selftests/powerpc: Fix wild_bctr test to work on ppc64

The selftest I recently added to test branching to an out-of-bounds
NIP doesn't work on 64-bit big endian. It does fail but not in the
right way. That is it SEGVs trying to load from the opd at BAD_NIP,
but it never gets as far as branching to BAD_NIP.

To fix it we need to create an opd which is reachable but which holds
the bad address.

Fixes: b7683fc66e ("selftests/powerpc: Add a test of wild bctr")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Michael Ellerman 2018-11-12 13:46:06 +11:00
parent 43c6494fa1
commit 2c7645b0f7

View file

@ -105,6 +105,20 @@ static void dump_regs(void)
}
}
#ifdef _CALL_AIXDESC
struct opd {
unsigned long ip;
unsigned long toc;
unsigned long env;
};
static struct opd bad_opd = {
.ip = BAD_NIP,
};
#define BAD_FUNC (&bad_opd)
#else
#define BAD_FUNC BAD_NIP
#endif
int test_wild_bctr(void)
{
int (*func_ptr)(void);
@ -133,7 +147,7 @@ int test_wild_bctr(void)
poison_regs();
func_ptr = (int (*)(void))BAD_NIP;
func_ptr = (int (*)(void))BAD_FUNC;
func_ptr();
FAIL_IF(1); /* we didn't segv? */