs.o libc/string/isequal.o drivers/pst.o halts.o scalls/ppoll.o kubsan.o scalls/mmap.o drivers/serial.o scalls/accept.o scalls/bind.o scalls/socket.o socket.o poll.o fs/fifo.o hashmap/hashmap.o fs/shm.o scalls/shm.o elf.o ksbrk.o sched/scheduler.o scalls/stat.o libc/string/copy.o libc/string/strncpy.o drivers/mouse.o libc/string/strlcpy.o libc/string/strcat.o drivers/vbe.o scalls/msleep.o scalls/uptime.o scalls/mkdir.o
+OBJ = arch/i386/boot.o init/kernel.o cpu/gdt.o cpu/reload_gdt.o cpu/idt.o cpu/io.o libc/stdio/print.o drivers/keyboard.o log.o drivers/pit.o libc/string/memcpy.o libc/string/strlen.o libc/string/memcmp.o drivers/ata.o libc/string/memset.o cpu/syscall.o  read_eip.o libc/exit/assert.o process.o cpu/int_syscall.o libc/string/strcpy.o arch/i386/mmu.o kmalloc.o fs/ext2.o fs/vfs.o fs/devfs.o cpu/spinlock.o random.o libc/string/strcmp.o crypto/ChaCha20/chacha20.o crypto/SHA1/sha1.o fs/tmpfs.o libc/string/isequal.o drivers/pst.o halts.o scalls/ppoll.o scalls/ftruncate.o kubsan.o scalls/mmap.o drivers/serial.o scalls/accept.o scalls/bind.o scalls/socket.o socket.o poll.o fs/fifo.o hashmap/hashmap.o fs/shm.o scalls/shm.o elf.o ksbrk.o sched/scheduler.o scalls/stat.o libc/string/copy.o libc/string/strncpy.o drivers/mouse.o libc/string/strlcpy.o libc/string/strcat.o drivers/vbe.o scalls/msleep.o scalls/uptime.o scalls/mkdir.o
 CFLAGS = -O2 -fsanitize=vla-bound,shift-exponent,pointer-overflow,shift,signed-integer-overflow,bounds -ggdb -ffreestanding -Wall -Werror -mgeneral-regs-only -Wimplicit-fallthrough -I./libc/include/ -I.
 INCLUDE=-I./includes/ -I./libc/include/
 
diff --git a/cpu/syscall.c b/cpu/syscall.c
index 4682c53..c072053 100644
--- a/cpu/syscall.c
+++ b/cpu/syscall.c
@@ -13,6 +13,7 @@
 #include <scalls/msleep.h>
 #include <scalls/ppoll.h>
 #include <scalls/shm.h>
+#include <scalls/ftruncate.h>
 #include <scalls/socket.h>
 #include <scalls/stat.h>
 #include <scalls/uptime.h>
diff --git a/fs/ext2.c b/fs/ext2.c
index 98ef2c7..14bcfcb 100644
--- a/fs/ext2.c
+++ b/fs/ext2.c
@@ -505,7 +505,7 @@ vfs_inode_t *ext2_open(const char *path) {
                           1 /*is_open*/, NULL /*internal_object*/, file_size,
                           ext2_open, ext2_create_file, ext2_read, ext2_write,
                           ext2_close, ext2_create_directory,
-                          NULL /*get_vm_object*/);
+                          NULL /*get_vm_object*/, NULL/*truncate*/);
 }
 
 uint64_t end_of_last_entry_position(int dir_inode, uint64_t *entry_offset,
@@ -697,7 +697,7 @@ vfs_inode_t *ext2_mount(void) {
                           0 /*can_write*/, 0 /*is_open*/,
                           NULL /*internal_object*/, 0 /*file_size*/, ext2_open,
                           ext2_create_file, ext2_read, ext2_write, ext2_close,
-                          ext2_create_directory, NULL /*get_vm_object*/);
+                          ext2_create_directory, NULL /*get_vm_object*/, NULL/*truncate*/);
 }
 
 void parse_superblock(void) {
diff --git a/fs/shm.c b/fs/shm.c
index 8668c9a..4d5f2ab 100644
--- a/fs/shm.c
+++ b/fs/shm.c
@@ -47,6 +47,19 @@ vfs_vm_object_t *shm_get_vm_object(uint64_t length, uint64_t offset,
   return p;
 }
 
