Hello Amit Daniel Kachhap,
The patch e9b60476bea0: "kselftest/arm64: Add utilities and a test to
validate mte memory" from Oct 2, 2020, leads to the following Smatch
static checker warning:
./tools/testing/selftests/arm64/mte/mte_common_util.c:336 mte_default_setup()
warn: bitwise AND condition is false here
./tools/testing/selftests/arm64/mte/mte_common_util.c
316 int mte_default_setup(void)
317 {
318 unsigned long hwcaps2 = getauxval(AT_HWCAP2);
319 unsigned long en = 0;
320 int ret;
321
322 if (!(hwcaps2 & HWCAP2_MTE)) {
323 ksft_print_msg("SKIP: MTE features unavailable\n");
324 return KSFT_SKIP;
325 }
326 /* Get current mte mode */
327 ret = prctl(PR_GET_TAGGED_ADDR_CTRL, en, 0, 0, 0);
328 if (ret < 0) {
329 ksft_print_msg("FAIL:prctl PR_GET_TAGGED_ADDR_CTRL with error =%d\n", ret);
330 return KSFT_FAIL;
331 }
332 if (ret & PR_MTE_TCF_SYNC)
333 mte_cur_mode = MTE_SYNC_ERR;
334 else if (ret & PR_MTE_TCF_ASYNC)
335 mte_cur_mode = MTE_ASYNC_ERR;
--> 336 else if (ret & PR_MTE_TCF_NONE)
It looks like the intent was to make PR_MTE_TCF_NONE into an ifdef
configurable thing but that never happened?
337 mte_cur_mode = MTE_NONE_ERR;
338
339 mte_cur_pstate_tco = mte_get_pstate_tco();
340 /* Disable PSTATE.TCO */
341 mte_disable_pstate_tco();
342 return 0;
343 }
regards,
dan carpenter
