Re: [Bug debuginfod/27983] ignore duplicate urls

[Mark Wielaard <mark@klomp.org>]

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Hi Noah,

On Mon, 2021-07-26 at 12:29 -0400, Noah Sanci via Elfutils-devel wrote:
> The realloc returning NULL issue has been resolved and the patch
> successfully rebased onto master. Please find these improvements
> attached.

This looks really good, but I found some small issues.

First it turns out reallocarray isn't available on some older systems.
This is easy to workaround though since it is a fairly simple function
we could provide ourselves if it isn't there. The attached patch does
that. I'll push it if it looks good.

Second there is a small memory leak found by valgrind. We only clean up
the server_url_list on failure, but we should also clean it up when we
are done on success:

diff --git a/debuginfod/debuginfod-client.c b/debuginfod/debuginfod-
client.c
index 9d049d33..0f65f115 100644
--- a/debuginfod/debuginfod-client.c
+++ b/debuginfod/debuginfod-client.c
@@ -1191,6 +1191,9 @@ debuginfod_query_server (debuginfod_client *c,
     }
 
   free (data);
+  for (int i = 0; i < num_urls; ++i)
+    free(server_url_list[i]);
+  free(server_url_list);
   free (server_urls);
 
   /* don't close fd - we're returning it */

Finally on some systems, but not all, one of the tests in run-
debuginfod-find.sh failed. In particular this one:

# check out the debuginfod logs for the new style status lines
# cat vlog$PORT2
grep -q 'UA:.*XFF:.*GET /buildid/.* 200 ' vlog$PORT2
grep -q 'UA:.*XFF:.*GET /metrics 200 ' vlog$PORT2
grep -q 'UA:.*XFF:.*GET /badapi 503 ' vlog$PORT2
grep -q 'UA:.*XFF:.*GET /buildid/deadbeef.* 404 ' vlog$PORT2

That last one changed error message from 404 to 503. This seems related
to the setting of DEBUGINFOD_URLS earlier by the new test you added. If
I change that to:

diff --git a/tests/run-debuginfod-find.sh b/tests/run-debuginfod-find.sh
index c2c3b9c3..ec639a38 100755
--- a/tests/run-debuginfod-find.sh
+++ b/tests/run-debuginfod-find.sh
@@ -367,8 +367,7 @@ wait_ready $PORT1 'found_sourcerefs_total{source=".rpm archive"}' $sourcefiles
 ########################################################################
 # PR27983 ensure no duplicate urls are used in when querying servers for files
 rm -rf $DEBUGINFOD_CACHE_PATH # clean it from previous tests
-export DEBUGINFOD_URLS="http://127.0.0.1:$PORT1 http://127.0.0.1:$PORT1 http://127.0.0.1:$PORT1 http:127.0.0.1:7999"
-env LD_LIBRARY_PATH=$ldpath ${abs_top_builddir}/debuginfod/debuginfod-find -v executable $BUILDID2 > vlog4 2>&1 || true
+env DEBUGINFOD_URLS="http://127.0.0.1:$PORT1 http://127.0.0.1:$PORT1 http://127.0.0.1:$PORT1 http:127.0.0.1:7999" LD_LIBRARY_PATH=$ldpath ${abs_top_builddir}/debuginfod/debuginfod-find -v executable $BUILDID2 > vlog4 2>&1 || true
 tempfiles vlog4
 if [ $( grep -c 'duplicate url: http://127.0.0.1:'$PORT1'.*' vlog4 ) -ne 2 ]; then
   echo "Duplicated servers remain";

Everything seems to pass everywhere.

run-debuginfod-find.sh is really convoluted and we really shouldn't add
more and more interacting tests to it. But if we do maybe we should use
the env DEBUGINFOD_URLS=... trick to minimize changing other tests in
the same file.

If you agree with the above two changes, could you resubmit the patch
with those?

Thanks,

Mark

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From 61210f91afa4084a46bd0f84d12aa6d3f29c1271 Mon Sep 17 00:00:00 2001
From: Mark Wielaard <mark@klomp.org>
Date: Wed, 28 Jul 2021 16:46:36 +0200
Subject: [PATCH] lib: Add static inline reallocarray fallback function

Signed-off-by: Mark Wielaard <mark@klomp.org>
---
 ChangeLog     |  4 ++++
 configure.ac  |  3 +++
 lib/ChangeLog |  4 ++++
 lib/system.h  | 14 ++++++++++++++
 4 files changed, 25 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index a01f6f9f..12b8f403 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2021-07-28  Mark Wielaard  <mark@klomp.org>
+
+	* configure.ac (AC_CHECK_DECLS): Add reallocarray check.
+
 2021-05-22  Mark Wielaard  <mark@klomp.org>
 
 	* configure.ac (AC_INIT): Set version to 0.185.
diff --git a/configure.ac b/configure.ac
index b348a717..7caff2c5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -425,6 +425,9 @@ AC_CHECK_DECLS([powerof2],[],[],[#include <sys/param.h>])
 AC_CHECK_DECLS([mempcpy],[],[],
                [#define _GNU_SOURCE
                 #include <string.h>])
+AC_CHECK_DECLS([reallocarray],[],[],
+               [#define _GNU_SOURCE
+                #include <stdlib.h>])
 
 AC_CHECK_FUNCS([process_vm_readv])
 
diff --git a/lib/ChangeLog b/lib/ChangeLog
index dd3ebcab..44366fec 100644
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,3 +1,7 @@
+2021-07-28  Mark Wielaard  <mark@klomp.org>
+
+	* system.h (reallocarray): New static inline fallback function.
+
 2021-04-19  Martin Liska  <mliska@suse.cz>
 
 	* system.h (startswith): New function.
diff --git a/lib/system.h b/lib/system.h
index cdf18ed7..58d9deee 100644
--- a/lib/system.h
+++ b/lib/system.h
@@ -38,6 +38,7 @@
 #include <byteswap.h>
 #include <unistd.h>
 #include <string.h>
+#include <stdlib.h>
 
 #if __BYTE_ORDER == __LITTLE_ENDIAN
 # define LE32(n)	(n)
@@ -70,6 +71,19 @@
     ((void *) ((char *) memcpy (dest, src, n) + (size_t) n))
 #endif
 
+#if !HAVE_DECL_REALLOCARRAY
+static inline void *
+reallocarray (void *ptr, size_t nmemb, size_t size)
+{
+  if (size > 0 && nmemb > SIZE_MAX / size)
+    {
+      errno = ENOMEM;
+      return NULL;
+    }
+  return realloc (ptr, nmemb * size);
+}
+#endif
+
 /* Return TRUE if the start of STR matches PREFIX, FALSE otherwise.  */
 
 static inline int
-- 
2.18.4