[PATCH] tests: Allow an extra pthread_kill frame in backtrace tests

[Mark Wielaard <mark@klomp.org>]

glibc 2.34 calls pthread_kill from the raise function. Before raise
directly called the (tg)kill syscall. So allow pthread_kill to be the
first frame in a backtrace where raise is expected. Also change some
asserts to fprintf plus abort to make it more clear why the testcase
fails.

https://sourceware.org/bugzilla/show_bug.cgi?id=28190

Signed-off-by: Mark Wielaard <mark@klomp.org>
---
 tests/ChangeLog   |  6 +++++
 tests/backtrace.c | 62 +++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 61 insertions(+), 7 deletions(-)

diff --git a/tests/ChangeLog b/tests/ChangeLog
index 34666609..3bfd1ca2 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,9 @@
+2021-08-04  Mark Wielaard  <mark@klomp.org>
+
+	PR28190
+	* backtrace.c (callback_verify): Check for pthread_kill as first
+	frame. Change asserts to fprintf plus abort.
+
 2021-07-26  Noah Sanci  <nsanci@redhat.com>
 
 	PR27982
diff --git a/tests/backtrace.c b/tests/backtrace.c
index 36c8b8c4..779335df 100644
--- a/tests/backtrace.c
+++ b/tests/backtrace.c
@@ -97,6 +97,9 @@ callback_verify (pid_t tid, unsigned frameno, Dwarf_Addr pc,
   static bool reduce_frameno = false;
   if (reduce_frameno)
     frameno--;
+  static bool pthread_kill_seen = false;
+  if (pthread_kill_seen)
+    frameno--;
   if (! use_raise_jmp_patching && frameno >= 2)
     frameno += 2;
   const char *symname2 = NULL;
@@ -107,11 +110,27 @@ callback_verify (pid_t tid, unsigned frameno, Dwarf_Addr pc,
 	       && (strcmp (symname, "__kernel_vsyscall") == 0
 		   || strcmp (symname, "__libc_do_syscall") == 0))
 	reduce_frameno = true;
+      else if (! pthread_kill_seen && symname
+	       && strncmp (symname, "pthread_kill",
+			   strlen ("pthread_kill")) == 0)
+	pthread_kill_seen = true;
       else
-	assert (symname && strcmp (symname, "raise") == 0);
+	{
+	  if (!symname || strcmp (symname, "raise") != 0)
+	    {
+	      fprintf (stderr,
+		       "case 0: expected symname 'raise' got '%s'\n", symname);
+	      abort ();
+	    }
+	}
       break;
     case 1:
-      assert (symname != NULL && strcmp (symname, "sigusr2") == 0);
+      if (symname == NULL || strcmp (symname, "sigusr2") != 0)
+	{
+	  fprintf (stderr,
+		   "case 1: expected symname 'sigusr2' got '%s'\n", symname);
+	  abort ();
+	}
       break;
     case 2: // x86_64 only
       /* __restore_rt - glibc maybe does not have to have this symbol.  */
@@ -120,11 +139,21 @@ callback_verify (pid_t tid, unsigned frameno, Dwarf_Addr pc,
       if (use_raise_jmp_patching)
 	{
 	  /* Verify we trapped on the very first instruction of jmp.  */
-	  assert (symname != NULL && strcmp (symname, "jmp") == 0);
+	  if (symname == NULL || strcmp (symname, "jmp") != 0)
+	    {
+	      fprintf (stderr,
+		       "case 3: expected symname 'raise' got '%s'\n", symname);
+	      abort ();
+	    }
 	  mod = dwfl_addrmodule (dwfl, pc - 1);
 	  if (mod)
 	    symname2 = dwfl_module_addrname (mod, pc - 1);
-	  assert (symname2 == NULL || strcmp (symname2, "jmp") != 0);
+	  if (symname2 == NULL || strcmp (symname2, "jmp") != 0)
+	    {
+	      fprintf (stderr,
+		       "case 3: expected symname2 'jmp' got '%s'\n", symname2);
+	      abort ();
+	    }
 	  break;
 	}
       FALLTHROUGH;
@@ -137,11 +166,22 @@ callback_verify (pid_t tid, unsigned frameno, Dwarf_Addr pc,
 	  duplicate_sigusr2 = true;
 	  break;
 	}
-      assert (symname != NULL && strcmp (symname, "stdarg") == 0);
+      if (symname == NULL || strcmp (symname, "stdarg") != 0)
+	{
+	  fprintf (stderr,
+		   "case 4: expected symname 'stdarg' got '%s'\n", symname);
+	  abort ();
+	}
       break;
     case 5:
       /* Verify we trapped on the very last instruction of child.  */
-      assert (symname != NULL && strcmp (symname, "backtracegen") == 0);
+      if (symname == NULL || strcmp (symname, "backtracegen") != 0)
+	{
+	  fprintf (stderr,
+		   "case 5: expected symname 'backtracegen' got '%s'\n",
+		   symname);
+	  abort ();
+	}
       mod = dwfl_addrmodule (dwfl, pc);
       if (mod)
 	symname2 = dwfl_module_addrname (mod, pc);
@@ -151,7 +191,15 @@ callback_verify (pid_t tid, unsigned frameno, Dwarf_Addr pc,
       // instructions or even inserts some padding instructions at the end
       // (which apparently happens on ppc64).
       if (use_raise_jmp_patching)
-        assert (symname2 == NULL || strcmp (symname2, "backtracegen") != 0);
+	{
+          if (symname2 != NULL && strcmp (symname2, "backtracegen") == 0)
+	    {
+	      fprintf (stderr,
+		       "use_raise_jmp_patching didn't expect symname2 "
+		       "'backtracegen'\n");
+	      abort ();
+	    }
+	}
       break;
   }
 }
-- 
2.18.4