From d94a7b5c516c0446d1c49e8446707a64b4b45148 Mon Sep 17 00:00:00 2001

From: Jakub Filak <jfilak@redhat.com>

Date: Tue, 2 Aug 2016 08:50:10 +0200

Subject: [PATCH] Honor frame number limit in GDB core unwinder

Related to #1260074

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

---

 lib/core_unwind.c          | 15 +++++++++++++++

 lib/core_unwind_elfutils.c |  6 ++----

 lib/internal_unwind.h      |  5 +++++

 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/lib/core_unwind.c b/lib/core_unwind.c

index b8c0235..05b94a5 100644

--- a/lib/core_unwind.c

+++ b/lib/core_unwind.c

@@ -429,6 +429,8 @@ sr_core_stacktrace_from_gdb(const char *gdb_output, const char *core_file,

     {

         struct sr_core_thread *core_thread = sr_core_thread_new();

+        unsigned long nframes = CORE_STACKTRACE_FRAME_LIMIT;

+        struct sr_gdb_frame *top_frame = gdb_thread->frames;

         for (struct sr_gdb_frame *gdb_frame = gdb_thread->frames;

              gdb_frame;

              gdb_frame = gdb_frame->next)

@@ -436,6 +438,19 @@ sr_core_stacktrace_from_gdb(const char *gdb_output, const char *core_file,

             if (gdb_frame->signal_handler_called)

                 continue;

+            if (nframes)

+                --nframes;

+            else

+                top_frame = top_frame->next;

+        }

+

+        for (struct sr_gdb_frame *gdb_frame = top_frame;

+             gdb_frame;

+             gdb_frame = gdb_frame->next)

+        {

+            if (gdb_frame->signal_handler_called)

+                continue;

+

             struct sr_core_frame *core_frame = resolve_frame(ch->dwfl,

                     gdb_frame->address, false);

diff --git a/lib/core_unwind_elfutils.c b/lib/core_unwind_elfutils.c

index 1482dba..d273a03 100644

--- a/lib/core_unwind_elfutils.c

+++ b/lib/core_unwind_elfutils.c

@@ -33,8 +33,6 @@

 #include <sys/ptrace.h>

 #include <sys/wait.h>

-#define FRAME_LIMIT 256

-

 struct frame_callback_arg

 {

     struct sr_core_frame **frames_tail;

@@ -84,8 +82,8 @@ frame_callback(Dwfl_Frame *frame, void *data)

 static void

 truncate_long_thread(struct sr_core_thread *thread, struct frame_callback_arg *frame_arg)

 {

-    /* Truncate the stacktrace to FRAME_LIMIT least recent frames. */

-    while (thread->frames && frame_arg->nframes > FRAME_LIMIT)

+    /* Truncate the stacktrace to CORE_STACKTRACE_FRAME_LIMIT least recent frames. */

+    while (thread->frames && frame_arg->nframes > CORE_STACKTRACE_FRAME_LIMIT)

     {

         struct sr_core_frame *old_frame = thread->frames;

         thread->frames = old_frame->next;

diff --git a/lib/internal_unwind.h b/lib/internal_unwind.h

index 84261c6..b9e162a 100644

--- a/lib/internal_unwind.h

+++ b/lib/internal_unwind.h

@@ -66,6 +66,11 @@ _set_error(char **error_msg, const char *fmt, ...) __sr_printf(2, 3);

         }                                    \

     } while(0)

+/* This macro is used as a limit for the number of function frames included in

+ * every single thread of a core stacktrace generated by satyr.

+ */

+#define CORE_STACKTRACE_FRAME_LIMIT 256

+

 struct exe_mapping_data

 {

     uint64_t start;

-- 

2.17.1