Tests of jump and function tables. (#13)

* Added code snippets for jumptables.

* Added -fno-plt mode for %rip-based calls.

* Added todo.

* Use itertools.product instead of nested loops.

* Added tests for indirect pointers.

test/templates/funtable.c

@@ -0,0 +1,5 @@
+int bar(int x, void (*f[])(int x)) {
+  if (x > 0)
+    f[0](x);
+  f[1](x);
+}

test/templates/gen_calls.py

@@ -5,56 +5,62 @@
 """
 
 # TODO: find a way to produce other snippets we see in disasm:
-#  call   *0x273a0(%rip)
-#  call   *%rax
-#  call   *0x8(%rax)
 #  addr32 call 0x5555555733e0
 #  call   0x555555576a00
 
 import os.path
+import itertools
 
 from common import set_basename, gcc, disasm, grep
 
 set_basename(os.path.basename(__file__))
 
-for gdb in [False, True]:
-    for pic in [False, True]:  # Do we need to test PIE too?
-        for direct in [False, True] if pic else [True]:
-            for strip in [False, True]:
-                # Print config
+for gdb, pic, plt, direct, strip in itertools.product([False, True],
+                                                      [False, True],  # Do we need to test PIE too?
+                                                      [False, True],
+                                                      [False, True],
+                                                      [False, True]):
+    # Print config
 
-                disasm_type = 'GDB' if gdb else 'objdump'
-                pic_type = 'position-INdependent' if pic else 'position-dependent'
-                call_type = 'PIC-call' if direct else 'PLT-call'
-                strip_type = 'stripped' if strip else 'UNstripped'
-                print(f"Checking {disasm_type} {pic_type} {call_type} {strip_type}")
+    disasm_type = 'GDB' if gdb else 'objdump'
+    pic_type = 'position-INdependent' if pic else 'position-dependent'
+    call_type = 'Non-PIC-call' if direct else 'PIC-call'
+    strip_type = 'stripped' if strip else 'UNstripped'
+    plt_type = 'PLT' if plt else 'PLT-less'
+    print(f"Checking {disasm_type} {pic_type} {plt_type} {call_type} {strip_type}")
 
-                # Generate object code
+    # Generate object code
 
-                flags = ['call.c', '-o', 'a.out',
-                         '-Wl,--defsym,_start=0', '-nostdlib', '-nostartfiles']
-                # DLL or executable?
-                if pic:
-                    flags += ['-fPIC', '-shared']
-                # Force non-PLT call for PIC code?
-                if direct and pic:
-                    flags.append('-DHIDDEN')
-                # Include debuginfo?
-                if not strip:
-                    flags.append('-g')
+    flags = ['call.c', '-o', 'a.out',
+             '-Wl,--defsym,_start=0', '-nostdlib', '-nostartfiles']
+    # DLL or executable?
+    if pic:
+        flags += ['-fPIC', '-shared']
+    # Use PLT?
+    if not plt:
+        flags += ['-fno-plt']
+    # Force non-PLT call for PIC code?
+    if direct and pic:
+        flags.append('-DHIDDEN')
+    # Include debuginfo?
+    if not strip:
+        # FIXME: for real stripping of symtab we need to run
+        # `strip a.out` and `strip -s a.out`.
+        # This should be done for other tests too.
+        flags.append('-g')
 
-                gcc(flags)
+    gcc(flags)
 
-                # Generate disasm
+    # Generate disasm
 
-                caller = 'bar'
-                out = disasm('a.out', not gdb, strip, caller)
+    caller = 'bar'
+    out = disasm('a.out', not gdb, strip, caller)
 
-                # Print snippets
+    # Print snippets
 
-                headers = grep(out, fr'<{caller}>:|Dump of')
-                calls = grep(out, r'call')
-                print('''\
+    headers = grep(out, fr'<{caller}>:|Dump of')
+    calls = grep(out, r'call')
+    print('''\
   headers:
     {0}
   calls:

test/templates/gen_funtable.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python3
+
+"""
+Generate different flavors of input assembly for testing.
+"""
+
+import os.path
+import itertools
+
+from common import set_basename, gcc, disasm, grep
+
+set_basename(os.path.basename(__file__))
+
+for gdb, pic, strip in itertools.product([False, True],
+                                         [False, True],  # Do we need to test PIE too?
+                                         [False, True]):
+    # Print config
+
+    disasm_type = 'GDB' if gdb else 'objdump'
+    pic_type = 'position-INdependent' if pic else 'position-dependent'
+    stripped = 'stripped' if strip else 'UNstripped'
+    print(f"Checking {disasm_type} {pic_type} {stripped}")
+
+    # Generate object code
+
+    flags = ['funtable.c', '-o', 'a.out',
+             '-Wl,--defsym,_start=0', '-nostdlib', '-nostartfiles', '-O2']
+    # DLL or executable?
+    if pic:
+        flags += ['-fPIC', '-shared']
+    # Include debuginfo?
+    if not strip:
+        flags.append('-g')
+
+    gcc(flags)
+
+    # Generate disasm
+
+    caller = 'bar'
+    out = disasm('a.out', not gdb, strip, caller)
+
+    # Print snippets
+
+    jumps = grep(out, r'\bcall')
+    print('''\
+  table calls:
+    {}
+'''.format('\n    '.join(jumps)))

test/templates/gen_jumps.py

@@ -5,47 +5,48 @@
 """
 
 import os.path
+import itertools
 
 from common import set_basename, gcc, disasm, grep
 
 set_basename(os.path.basename(__file__))
 
