[asterisk-commits] wdoekes: trunk r396822 - in /trunk: include/asterisk/ main/
SVN commits to the Asterisk project
asterisk-commits at lists.digium.com
Fri Aug 16 02:19:03 CDT 2013
Author: wdoekes
Date: Fri Aug 16 02:18:51 2013
New Revision: 396822
URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=396822
Log:
Prevent heap alloc functions from running out of stack space.
When asterisk has run out of memory (for whatever reason), the alloc
function logs a message. Logging requires memory. A recipe for
infinite recursion.
Stop the recursion by comparing the function call depth for sane values
before attempting another OOM log message.
Review: https://reviewboard.asterisk.org/r/2743/
Modified:
trunk/include/asterisk/utils.h
trunk/main/pbx.c
trunk/main/utils.c
Modified: trunk/include/asterisk/utils.h
URL: http://svnview.digium.com/svn/asterisk/trunk/include/asterisk/utils.h?view=diff&rev=396822&r1=396821&r2=396822
==============================================================================
--- trunk/include/asterisk/utils.h (original)
+++ trunk/include/asterisk/utils.h Fri Aug 16 02:18:51 2013
@@ -25,6 +25,7 @@
#include "asterisk/network.h"
+#include <execinfo.h>
#include <time.h> /* we want to override localtime_r */
#include <unistd.h>
#include <string.h>
@@ -483,8 +484,24 @@
#ifndef __AST_DEBUG_MALLOC
+/* This buffer is in static memory. We never intend to read it,
+ * nor do we care about multiple threads writing to it at the
+ * same time. We only want to know if we're recursing too deep
+ * already. 60 entries should be more than enough. Function call
+ * depth rarely exceeds 20 or so. */
+#define _AST_MEM_BACKTRACE_BUFLEN 60
+extern void *_ast_mem_backtrace_buffer[_AST_MEM_BACKTRACE_BUFLEN];
+
#define MALLOC_FAILURE_MSG \
- ast_log(LOG_ERROR, "Memory Allocation Failure in function %s at line %d of %s\n", func, lineno, file);
+ { \
+ /* Ok, this sucks. But if we're already out of mem, we don't \
+ * want the logger to create infinite recursion (and a crash). */ \
+ if (backtrace(_ast_mem_backtrace_buffer, _AST_MEM_BACKTRACE_BUFLEN) < \
+ _AST_MEM_BACKTRACE_BUFLEN) { \
+ ast_log(LOG_ERROR, "Memory Allocation Failure in function %s at line %d of %s\n", func, lineno, file); \
+ } \
+ }
+
/*!
* \brief A wrapper for malloc()
*
Modified: trunk/main/pbx.c
URL: http://svnview.digium.com/svn/asterisk/trunk/main/pbx.c?view=diff&rev=396822&r1=396821&r2=396822
==============================================================================
--- trunk/main/pbx.c (original)
+++ trunk/main/pbx.c Fri Aug 16 02:18:51 2013
@@ -7281,6 +7281,81 @@
return CLI_SUCCESS;
}
+#if 0
+/* This code can be used to test if the system survives running out of memory.
+ * It might be an idea to put this in only if ENABLE_AUTODESTRUCT_TESTS is enabled.
+ *
+ * If you want to test this, these Linux sysctl flags might be appropriate:
+ * vm.overcommit_memory = 2
+ * vm.swappiness = 0
+ *
+ * <@Corydon76-home> I envision 'core eat disk space' and 'core eat file descriptors' now
+ * <@mjordan> egads
+ * <@mjordan> it's literally the 'big red' auto-destruct button
+ * <@mjordan> if you were wondering who even builds such a thing.... well, now you know
+ * ...
+ * <@Corydon76-home> What about if they lived only if you defined TEST_FRAMEWORK? Shouldn't have those on production machines
+ * <@mjordan> I think accompanied with an update to one of our README files that "no, really, TEST_FRAMEWORK isn't for you", I'd be fine
+ */
+static char *handle_eat_memory(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+{
+ void **blocks;
+ int blocks_pos = 0;
+ const int blocks_max = 50000;
+ long long int allocated = 0;
+ int sizes[] = {
+ 100 * 1024 * 1024,
+ 100 * 1024,
+ 2 * 1024,
+ 400,
+ 0
+ };
+ int i;
+
+ switch (cmd) {
+ case CLI_INIT:
+ /* To do: add method to free memory again? 5 minutes? */
+ e->command = "core eat memory";
+ e->usage =
+ "Usage: core eat memory\n"
+ " Eats all available memory so you can test if the system survives\n";
+ return NULL;
+ case CLI_GENERATE:
+ return NULL;
+ }
+
+ blocks = ast_malloc(sizeof(void*) * blocks_max);
+ if (!blocks) {
+ ast_log(LOG_ERROR, "Already out of mem?\n");
+ return CLI_SUCCESS;
+ }
+
+ for (i = 0; sizes[i]; ++i) {
+ int alloc_size = sizes[i];
+ ast_log(LOG_WARNING, "Allocating %d sized blocks (got %d blocks already)\n", alloc_size, blocks_pos);
+ while (1) {
+ void *block;
+ if (blocks_pos >= blocks_max) {
+ ast_log(LOG_ERROR, "Memory buffer too small? Run me again :)\n");
+ break;
+ }
+
+ block = ast_malloc(alloc_size);
+ if (!block) {
+ break;
+ }
+
+ blocks[blocks_pos++] = block;
+ allocated += alloc_size;
+ }
+ }
+
+ /* No freeing of the mem! */
+ ast_log(LOG_WARNING, "Allocated %lld bytes total!\n", allocated);
+ return CLI_SUCCESS;
+}
+#endif
+
static char *handle_show_applications(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
struct ast_app *aa;
@@ -8162,6 +8237,9 @@
* CLI entries for upper commands ...
*/
static struct ast_cli_entry pbx_cli[] = {
+#if 0
+ AST_CLI_DEFINE(handle_eat_memory, "Eats all available memory"),
+#endif
AST_CLI_DEFINE(handle_show_applications, "Shows registered dialplan applications"),
AST_CLI_DEFINE(handle_show_functions, "Shows registered dialplan functions"),
AST_CLI_DEFINE(handle_show_switches, "Show alternative switches"),
Modified: trunk/main/utils.c
URL: http://svnview.digium.com/svn/asterisk/trunk/main/utils.c?view=diff&rev=396822&r1=396821&r2=396822
==============================================================================
--- trunk/main/utils.c (original)
+++ trunk/main/utils.c Fri Aug 16 02:18:51 2013
@@ -73,6 +73,8 @@
static char base64[64];
static char b2a[256];
+
+void *_ast_mem_backtrace_buffer[_AST_MEM_BACKTRACE_BUFLEN];
AST_THREADSTORAGE(inet_ntoa_buf);
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