realloc, vsnprintf

2a78d8e2 · Nickolai Zeldovich · 2bb471ef · 2a78d8e2 · 2a78d8e2
--- a/include/user.h
+++ b/include/user.h
+#include <stdarg.h>
 BEGIN_DECLS
 struct stat;
 struct ipcmsg;
@@ -61,6 +63,7 @@ void forkt_setup(u64 pid);
 void printf(const char*, ...);
 void fprintf(int, const char*, ...);
 void snprintf(char *buf, unsigned int n, const char *fmt, ...);
+void vsnprintf(char *buf, u32 n, const char *fmt, va_list ap);
 void die(const char* errstr, ...) __attribute__((noreturn));
 #define assert(c) if (!(c)) { fprintf(2, "%s:%d: ", __FILE__, __LINE__); die("assertion failure"); }

--- a/lib/umalloc.cc
+++ b/lib/umalloc.cc
@@ -109,3 +109,14 @@ initmalloc(void)
 {
  initlock(&lock);
 }
+extern "C" void* realloc(void* ap, size_t nbytes);
+void*
+realloc(void* ap, size_t nbytes)
+{
+  Header *bp = (header*) ap - 1;
+  void* n = malloc(nbytes);
+  memcpy(n, ap, bp->s.size);
+  free(ap);
+  return n;
+}