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Use rand_s on MinGW-w64, fix array bound overflow.

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2016-09-21  Janne Blomqvist  <jb@gcc.gnu.org>

	* intrinsics/random.c (getosrandom): Use rand_s() on
	MinGW-w64. Fix bounds overflow in fallback code.

From-SVN: r240309
This commit is contained in:
Janne Blomqvist 2016-09-21 13:07:06 +03:00
parent bc084f84b3
commit 9ad5c32a21
2 changed files with 21 additions and 4 deletions
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5
libgfortran/ChangeLog
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@ -1,3 +1,8 @@
2016-09-21 Janne Blomqvist <jb@gcc.gnu.org>
* intrinsics/random.c (getosrandom): Use rand_s() on
MinGW-w64. Fix bounds overflow in fallback code.
2016-09-19 Andre Vehreschild <vehre@gcc.gnu.org>
* caf/libcaf.h: Add caf_reference_type.

20
libgfortran/intrinsics/random.c
View File

@ -24,6 +24,9 @@ a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* For rand_s. */
#define _CRT_RAND_S
#include "libgfortran.h"
#include <gthr.h>
#include <string.h>
@ -43,6 +46,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
#ifdef __MINGW32__
#define HAVE_GETPID 1
#include <process.h>
#include <_mingw.h> /* For __MINGW64_VERSION_MAJOR */
#endif
extern void random_r4 (GFC_REAL_4 *);
@ -281,7 +285,7 @@ jump (xorshift1024star_state* rs)
#define Q 127773 /* M / A (To avoid overflow on A * seed) */
#define R 2836 /* M % A (To avoid overflow on A * seed) */
static uint32_t
__attribute__((unused)) static uint32_t
lcg_parkmiller(uint32_t seed)
{
uint32_t hi = seed / Q;
@ -297,14 +301,21 @@ lcg_parkmiller(uint32_t seed)
#undef Q
#undef R
/* Get some random bytes from the operating system in order to seed
the PRNG. */
static int
getosrandom (void *buf, size_t buflen)
{
/* TODO: On Windows one could use CryptGenRandom
/* rand_s is available in MinGW-w64 but not plain MinGW. */
#ifdef __MINGW64_VERSION_MAJOR
unsigned int* b = buf;
for (unsigned i = 0; i < buflen / sizeof (unsigned int); i++)
rand_s (&b[i]);
return buflen;
#else
/*
TODO: When glibc adds a wrapper for the getrandom() system call
on Linux, one could use that.
@ -333,12 +344,13 @@ getosrandom (void *buf, size_t buflen)
seed ^= pid;
#endif
uint32_t* ub = buf;
for (size_t i = 0; i < buflen; i++)
for (size_t i = 0; i < buflen / sizeof (uint32_t); i++)
{
ub[i] = seed;
seed = lcg_parkmiller (seed);
}
return buflen;
#endif /* __MINGW64_VERSION_MAJOR */
}