libc-top-half/musl/src/ldso/dlerror.c

   1 #include <dlfcn.h>
   2 #include <stdlib.h>
   3 #include <stdarg.h>
   4 #include "pthread_impl.h"
   5 #include "dynlink.h"
   6
   7 char *dlerror()
   8 {
   9         pthread_t self = __pthread_self();
  10         if (!self->dlerror_flag) return 0;
  11         self->dlerror_flag = 0;
  12         char *s = self->dlerror_buf;
  13         if (s == (void *)-1)
  14                 return "Dynamic linker failed to allocate memory for error message";
  15         else
  16                 return s;
  17 }
  18
  19 void __dl_thread_cleanup(void)
  20 {
  21         pthread_t self = __pthread_self();
  22         if (self->dlerror_buf != (void *)-1)
  23                 free(self->dlerror_buf);
  24 }
  25
  26 hidden void __dl_vseterr(const char *fmt, va_list ap)
  27 {
  28         va_list ap2;
  29         va_copy(ap2, ap);
  30         pthread_t self = __pthread_self();
  31         if (self->dlerror_buf != (void *)-1)
  32                 free(self->dlerror_buf);
  33         size_t len = vsnprintf(0, 0, fmt, ap2);
  34         va_end(ap2);
  35         char *buf = malloc(len+1);
  36         if (buf) {
  37                 vsnprintf(buf, len+1, fmt, ap);
  38         } else {
  39                 buf = (void *)-1;
  40         }
  41         self->dlerror_buf = buf;
  42         self->dlerror_flag = 1;
  43 }
  44
  45 hidden void __dl_seterr(const char *fmt, ...)
  46 {
  47         va_list ap;
  48         va_start(ap, fmt);
  49         __dl_vseterr(fmt, ap);
  50         va_end(ap);
  51 }
  52
  53 static int stub_invalid_handle(void *h)
  54 {
  55         __dl_seterr("Invalid library handle %p", (void *)h);
  56         return 1;
  57 }
  58
  59 weak_alias(stub_invalid_handle, __dl_invalid_handle);