[tor-commits] [tor/master] Add new tor_assert_nonfatal*() macros.
nickm at torproject.org
nickm at torproject.org
Thu Apr 14 20:26:00 UTC 2016
commit a885271c08d2337b35c203c0b27509d0aa32dbf6
Author: Nick Mathewson <nickm at torproject.org>
Date: Tue Apr 5 09:40:51 2016 -0400
Add new tor_assert_nonfatal*() macros.
Unlike tor_assert(), these macros don't abort the process. They're
good for checking conditions we want to warn about, but which don't
warrant a full crash.
This commit also changes the default implementation for
tor_fragile_assert() to tor_assert_nonfatal_unreached_once().
Closes ticket 18613.
---
changes/assert_nonfatal | 5 +++++
src/common/util_bug.c | 24 ++++++++++++++++++++++++
src/common/util_bug.h | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
src/or/main.c | 8 +++-----
src/or/policies.c | 2 +-
src/or/rephist.c | 4 ++--
6 files changed, 82 insertions(+), 10 deletions(-)
diff --git a/changes/assert_nonfatal b/changes/assert_nonfatal
new file mode 100644
index 0000000..0cbee44
--- /dev/null
+++ b/changes/assert_nonfatal
@@ -0,0 +1,5 @@
+ o Minor features (safety, debugging):
+
+ * Add a set of macros to check nonfatal assertions, for internal
+ use. Migrating more of our checks to these should help us avoid
+ needless crash bugs. Closes ticket 18613.
diff --git a/src/common/util_bug.c b/src/common/util_bug.c
index 139d139..606c665 100644
--- a/src/common/util_bug.c
+++ b/src/common/util_bug.c
@@ -26,3 +26,27 @@ tor_assertion_failed_(const char *fname, unsigned int line,
log_backtrace(LOG_ERR, LD_BUG, buf);
}
+
+void
+tor_bug_occurred_(const char *fname, unsigned int line,
+ const char *func, const char *expr,
+ int once)
+{
+ char buf[256];
+ const char *once_str = once ?
+ " (Future instances of this warning will be silenced.)": "";
+ if (! expr) {
+ log_warn(LD_BUG, "%s:%u: %s: This line should not have been reached.%s",
+ fname, line, func, once_str);
+ tor_snprintf(buf, sizeof(buf),
+ "Line unexpectedly reached at %s at %s:%u",
+ func, fname, line);
+ } else {
+ log_warn(LD_BUG, "%s:%u: %s: Non-fatal assertion %s failed.%s",
+ fname, line, func, expr, once_str);
+ tor_snprintf(buf, sizeof(buf),
+ "Non-fatal assertion %s failed in %s at %s:%u",
+ expr, func, fname, line);
+ }
+ log_backtrace(LOG_WARN, LD_BUG, buf);
+}
diff --git a/src/common/util_bug.h b/src/common/util_bug.h
index 5414c53..ce54266 100644
--- a/src/common/util_bug.h
+++ b/src/common/util_bug.h
@@ -46,13 +46,58 @@
} STMT_END
#endif
+#define tor_assert_unreached() tor_assert(0)
+
+/* Non-fatal bug assertions. The "unreached" variants mean "this line should
+ * never be reached." The "once" variants mean "Don't log a warning more than
+ * once".
