Fix getrandom on Ubuntu 16.04 (GLIBC 2.23) (#14)

* use system call SYS_getrandom * Add Ubuntu 16.04 to Travis CI script
mirage · Feb 26, 2020 · b4f3eb0 · b4f3eb0
1 parent b390b50
commit b4f3eb0
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Showing 2 changed files with 11 additions and 3 deletions.
diff --git a/.travis.yml b/.travis.yml
@@ -11,5 +11,7 @@ matrix:
   include:
   - os: osx
     env: OCAML_VERSION=4.08
+  - dist: xenial
+    env: OCAML_VERSION=4.08
 notifications:
   email: false
diff --git a/rng/unix/mc_getrandom_stubs.c b/rng/unix/mc_getrandom_stubs.c
@@ -6,9 +6,16 @@
 #include <caml/bigarray.h>
 
 #if defined(__linux)
+# include <errno.h>
 // on Linux, we use getrandom and loop
-#include <sys/random.h>
-#include <errno.h>
+
+# if __GLIBC__ && __GLIBC__ <= 2 && __GLIBC_MINOR__ < 25
+# include <sys/syscall.h>
+# define getrandom(buf, len, flags) syscall(SYS_getrandom, (buf), (len), (flags))
+# else
+# include <sys/random.h>
+# define getrandom(buf, len, flags) getrandom((buf), (len), (flags))
+# endif
 
 void raw_getrandom (uint8_t *data, uint32_t len) {
   int r, off = 0;
@@ -19,7 +26,6 @@ void raw_getrandom (uint8_t *data, uint32_t len) {
     off += r;
   }
 }
-
 #elif (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__APPLE__))
 // on BSD and macOS, loop (in pieces of 256) getentropy
 #if defined(__APPLE__)