From: Anshuman Khandual <khandual@linux.vnet.ibm.com>
To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Cc: mikey@neuling.org, shuahkh@osg.samsung.com, anton@samba.org
Subject: [PATCH V2 09/12] selftests, powerpc: Add test for DSCR value inheritence across fork
Date: Tue, 13 Jan 2015 15:52:37 +0530 [thread overview]
Message-ID: <1421144560-15901-10-git-send-email-khandual@linux.vnet.ibm.com> (raw)
In-Reply-To: <1421144560-15901-1-git-send-email-khandual@linux.vnet.ibm.com>
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.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
---
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 <anton@au.ibm.com>, IBM
+ * Copyright (C) 2015 Anshuman Khandual <khandual@linux.vnet.ibm.com>, 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
next prev parent reply other threads:[~2015-01-13 10:23 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-13 10:22 [PATCH V2 00/12] POWER DSCR fixes, improvements, docs and tests Anshuman Khandual
2015-01-13 10:22 ` [PATCH V2 01/12] powerpc: Fix handling of DSCR related facility unavailable exception Anshuman Khandual
2015-01-13 10:22 ` [PATCH V2 02/12] powerpc, process: Remove the unused extern dscr_default Anshuman Khandual
2015-01-13 10:22 ` [PATCH V2 03/12] powerpc, offset: Change PACA_DSCR to PACA_DSCR_DEFAULT Anshuman Khandual
2015-01-13 10:22 ` [PATCH V2 04/12] powerpc, dscr: Added some in-code documentation Anshuman Khandual
2015-01-13 10:22 ` [PATCH V2 05/12] documentation, powerpc: Add documentation for DSCR support Anshuman Khandual
2015-01-13 10:22 ` [PATCH V2 06/12] selftests, powerpc: Add test for system wide DSCR default Anshuman Khandual
2015-01-13 15:22 ` Shuah Khan
2015-01-13 23:44 ` Michael Ellerman
2015-01-20 21:40 ` Dave Jones
2015-01-21 6:51 ` Michael Ellerman
2015-03-27 12:01 ` [V2, " Michael Ellerman
2015-04-09 10:31 ` Anshuman Khandual
2015-04-09 12:38 ` Anshuman Khandual
2015-01-13 10:22 ` [PATCH V2 07/12] selftests, powerpc: Add test for explicitly changing DSCR value Anshuman Khandual
2015-01-13 15:23 ` Shuah Khan
2015-01-13 10:22 ` [PATCH V2 08/12] selftests, powerpc: Add test for DSCR SPR numbers Anshuman Khandual
2015-01-13 15:23 ` Shuah Khan
2015-01-13 10:22 ` Anshuman Khandual [this message]
2015-01-13 15:24 ` [PATCH V2 09/12] selftests, powerpc: Add test for DSCR value inheritence across fork Shuah Khan
2015-01-13 10:22 ` [PATCH V2 10/12] selftests, powerpc: Add test for DSCR inheritence across fork & exec Anshuman Khandual
2015-01-13 15:24 ` Shuah Khan
2015-01-13 10:22 ` [PATCH V2 11/12] selftests, powerpc: Add test for all DSCR sysfs interfaces Anshuman Khandual
2015-01-13 15:24 ` Shuah Khan
2015-01-13 10:22 ` [PATCH V2 12/12] selftests, powerpc: Add thread based stress test for " Anshuman Khandual
2015-01-13 15:24 ` Shuah Khan
2015-02-04 8:21 ` [PATCH V2 00/12] POWER DSCR fixes, improvements, docs and tests Anshuman Khandual
2015-02-04 8:36 ` Anshuman Khandual
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