[Buildroot] [git commit] package/syslog-ng: fix runtime in 32-bit

Arnout Vandecappelle (Essensium/Mind) arnout at mind.be
Sat Sep 21 18:59:41 UTC 2019


commit: https://git.buildroot.net/buildroot/commit/?id=ee6b98b1ea094dbe5b427373a170ef93c08099d5
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/master

When this line:
  unix-stream ("/dev/log");
is used as source in the .conf file and syslog-ng receives a message
(sent for test purposes using 'logger') the server throws the exception:
ERROR:lib/window-size-counter.c:76:window_size_counter_sub: assertion failed: (old_value >= value)

Even after replacing that config by:
  unix-dgram ("/dev/log");
when the server is stopped it throws the same exception.

Add one upstream patch to fix both issues.

Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/295369456

Signed-off-by: Ricardo Martincoski <ricardo.martincoski at gmail.com>
Cc: Chris Packham <judge.packham at gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
---
 ...dd-explicit-un-initialized-state-to-Windo.patch | 118 +++++++++++++++++++++
 1 file changed, 118 insertions(+)

diff --git a/package/syslog-ng/0002-logsource-add-explicit-un-initialized-state-to-Windo.patch b/package/syslog-ng/0002-logsource-add-explicit-un-initialized-state-to-Windo.patch
new file mode 100644
index 0000000000..1ddf0be1fd
--- /dev/null
+++ b/package/syslog-ng/0002-logsource-add-explicit-un-initialized-state-to-Windo.patch
@@ -0,0 +1,118 @@
+From e350607f27b78094fb72422faf5394384ae6193b Mon Sep 17 00:00:00 2001
+From: Laszlo Budai <laszlo.budai at outlook.com>
+Date: Thu, 29 Aug 2019 17:09:39 +0200
+Subject: [PATCH] logsource: add explicit (un)initialized state to
+ WindowSizeCounter
+
+Fixes: #2893
+
+On 32 bit systems (or non-64 bit systems), syslog-ng could abort during
+shutdown.
+
+What was the reason of the abort?
+a) in `log_source_set_options` where we set the initial window size
+conditionally, the condition was false thus the `full_window_size`
+remained 0
+b) when `log_source_free` is called during shutdown,
+ * `_release_dynamic_window` called unconditionally and
+ *  a dynamic_part is calculated as full_window_size(=0) - init_window_size(=default 100),
+ so dynamic_part = -100
+ * window_size is decremented by dynamic_part(-100) and the
+ `window_size_counter_sub` asserts on old_value >= value, and this
+ assert failed, so syslog-ng aborted
+
+So the questions are
+1) why we did not set initial window size?
+2) why old_value was not greater than value?
+
+Answers:
+1) the value we get from `window_size_counter_get` is the masked
+value... on 64 bit systems this value is a 63 bits of `1` and it is compared to
+a 32 bits of `1` but the 63 bits are truncated to 32 thanks to an explicit cast
+And what if we are on a 32 bits system?
+Well... the sizeof(gsize) is 4 , sizeof(gint) is also 4 on these
+systems. This means that the `window_size_counter_get` returns 31 bits of
+`-1`, and it is compared to 32 bits of `1` : they are obviously not
+equals -> we won't set full_window_size
+
+2) old_value is a -1, which is masked, so the actual old value is 2^31-1, while new value is a
+-100, which is (2^32-100), so on a 32 bits system 31 bit negative value is
+compared to a  to 32 bits negative value...
+
+Proposed solution:
+ * add a initialized state to LogSource: this is checked/(set to TRUE) only in
+ `log_source_set_options`, and set to FALSE only in `log_source_init_instance`
+
+Signed-off-by: Laszlo Budai <laszlo.budai at outlook.com>
+[Retrieved from:
+https://github.com/syslog-ng/syslog-ng/commit/e350607f27b78094fb72422faf5394384ae6193b]
+Signed-off-by: Ricardo Martincoski <ricardo.martincoski at gmail.com>
+---
+ lib/logsource.c | 23 +++++++++++++++++------
+ lib/logsource.h |  1 +
+ 2 files changed, 18 insertions(+), 6 deletions(-)
+
+diff --git a/lib/logsource.c b/lib/logsource.c
+index 3f38b66e8..67e1c1570 100644
+--- a/lib/logsource.c
++++ b/lib/logsource.c
+@@ -633,7 +633,20 @@ log_source_queue(LogPipe *s, LogMessage *msg, const LogPathOptions *path_options
+                   evt_tag_printf("msg", "%p", msg));
+ 
+   msg_set_context(NULL);
++}
++
++static void
++_initialize_window(LogSource *self, gint init_window_size)
++{
++  self->window_initialized = TRUE;
++  window_size_counter_set(&self->window_size, init_window_size);
++  self->full_window_size = init_window_size;
++}
+ 
++static gboolean
++_is_window_initialized(LogSource *self)
++{
++  return self->window_initialized;
+ }
+ 
+ void
+@@ -645,11 +658,9 @@ log_source_set_options(LogSource *self, LogSourceOptions *options,
+    * configuration and we received a SIGHUP.  This means that opened
+    * connections will not have their window_size changed. */
+ 
+-  if ((gint)window_size_counter_get(&self->window_size, NULL) == -1)
+-    {
+-      window_size_counter_set(&self->window_size, options->init_window_size);
+-      self->full_window_size = options->init_window_size;
+-    }
++  if (!_is_window_initialized(self))
++    _initialize_window(self, options->init_window_size);
++
+   self->options = options;
+   if (self->stats_id)
+     g_free(self->stats_id);
+@@ -679,7 +690,7 @@ log_source_init_instance(LogSource *self, GlobalConfig *cfg)
+   self->super.free_fn = log_source_free;
+   self->super.init = log_source_init;
+   self->super.deinit = log_source_deinit;
+-  window_size_counter_set(&self->window_size, (gsize)-1);
++  self->window_initialized = FALSE;
+   self->ack_tracker = NULL;
+ }
+ 
+diff --git a/lib/logsource.h b/lib/logsource.h
+index 370842efc..75d492604 100644
+--- a/lib/logsource.h
++++ b/lib/logsource.h
+@@ -71,6 +71,7 @@ struct _LogSource
+   gchar *stats_instance;
+   WindowSizeCounter window_size;
+   DynamicWindow dynamic_window;
++  gboolean window_initialized;
+   /* full_window_size = static + dynamic */
+   gsize full_window_size;
+   atomic_gssize window_size_to_be_reclaimed;
+-- 
+2.17.1
+


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