selftests/powerpc: Add transactional syscall test

Check that a syscall made during an active transaction will fail with
the correct failure code and that one made during a suspended
transaction will succeed.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/tools/testing/selftests/powerpc/tm/.gitignore b/tools/testing/selftests/powerpc/tm/.gitignore
index 33d02cc54a3ed1b4e49f60fc9f60b98d9d341441..2699635d2cd93dd721f83fc54f7f2d55cb7c5a00 100644 (file)
--- a/tools/testing/selftests/powerpc/tm/.gitignore
+++ b/tools/testing/selftests/powerpc/tm/.gitignore
@@ -1 +1,2 @@
 tm-resched-dscr
+tm-syscall

diff --git a/tools/testing/selftests/powerpc/tm/Makefile b/tools/testing/selftests/powerpc/tm/Makefile
index 2cede239a074dd110aa9ff3a6119b55f9c9d4ff6..122cf1830de8ed63c5eb5decdbd20b6ea8138608 100644 (file)
--- a/tools/testing/selftests/powerpc/tm/Makefile
+++ b/tools/testing/selftests/powerpc/tm/Makefile
@@ -1,9 +1,12 @@
-PROGS := tm-resched-dscr
+PROGS := tm-resched-dscr tm-syscall
 
 all: $(PROGS)
 
 $(PROGS): ../harness.c
 
+tm-syscall: tm-syscall-asm.S
+tm-syscall: CFLAGS += -mhtm
+
 run_tests: all
        @-for PROG in $(PROGS); do \
                ./$$PROG; \

diff --git a/tools/testing/selftests/powerpc/tm/tm-syscall-asm.S b/tools/testing/selftests/powerpc/tm/tm-syscall-asm.S
new file mode 100644 (file)
index 0000000..431f61a
--- /dev/null
+++ b/tools/testing/selftests/powerpc/tm/tm-syscall-asm.S
@@ -0,0 +1,27 @@
+#include <ppc-asm.h>
+#include <asm/unistd.h>
+
+       .text
+FUNC_START(getppid_tm_active)
+       tbegin.
+       beq 1f
+       li      r0, __NR_getppid
+       sc
+       tend.
+       blr
+1:
+       li      r3, -1
+       blr
+
+FUNC_START(getppid_tm_suspended)
+       tbegin.
+       beq 1f
+       li      r0, __NR_getppid
+       tsuspend.
+       sc
+       tresume.
+       tend.
+       blr
+1:
+       li      r3, -1
+       blr

diff --git a/tools/testing/selftests/powerpc/tm/tm-syscall.c b/tools/testing/selftests/powerpc/tm/tm-syscall.c
new file mode 100644 (file)
index 0000000..3ed8d4b
--- /dev/null
+++ b/tools/testing/selftests/powerpc/tm/tm-syscall.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright 2015, Sam Bobroff, IBM Corp.
+ * Licensed under GPLv2.
+ *
+ * Test the kernel's system call code to ensure that a system call
+ * made from within an active HTM transaction is aborted with the
+ * correct failure code.
+ * Conversely, ensure that a system call made from within a
+ * suspended transaction can succeed.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <asm/tm.h>
+#include <asm/cputable.h>
+#include <linux/auxvec.h>
+#include <sys/time.h>
+#include <stdlib.h>
+
+#include "utils.h"
+
+extern int getppid_tm_active(void);
+extern int getppid_tm_suspended(void);
+
+unsigned retries = 0;
+
+#define TEST_DURATION 10 /* seconds */
+#define TM_RETRIES 100
+
+long failure_code(void)
+{
+       return __builtin_get_texasru() >> 24;
+}
+
+bool failure_is_persistent(void)
+{
+       return (failure_code() & TM_CAUSE_PERSISTENT) == TM_CAUSE_PERSISTENT;
+}
+
+bool failure_is_syscall(void)
+{
+       return (failure_code() & TM_CAUSE_SYSCALL) == TM_CAUSE_SYSCALL;
+}
+
+pid_t getppid_tm(bool suspend)
+{
+       int i;
+       pid_t pid;
+
+       for (i = 0; i < TM_RETRIES; i++) {
+               if (suspend)
+                       pid = getppid_tm_suspended();
+               else
+                       pid = getppid_tm_active();
+
+               if (pid >= 0)
+                       return pid;
+
+               if (failure_is_persistent()) {
+                       if (failure_is_syscall())
+                               return -1;
+
+                       printf("Unexpected persistent transaction failure.\n");
+                       printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n",
+                              __builtin_get_texasr(), __builtin_get_tfiar());
+                       exit(-1);
+               }
+
+               retries++;
+       }
+
+       printf("Exceeded limit of %d temporary transaction failures.\n", TM_RETRIES);
+       printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n",
+              __builtin_get_texasr(), __builtin_get_tfiar());
+
+       exit(-1);
+}
+
+int tm_syscall(void)
+{
+       unsigned count = 0;
+       struct timeval end, now;
+
+       SKIP_IF(!((long)get_auxv_entry(AT_HWCAP2) & PPC_FEATURE2_HTM));
+       setbuf(stdout, NULL);
+
+       printf("Testing transactional syscalls for %d seconds...\n", TEST_DURATION);
+
+       gettimeofday(&end, NULL);
+       now.tv_sec = TEST_DURATION;
+       now.tv_usec = 0;
+       timeradd(&end, &now, &end);
+
+       for (count = 0; timercmp(&now, &end, <); count++) {
+               /*
+                * Test a syscall within a suspended transaction and verify
+                * that it succeeds.
+                */
+               FAIL_IF(getppid_tm(true) == -1); /* Should succeed. */
+
+               /*
+                * Test a syscall within an active transaction and verify that
+                * it fails with the correct failure code.
+                */
+               FAIL_IF(getppid_tm(false) != -1);  /* Should fail... */
+               FAIL_IF(!failure_is_persistent()); /* ...persistently... */
+               FAIL_IF(!failure_is_syscall());    /* ...with code syscall. */
+               gettimeofday(&now, 0);
+       }
+
+       printf("%d active and suspended transactions behaved correctly.\n", count);
+       printf("(There were %d transaction retries.)\n", retries);
+
+       return 0;
+}
+
+int main(void)
+{
+       return test_harness(tm_syscall, "tm_syscall");
+}