-for gdb in [False, True]:
-    for pic in [False, True]:  # Do we need to test PIE too?
-        for opt in [False, True]:
-            for strip in [False, True]:
-                # Print config
+for gdb, pic, opt, strip in itertools.product([False, True],
+                                              [False, True],  # Do we need to test PIE too?
+                                              [False, True],
+                                              [False, True]):
+    # Print config
 
-                disasm_type = 'GDB' if gdb else 'objdump'
-                pic_type = 'position-INdependent' if pic else 'position-dependent'
-                opt_type = 'optimized' if opt else 'UNoptimized'
-                stripped = 'stripped' if strip else 'UNstripped'
-                print(f"Checking {disasm_type} {pic_type} {opt_type} {stripped}")
+    disasm_type = 'GDB' if gdb else 'objdump'
+    pic_type = 'position-INdependent' if pic else 'position-dependent'
+    opt_type = 'optimized' if opt else 'UNoptimized'
+    stripped = 'stripped' if strip else 'UNstripped'
+    print(f"Checking {disasm_type} {pic_type} {opt_type} {stripped}")
 
-                # Generate object code
+    # Generate object code
 
-                flags = ['jump.c', '-o', 'a.out',
-                         '-Wl,--defsym,_start=0', '-nostdlib', '-nostartfiles']
-                # DLL or executable?
-                if pic:
-                    flags += ['-fPIC', '-shared']
-                if opt:
-                    flags.append('-O2')
-                # Include debuginfo?
-                if not strip:
-                    flags.append('-g')
+    flags = ['jump.c', '-o', 'a.out',
+             '-Wl,--defsym,_start=0', '-nostdlib', '-nostartfiles']
+    # DLL or executable?
+    if pic:
+        flags += ['-fPIC', '-shared']
+    if opt:
+        flags.append('-O2')
+    # Include debuginfo?
+    if not strip:
+        flags.append('-g')
 
-                gcc(flags)
+    gcc(flags)
 
-                # Generate disasm
+    # Generate disasm
 
-                caller = 'bar'
-                out = disasm('a.out', not gdb, strip, caller)
+    caller = 'bar'
+    out = disasm('a.out', not gdb, strip, caller)
 
-                # Print snippets
+    # Print snippets
 
-                jumps = grep(out, r'\bj')
-                print('''\
+    jumps = grep(out, r'\bj')
+    print('''\
   jumps:
     {}
 '''.format('\n    '.join(jumps)))

test/templates/gen_jumptable.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python3
+
+"""
+Generate different flavors of input assembly for testing.
+"""
+
+import os.path
+import itertools
+
+from common import set_basename, gcc, disasm, grep
+
+set_basename(os.path.basename(__file__))
+
+for gdb, pic, strip in itertools.product([False, True],
+                                         [False, True],  # Do we need to test PIE too?
+                                         [False, True]):
+    # Print config
+
+    disasm_type = 'GDB' if gdb else 'objdump'
+    pic_type = 'position-INdependent' if pic else 'position-dependent'
+    stripped = 'stripped' if strip else 'UNstripped'
+    print(f"Checking {disasm_type} {pic_type} {stripped}")
+
+    # Generate object code
+
+    flags = ['jumptable.c', '-o', 'a.out',
+             '-Wl,--defsym,_start=0', '-nostdlib', '-nostartfiles', '-O2']
+    # DLL or executable?
+    if pic:
+        flags += ['-fPIC', '-shared']
+    # Include debuginfo?
+    if not strip:
+        flags.append('-g')
+
+    gcc(flags)
+
+    # Generate disasm
+
+    caller = 'bar'
+    out = disasm('a.out', not gdb, strip, caller)
+
+    # Print snippets
+
+    jumps = grep(out, r'\bjmp')
+    print('''\
+  table jumps:
+    {}
+'''.format('\n    '.join(jumps)))

test/templates/jumptable.c

@@ -0,0 +1,27 @@
+__attribute__((noinline)) void foo() {}
+__attribute__((noinline)) void baz() {}
+
+int bar(int x) {
+  // Should generate jumptable
+  switch (x) {
+  case 0:
+    return 10;
+  case 1:
+    baz("-14");
+  case 3:
+    return -25;
+  case 4:
+    return -27;
+  case 5:
+    return 35;
+  case 6:
+    return 99;
+  case 7:
+    return 33;
+  case 8:
+    return 12;
+  case 9:
+    foo();
+    return 12;
+  }
+}