From fe2a1bb1dbff1bc7b8c24eb1f691a544488617fa Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Thu, 25 Sep 2014 16:45:11 +1000 Subject: [PATCH] selftests/powerpc: Add test of load_unaligned_zero_pad() It is a rarely exercised case, so we want to have a test to ensure it works as required. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/word-at-a-time.h | 13 +- tools/testing/selftests/powerpc/Makefile | 2 +- .../testing/selftests/powerpc/primitives/Makefile | 17 +++ .../selftests/powerpc/primitives/asm/asm-compat.h | 1 + .../selftests/powerpc/primitives/asm/ppc-opcode.h | 0 .../powerpc/primitives/load_unaligned_zeropad.c | 147 +++++++++++++++++++++ .../selftests/powerpc/primitives/word-at-a-time.h | 1 + 7 files changed, 179 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/powerpc/primitives/Makefile create mode 120000 tools/testing/selftests/powerpc/primitives/asm/asm-compat.h create mode 100644 tools/testing/selftests/powerpc/primitives/asm/ppc-opcode.h create mode 100644 tools/testing/selftests/powerpc/primitives/load_unaligned_zeropad.c create mode 120000 tools/testing/selftests/powerpc/primitives/word-at-a-time.h diff --git a/arch/powerpc/include/asm/word-at-a-time.h b/arch/powerpc/include/asm/word-at-a-time.h index 07cc121..ea52b51 100644 --- a/arch/powerpc/include/asm/word-at-a-time.h +++ b/arch/powerpc/include/asm/word-at-a-time.h @@ -116,6 +116,15 @@ static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, #endif +/* + * We use load_unaligned_zero() in a selftest, which builds a userspace + * program. Some linker scripts seem to discard the .fixup section, so allow + * the test code to use a different section name. + */ +#ifndef FIXUP_SECTION +#define FIXUP_SECTION ".fixup" +#endif + static inline unsigned long load_unaligned_zeropad(const void *addr) { unsigned long ret, offset, tmp; @@ -123,7 +132,7 @@ static inline unsigned long load_unaligned_zeropad(const void *addr) asm( "1: " PPC_LL "%[ret], 0(%[addr])\n" "2:\n" - ".section .fixup,\"ax\"\n" + ".section " FIXUP_SECTION ",\"ax\"\n" "3: " #ifdef __powerpc64__ "clrrdi %[tmp], %[addr], 3\n\t" @@ -156,4 +165,6 @@ static inline unsigned long load_unaligned_zeropad(const void *addr) return ret; } +#undef FIXUP_SECTION + #endif /* _ASM_WORD_AT_A_TIME_H */ diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile index 74a78ce..f6ff90a 100644 --- a/tools/testing/selftests/powerpc/Makefile +++ b/tools/testing/selftests/powerpc/Makefile @@ -13,7 +13,7 @@ CFLAGS := -Wall -O2 -flto -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(CUR export CC CFLAGS -TARGETS = pmu copyloops mm tm +TARGETS = pmu copyloops mm tm primitives endif diff --git a/tools/testing/selftests/powerpc/primitives/Makefile b/tools/testing/selftests/powerpc/primitives/Makefile new file mode 100644 index 0000000..ea737ca --- /dev/null +++ b/tools/testing/selftests/powerpc/primitives/Makefile @@ -0,0 +1,17 @@ +CFLAGS += -I$(CURDIR) + +PROGS := load_unaligned_zeropad + +all: $(PROGS) + +$(PROGS): ../harness.c + +run_tests: all + @-for PROG in $(PROGS); do \ + ./$$PROG; \ + done; + +clean: + rm -f $(PROGS) *.o + +.PHONY: all run_tests clean diff --git a/tools/testing/selftests/powerpc/primitives/asm/asm-compat.h b/tools/testing/selftests/powerpc/primitives/asm/asm-compat.h new file mode 120000 index 0000000..b14255e --- /dev/null +++ b/tools/testing/selftests/powerpc/primitives/asm/asm-compat.h @@ -0,0 +1 @@ +../.././../../../../arch/powerpc/include/asm/asm-compat.h \ No newline at end of file diff --git a/tools/testing/selftests/powerpc/primitives/asm/ppc-opcode.h b/tools/testing/selftests/powerpc/primitives/asm/ppc-opcode.h new file mode 100644 index 0000000..e69de29 diff --git a/tools/testing/selftests/powerpc/primitives/load_unaligned_zeropad.c b/tools/testing/selftests/powerpc/primitives/load_unaligned_zeropad.c new file mode 100644 index 0000000..d1b6475 --- /dev/null +++ b/tools/testing/selftests/powerpc/primitives/load_unaligned_zeropad.c @@ -0,0 +1,147 @@ +/* + * Userspace test harness for load_unaligned_zeropad. Creates two + * pages and uses mprotect to prevent access to the second page and + * a SEGV handler that walks the exception tables and runs the fixup + * routine. + * + * The results are compared against a normal load that is that is + * performed while access to the second page is enabled via mprotect. + * + * Copyright (C) 2014 Anton Blanchard , IBM + * + * 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 +#include +#include +#include +#include +#include +#include + +#define FIXUP_SECTION ".ex_fixup" + +#include "word-at-a-time.h" + +#include "utils.h" + + +static int page_size; +static char *mem_region; + +static int protect_region(void) +{ + if (mprotect(mem_region + page_size, page_size, PROT_NONE)) { + perror("mprotect"); + return 1; + } + + return 0; +} + +static int unprotect_region(void) +{ + if (mprotect(mem_region + page_size, page_size, PROT_READ|PROT_WRITE)) { + perror("mprotect"); + return 1; + } + + return 0; +} + +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 int segv_error; + +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); + segv_error++; +} + +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); +} + +static int do_one_test(char *p, int page_offset) +{ + unsigned long should; + unsigned long got; + + FAIL_IF(unprotect_region()); + should = *(unsigned long *)p; + FAIL_IF(protect_region()); + + got = load_unaligned_zeropad(p); + + if (should != got) + printf("offset %u load_unaligned_zeropad returned 0x%lx, should be 0x%lx\n", page_offset, got, should); + + return 0; +} + +static int test_body(void) +{ + unsigned long i; + + page_size = getpagesize(); + mem_region = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE, + MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); + + FAIL_IF(mem_region == MAP_FAILED); + + for (i = 0; i < page_size; i++) + mem_region[i] = i; + + memset(mem_region+page_size, 0, page_size); + + setup_segv_handler(); + + for (i = 0; i < page_size; i++) + FAIL_IF(do_one_test(mem_region+i, i)); + + FAIL_IF(segv_error); + + return 0; +} + +int main(void) +{ + return test_harness(test_body, "load_unaligned_zeropad"); +} diff --git a/tools/testing/selftests/powerpc/primitives/word-at-a-time.h b/tools/testing/selftests/powerpc/primitives/word-at-a-time.h new file mode 120000 index 0000000..eb74401 --- /dev/null +++ b/tools/testing/selftests/powerpc/primitives/word-at-a-time.h @@ -0,0 +1 @@ +../../../../../arch/powerpc/include/asm/word-at-a-time.h \ No newline at end of file -- 2.7.4