old-cross-binutils/gdb/testsuite/gdb.arch/insn-reloc.c
Pierre Langlois 4f51c22aca Add a gdb.trace test for instruction relocation
This test case makes sure that relocating PC relative instructions does
not change their behaviors.  All PC relative AArch64 instructions are
covered.  While call and jump (32 bit relative) instructions are covered
on x86.

The test case creates a static array of function pointers for each
supported architecture.  Each function in this array tests a specific
instruction using inline assembly.  They all need to contain a symbol in
the form of 'set_point\[0-9\]+' and finish by either calling pass or
fail.  The number of 'set_pointN' needs to go from 0 to
(ARRAY_SIZE - 1).

The test will:
- look up the number of function pointers in the static array.
- set fast tracepoints on each 'set_point\[0-9\]+' symbol, one in each
  functions from 0 to (ARRAY_SIZE - 1).
- run the trace experiment and make sure the pass function is called for
  every function.

gdb/testsuite/ChangeLog:

	* gdb.arch/insn-reloc.c: New file.
	* gdb.arch/ftrace-insn-reloc.exp: New file.
2015-09-21 15:01:05 +01:00

508 lines
9 KiB
C

/* This testcase is part of GDB, the GNU debugger.
Copyright 2015 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <stddef.h>
#include <stdint.h>
typedef void (*testcase_ftype)(void);
/* Each function checks the correctness of the instruction being
relocated due to a fast tracepoint. Call function pass if it is
correct, otherwise call function fail. GDB sets a breakpoints on
pass and fail in order to check the correctness. */
static void
pass (void)
{
}
static void
fail (void)
{
}
#if (defined __x86_64__ || defined __i386__)
#ifdef SYMBOL_PREFIX
#define SYMBOL(str) SYMBOL_PREFIX #str
#else
#define SYMBOL(str) #str
#endif
/* Make sure we can relocate a CALL instruction. CALL instructions are
5 bytes long so we can always set a fast tracepoints on them.
JMP set_point0
f:
MOV $1, %[ok]
JMP end
set_point0:
CALL f ; tracepoint here.
end:
*/
static void
can_relocate_call (void)
{
int ok = 0;
asm (" .global " SYMBOL (set_point0) "\n"
" jmp " SYMBOL (set_point0) "\n"
"0:\n"
" mov $1, %[ok]\n"
" jmp 1f\n"
SYMBOL (set_point0) ":\n"
" call 0b\n"
"1:\n"
: [ok] "=r" (ok));
if (ok == 1)
pass ();
else
fail ();
}
/* Make sure we can relocate a JMP instruction. We need the JMP
instruction to be 5 bytes long in order to set a fast tracepoint on
it. To do this, we emit the opcode directly.
JMP next ; tracepoint here.
next:
MOV $1, %[ok]
*/
static void
can_relocate_jump (void)
{
int ok = 0;
asm (" .global " SYMBOL (set_point1) "\n"
SYMBOL (set_point1) ":\n"
".byte 0xe9\n" /* jmp */
".byte 0x00\n"
".byte 0x00\n"
".byte 0x00\n"
".byte 0x00\n"
" mov $1, %[ok]\n"
: [ok] "=r" (ok));
if (ok == 1)
pass ();
else
fail ();
}
#elif (defined __aarch64__)
/* Make sure we can relocate a B instruction.
B set_point0
set_ok:
MOV %[ok], #1
B end
set_point0:
B set_ok ; tracepoint here.
MOV %[ok], #0
end
*/
static void
can_relocate_b (void)
{
int ok = 0;
asm (" b set_point0\n"
"0:\n"
" mov %[ok], #1\n"
" b 1f\n"
"set_point0:\n"
" b 0b\n"
" mov %[ok], #0\n"
"1:\n"
: [ok] "=r" (ok));
if (ok == 1)
pass ();
else
fail ();
}
/* Make sure we can relocate a B.cond instruction.
MOV x0, #8
TST x0, #8 ; Clear the Z flag.
B set_point1
set_ok:
MOV %[ok], #1
B end
set_point1:
B.NE set_ok ; tracepoint here.
MOV %[ok], #0
end
*/
static void
can_relocate_bcond (void)
{
int ok = 0;
asm (" mov x0, #8\n"
" tst x0, #8\n"
" b set_point1\n"
"0:\n"
" mov %[ok], #1\n"
" b 1f\n"
"set_point1:\n"
" b.ne 0b\n"
" mov %[ok], #0\n"
"1:\n"
: [ok] "=r" (ok)
:
: "0", "cc");
if (ok == 1)
pass ();
else
fail ();
}
/* Make sure we can relocate a CBZ instruction.
MOV x0, #0
B set_point2
set_ok:
MOV %[ok], #1
B end
set_point2:
CBZ x0, set_ok ; tracepoint here.
MOV %[ok], #0
end
*/
static void
can_relocate_cbz (void)
{
int ok = 0;
asm (" mov x0, #0\n"
" b set_point2\n"
"0:\n"
" mov %[ok], #1\n"
" b 1f\n"
"set_point2:\n"
" cbz x0, 0b\n"
" mov %[ok], #0\n"
"1:\n"
: [ok] "=r" (ok)
:
: "0");
if (ok == 1)
