libk: create a subset libc for kernel use

Create a subset of the C library for use inside the kernel.

Signed-off-by: Danny Holman <dholman@gymli.org>

3 files changed, 25 insertions, 17 deletions

diff --git a/kernel/io.c b/libk/io.c
index 0a4ba6d..eedc171 100644
--- a/kernel/io.c
+++ b/libk/io.c
@@ -1,10 +1,7 @@
-#include <kernel/io.h>
-#include <kernel/framebuffer.h>
-#include <kernel/data/ringbuf.h>
-#include <kernel/string.h>
-
-static int ringbuf_init = 0;
-static struct ringbuf rb;
+#include <libk/io.h>
+#include <libk/string.h>
+#include <kernel/video/framebuffer.h>
+#include <kernel/tty/tty_vga.h>
 
 char* convert(unsigned int num, int base) {
         static char rep[] = "0123456789ABCDEF";
@@ -23,15 +20,11 @@ char* convert(unsigned int num, int base) {
 }
 
 int vkprintf(const char *fmt, va_list args) {
-        if (ringbuf_init == 0) {
-                rb_init(&rb, 1024, 4096);
-                ringbuf_init = 1;
-        }
-
         char *s;
         int i;
 
         char buffer[4096];
+        memset(buffer, 0, 4096);
         for (size_t n = 0; n < strlen(fmt); n++) {
                 if (fmt[n] != '%') {
                         buffer[strlen(buffer)] = fmt[n];
@@ -67,7 +60,8 @@ int vkprintf(const char *fmt, va_list args) {
                                 break;
                 }
         }
-        rb_push_back(&rb, buffer, strlen(buffer));
+        //tty_write(buffer, strlen(buffer));
+        fb_write(buffer, strlen(buffer));
         memset(buffer, 0, 4096);
         return 0;
 }
diff --git a/libk/stack_protector.c b/libk/stack_protector.c
new file mode 100644
index 0000000..78d0302
--- /dev/null
+++ b/libk/stack_protector.c
@@ -0,0 +1,11 @@
+#include <kernel/panic.h>
+#include <stdint.h>
+#include <stddef.h>
+
+#define STACK_CHK_GUARD 0x32E3429E
+
+uintptr_t __stack_chk_guard = STACK_CHK_GUARD;
+
+__attribute__((noreturn)) void __stack_chk_fail(void) {
+        panic("STACK SMASHING IN KERNEL ADDRESS SPACE");
+}
diff --git a/kernel/string.c b/libk/string.c
index fa0fd3f..be59397 100644
--- a/kernel/string.c
+++ b/libk/string.c
@@ -1,4 +1,4 @@
-#include <kernel/string.h>
+#include <libk/string.h>
 
 int memcmp(const void *str1, const void *str2, size_t n) {
         unsigned char const *p1 = str1;
@@ -32,16 +32,15 @@ void* memcpy(void* __restrict dest, const void* __restrict src, size_t n) {
 }
 
 char* strncpy(char* __restrict dest, const char* __restrict src, size_t n) {
-        for (int i = 0; i < n; i++) {
+        for (size_t i = 0; i < n; i++) {
                 if (src[i] == '\0')
                         break;
                 dest[i] = src[i];
         }
+        return dest;
 }
 
 char* strcpy(char* __restrict dest, const char* __restrict src) {
-        if (strlen(src) > strlen(dest))
-                return NULL;
         return (char*)memcpy(dest, src, strlen(src));
 }
 
@@ -49,6 +48,10 @@ char* strcat(char* __restrict dest, const char* __restrict src) {
         return (char*)memcpy(&dest[strlen(dest)], src, strlen(src));
 }
 
+char* strncat(char* __restrict dest, const char* __restrict src, size_t n) {
+        return (char*)memcpy(&dest[strlen(dest)], src, n);
+}
+
 void* memmove(void* __restrict dest, const void* __restrict src, size_t n) {
         if (dest == src)
                 return dest;