Fix false positives from valgrind: prctl(PR_GET_DUMPABLE)

[tools/e2fsprogs.git] / lib / blkid / cache.c

diff --git a/lib/blkid/cache.c b/lib/blkid/cache.c
index bfa104e..b47b488 100644 (file)
--- a/lib/blkid/cache.c
+++ b/lib/blkid/cache.c
@@ -10,11 +10,68 @@
  * %End-Header%
  */
 
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
 #include <stdlib.h>
+#include <string.h>
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#else
+#define PR_GET_DUMPABLE 3
+#endif
+#if (!defined(HAVE_PRCTL) && defined(linux))
+#include <sys/syscall.h>
+#endif
 #include "blkidP.h"
 
 int blkid_debug_mask = 0;
 
+
+static char *safe_getenv(const char *arg)
+{
+       if ((getuid() != geteuid()) || (getgid() != getegid()))
+               return NULL;
+#if HAVE_PRCTL
+       if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
+               return NULL;
+#else
+#if (defined(linux) && defined(SYS_prctl))
+       if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
+               return NULL;
+#endif
+#endif
+
+#ifdef HAVE___SECURE_GETENV
+       return __secure_getenv(arg);
+#else
+       return getenv(arg);
+#endif
+}
+
+#if 0 /* ifdef CONFIG_BLKID_DEBUG */
+static blkid_debug_dump_cache(int mask, blkid_cache cache)
+{
+       struct list_head *p;
+
+       if (!cache) {
+               printf("cache: NULL\n");
+               return;
+       }
+
+       printf("cache: time = %lu\n", cache->bic_time);
+       printf("cache: flags = 0x%08X\n", cache->bic_flags);
+
+       list_for_each(p, &cache->bic_devs) {
+               blkid_dev dev = list_entry(p, struct blkid_struct_dev, bid_devs);
+               blkid_debug_dump_dev(dev);
+       }
+}
+#endif
+
 int blkid_get_cache(blkid_cache *ret_cache, const char *filename)
 {
        blkid_cache cache;
@@ -38,7 +95,11 @@ int blkid_get_cache(blkid_cache *ret_cache, const char *filename)
        INIT_LIST_HEAD(&cache->bic_devs);
        INIT_LIST_HEAD(&cache->bic_tags);
 
-       if (!filename || !strlen(filename))
+       if (filename && !strlen(filename))
+               filename = 0;
+       if (!filename) 
+               filename = safe_getenv("BLKID_FILE");
+       if (!filename)
                filename = BLKID_CACHE_FILE;
        cache->bic_filename = blkid_strdup(filename);
        
@@ -57,7 +118,7 @@ void blkid_put_cache(blkid_cache cache)
 
        DBG(DEBUG_CACHE, printf("freeing cache struct\n"));
        
-       /* DEB_DUMP_CACHE(cache); */
+       /* DBG(DEBUG_CACHE, blkid_debug_dump_cache(cache)); */
 
        while (!list_empty(&cache->bic_devs)) {
                blkid_dev dev = list_entry(cache->bic_devs.next,