+int shm_ftruncate(vfs_fd_t *fd, size_t length) {
+  vfs_vm_object_t *p = fd->inode->internal_object;
+  p->size = length;
+  p->virtual_object = ksbrk(length);
+  int n = (uintptr_t)align_page((void *)(uint32_t)length) / 0x1000;
+  p->object = kmalloc(sizeof(void *) * n);
+  for (int i = 0; i < n; i++)
+    p->object[i] =
+        (void *)(get_page(p->virtual_object + (i * 0x1000), NULL, 0, 0)->frame *
+                 0x1000);
+  return 0;
+}
+
 int shm_open(const char *name, int oflag, mode_t mode) {
   // Try to find or create a new shared memory object.
   vfs_vm_object_t *internal_object =
@@ -60,11 +73,11 @@ int shm_open(const char *name, int oflag, mode_t mode) {
     hashmap_add_entry(shared_memory_objects, name, internal_object, NULL, 0);
   }
 
-  vfs_inode_t *inode =
-      vfs_create_inode(0 /*inode_num*/, 0 /*type*/, 1 /*has_data*/,
-                       1 /*can_write*/, 1 /*is_open*/, internal_object,
-                       0 /*file_size*/, NULL /*open*/, NULL /*create_file*/,
-                       shm_read, shm_write, NULL /*close*/, NULL/*create_directory*/, shm_get_vm_object);
+  vfs_inode_t *inode = vfs_create_inode(
+      0 /*inode_num*/, 0 /*type*/, 1 /*has_data*/, 1 /*can_write*/,
+      1 /*is_open*/, internal_object, 0 /*file_size*/, NULL /*open*/,
+      NULL /*create_file*/, shm_read, shm_write, NULL /*close*/,
+      NULL /*create_directory*/, shm_get_vm_object, shm_ftruncate);
 
   vfs_fd_t *fd_ptr;
   int fd = vfs_create_fd(oflag, mode, inode, &fd_ptr);
@@ -79,20 +92,3 @@ int shm_unlink(const char *name) {
   (void)name;
   return 0;
 }
-
-int ftruncate(int fildes, uint64_t length) {
-  kprintf("ftruncate: %d\n", length);
-  vfs_fd_t *fd = get_current_task()->file_descriptors[fildes];
-  if (!fd)
-    return -EBADF;
-  vfs_vm_object_t *p = fd->inode->internal_object;
-  p->size = length;
-  p->virtual_object = ksbrk(length);
-  int n = (uintptr_t)align_page((void *)(uint32_t)length) / 0x1000;
-  p->object = kmalloc(sizeof(void *) * n);
-  for (int i = 0; i < n; i++)
-    p->object[i] =
-        (void *)(get_page(p->virtual_object + (i * 0x1000), NULL, 0, 0)->frame *
-                 0x1000);
-  return 0;
-}
diff --git a/fs/tmpfs.c b/fs/tmpfs.c
index 575ab0c..a9a3c1f 100644
--- a/fs/tmpfs.c
+++ b/fs/tmpfs.c
@@ -48,7 +48,7 @@ void dual_pipe(int fd[2]) {
         0 /*inode_num*/, 0 /*type*/, has_data, can_write, is_open,
         internal_object, 0 /*file_size*/, NULL /*open*/, NULL /*create_file*/,
         tmp_read, tmp_write, tmp_close, NULL /*create_directory*/,
-        NULL /*get_vm_object*/);
+        NULL /*get_vm_object*/, NULL /*truncate*/);
     assert(inode);
 
     vfs_fd_t *fd_ptr;
@@ -77,7 +77,8 @@ void pipe(int fd[2]) {
     vfs_inode_t *inode = vfs_create_inode(
         0 /*inode_num*/, 0 /*type*/, has_data, can_write, is_open,
         internal_object, 0 /*file_size*/, NULL /*open*/, NULL /*create_file*/,
-        tmp_read, tmp_write, tmp_close, NULL/*create_directory*/, NULL /*get_vm_object*/);
+        tmp_read, tmp_write, tmp_close, NULL /*create_directory*/,
+        NULL /*get_vm_object*/, NULL/*truncate*/);
     assert(inode);
 
