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Commit f10d4424 authored by Cyril Bur's avatar Cyril Bur Committed by Michael Ellerman
Browse files

selftests/powerpc: Add checks for transactional GPRs in signal contexts 



If a thread receives a signal while transactional the kernel creates a
second context to show the transactional state of the process. This
test loads some known values and waits for a signal and confirms that
the expected values are in the signal context.

Signed-off-by: default avatarCyril Bur <cyrilbur@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent ef186331

tools/testing/selftests/powerpc/tm/Makefile

+6 −1
Original line number Diff line number Diff line 
SIGNAL_CONTEXT_CHK_TESTS := tm-signal-context-chk-gpr



TEST_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv tm-signal-stack \

	tm-vmxcopy tm-fork tm-tar tm-tmspr tm-exec tm-execed

	tm-vmxcopy tm-fork tm-tar tm-tmspr $(SIGNAL_CONTEXT_CHK_TESTS)



all: $(TEST_PROGS)
@@ -11,6 +13,9 @@ tm-syscall: tm-syscall-asm.S 
tm-syscall: CFLAGS += -I../../../../../usr/include

tm-tmspr: CFLAGS += -pthread



$(SIGNAL_CONTEXT_CHK_TESTS): tm-signal.S

$(SIGNAL_CONTEXT_CHK_TESTS): CFLAGS += -mhtm -m64 -mvsx



include ../../lib.mk



clean:

tools/testing/selftests/powerpc/tm/tm-signal-context-chk-gpr.c

0 → 100644
+90 −0
Original line number Diff line number Diff line 
/*

 * Copyright 2016, Cyril Bur, IBM Corp.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version

 * 2 of the License, or (at your option) any later version.

 *

 *

 * Test the kernel's signal frame code.

 *

 * The kernel sets up two sets of ucontexts if the signal was to be

 * delivered while the thread was in a transaction.

 * Expected behaviour is that the checkpointed state is in the user

 * context passed to the signal handler. The speculated state can be

 * accessed with the uc_link pointer.

 *

 * The rationale for this is that if TM unaware code (which linked

 * against TM libs) installs a signal handler it will not know of the

 * speculative nature of the 'live' registers and may infer the wrong

 * thing.

 */



#include <stdlib.h>

#include <stdio.h>

#include <signal.h>

#include <unistd.h>



#include <altivec.h>



#include "utils.h"

#include "tm.h"



#define MAX_ATTEMPT 500000



#define NV_GPR_REGS 18



long tm_signal_self_context_load(pid_t pid, long *gprs, double *fps, vector int *vms, vector int *vss);



static sig_atomic_t fail;



static long gps[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,

					 -1,-2,-3,-4,-5,-6,-7,-8,-9,-10,-11,-12,-13,-14,-15,-16,-17,-18};



static void signal_usr1(int signum, siginfo_t *info, void *uc)

{

	int i;

	ucontext_t *ucp = uc;

	ucontext_t *tm_ucp = ucp->uc_link;



	for (i = 0; i < NV_GPR_REGS && !fail; i++) {

		fail = (ucp->uc_mcontext.gp_regs[i + 14] != gps[i]);

		fail |= (tm_ucp->uc_mcontext.gp_regs[i + 14] != gps[i + NV_GPR_REGS]);

		if (fail)

			printf("Failed on %d GPR %lu or %lu\n", i,

					ucp->uc_mcontext.gp_regs[i + 14], tm_ucp->uc_mcontext.gp_regs[i + 14]);

	}

}



static int tm_signal_context_chk_gpr()

{

	struct sigaction act;

	int i;

	long rc;

	pid_t pid = getpid();



	SKIP_IF(!have_htm());



	act.sa_sigaction = signal_usr1;

	sigemptyset(&act.sa_mask);

	act.sa_flags = SA_SIGINFO;

	if (sigaction(SIGUSR1, &act, NULL) < 0) {

		perror("sigaction sigusr1");

		exit(1);

	}



	i = 0;

	while (i < MAX_ATTEMPT && !fail) {

		rc = tm_signal_self_context_load(pid, gps, NULL, NULL, NULL);

		FAIL_IF(rc != pid);

		i++;

	}



	return fail;

}



int main(void)

{

	return test_harness(tm_signal_context_chk_gpr, "tm_signal_context_chk_gpr");

}

tools/testing/selftests/powerpc/tm/tm-signal.S

0 → 100644
+114 −0
Original line number Diff line number Diff line 
/*

 * Copyright 2015, Cyril Bur, IBM Corp.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version

 * 2 of the License, or (at your option) any later version.

