@@ -1,3 +1,4 @@
tm-resched-dscr
tm-syscall
tm-signal-msr-resv
+tm-signal-stack
@@ -1,4 +1,4 @@
-TEST_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv
+TEST_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv tm-signal-stack
all: $(TEST_PROGS)
new file mode 100644
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2015, Michael Neuling, IBM Corp.
+ * Licensed under GPLv2.
+ *
+ * Test the kernel's signal delievery code to ensure that we don't
+ * trelaim twice in the kernel signal delivery code. This can happen
+ * if we trigger a signal when in a transaction and the stack pointer
+ * is bogus.
+ *
+ * This test case registers a SEGV handler, sets the stack pointer
+ * (r1) to NULL, starts a transaction and then generates a SEGV. The
+ * SEGV should be handled but we exit here as the stack pointer is
+ * invalid and hance we can't sigreturn. We only need to check that
+ * this flow doesn't crash the kernel.
+ */
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <signal.h>
+
+#include "utils.h"
+
+void signal_segv(int signum)
+{
+ /* This should never actually run since stack is foobar */
+ exit(1);
+}
+
+int tm_signal_stack()
+{
+ int pid;
+
+ pid = fork();
+ if (pid < 0)
+ exit(1);
+
+ if (pid) { /* Parent */
+ /*
+ * It's likely the whole machine will crash here so if
+ * the child ever exits, we are good.
+ */
+ wait(NULL);
+ return 0;
+ }
+
+ /*
+ * The flow here is:
+ * 1) register a signal handler (so signal delievery occurs)
+ * 2) make stack pointer (r1) = NULL
+ * 3) start transaction
+ * 4) cause segv
+ */
+ if (signal(SIGSEGV, signal_segv) == SIG_ERR)
+ exit(1);
+ asm volatile("li 1, 0 ;" /* stack ptr == NULL */
+ "1:"
+ ".long 0x7C00051D ;" /* tbegin */
+ "beq 1b ;" /* retry forever */
+ ".long 0x7C0005DD ; ;" /* tsuspend */
+ "ld 2, 0(1) ;" /* trigger segv" */
+ : : : "memory");
+
+ /* This should never get here due to above segv */
+ return 1;
+}
+
+int main(void)
+{
+ return test_harness(tm_signal_stack, "tm_signal_stack");
+}
Test the kernels signal generation code to ensure it can handle an invalid stack pointer when transactional. Signed-off-by: Michael Neuling <mikey@neuling.org> --- tools/testing/selftests/powerpc/tm/.gitignore | 1 + tools/testing/selftests/powerpc/tm/Makefile | 2 +- .../testing/selftests/powerpc/tm/tm-signal-stack.c | 73 ++++++++++++++++++++++ 3 files changed, 75 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/powerpc/tm/tm-signal-stack.c