Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755516AbbDJIdE (ORCPT ); Fri, 10 Apr 2015 04:33:04 -0400 Received: from e23smtp06.au.ibm.com ([202.81.31.148]:54287 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754625AbbDJIba (ORCPT ); Fri, 10 Apr 2015 04:31:30 -0400 From: Anshuman Khandual To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Cc: mikey@neuling.org, shuahkh@osg.samsung.com, mpe@ellerman.id.au Subject: [PATCH V3 09/13] selftests, powerpc: Add test for DSCR value inheritence across fork Date: Fri, 10 Apr 2015 14:00:08 +0530 Message-Id: <1428654612-23539-10-git-send-email-khandual@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1428654612-23539-1-git-send-email-khandual@linux.vnet.ibm.com> References: <1428654612-23539-1-git-send-email-khandual@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15041008-0021-0000-0000-0000010D7804 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3882 Lines: 133 This patch adds a test to verify that the changed DSCR value inside any process would be inherited to it's child process across the fork system call. Acked-by: Shuah Khan Signed-off-by: Anshuman Khandual --- tools/testing/selftests/powerpc/dscr/Makefile | 3 +- .../selftests/powerpc/dscr/dscr_inherit_test.c | 96 ++++++++++++++++++++++ 2 files changed, 98 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c diff --git a/tools/testing/selftests/powerpc/dscr/Makefile b/tools/testing/selftests/powerpc/dscr/Makefile index ae865d8..81239e2 100644 --- a/tools/testing/selftests/powerpc/dscr/Makefile +++ b/tools/testing/selftests/powerpc/dscr/Makefile @@ -1,4 +1,5 @@ -PROGS := dscr_default_test dscr_explicit_test dscr_user_test +PROGS := dscr_default_test dscr_explicit_test dscr_user_test \ + dscr_inherit_test CFLAGS := $(CFLAGS) -lpthread diff --git a/tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c b/tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c new file mode 100644 index 0000000..f1add77 --- /dev/null +++ b/tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c @@ -0,0 +1,96 @@ +/* + * POWER Data Stream Control Register (DSCR) fork test + * + * This testcase modifies the DSCR using mtspr, forks and then + * verifies that the child process has the correct changed DSCR + * value using mfspr. + * + * When using the privilege state SPR, the instructions such as + * mfspr or mtspr are priviledged and the kernel emulates them + * for us. Instructions using problem state SPR can be exuecuted + * directly without any emulation if the HW supports them. Else + * they also get emulated by the kernel. + * + * Copyright (C) 2012 Anton Blanchard , IBM + * Copyright (C) 2015 Anshuman Khandual , 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 "dscr.h" + +int test_body(void) +{ + unsigned long i, dscr = 0; + pid_t pid; + + srand(getpid()); + set_dscr(dscr); + + for (i = 0; i < COUNT; i++) { + unsigned long cur_dscr, cur_dscr_usr; + + dscr++; + if (dscr > DSCR_MAX) + dscr = 0; + + if (i % 2 == 0) + set_dscr_usr(dscr); + else + set_dscr(dscr); + + /* + * XXX: Force a context switch out so that DSCR + * current value is copied into the thread struct + * which is required for the child to inherit the + * changed value. + */ + sleep(1); + + pid = fork(); + if (pid == -1) { + perror("fork() failed\n"); + exit(1); + } else if (pid) { + int status; + + if (waitpid(pid, &status, 0) == -1) { + perror("waitpid() failed\n"); + exit(1); + } + + if (!WIFEXITED(status)) { + fprintf(stderr, "Child didn't exit cleanly\n"); + exit(1); + } + + if (WEXITSTATUS(status) != 0) { + fprintf(stderr, "Child didn't exit cleanly\n"); + return 1; + } + } else { + cur_dscr = get_dscr(); + if (cur_dscr != dscr) { + fprintf(stderr, "Kernel DSCR should be %ld " + "but is %ld\n", dscr, cur_dscr); + exit(1); + } + + cur_dscr_usr = get_dscr_usr(); + if (cur_dscr_usr != dscr) { + fprintf(stderr, "User DSCR should be %ld " + "but is %ld\n", dscr, cur_dscr_usr); + exit(1); + } + exit(0); + } + } + return 0; +} + +int main(int argc, char *argv[]) +{ + return test_harness(test_body, "dscr_inherit_test"); +} -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/