 */



#include "../basic_asm.h"

#include "../gpr_asm.h"

#include "../fpu_asm.h"

#include "../vmx_asm.h"

#include "../vsx_asm.h"



/*

 * Large caveat here being that the caller cannot expect the

 * signal to always be sent! The hardware can (AND WILL!) abort

 * the transaction between the tbegin and the tsuspend (however

 * unlikely it seems or infrequently it actually happens).

 * You have been warned.

 */

/* long tm_signal_self(pid_t pid, long *gprs, double *fps, vector *vms, vector *vss); */

FUNC_START(tm_signal_self_context_load)

	PUSH_BASIC_STACK(512)

	/*

	 * Don't strictly need to save and restore as it depends on if

	 * we're going to use them, however this reduces messy logic

	 */

	PUSH_VMX(STACK_FRAME_LOCAL(5,0),r8)

	PUSH_FPU(512)

	PUSH_NVREGS_BELOW_FPU(512)

	std r3, STACK_FRAME_PARAM(0)(sp) /* pid */

	std r4, STACK_FRAME_PARAM(1)(sp) /* gps */

	std r5, STACK_FRAME_PARAM(2)(sp) /* fps */

	std r6, STACK_FRAME_PARAM(3)(sp) /* vms */

	std r7, STACK_FRAME_PARAM(4)(sp) /* vss */



	ld r3, STACK_FRAME_PARAM(1)(sp)

	cmpdi r3, 0

	beq skip_gpr_lc

	bl load_gpr

skip_gpr_lc:

	ld r3, STACK_FRAME_PARAM(2)(sp)

	cmpdi	r3, 0

	beq	skip_fpu_lc

	bl load_fpu

skip_fpu_lc:

	ld r3, STACK_FRAME_PARAM(3)(sp)

	cmpdi r3, 0

	beq	skip_vmx_lc

	bl load_vmx

skip_vmx_lc:

	ld r3, STACK_FRAME_PARAM(4)(sp)

	cmpdi	r3, 0

	beq	skip_vsx_lc

	bl load_vsx

skip_vsx_lc:

	/*

	 * Set r3 (return value) before tbegin. Use the pid as a known

	 * 'all good' return value, zero is used to indicate a non-doomed

	 * transaction.

	 */

	ld	r3, STACK_FRAME_PARAM(0)(sp)

	tbegin.

	beq	1f

	tsuspend. /* Can't enter a syscall transactionally */

	ld	r3, STACK_FRAME_PARAM(1)(sp)

	cmpdi	r3, 0

	beq skip_gpr_lt

	/* Get the second half of the array */

	addi	r3, r3, 8 * 18

	bl load_gpr

skip_gpr_lt:

	ld r3, STACK_FRAME_PARAM(2)(sp)

	cmpdi	r3, 0

	beq	skip_fpu_lt

	/* Get the second half of the array */

	addi	r3, r3, 8 * 18

	bl load_fpu

skip_fpu_lt:

	ld r3, STACK_FRAME_PARAM(3)(sp)

	cmpdi r3, 0

	beq	skip_vmx_lt

	/* Get the second half of the array */

	addi	r3, r3, 16 * 12

	bl load_vmx

skip_vmx_lt:

	ld r3, STACK_FRAME_PARAM(4)(sp)

	cmpdi	r3, 0

	beq	skip_vsx_lt

	/* Get the second half of the array */

	addi	r3, r3, 16 * 12

	bl load_vsx

skip_vsx_lt:

	li	r0, 37 /* sys_kill */

	ld r3, STACK_FRAME_PARAM(0)(sp) /* pid */

	li r4, 10 /* SIGUSR1 */

	sc /* Taking the signal will doom the transaction */

	tabort. 0

	tresume. /* Be super sure we abort */

	/*

	 * This will cause us to resume doomed transaction and cause

	 * hardware to cleanup, we'll end up at 1: anything between

	 * tresume. and 1: shouldn't ever run.

	 */

	li r3, 0

	1:

	POP_VMX(STACK_FRAME_LOCAL(5,0),r4)

	POP_FPU(512)

	POP_NVREGS_BELOW_FPU(512)

	POP_BASIC_STACK(512)

	blr

FUNC_END(tm_signal_self_context_load)