diff options
Diffstat (limited to 'tools/testing/selftests/powerpc/mm/wild_bctr.c')
| -rw-r--r-- | tools/testing/selftests/powerpc/mm/wild_bctr.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/mm/wild_bctr.c b/tools/testing/selftests/powerpc/mm/wild_bctr.c new file mode 100644 index 000000000..f2fa101c5 --- /dev/null +++ b/tools/testing/selftests/powerpc/mm/wild_bctr.c @@ -0,0 +1,170 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2018, Michael Ellerman, IBM Corp. + * + * Test that an out-of-bounds branch to counter behaves as expected. + */ + +#include <setjmp.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/mman.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <ucontext.h> +#include <unistd.h> + +#include "utils.h" + + +#define BAD_NIP 0x788c545a18000000ull + +static struct pt_regs signal_regs; +static jmp_buf setjmp_env; + +static void save_regs(ucontext_t *ctxt) +{ + struct pt_regs *regs = ctxt->uc_mcontext.regs; + + memcpy(&signal_regs, regs, sizeof(signal_regs)); +} + +static void segv_handler(int signum, siginfo_t *info, void *ctxt_v) +{ + save_regs(ctxt_v); + longjmp(setjmp_env, 1); +} + +static void usr2_handler(int signum, siginfo_t *info, void *ctxt_v) +{ + save_regs(ctxt_v); +} + +static int ok(void) +{ + printf("Everything is OK in here.\n"); + return 0; +} + +#define REG_POISON 0x5a5a +#define POISONED_REG(n) ((((unsigned long)REG_POISON) << 48) | ((n) << 32) | \ + (((unsigned long)REG_POISON) << 16) | (n)) + +static inline void poison_regs(void) +{ + #define POISON_REG(n) \ + "lis " __stringify(n) "," __stringify(REG_POISON) ";" \ + "addi " __stringify(n) "," __stringify(n) "," __stringify(n) ";" \ + "sldi " __stringify(n) "," __stringify(n) ", 32 ;" \ + "oris " __stringify(n) "," __stringify(n) "," __stringify(REG_POISON) ";" \ + "addi " __stringify(n) "," __stringify(n) "," __stringify(n) ";" + + asm (POISON_REG(15) + POISON_REG(16) + POISON_REG(17) + POISON_REG(18) + POISON_REG(19) + POISON_REG(20) + POISON_REG(21) + POISON_REG(22) + POISON_REG(23) + POISON_REG(24) + POISON_REG(25) + POISON_REG(26) + POISON_REG(27) + POISON_REG(28) + POISON_REG(29) + : // inputs + : // outputs + : "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", + "26", "27", "28", "29" + ); + #undef POISON_REG +} + +static int check_regs(void) +{ + unsigned long i; + + for (i = 15; i <= 29; i++) + FAIL_IF(signal_regs.gpr[i] != POISONED_REG(i)); + + printf("Regs OK\n"); + return 0; +} + +static void dump_regs(void) +{ + for (int i = 0; i < 32; i += 4) { + printf("r%02d 0x%016lx r%02d 0x%016lx " \ + "r%02d 0x%016lx r%02d 0x%016lx\n", + i, signal_regs.gpr[i], + i+1, signal_regs.gpr[i+1], + i+2, signal_regs.gpr[i+2], + i+3, signal_regs.gpr[i+3]); + } +} + +#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); + struct sigaction segv = { + .sa_sigaction = segv_handler, + .sa_flags = SA_SIGINFO + }; + struct sigaction usr2 = { + .sa_sigaction = usr2_handler, + .sa_flags = SA_SIGINFO + }; + + FAIL_IF(sigaction(SIGSEGV, &segv, NULL)); + FAIL_IF(sigaction(SIGUSR2, &usr2, NULL)); + + bzero(&signal_regs, sizeof(signal_regs)); + + if (setjmp(setjmp_env) == 0) { + func_ptr = ok; + func_ptr(); + + kill(getpid(), SIGUSR2); + printf("Regs before:\n"); + dump_regs(); + bzero(&signal_regs, sizeof(signal_regs)); + + poison_regs(); + + func_ptr = (int (*)(void))BAD_FUNC; + func_ptr(); + + FAIL_IF(1); /* we didn't segv? */ + } + + FAIL_IF(signal_regs.nip != BAD_NIP); + + printf("All good - took SEGV as expected branching to 0x%llx\n", BAD_NIP); + + dump_regs(); + FAIL_IF(check_regs()); + + return 0; +} + +int main(void) +{ + return test_harness(test_wild_bctr, "wild_bctr"); +} |