Add a test to check if FP/VSX registers are sane (restored correctly) after a VSX unavailable exception is caught in the middle of a transaction.
Signed-off-by: Gustavo Romero <grom...@linux.vnet.ibm.com> Signed-off-by: Breno Leitao <lei...@debian.org> --- tools/testing/selftests/powerpc/tm/Makefile | 3 +- .../testing/selftests/powerpc/tm/tm-vsx-unavail.c | 144 +++++++++++++++++++++ 2 files changed, 146 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/powerpc/tm/tm-vsx-unavail.c diff --git a/tools/testing/selftests/powerpc/tm/Makefile b/tools/testing/selftests/powerpc/tm/Makefile index 958c11c..d0ffbb8 100644 --- a/tools/testing/selftests/powerpc/tm/Makefile +++ b/tools/testing/selftests/powerpc/tm/Makefile @@ -2,7 +2,7 @@ SIGNAL_CONTEXT_CHK_TESTS := tm-signal-context-chk-gpr tm-signal-context-chk-fpu tm-signal-context-chk-vmx tm-signal-context-chk-vsx TEST_GEN_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv tm-signal-stack \ - tm-vmxcopy tm-fork tm-tar tm-tmspr tm-vmx-unavail \ + tm-vmxcopy tm-fork tm-tar tm-tmspr tm-vmx-unavail tm-vsx-unavail \ $(SIGNAL_CONTEXT_CHK_TESTS) include ../../lib.mk @@ -15,6 +15,7 @@ $(OUTPUT)/tm-syscall: tm-syscall-asm.S $(OUTPUT)/tm-syscall: CFLAGS += -I../../../../../usr/include $(OUTPUT)/tm-tmspr: CFLAGS += -pthread $(OUTPUT)/tm-vmx-unavail: CFLAGS += -pthread -m64 +$(OUTPUT)/tm-vsx-unavail: CFLAGS += -pthread -m64 SIGNAL_CONTEXT_CHK_TESTS := $(patsubst %,$(OUTPUT)/%,$(SIGNAL_CONTEXT_CHK_TESTS)) $(SIGNAL_CONTEXT_CHK_TESTS): tm-signal.S diff --git a/tools/testing/selftests/powerpc/tm/tm-vsx-unavail.c b/tools/testing/selftests/powerpc/tm/tm-vsx-unavail.c new file mode 100644 index 0000000..7ff933a --- /dev/null +++ b/tools/testing/selftests/powerpc/tm/tm-vsx-unavail.c @@ -0,0 +1,144 @@ +/* + * Copyright 2017, Gustavo Romero and Breno Leitao, IBM Corp. + * Licensed under GPLv2. + * + * Force VSX unavailable exception during a transaction and see + * if it corrupts the checkpointed FP registers state after the abort. + */ + +#define _GNU_SOURCE + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <inttypes.h> +#include <pthread.h> +#include <sched.h> + +#include "tm.h" +#include "utils.h" + +int passed; + +void *ping(void *not_used) +{ + asm goto( + // r3 = 0x5555555555555555 + "lis 3, 0x5555 ;" + "ori 3, 3, 0x5555 ;" + "sldi 3, 3, 32 ;" + "oris 3, 3, 0x5555 ;" + "ori 3, 3, 0x5555 ;" + + //r4 = 0xFFFFFFFFFFFFFFFF + "lis 4, 0xFFFF ;" + "ori 4, 4, 0xFFFF ;" + "sldi 4, 4, 32 ;" + "oris 4, 4, 0xFFFF ;" + "ori 4, 4, 0xFFFF ;" + + // vs33 and vs34 will just be used to construct vs0 from r3 and + // r4. Both won't be used in any other place after that. + "mtvsrd 33, 3 ;" + "mtvsrd 34, 4 ;" + + // vs0 = (r3 || r4) = 0x5555555555555555FFFFFFFFFFFFFFFF + "xxmrghd 0, 33, 34 ;" + + + // Wait ~8s so we have a sufficient amount of context + // switches so load_fp and load_vec overflow and MSR.FP, MSR.VEC + // and MSR.VSX are disabled. + " lis 7, 0x1 ;" + " ori 7, 7, 0xBFFE ;" + " sldi 7, 7, 15 ;" + "1: addi 7, 7, -1 ;" + " cmpdi 7, 0 ;" + " bne 1b ;" + + // Any floating-point instruction in here. + // N.B. 'fmr' is *not touching* any previously set register, + // i.e. it's not touching vs0. + "fmr 10, 10 ;" + + // vs0 is *still* 0x5555555555555555FFFFFFFFFFFFFFFF, right? + // Get in a transaction and cause a VSX unavailable exception. + "2: tbegin. ;" // Begin HTM + " beq 3f ;" // Failure handler + " xxmrghd 10, 10, 10 ;" // VSX unavailable in TM + " tend. ;" // End HTM + "3: nop ;" // Fall through to code below + + // Immediately after a transaction failure we save vs0 to two + // general purpose registers to check its value. We need to have + // the same value as before we entered in transactional state. + + // vs0 should be *still* 0x5555555555555555FFFFFFFFFFFFFFFF + + // Save high half - MSB (64bit). + "mfvsrd 5, 0 ;" + + // Save low half - LSB (64bit). + // We mess with vs3, but it's not important. + "xxsldwi 3, 0, 0, 2 ;" + "mfvsrd 6, 3 ;" + + // N.B. r3 and r4 never changed since they were used to + // construct the initial vs0 value, hence we can use them to do + // the comparison. r3 and r4 will be destroy but it's ok. + "cmpd 3, 5 ;" // compare r3 to r5 + "bne %[value_mismatch] ;" + "cmpd 4, 6 ;" // compare r4 to r6 + "bne %[value_mismatch] ;" + "b %[value_ok] ;" + : + : + : "r3", "r4", "vs33", "vs34", "vs0", + "vs10", "fr10", "r7", "r5", "r6", "vs3" + : value_mismatch, value_ok + ); +value_mismatch: + passed = 0; + return NULL; +value_ok: + passed = 1; + return NULL; +} + +void *pong(void *not_used) +{ + while (1) + sched_yield(); // will be classed as interactive-like thread +} + +int tm_vsx_unavail_test(void) +{ + pthread_t t0, t1; + pthread_attr_t attr; + cpu_set_t cpuset; + + // Set only CPU 0 in the mask. Both threads will be bound to cpu 0 + CPU_ZERO(&cpuset); + CPU_SET(0, &cpuset); + + // Init pthread attribute + pthread_attr_init(&attr); + + // Set CPU 0 mask into the pthread attribute + pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &cpuset); + + // 'pong' thread used to induce context switches on 'ping' thread + pthread_create(&t1, &attr /* bound to cpu 0 */, pong, NULL); + + printf("Checking if FP/VSX is sane after a VSX exception in TM...\n"); + + pthread_create(&t0, &attr /* bound to cpu 0 as well */, ping, NULL); + pthread_join(t0, NULL); + + return passed ? EXIT_SUCCESS : EXIT_FAILURE; +} + +int main(int argc, char **argv) +{ + return test_harness(tm_vsx_unavail_test, "tm_vsx_unavail_test"); +} -- 2.7.4