pass ();
else
fail ();
}
/* Make sure we can relocate a CBNZ instruction.
MOV x0, #8
B set_point3
set_ok:
MOV %[ok], #1
B end
set_point3:
CBNZ x0, set_ok ; tracepoint here.
MOV %[ok], #0
end
*/
static void
can_relocate_cbnz (void)
{
int ok = 0;
asm (" mov x0, #8\n"
" b set_point3\n"
"0:\n"
" mov %[ok], #1\n"
" b 1f\n"
"set_point3:\n"
" cbnz x0, 0b\n"
" mov %[ok], #0\n"
"1:\n"
: [ok] "=r" (ok)
:
: "0");
if (ok == 1)
pass ();
else
fail ();
}
/* Make sure we can relocate a TBZ instruction.
MOV x0, #8
MVN x0, x0 ; Clear bit 3.
B set_point4
set_ok:
MOV %[ok], #1
B end
set_point4:
TBZ x0, #3, set_ok ; tracepoint here.
MOV %[ok], #0
end
*/
static void
can_relocate_tbz (void)
{
int ok = 0;
asm (" mov x0, #8\n"
" mvn x0, x0\n"
" b set_point4\n"
"0:\n"
" mov %[ok], #1\n"
" b 1f\n"
"set_point4:\n"
" tbz x0, #3, 0b\n"
" mov %[ok], #0\n"
"1:\n"
: [ok] "=r" (ok)
:
: "0");
if (ok == 1)
pass ();
else
fail ();
}
/* Make sure we can relocate a TBNZ instruction.
MOV x0, #8 ; Set bit 3.
B set_point5
set_ok:
MOV %[ok], #1
B end
set_point5:
TBNZ x0, #3, set_ok ; tracepoint here.
MOV %[ok], #0
end
*/
static void
can_relocate_tbnz (void)
{
int ok = 0;
asm (" mov x0, #8\n"
" b set_point5\n"
"0:\n"
" mov %[ok], #1\n"
" b 1f\n"
"set_point5:\n"
" tbnz x0, #3, 0b\n"
" mov %[ok], #0\n"
"1:\n"
: [ok] "=r" (ok)
:
: "0");
if (ok == 1)
pass ();
else
fail ();
}
/* Make sure we can relocate an ADR instruction with a positive offset.
set_point6:
ADR x0, target ; tracepoint here.
BR x0 ; jump to target
MOV %[ok], #0
B end
target:
MOV %[ok], #1
end
*/
static void
can_relocate_adr_forward (void)
{
int ok = 0;
asm ("set_point6:\n"
" adr x0, 0f\n"
" br x0\n"
" mov %[ok], #0\n"
" b 1f\n"
"0:\n"
" mov %[ok], #1\n"
"1:\n"
: [ok] "=r" (ok)
:
: "0");
if (ok == 1)
pass ();
else
fail ();
}
/* Make sure we can relocate an ADR instruction with a negative offset.
B set_point7
target:
MOV %[ok], #1
B end
set_point7:
ADR x0, target ; tracepoint here.
BR x0 ; jump to target
MOV %[ok], #0
end
*/
static void
can_relocate_adr_backward (void)
{
int ok = 0;
asm ("b set_point7\n"
"0:\n"
" mov %[ok], #1\n"
" b 1f\n"
"set_point7:\n"
" adr x0, 0b\n"
" br x0\n"
" mov %[ok], #0\n"
"1:\n"
: [ok] "=r" (ok)
:
: "0");
if (ok == 1)
pass ();
else
fail ();
}
/* Make sure we can relocate an ADRP instruction.
set_point8:
ADRP %[addr], set_point8 ; tracepoint here.
ADR %[pc], set_point8
ADR computes the address of the given label. While ADRP gives us its
page, on a 4K boundary. We can check ADRP executed normally by
making sure the result of ADR and ADRP are equivalent, except for the
12 lowest bits which should be cleared.
*/
static void
can_relocate_adrp (void)
{
uintptr_t page;
uintptr_t pc;
asm ("set_point8:\n"
" adrp %[page], set_point8\n"
" adr %[pc], set_point8\n"
: [page] "=r" (page), [pc] "=r" (pc));
if (page == (pc & ~0xfff))
pass ();
else
fail ();
}
/* Make sure we can relocate an LDR instruction, where the memory to
read is an offset from the current PC.
B set_point9
data:
.word 0x0cabba9e
set_point9:
LDR %[result], data ; tracepoint here.
*/
static void
can_relocate_ldr (void)
{
uint32_t result = 0;
asm ("b set_point9\n"
"0:\n"
" .word 0x0cabba9e\n"
"set_point9:\n"
" ldr %w[result], 0b\n"
: [result] "=r" (result));
if (result == 0x0cabba9e)
pass ();
else
fail ();
}
#endif
/* Functions testing relocations need to be placed here. GDB will read
n_testcases to know how many fast tracepoints to place. It will look
for symbols in the form of 'set_point\[0-9\]+' so each functions
needs one, starting at 0. */
static testcase_ftype testcases[] = {
#if (defined __x86_64__ || defined __i386__)
can_relocate_call,
can_relocate_jump
#elif (defined __aarch64__)
can_relocate_b,
can_relocate_bcond,
can_relocate_cbz,
can_relocate_cbnz,
can_relocate_tbz,
can_relocate_tbnz,
can_relocate_adr_forward,
can_relocate_adr_backward,
can_relocate_adrp,
can_relocate_ldr
#endif
};
static size_t n_testcases = (sizeof (testcases) / sizeof (testcase_ftype));
int
main ()
{
int i = 0;
for (i = 0; i < n_testcases; i++)
testcases[i] ();
return 0;
}