     vfs_fd_t *fd_ptr;
diff --git a/fs/vfs.c b/fs/vfs.c
index 5f61d89..0c616a2 100644
--- a/fs/vfs.c
+++ b/fs/vfs.c
@@ -32,7 +32,8 @@ vfs_inode_t *vfs_create_inode(
     void (*close)(vfs_fd_t *fd),
     int (*create_directory)(const char *path, int mode),
     vfs_vm_object_t *(*get_vm_object)(uint64_t length, uint64_t offset,
-                                      vfs_fd_t *fd)) {
+                                      vfs_fd_t *fd),
+    int (*truncate)(vfs_fd_t *fd, size_t length)) {
   vfs_inode_t *r = kmalloc(sizeof(inode_t));
   r->inode_num = inode_num;
   r->type = type;
@@ -48,6 +49,7 @@ vfs_inode_t *vfs_create_inode(
   r->close = close;
   r->create_directory = create_directory;
   r->get_vm_object = get_vm_object;
+  r->truncate = truncate;
   return r;
 }
 
@@ -291,6 +293,21 @@ int vfs_dup2(int org_fd, int new_fd) {
   return 1;
 }
 
+int vfs_ftruncate(int fd, size_t length) {
+  vfs_fd_t *fd_ptr = get_vfs_fd(fd);
+  if (!fd_ptr)
+    return -EBADF;
+  if (!(fd_ptr->flags & O_READ))
+    return -EINVAL;
+  vfs_inode_t *inode = fd_ptr->inode;
+  if (!inode)
+    return -EINVAL;
+  if (!inode->truncate)
+    return -EINVAL;
+
+  return inode->truncate(fd_ptr, length);
+}
+
 void vfs_mount(char *path, vfs_inode_t *local_root) {
   int len = strlen(path);
   mounts[num_mounts].path = kmalloc_eternal(len + 1);
diff --git a/fs/vfs.h b/fs/vfs.h
index b8a9984..f8a4b19 100644
--- a/fs/vfs.h
+++ b/fs/vfs.h
@@ -68,6 +68,7 @@ struct vfs_inode {
   int (*create_directory)(const char *path, int mode);
   vfs_vm_object_t *(*get_vm_object)(uint64_t length, uint64_t offset,
                                     vfs_fd_t *fd);
+  int (*truncate)(vfs_fd_t *fd, size_t length);
 };
 
 int vfs_close(int fd);
@@ -83,6 +84,7 @@ int vfs_dup2(int org_fd, int new_fd);
 vfs_inode_t *vfs_internal_open(const char *file);
 int vfs_mkdir(const char *path, int mode);
 int vfs_create_fd(int flags, int mode, vfs_inode_t *inode, vfs_fd_t **fd);
+int vfs_ftruncate(int fd, size_t length);
 vfs_inode_t *vfs_create_inode(
     int inode_num, int type, uint8_t has_data, uint8_t can_write,
     uint8_t is_open, void *internal_object, uint64_t file_size,
@@ -93,5 +95,6 @@ vfs_inode_t *vfs_create_inode(
     void (*close)(vfs_fd_t *fd),
     int (*create_directory)(const char *path, int mode),
     vfs_vm_object_t *(*get_vm_object)(uint64_t length, uint64_t offset,
-                                      vfs_fd_t *fd));
+                                      vfs_fd_t *fd),
+    int (*truncate)(vfs_fd_t *fd, size_t length));
 #endif
diff --git a/scalls/shm.c b/scalls/shm.c
index 2e8924f..979084a 100644
--- a/scalls/shm.c
+++ b/scalls/shm.c
@@ -4,7 +4,3 @@
 int syscall_shm_open(SYS_SHM_OPEN_PARAMS *args) {
   return shm_open(args->name, args->oflag, args->mode);
 }
-
-int syscall_ftruncate(SYS_FTRUNCATE_PARAMS *args) {
-  return ftruncate(args->fildes, args->length);
-}
diff --git a/scalls/shm.h b/scalls/shm.h
index 6d4e13e..80e4366 100644
--- a/scalls/shm.h
+++ b/scalls/shm.h
@@ -10,11 +10,5 @@ typedef struct SYS_SHM_OPEN_PARAMS {
   mode_t mode;
 } __attribute__((packed)) SYS_SHM_OPEN_PARAMS;
 
