selftests/powerpc: New TM signal self test (a65329aa) · Commits · 戴 / test

tools/testing/selftests/powerpc/include/reg.h

+8 −0

Original line number	Diff line number	Diff line
		@@ -77,6 +77,14 @@
		#define TEXASR_TE 0x0000000004000000
		#define TEXASR_ROT 0x0000000002000000

		/* MSR register bits */
		#define MSR_TS_S_LG 33 /* Trans Mem state: Suspended */

		#define __MASK(X) (1UL<<(X))

		/* macro to check TM MSR bits */
		#define MSR_TS_S __MASK(MSR_TS_S_LG) /* Transaction Suspended */

		/* Vector Instructions */
		#define VSX_XX1(xs, ra, rb) (((xs) & 0x1f) << 21 \| ((ra) << 16) \| \
		((rb) << 11) \| (((xs) >> 5)))

tools/testing/selftests/powerpc/include/utils.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -102,8 +102,10 @@ do { \

		#if defined(__powerpc64__)
		#define UCONTEXT_NIA(UC) (UC)->uc_mcontext.gp_regs[PT_NIP]
		#define UCONTEXT_MSR(UC) (UC)->uc_mcontext.gp_regs[PT_MSR]
		#elif defined(__powerpc__)
		#define UCONTEXT_NIA(UC) (UC)->uc_mcontext.uc_regs->gregs[PT_NIP]
		#define UCONTEXT_MSR(UC) (UC)->uc_mcontext.uc_regs->gregs[PT_MSR]
		#else
		#error implement UCONTEXT_NIA
		#endif

tools/testing/selftests/powerpc/tm/.gitignore

+1 −0

Original line number	Diff line number	Diff line
		@@ -11,6 +11,7 @@ tm-signal-context-chk-fpu
		tm-signal-context-chk-gpr
		tm-signal-context-chk-vmx
		tm-signal-context-chk-vsx
		tm-signal-context-force-tm
		tm-signal-sigreturn-nt
		tm-vmx-unavail
		tm-unavailable

tools/testing/selftests/powerpc/tm/Makefile

+3 −1

Original line number	Diff line number	Diff line
		@@ -4,7 +4,8 @@ SIGNAL_CONTEXT_CHK_TESTS := tm-signal-context-chk-gpr tm-signal-context-chk-fpu

		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-unavailable tm-trap \
		$(SIGNAL_CONTEXT_CHK_TESTS) tm-sigreturn tm-signal-sigreturn-nt
		$(SIGNAL_CONTEXT_CHK_TESTS) tm-sigreturn tm-signal-sigreturn-nt \
		tm-signal-context-force-tm

		top_srcdir = ../../../../..
		include ../../lib.mk
		@@ -20,6 +21,7 @@ $(OUTPUT)/tm-vmx-unavail: CFLAGS += -pthread -m64
		$(OUTPUT)/tm-resched-dscr: ../pmu/lib.c
		$(OUTPUT)/tm-unavailable: CFLAGS += -O0 -pthread -m64 -Wno-error=uninitialized -mvsx
		$(OUTPUT)/tm-trap: CFLAGS += -O0 -pthread -m64
		$(OUTPUT)/tm-signal-context-force-tm: CFLAGS += -pthread -m64

		SIGNAL_CONTEXT_CHK_TESTS := $(patsubst %,$(OUTPUT)/%,$(SIGNAL_CONTEXT_CHK_TESTS))
		$(SIGNAL_CONTEXT_CHK_TESTS): tm-signal.S

tools/testing/selftests/powerpc/tm/tm-signal-context-force-tm.c

0 → 100644

+184 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/*
		* Copyright 2018, Breno Leitao, Gustavo Romero, IBM Corp.
		*
		* This test raises a SIGUSR1 signal, and toggle the MSR[TS]
		* fields at the signal handler. With MSR[TS] being set, the kernel will
		* force a recheckpoint, which may cause a segfault when returning to
		* user space. Since the test needs to re-run, the segfault needs to be
		* caught and handled.
		*
		* In order to continue the test even after a segfault, the context is
		* saved prior to the signal being raised, and it is restored when there is
		* a segmentation fault. This happens for COUNT_MAX times.
		*
		* This test never fails (as returning EXIT_FAILURE). It either succeeds,
		* or crash the kernel (on a buggy kernel).
		*/

		#define _GNU_SOURCE
		#include <stdio.h>
		#include <stdlib.h>
		#include <signal.h>
		#include <string.h>
		#include <ucontext.h>
		#include <unistd.h>
		#include <sys/mman.h>

		#include "tm.h"
		#include "utils.h"
		#include "reg.h"

