Fix 'test_debuginfo' from failing if a symbol has multiple aliases

The first symbol from /proc/kallsyms is read by 'test_debuginfo'
and the name obtained here is compared against the name obtained
from the BPF.ksym() library call. In some architectures such as
powerpc64le, a kernel symbol may have multiple aliases that refer
to the same address. So, to avoid the test from failing, we need
to compare the name returned by BPF.ksym() against all possible
aliases for the given address in /proc/kallsyms and look for a
match.
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>

tests/python/test_debuginfo.py

@@ -9,12 +9,27 @@ from unittest import main, TestCase
 
 class TestKSyms(TestCase):
     def grab_sym(self):
-        # Grab the first symbol in kallsyms that has type 't'.
+        address = ""
+        aliases = []
+
+        # Grab the first symbol in kallsyms that has type 't' or 'T'.
+        # Also, find all aliases of this symbol which are identifiable
+        # by the same address.
         with open("/proc/kallsyms") as f:
             for line in f:
-                (addr, t, name) = line.strip().split()
-                if t == "t":
-                    return (addr, name)
+
+                # Extract the first 3 columns only. The 4th column
+                # containing the module name may not exist for all
+                # symbols.
+                (addr, t, name) = line.strip().split()[:3]
+                if t == "t" or t == "T":
+                    if not address:
+                        address = addr
+                    if addr == address:
+                        aliases.append(name)
+
+        # Return all aliases of the first symbol.
+        return (address, aliases)
 
     def test_ksymname(self):
         sym = BPF.ksymname("__kmalloc")
@@ -22,9 +37,10 @@ class TestKSyms(TestCase):
         self.assertNotEqual(sym, 0)
 
     def test_ksym(self):
-        (addr, name) = self.grab_sym()
+        (addr, aliases) = self.grab_sym()
         sym = BPF.ksym(int(addr, 16))
-        self.assertEqual(sym, name)
+        found = sym in aliases
+        self.assertTrue(found)
 
 class Harness(TestCase):
     def setUp(self):