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Commit 2679f63f authored by Michael Ellerman's avatar Michael Ellerman
Browse files

selftests/powerpc/64: Test exception cases in copy_tofrom_user 



This adds a set of test cases to test the behaviour of
copy_tofrom_user when exceptions are encountered accessing the
source or destination.  Currently, copy_tofrom_user does not always
copy as many bytes as possible when an exception occurs on a store
to the destination, and that is reflected in failures in these tests.

Based on a test program from Anton Blanchard.

[paulus@ozlabs.org - test all three paths, wrote commit description,
 made EX_TABLE create an exception table.]

Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 98c45f51

tools/testing/selftests/powerpc/copyloops/.gitignore

+3 −0
Original line number Diff line number Diff line
@@ -8,3 +8,6 @@ memcpy_64_t1 
memcpy_64_t2

memcpy_power7_t0

memcpy_power7_t1

copyuser_64_exc_t0

copyuser_64_exc_t1

copyuser_64_exc_t2

tools/testing/selftests/powerpc/copyloops/Makefile

+10 −2
Original line number Diff line number Diff line
@@ -12,9 +12,10 @@ ASFLAGS = $(CFLAGS) -Wa,-mpower4 
TEST_GEN_PROGS := copyuser_64_t0 copyuser_64_t1 copyuser_64_t2 \

		copyuser_p7_t0 copyuser_p7_t1 \

		memcpy_64_t0 memcpy_64_t1 memcpy_64_t2 \

		memcpy_p7_t0 memcpy_p7_t1

		memcpy_p7_t0 memcpy_p7_t1 \

		copyuser_64_exc_t0 copyuser_64_exc_t1 copyuser_64_exc_t2



EXTRA_SOURCES := validate.c ../harness.c

EXTRA_SOURCES := validate.c ../harness.c stubs.S



include ../../lib.mk
@@ -42,3 +43,10 @@ $(OUTPUT)/memcpy_p7_t%: memcpy_power7.S $(EXTRA_SOURCES) 
		-D COPY_LOOP=test_memcpy_power7 \

		-D SELFTEST_CASE=$(subst memcpy_p7_t,,$(notdir $@)) \

		-o $@ $^



$(OUTPUT)/copyuser_64_exc_t%: copyuser_64.S exc_validate.c ../harness.c \

		copy_tofrom_user_reference.S stubs.S

	$(CC) $(CPPFLAGS) $(CFLAGS) \

		-D COPY_LOOP=test___copy_tofrom_user_base \

		-D SELFTEST_CASE=$(subst copyuser_64_exc_t,,$(notdir $@)) \

		-o $@ $^

tools/testing/selftests/powerpc/copyloops/asm/ppc_asm.h

+8 −19
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef __SELFTESTS_POWERPC_PPC_ASM_H

#define __SELFTESTS_POWERPC_PPC_ASM_H

#include <ppc-asm.h>



#define CONFIG_ALTIVEC
@@ -26,25 +28,10 @@ 


#define PPC_MTOCRF(A, B)	mtocrf A, B



#define EX_TABLE(x, y)



FUNC_START(enter_vmx_usercopy)

	li	r3,1

	blr



FUNC_START(exit_vmx_usercopy)

	li	r3,0

	blr



FUNC_START(enter_vmx_ops)

	li	r3,1

	blr



FUNC_START(exit_vmx_ops)

	blr



FUNC_START(__copy_tofrom_user_base)

	blr

#define EX_TABLE(x, y)			\

	.section __ex_table,"a";	\

	.8byte	x, y;			\

	.previous



#define BEGIN_FTR_SECTION		.if test_feature

#define FTR_SECTION_ELSE		.else
@@ -56,3 +43,5 @@ FUNC_START(__copy_tofrom_user_base) 


/* Default to taking the first of any alternative feature sections */

test_feature = 1



#endif /* __SELFTESTS_POWERPC_PPC_ASM_H */

tools/testing/selftests/powerpc/copyloops/copy_tofrom_user_reference.S

0 → 100644
+24 −0
Original line number Diff line number Diff line 
#include <asm/ppc_asm.h>



