Added errno.h, fixed vfs mapper find()

include/sys/errno.h

@@ -35,4 +35,6 @@
 #define EDOM            33
 #define ERANGE          34
 
+#if defined(__KERNEL__)
 const char *kstrerror(int e);
+#endif

sys/vfs/vfs.c

@@ -264,6 +264,12 @@ static int vfs_find_tree(struct vfs_node *root_node, const char *path, struct vf
             }
         }
 
+        // Check if the node belongs to a mapper-based filesystem
+        _assert(root_vnode->fs && root_vnode->fs->cls);
+        if (root_vnode->fs->cls->opt & FS_NODE_MAPPER) {
+            return -ENOENT;
+        }
+
         // 3.2. Nothing found in path tree - request the fs to find
         //      the vnode for the path element given
         vnode_t *child_vnode = NULL;

usr/Makefile

@@ -26,7 +26,10 @@ libc_OBJS=$(O)/libc/crt0.o \
 		  $(O)/libc/syscall.o \
 		  $(O)/libc/vsnprintf.o \
 		  $(O)/libc/printf.o \
-		  $(O)/libc/string.o
+		  $(O)/libc/string.o \
+		  $(O)/libc/errno.o \
+		  $(O)/libc/stdio.o \
+		  $(O)/libc/init.o
 
 sys_CRTBEGIN=$(shell $(CC) $(CFLAGS) -print-file-name=crtbegin.o)
 sys_CRTEND=$(shell $(CC) $(CFLAGS) -print-file-name=crtend.o)

usr/init.c

@@ -1,12 +1,13 @@
 #include <sys/fcntl.h>
 #include <unistd.h>
 #include <stdint.h>
+#include <errno.h>
 #include <stdio.h>
 
 int main(int argc, char **argv) {
     char c;
 
-    printf("Hello, World!\n");
+    puts("Hello, World!");
 
     struct stat test_stat;
     if (stat("/init", &test_stat) == 0) {
@@ -17,12 +18,14 @@ int main(int argc, char **argv) {
                                       test_stat.st_mode & 0x7);
     }
 
-    if (stat("/etc/file.txt", &test_stat) == 0) {
+    if (stat("/1etc/file.txt", &test_stat) == 0) {
         printf("stat(\"/etc/file.txt\"):\n");
         printf(" st_size = %u\n", test_stat.st_size);
         printf(" st_mode = %d%d%d\n", (test_stat.st_mode >> 6) & 0x7,
                                       (test_stat.st_mode >> 3) & 0x7,
                                       test_stat.st_mode & 0x7);
+    } else {
+        perror("stat()");
     }
 
     int fd = open("/etc/file.txt", O_RDONLY, 0);

usr/libc/crt0.S

@@ -11,6 +11,8 @@ _start:
     pushq %rbp
     movq %rsp, %rbp
 
+    call __libc_init
+
     call _init
 
     // Ignore %rdi/%rsi for now

usr/libc/errno.c

@@ -0,0 +1,57 @@
+#include <errno.h>
+#include <stdio.h>
+
+static const char *err_strings0[35] = {
+    "Success",
+    "Operation not permitted",
+    "No such file or directory",
+    "No such process",
+    "Interrupted system call",
+    "I/O error",
+    "No such device or address",
+    "Argument list too long",
+    "Exec format error",
+    "Bad file number",
+    "No child processes",
+    "Try again",
+    "Out of memory",
+    "Permission denied",
+    "Bad address",
+    "Block device required",
+    "Device or resource busy",
+    "File exists",
+    "Cross-device link",
+    "No such device",
+    "Not a directory",
+    "Is a directory",
+    "Invalid argument",
+    "File table overflow",
+    "Too many open files",
+    "Not a typewriter",
+    "Text file busy",
+    "File too large",
+    "No space left on device",
+    "Illegal seek",
+    "Read-only file system",
+    "Too many links",
+    "Broken pipe",
+    "Math argument out of domain of func",
+    "Math result not representable"
+};
+
+int errno;
+
+char *strerror(int n) {
+    if (n >= 0 && n <= 34) {
+        return (char *) err_strings0[n];
+    }
+    return (char *) "Unknown error";
+}
+
+void perror(const char *e) {
+    if (e && *e) {
+        printf("%s: %s\n", e, strerror(errno));
+    } else {
+        puts(strerror(errno));
+    }
+}

usr/libc/include/errno.h

@@ -0,0 +1,7 @@
+#pragma once
+#include <sys/errno.h>
+
+extern int errno;
+
+char *strerror(int errnum);
+void perror(const char *s);

usr/libc/include/stdio.h

@@ -1,2 +1,5 @@
 #pragma once
+
+int puts(const char *s);
+
 #include "bits/printf.h"

usr/libc/init.c

@@ -0,0 +1,5 @@
+#include <errno.h>
+
+void __libc_init(void) {
+    errno = 0;
+}

usr/libc/stdio.c

@@ -0,0 +1,14 @@
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+
+int puts(const char *s) {
+    size_t l = strlen(s);
+    int w = write(STDOUT_FILENO, s, l);
+    char c = '\n';
+
+    if (w == l) {
+        write(STDOUT_FILENO, &c, 1);
+    }
+    return w;
+}

usr/libc/syscall.c

@@ -1,4 +1,5 @@
 #include "bits/syscall.h"
+#include <errno.h>
 
 #define ASM_REGISTER(name) \
         register uint64_t name asm (#name)
@@ -39,16 +40,24 @@
         rax; \
     })
 
+#define SET_ERRNO(t, r)                     ({ \
+        t res = (t) r; \
+        if (res < 0) { \
+            errno = -res; \
+        } \
+        res; \
+    })
+
 ssize_t write(int fd, const void *buf, size_t count) {
-    return (ssize_t) ASM_SYSCALL3(SYSCALL_NR_WRITE, fd, buf, count);
+    return SET_ERRNO(ssize_t, ASM_SYSCALL3(SYSCALL_NR_WRITE, fd, buf, count));
 }
 
 ssize_t read(int fd, void *buf, size_t count) {
-    return (ssize_t) ASM_SYSCALL3(SYSCALL_NR_READ, fd, buf, count);
+    return SET_ERRNO(ssize_t, ASM_SYSCALL3(SYSCALL_NR_READ, fd, buf, count));
 }
 
 int open(const char *filename, int flags, int mode) {
-    return (int) ASM_SYSCALL3(SYSCALL_NR_OPEN, filename, flags, mode);
+    return SET_ERRNO(int, ASM_SYSCALL3(SYSCALL_NR_OPEN, filename, flags, mode));
 }
 
 void close(int fd) {
@@ -56,7 +65,7 @@ void close(int fd) {
 }
 
 int stat(const char *filename, struct stat *st) {
-    return (int) ASM_SYSCALL2(SYSCALL_NR_STAT, filename, st);
+    return SET_ERRNO(int, ASM_SYSCALL2(SYSCALL_NR_STAT, filename, st));
 }
 
 __attribute__((noreturn)) void exit(int code) {