diff options
| -rw-r--r-- | configure.ac | 10 | ||||
| -rw-r--r-- | src/journal/mmap-cache.c | 14 |
2 files changed, 21 insertions, 3 deletions
diff --git a/configure.ac b/configure.ac index ea74fcd16a..e14f3cfe68 100644 --- a/configure.ac +++ b/configure.ac @@ -1328,9 +1328,9 @@ AC_ARG_ENABLE(tests, AM_CONDITIONAL(ENABLE_TESTS, [test x$enable_tests = xyes]) AC_ARG_ENABLE(debug, - [AC_HELP_STRING([--enable-debug@<:@=LIST@:>@], [enable extra debugging (hashmap)])], + [AC_HELP_STRING([--enable-debug@<:@=LIST@:>@], [enable extra debugging (hashmap,mmap-cache)])], [if test "x$enableval" = "xyes"; then - enableval="hashmap" + enableval="hashmap,mmap-cache" fi saved_ifs="$IFS" IFS="$IFS$PATH_SEPARATOR," @@ -1339,6 +1339,9 @@ AC_ARG_ENABLE(debug, hashmap) enable_debug_hashmap=yes ;; + mmap-cache) + enable_debug_mmap_cache=yes + ;; esac done IFS="$saved_ifs"],[]) @@ -1348,6 +1351,9 @@ AS_IF([test x$enable_debug_hashmap = xyes], [ AC_DEFINE(ENABLE_DEBUG_HASHMAP, 1, [Define if hashmap debugging is to be enabled]) enable_debug="hashmap $enable_debug" ]) +AS_IF([test x$enable_debug_mmap_cache = xyes], [ + AC_DEFINE(ENABLE_DEBUG_MMAP_CACHE, 1, [Define if mmap cache debugging is to be enabled]) + enable_debug="mmap-cache $enable_debug" ]) test -z "$enable_debug" && enable_debug="none" diff --git a/src/journal/mmap-cache.c b/src/journal/mmap-cache.c index b7db6f1da5..c57c1623c5 100644 --- a/src/journal/mmap-cache.c +++ b/src/journal/mmap-cache.c @@ -83,7 +83,13 @@ struct MMapCache { }; #define WINDOWS_MIN 64 -#define WINDOW_SIZE (8ULL*1024ULL*1024ULL) + +#ifdef ENABLE_DEBUG_MMAP_CACHE +/* Tiny windows increase mmap activity and the chance of exposing unsafe use. */ +# define WINDOW_SIZE (page_size()) +#else +# define WINDOW_SIZE (8ULL*1024ULL*1024ULL) +#endif MMapCache* mmap_cache_new(void) { MMapCache *m; @@ -187,11 +193,17 @@ static void context_detach_window(Context *c) { if (!w->contexts && w->keep_always == 0) { /* Not used anymore? */ +#ifdef ENABLE_DEBUG_MMAP_CACHE + /* Unmap unused windows immediately to expose use-after-unmap + * by SIGSEGV. */ + window_free(w); +#else LIST_PREPEND(unused, c->cache->unused, w); if (!c->cache->last_unused) c->cache->last_unused = w; w->in_unused = true; +#endif } } |