+ */
+
+#ifdef ALL_BUGS_ARE_FATAL
+#define tor_assert_nonfatal_unreached() tor_assert(0)
+#define tor_assert_nonfatal(cond) tor_assert((cond))
+#define tor_assert_nonfatal_unreached_once() tor_assert(0)
+#define tor_assert_nonfatal_once(cond) tor_assert((cond))
+#elif defined(TOR_UNIT_TESTS) && defined(DISABLE_ASSERTS_IN_UNIT_TESTS)
+#define tor_assert_nonfatal_unreached() STMT_NIL
+#define tor_assert_nonfatal(cond) ((void)(cond))
+#define tor_assert_nonfatal_unreached_once() STMT_NIL
+#define tor_assert_nonfatal_once(cond) ((void)(cond))
+#else /* Normal case, !ALL_BUGS_ARE_FATAL, !DISABLE_ASSERTS_IN_UNIT_TESTS */
+#define tor_assert_nonfatal_unreached() STMT_BEGIN \
+ tor_bug_occurred_(SHORT_FILE__, __LINE__, __func__, NULL, 0); \
+ STMT_END
+#define tor_assert_nonfatal(cond) STMT_BEGIN \
+ if (PREDICT_UNLIKELY(!(cond))) { \
+ tor_bug_occurred_(SHORT_FILE__, __LINE__, __func__, #cond, 0); \
+ } \
+ STMT_END
+#define tor_assert_nonfatal_unreached_once() STMT_BEGIN \
+ static int warning_logged__ = 0; \
+ if (!warning_logged__) { \
+ warning_logged__ = 1; \
+ tor_bug_occurred_(SHORT_FILE__, __LINE__, __func__, NULL, 1); \
+ } \
+ STMT_END
+#define tor_assert_nonfatal_once(cond) STMT_BEGIN \
+ static int warning_logged__ = 0; \
+ if (!warning_logged__ && PREDICT_UNLIKELY(!(cond))) { \
+ warning_logged__ = 1; \
+ tor_bug_occurred_(SHORT_FILE__, __LINE__, __func__, #cond, 1); \
+ } \
+ STMT_END
+#endif
+
/** Define this if you want Tor to crash when any problem comes up,
* so you can get a coredump and track things down. */
-// #define tor_fragile_assert() tor_assert(0)
-#define tor_fragile_assert()
+// #define tor_fragile_assert() tor_assert_unreached(0)
+#define tor_fragile_assert() tor_assert_nonfatal_unreached_once()
void tor_assertion_failed_(const char *fname, unsigned int line,
const char *func, const char *expr);
+void tor_bug_occurred_(const char *fname, unsigned int line,
+ const char *func, const char *expr,
+ int once);
#endif
diff --git a/src/or/main.c b/src/or/main.c
index a2cf5b1..7c5e685 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -1643,8 +1643,8 @@ rotate_x509_certificate_callback(time_t now, const or_options_t *options)
* TLS context. */
log_info(LD_GENERAL,"Rotating tls context.");
if (router_initialize_tls_context() < 0) {
- log_warn(LD_BUG, "Error reinitializing TLS context");
- tor_assert(0);
+ log_err(LD_BUG, "Error reinitializing TLS context");
+ tor_assert_unreached();
}
/* We also make sure to rotate the TLS connections themselves if they've
@@ -2563,9 +2563,7 @@ run_main_loop_once(void)
return -1;
#endif
} else {
- if (ERRNO_IS_EINPROGRESS(e))
- log_warn(LD_BUG,
- "libevent call returned EINPROGRESS? Please report.");
+ tor_assert_nonfatal_once(! ERRNO_IS_EINPROGRESS(e));
log_debug(LD_NET,"libevent call interrupted.");
/* You can't trust the results of this poll(). Go back to the
* top of the big for loop. */
diff --git a/src/or/policies.c b/src/or/policies.c
index f9718b6..2703d7e 100644
--- a/src/or/policies.c
+++ b/src/or/policies.c
@@ -103,7 +103,7 @@ policy_expand_private(smartlist_t **policy)
if (tor_addr_parse_mask_ports(private_nets[i], 0,
&newpolicy.addr,
&newpolicy.maskbits, &port_min, &port_max)<0) {
- tor_assert(0);
+ tor_assert_unreached();
}
smartlist_add(tmp, addr_policy_get_canonical_entry(&newpolicy));
}
diff --git a/src/or/rephist.c b/src/or/rephist.c
index fe0ca91..b94ad29 100644
--- a/src/or/rephist.c
+++ b/src/or/rephist.c
@@ -3214,7 +3214,7 @@ rep_hist_free_all(void)
rep_hist_desc_stats_term();
total_descriptor_downloads = 0;
- tor_assert(rephist_total_alloc == 0);
- tor_assert(rephist_total_num == 0);
+ tor_assert_nonfatal(rephist_total_alloc == 0);
+ tor_assert_nonfatal_once(rephist_total_num == 0);
}
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