From 4eee77568fe24bcb9341ee9c2eaa74cb048103cb Mon Sep 17 00:00:00 2001

From: Jakub Filak <jfilak@redhat.com>

Date: Thu, 13 Nov 2014 12:08:07 +0100

Subject: [PATCH] gdb: make gdb aware of the abrt's debuginfo dir

A debuginfo package might ship an auto-loaded gdb script. If abrt

unpacks that package into the abrt's debuginfo cache dir and points gdb

to that directory, gdb refuses to auto-loaded that gdb scripts and

produces a plenty of warning messages that abrt writes to 'backtrace'

file.

The previous solution of this issue was to turn auto-load off completely

but it turned the pretty printer off too.

The correct solution is to add the abrt's debuginfo cache directory to

auto-load safe-path and auto-load scripts-dir settings.

Thanks Jan Kratochvil <jkratoch@redhat.com>

Requires: rhbz#1163335

Signed-off-by: Jakub Filak <jfilak@redhat.com>

---

 src/lib/hooklib.c | 83 ++++++++++++++++++++++++++++++++++++-------------------

 1 file changed, 55 insertions(+), 28 deletions(-)

diff --git a/src/lib/hooklib.c b/src/lib/hooklib.c

index 4a50727..1d45cdd 100644

--- a/src/lib/hooklib.c

+++ b/src/lib/hooklib.c

@@ -252,11 +252,12 @@ char *get_backtrace(const char *dump_dir_name, unsigned timeout_sec, const char

     /* Let user know what's going on */

     log(_("Generating backtrace"));

-    char *args[21];

-    args[0] = (char*)"gdb";

-    args[1] = (char*)"-batch";

-    args[2] = (char*)"-ex";

+    unsigned i = 0;

+    char *args[25];

+    args[i++] = (char*)"gdb";

+    args[i++] = (char*)"-batch";

     struct strbuf *set_debug_file_directory = strbuf_new();

+    unsigned auto_load_base_index = 0;

     if(debuginfo_dirs == NULL)

     {

         // set non-existent debug file directory to prevent resolving

@@ -266,6 +267,8 @@ char *get_backtrace(const char *dump_dir_name, unsigned timeout_sec, const char

     else

     {

         strbuf_append_str(set_debug_file_directory, "set debug-file-directory /usr/lib/debug");

+

+        struct strbuf *debug_directories = strbuf_new();

         const char *p = debuginfo_dirs;

         while (1)

         {

@@ -274,11 +277,25 @@ char *get_backtrace(const char *dump_dir_name, unsigned timeout_sec, const char

             if (*p == '\0')

                 break;

             const char *colon_or_nul = strchrnul(p, ':');

-            strbuf_append_strf(set_debug_file_directory, ":%.*s/usr/lib/debug", (int)(colon_or_nul - p), p);

+            strbuf_append_strf(debug_directories, "%s%.*s/usr/lib/debug", (debug_directories->len == 0 ? "" : ":"),

+                                                                          (int)(colon_or_nul - p), p);

             p = colon_or_nul;

         }

+

+        strbuf_append_strf(set_debug_file_directory, ":%s", debug_directories->buf);

+

+        args[i++] = (char*)"-iex";

+        auto_load_base_index = i;

+        args[i++] = xasprintf("add-auto-load-safe-path %s", debug_directories->buf);

+        args[i++] = (char*)"-iex";

+        args[i++] = xasprintf("add-auto-load-scripts-directory %s", debug_directories->buf);

+

+        strbuf_free(debug_directories);

     }

-    args[3] = strbuf_free_nobuf(set_debug_file_directory);

+

+    args[i++] = (char*)"-ex";

+    const unsigned debug_dir_cmd_index = i++;

+    args[debug_dir_cmd_index] = strbuf_free_nobuf(set_debug_file_directory);

     /* "file BINARY_FILE" is needed, without it gdb cannot properly

      * unwind the stack. Currently the unwind information is located

@@ -300,27 +317,31 @@ char *get_backtrace(const char *dump_dir_name, unsigned timeout_sec, const char

      * TODO: check mtimes on COREFILE and BINARY_FILE and not supply

      * BINARY_FILE if it is newer (to at least avoid gdb complaining).