_GLOBAL(copy_tofrom_user_reference)

	cmpdi	r5,0

	beq	4f



	mtctr	r5



1:	lbz	r6,0(r4)

2:	stb	r6,0(r3)

	addi	r3,r3,1

	addi	r4,r4,1

	bdnz	1b



3:	mfctr	r3

	blr



4:	mr	r3,r5

	blr



.section __ex_table,"a"

	.llong	1b,3b

	.llong	2b,3b

.text

tools/testing/selftests/powerpc/copyloops/exc_validate.c

0 → 100644
+124 −0
Original line number Diff line number Diff line 
#include <stdlib.h>

#include <string.h>

#include <stdio.h>

#include <signal.h>

#include <unistd.h>

#include <sys/mman.h>



#include "utils.h"



extern char __start___ex_table[];

extern char __stop___ex_table[];



#if defined(__powerpc64__)

#define UCONTEXT_NIA(UC)	(UC)->uc_mcontext.gp_regs[PT_NIP]

#elif defined(__powerpc__)

#define UCONTEXT_NIA(UC)	(UC)->uc_mcontext.uc_regs->gregs[PT_NIP]

#else

#error implement UCONTEXT_NIA

#endif



static void segv_handler(int signr, siginfo_t *info, void *ptr)

{

	ucontext_t *uc = (ucontext_t *)ptr;

	unsigned long addr = (unsigned long)info->si_addr;

	unsigned long *ip = &UCONTEXT_NIA(uc);

	unsigned long *ex_p = (unsigned long *)__start___ex_table;



	while (ex_p < (unsigned long *)__stop___ex_table) {

		unsigned long insn, fixup;



		insn = *ex_p++;

		fixup = *ex_p++;



		if (insn == *ip) {

			*ip = fixup;

			return;

		}

	}



	printf("No exception table match for NIA %lx ADDR %lx\n", *ip, addr);

	abort();

}



static void setup_segv_handler(void)

{

	struct sigaction action;



	memset(&action, 0, sizeof(action));

	action.sa_sigaction = segv_handler;

	action.sa_flags = SA_SIGINFO;

	sigaction(SIGSEGV, &action, NULL);

}



unsigned long COPY_LOOP(void *to, const void *from, unsigned long size);

unsigned long test_copy_tofrom_user_reference(void *to, const void *from, unsigned long size);



static int total_passed;

static int total_failed;



static void do_one_test(char *dstp, char *srcp, unsigned long len)

{

	unsigned long got, expected;



	got = COPY_LOOP(dstp, srcp, len);

	expected = test_copy_tofrom_user_reference(dstp, srcp, len);



	if (got != expected) {

		total_failed++;

		printf("FAIL from=%p to=%p len=%ld returned %ld, expected %ld\n",

		       srcp, dstp, len, got, expected);

		//abort();

	} else

		total_passed++;

}



//#define MAX_LEN 512

#define MAX_LEN 16



int test_copy_exception(void)

{

	int page_size;

	static char *p, *q;

	unsigned long src, dst, len;



	page_size = getpagesize();

	p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE,

		MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);



	if (p == MAP_FAILED) {

		perror("mmap");

		exit(1);

	}



	memset(p, 0, page_size);



	setup_segv_handler();



	if (mprotect(p + page_size, page_size, PROT_NONE)) {

		perror("mprotect");

		exit(1);

	}



	q = p + page_size - MAX_LEN;



	for (src = 0; src < MAX_LEN; src++) {

		for (dst = 0; dst < MAX_LEN; dst++) {

			for (len = 0; len < MAX_LEN+1; len++) {

				// printf("from=%p to=%p len=%ld\n", q+dst, q+src, len);

				do_one_test(q+dst, q+src, len);

			}

		}

	}



	printf("Totals:\n");

	printf("  Pass: %d\n", total_passed);

	printf("  Fail: %d\n", total_failed);



	return 0;

}



int main(void)

{

	return test_harness(test_copy_exception, str(COPY_LOOP));

}