-typedef struct SYS_FTRUNCATE_PARAMS {
-  int fildes;
-  uint64_t length;
-} __attribute__((packed)) SYS_FTRUNCATE_PARAMS;
-
 int syscall_shm_open(SYS_SHM_OPEN_PARAMS *args);
-int syscall_ftruncate(SYS_FTRUNCATE_PARAMS *args);
 #endif
diff --git a/socket.c b/socket.c
index 8328b38..59f86bf 100644
--- a/socket.c
+++ b/socket.c
@@ -128,7 +128,7 @@ int socket(int domain, int type, int protocol) {
       0 /*inode_num*/, FS_TYPE_UNIX_SOCKET, 0 /*has_data*/, 1 /*can_write*/,
       1 /*is_open*/, new_socket /*internal_object*/, 0 /*file_size*/,
       NULL /*open*/, NULL /*create_file*/, socket_read, socket_write,
-      socket_close, NULL/*create_directory*/, NULL /*get_vm_object*/);
+      socket_close, NULL/*create_directory*/, NULL /*get_vm_object*/, NULL/*truncate*/);
 
   vfs_fd_t *fd;
   int n = vfs_create_fd(O_RDWR | O_NONBLOCK, 0, inode, &fd);
diff --git a/userland/libc/Makefile b/userland/libc/Makefile
index 0681eda..704bf79 100644
--- a/userland/libc/Makefile
+++ b/userland/libc/Makefile
@@ -2,7 +2,7 @@ CC="i686-sb-gcc"
 AR="i686-sb-ar"
 AS="i686-sb-as"
 CFLAGS = -ggdb -ffreestanding -O2 -Wall -pedantic -Wimplicit-fallthrough -I./include/ -static
-OBJ=crt0.o libc.o malloc/malloc.o pty.o sys/mman/mmap.o memset.o assert.o stdio/snprintf.o stdio/vfprintf.o string/memcpy.o string/memcmp.o string/strcmp.o ubsan.o string/strcpy.o isspace.o stdio/puts.o stdio/putchar.o dirent/opendir.o dirent/readdir.o dirent/closedir.o unistd/getopt.o dirent/scandir.o dirent/alphasort.o stdio/printf.o stdio/vdprintf.o stdio/vprintf.o stdio/dprintf.o stdio/vprintf.o string/strlen.o string/strnlen.o stdio/stdin.o stdio/getchar.o stdio/fgetc.o arpa/inet/htons.o arpa/inet/htonl.o stdio/fread.o stdio/fwrite.o stdio/fopen.o stdio/fclose.o stdio/fseek.o ctype/isascii.o stdio/fprintf.o stdlib/atoi.o stdlib/strtol.o ctype/toupper.o ctype/tolower.o string/strcat.o string/strchr.o string/sscanf.o sys/stat/stat.o stdlib/getenv.o string/strrchr.o stdio/ftell.o stdio/tmpfile.o stdio/fgets.o stdio/feof.o stdio/fscanf.o stdio/ungetc.o string/strncmp.o stdio/fputc.o string/strncpy.o stdio/remove.o stdio/ferror.o stdio/fputs.o stdlib/rand.o stdlib/srand.o unistd/getpid.o stdlib/strtoul.o stdio/fflush.o stdlib/abort.o string/strcspn.o time/localtime.o time/time.o time/clock_gettime.o time/gmtime.o time/strftime.o string/strpbrk.o ctype/isdigit.o ctype/isalpha.o ctype/isxdigit.o ctype/ispunct.o stdio/setvbuf.o stdio/fileno.o stdio/putc.o stdio/sprintf.o stdlib/abs.o string/strspn.o stdlib/qsort.o string/memmove.o setjmp/longjmp.o setjmp/setjmp.o libgen/basename.o string/strdup.o string/strndup.o string/strlcpy.o stdlib/atexit.o stdio/open_memstream.o libgen/dirname.o unistd/unlink.o string/strstr.o string/strcasecmp.o string/strncasecmp.o stdlib/mkstemp.o string/strtok.o unistd/execvp.o unistd/_exit.o ctype/isalnum.o time/ctime_r.o stdlib/strtold.o sys/time/gettimeofday.o stdio/fgetpos.o stdio/fsetpos.o ctype/isprint.o stdlib/system.o stdio/tmpnam.o unistd/msleep.o stdlib/atof.o stdlib/strtod.o stdio/rename.o sys/stat/mkdir.o unistd/uptime.o
+OBJ=crt0.o libc.o malloc/malloc.o pty.o sys/mman/mmap.o memset.o assert.o stdio/snprintf.o stdio/vfprintf.o string/memcpy.o string/memcmp.o string/strcmp.o ubsan.o string/strcpy.o isspace.o stdio/puts.o stdio/putchar.o dirent/opendir.o dirent/readdir.o dirent/closedir.o unistd/getopt.o dirent/scandir.o dirent/alphasort.o stdio/printf.o stdio/vdprintf.o stdio/vprintf.o stdio/dprintf.o stdio/vprintf.o string/strlen.o string/strnlen.o stdio/stdin.o stdio/getchar.o stdio/fgetc.o arpa/inet/htons.o arpa/inet/htonl.o stdio/fread.o stdio/fwrite.o stdio/fopen.o stdio/fclose.o stdio/fseek.o ctype/isascii.o stdio/fprintf.o stdlib/atoi.o stdlib/strtol.o ctype/toupper.o ctype/tolower.o string/strcat.o string/strchr.o string/sscanf.o sys/stat/stat.o stdlib/getenv.o string/strrchr.o stdio/ftell.o stdio/tmpfile.o stdio/fgets.o stdio/feof.o stdio/fscanf.o stdio/ungetc.o string/strncmp.o stdio/fputc.o string/strncpy.o stdio/remove.o stdio/ferror.o stdio/fputs.o stdlib/rand.o stdlib/srand.o unistd/getpid.o stdlib/strtoul.o stdio/fflush.o stdlib/abort.o string/strcspn.o time/localtime.o time/time.o time/clock_gettime.o time/gmtime.o time/strftime.o string/strpbrk.o ctype/isdigit.o ctype/isalpha.o ctype/isxdigit.o ctype/ispunct.o stdio/setvbuf.o stdio/fileno.o stdio/putc.o stdio/sprintf.o stdlib/abs.o string/strspn.o stdlib/qsort.o string/memmove.o setjmp/longjmp.o setjmp/setjmp.o libgen/basename.o string/strdup.o string/strndup.o string/strlcpy.o stdlib/atexit.o stdio/open_memstream.o libgen/dirname.o unistd/unlink.o string/strstr.o string/strcasecmp.o string/strncasecmp.o stdlib/mkstemp.o string/strtok.o unistd/execvp.o unistd/_exit.o ctype/isalnum.o time/ctime_r.o stdlib/strtold.o sys/time/gettimeofday.o stdio/fgetpos.o stdio/fsetpos.o ctype/isprint.o stdlib/system.o stdio/tmpnam.o unistd/msleep.o stdlib/atof.o stdlib/strtod.o stdio/rename.o sys/stat/mkdir.o unistd/uptime.o unistd/ftruncate.o
 all: libc.a
 