      */

-    args[4] = (char*)"-ex";

-    args[5] = xasprintf("file %s", executable);

+    args[i++] = (char*)"-ex";

+    const unsigned file_cmd_index = i++;

+    args[file_cmd_index] = xasprintf("file %s", executable);

     free(executable);

-    args[6] = (char*)"-ex";

-    args[7] = xasprintf("core-file %s/"FILENAME_COREDUMP, dump_dir_name);

+    args[i++] = (char*)"-ex";

+    const unsigned core_cmd_index = i++;

+    args[core_cmd_index] = xasprintf("core-file %s/"FILENAME_COREDUMP, dump_dir_name);

-    args[8] = (char*)"-ex";

+    args[i++] = (char*)"-ex";

+    const unsigned bt_cmd_index = i++;

     /*args[9] = ... see below */

-    args[10] = (char*)"-ex";

-    args[11] = (char*)"info sharedlib";

+    args[i++] = (char*)"-ex";

+    args[i++] = (char*)"info sharedlib";

     /* glibc's abort() stores its message in __abort_msg variable */

-    args[12] = (char*)"-ex";

-    args[13] = (char*)"print (char*)__abort_msg";

-    args[14] = (char*)"-ex";

-    args[15] = (char*)"print (char*)__glib_assert_msg";

-    args[16] = (char*)"-ex";

-    args[17] = (char*)"info all-registers";

-    args[18] = (char*)"-ex";

-    args[19] = (char*)"disassemble";

-    args[20] = NULL;

+    args[i++] = (char*)"-ex";

+    args[i++] = (char*)"print (char*)__abort_msg";

+    args[i++] = (char*)"-ex";

+    args[i++] = (char*)"print (char*)__glib_assert_msg";

+    args[i++] = (char*)"-ex";

+    args[i++] = (char*)"info all-registers";

+    args[i++] = (char*)"-ex";

+    const unsigned dis_cmd_index = i++;

+    args[dis_cmd_index] = (char*)"disassemble";

+    args[i++] = NULL;

     /* Get the backtrace, but try to cap its size */

     /* Limit bt depth. With no limit, gdb sometimes OOMs the machine */

@@ -330,9 +351,9 @@ char *get_backtrace(const char *dump_dir_name, unsigned timeout_sec, const char

     char *bt = NULL;

     while (1)

     {

-        args[9] = xasprintf("%s backtrace %u%s", thread_apply_all, bt_depth, full);

+        args[bt_cmd_index] = xasprintf("%s backtrace %u%s", thread_apply_all, bt_depth, full);

         bt = exec_vp(args, /*redirect_stderr:*/ 1, timeout_sec, NULL);

-        free(args[9]);

+        free(args[bt_cmd_index]);

         if ((bt && strnlen(bt, 256*1024) < 256*1024) || bt_depth <= 32)

         {

             break;

@@ -357,7 +378,7 @@ char *get_backtrace(const char *dump_dir_name, unsigned timeout_sec, const char

          * End of assembler dump.

          * (IOW: "empty" dump)

          */

-        args[19] = (char*)"disassemble $pc-20, $pc+64";

+        args[dis_cmd_index] = (char*)"disassemble $pc-20, $pc+64";

         if (bt_depth <= 64 && thread_apply_all[0] != '\0')

         {

@@ -373,9 +394,15 @@ char *get_backtrace(const char *dump_dir_name, unsigned timeout_sec, const char

         }

     }

-    free(args[3]);

-    free(args[5]);

-    free(args[7]);

+    if (auto_load_base_index > 0)

+    {

+        free(args[auto_load_base_index]);

+        free(args[auto_load_base_index + 2]);

+    }

+

+    free(args[debug_dir_cmd_index]);

+    free(args[file_cmd_index]);

+    free(args[core_cmd_index]);

     return bt;

 }

-- 

2.1.0