		#define COUNT_MAX 5000 /* Number of interactions */

		/*
		* This test only runs on 64 bits system. Unsetting MSR_TS_S to avoid
		* compilation issue on 32 bits system. There is no side effect, since the
		* whole test will be skipped if it is not running on 64 bits system.
		*/
		#ifndef __powerpc64__
		#undef MSR_TS_S
		#define MSR_TS_S 0
		#endif

		/* Setting contexts because the test will crash and we want to recover */
		ucontext_t init_context, main_context;

		static int count, first_time;

		void usr_signal_handler(int signo, siginfo_t si, void uc)
		{
		ucontext_t *ucp = uc;
		int ret;

		/*
		* Allocating memory in a signal handler, and never freeing it on
		* purpose, forcing the heap increase, so, the memory leak is what
		* we want here.
		*/
		ucp->uc_link = mmap(NULL, sizeof(ucontext_t),
		PROT_READ \| PROT_WRITE,
		MAP_PRIVATE \| MAP_ANONYMOUS, 0, 0);
		if (ucp->uc_link == (void *)-1) {
		perror("Mmap failed");
		exit(-1);
		}

		/* Forcing the page to be allocated in a page fault */
		ret = madvise(ucp->uc_link, sizeof(ucontext_t), MADV_DONTNEED);
		if (ret) {
		perror("madvise failed");
		exit(-1);
		}

		memcpy(&ucp->uc_link->uc_mcontext, &ucp->uc_mcontext,
		sizeof(ucp->uc_mcontext));

		/* Forcing to enable MSR[TM] */
		UCONTEXT_MSR(ucp) \|= MSR_TS_S;

		/*
		* A fork inside a signal handler seems to be more efficient than a
		* fork() prior to the signal being raised.
		*/
		if (fork() == 0) {
		/*
		* Both child and parent will return, but, child returns
		* with count set so it will exit in the next segfault.
		* Parent will continue to loop.
		*/
		count = COUNT_MAX;
		}

		/*
		* If the change above does not hit the bug, it will cause a
		* segmentation fault, since the ck structures are NULL.
		*/
		}

		void seg_signal_handler(int signo, siginfo_t si, void uc)
		{
		if (count == COUNT_MAX) {
		/* Return to tm_signal_force_msr() and exit */
		setcontext(&main_context);
		}

		count++;

		/* Reexecute the test */
		setcontext(&init_context);
		}

		void tm_trap_test(void)
		{
		struct sigaction usr_sa, seg_sa;
		stack_t ss;

		usr_sa.sa_flags = SA_SIGINFO \| SA_ONSTACK;
		usr_sa.sa_sigaction = usr_signal_handler;

		seg_sa.sa_flags = SA_SIGINFO;
		seg_sa.sa_sigaction = seg_signal_handler;

		/*
		* Set initial context. Will get back here from
		* seg_signal_handler()
		*/
		getcontext(&init_context);

		/* Allocated an alternative signal stack area */
		ss.ss_sp = mmap(NULL, SIGSTKSZ, PROT_READ \| PROT_WRITE,
		MAP_PRIVATE \| MAP_ANONYMOUS, 0, 0);
		ss.ss_size = SIGSTKSZ;
		ss.ss_flags = 0;

		if (ss.ss_sp == (void *)-1) {
		perror("mmap error\n");
		exit(-1);
		}

		/* Force the allocation through a page fault */
		if (madvise(ss.ss_sp, SIGSTKSZ, MADV_DONTNEED)) {
		perror("madvise\n");
		exit(-1);
		}

		/* Setting an alternative stack to generate a page fault when
		* the signal is raised.
		*/
		if (sigaltstack(&ss, NULL)) {
		perror("sigaltstack\n");
		exit(-1);
		}

		/* The signal handler will enable MSR_TS */
		sigaction(SIGUSR1, &usr_sa, NULL);
		/* If it does not crash, it will segfault, avoid it to retest */
		sigaction(SIGSEGV, &seg_sa, NULL);

		raise(SIGUSR1);
		}

		int tm_signal_context_force_tm(void)
		{
		SKIP_IF(!have_htm());
		/*
		* Skipping if not running on 64 bits system, since I think it is
		* not possible to set mcontext's [MSR] with TS, due to it being 32
		* bits.
		*/
		SKIP_IF(!is_ppc64le());

		/* Will get back here after COUNT_MAX interactions */
		getcontext(&main_context);

		if (!first_time++)
		tm_trap_test();

		return EXIT_SUCCESS;
		}

		int main(int argc, char **argv)
		{
		test_harness(tm_signal_context_force_tm, "tm_signal_context_force_tm");
		}

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