 %.o: %.c
diff --git a/userland/libc/include/unistd.h b/userland/libc/include/unistd.h
index e43dc33..7d74097 100644
--- a/userland/libc/include/unistd.h
+++ b/userland/libc/include/unistd.h
@@ -10,7 +10,7 @@ extern int opterr, optind, optopt;
 extern char *optarg;
 
 int close(int fildes);
-int ftruncate(int fildes, uint64_t length);
+int ftruncate(int fildes, size_t length);
 int execv(char *path, char **argv);
 int pipe(int fd[2]);
 int dup2(int org_fd, int new_fd);
diff --git a/userland/libc/libc.c b/userland/libc/libc.c
index 90c0323..e2f064d 100644
--- a/userland/libc/libc.c
+++ b/userland/libc/libc.c
@@ -315,8 +315,3 @@ int shm_open(const char *name, int oflag, mode_t mode) {
   };
   RC_ERRNO(syscall(SYS_SHM_OPEN, &args, 0, 0, 0, 0));
 }
-
-int ftruncate(int fildes, uint64_t length) {
-  SYS_FTRUNCATE_PARAMS args = {.fildes = fildes, .length = length};
-  RC_ERRNO(syscall(SYS_FTRUNCATE, &args, 0, 0, 0, 0));
-}
diff --git a/userland/libc/unistd/ftruncate.c b/userland/libc/unistd/ftruncate.c
new file mode 100644
index 0000000..cf35944
--- /dev/null
+++ b/userland/libc/unistd/ftruncate.c
@@ -0,0 +1,6 @@
+#include <syscall.h>
+#include <unistd.h>
+
+int ftruncate(int fildes, size_t length) {
+  RC_ERRNO(syscall(SYS_FTRUNCATE, fildes, length, 0, 0, 0));
+}