A new self test that forces MSR[TS] to be set without calling any TM
instruction. This test also tries to cause a page fault at a signal
handler, exactly between MSR[TS] set and tm_recheckpoint(), forcing
thread->texasr to be rewritten with TEXASR[FS] = 0, which will cause a BUG
when tm_recheckpoint() is called.
This test is not deterministic, since it is hard to guarantee that the page
access will cause a page fault. In order to force more page faults at
signal context, the signal handler and the ucontext are being mapped into a
MADV_DONTNEED memory chunks.
Tests have shown that the bug could be exposed with few interactions in a
buggy kernel. This test is configured to loop 5000x, having a good chance
to hit the kernel issue in just one run. This self test takes less than
two seconds to run.
This test uses set/getcontext because the kernel will recheckpoint
zeroed structures, causing the test to segfault, which is undesired because
the test needs to rerun, so, there is a signal handler for SIGSEGV which
will restart the test.
v2: Uses the MADV_DONTNEED memory advice
v3: Fix memcpy and 32-bits compilation
v4: Does not define unused macros
Signed-off-by: Breno Leitao
---
tools/testing/selftests/powerpc/include/reg.h | 8 +
.../testing/selftests/powerpc/include/utils.h | 2 +
tools/testing/selftests/powerpc/tm/.gitignore | 1 +
tools/testing/selftests/powerpc/tm/Makefile | 4 +-
.../powerpc/tm/tm-signal-context-force-tm.c | 184 ++
5 files changed, 198 insertions(+), 1 deletion(-)
create mode 100644
tools/testing/selftests/powerpc/tm/tm-signal-context-force-tm.c
diff --git a/tools/testing/selftests/powerpc/include/reg.h
b/tools/testing/selftests/powerpc/include/reg.h
index 52b4710469d2..a69ab6e2afd9 100644
--- a/tools/testing/selftests/powerpc/include/reg.h
+++ b/tools/testing/selftests/powerpc/include/reg.h
@@ -77,6 +77,14 @@
#define TEXASR_TE 0x0400
#define TEXASR_ROT 0x0200
+/* MSR register bits */
+#define MSR_TS_S_LG 33 /* Trans Mem state: Suspended */
+
+#define __MASK(X) (1UL<<(X))
+
+/* macro to check TM MSR bits */
+#define MSR_TS_S__MASK(MSR_TS_S_LG) /* Transaction Suspended */
+
/* Vector Instructions */
#define VSX_XX1(xs, ra, rb)(((xs) & 0x1f) << 21 | ((ra) << 16) | \
((rb) << 11) | (((xs) >> 5)))
diff --git a/tools/testing/selftests/powerpc/include/utils.h
b/tools/testing/selftests/powerpc/include/utils.h
index ae43a614835d..7636bf45d5d5 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h
@@ -102,8 +102,10 @@ do {
\
#if defined(__powerpc64__)
#define UCONTEXT_NIA(UC) (UC)->uc_mcontext.gp_regs[PT_NIP]
+#define UCONTEXT_MSR(UC) (UC)->uc_mcontext.gp_regs[PT_MSR]
#elif defined(__powerpc__)
#define UCONTEXT_NIA(UC) (UC)->uc_mcontext.uc_regs->gregs[PT_NIP]
+#define UCONTEXT_MSR(UC) (UC)->uc_mcontext.uc_regs->gregs[PT_MSR]
#else
#error implement UCONTEXT_NIA
#endif
diff --git a/tools/testing/selftests/powerpc/tm/.gitignore
b/tools/testing/selftests/powerpc/tm/.gitignore
index 208452a93e2c..951fe855f7cd 100644
--- a/tools/testing/selftests/powerpc/tm/.gitignore
+++ b/tools/testing/selftests/powerpc/tm/.gitignore
@@ -11,6 +11,7 @@ tm-signal-context-chk-fpu
tm-signal-context-chk-gpr
tm-signal-context-chk-vmx
tm-signal-context-chk-vsx
+tm-signal-context-force-tm
tm-signal-sigreturn-nt
tm-vmx-unavail
tm-unavailable
diff --git a/tools/testing/selftests/powerpc/tm/Makefile
b/tools/testing/selftests/powerpc/tm/Makefile
index 75a685359129..c0734ed0ef56 100644
--- a/tools/testing/selftests/powerpc/tm/Makefile
+++ b/tools/testing/selftests/powerpc/tm/Makefile
@@ -4,7 +4,8 @@ SIGNAL_CONTEXT_CHK_TESTS := tm-signal-context-chk-gpr
tm-signal-context-chk-fpu
TEST_GEN_PROGS := tm-resched-dscr tm-syscall tm-signal-msr-resv
tm-signal-stack \
tm-vmxcopy tm-fork tm-tar tm-tmspr tm-vmx-unavail tm-unavailable
tm-trap \
- $(SIGNAL_CONTEXT_CHK_TESTS) tm-sigreturn tm-signal-sigreturn-nt
+ $(SIGNAL_CONTEXT_CHK_TESTS) tm-sigreturn tm-signal-sigreturn-nt \
+ tm-signal-context-force-tm
top_srcdir = ../../../../..
include ../../lib.mk
@@ -20,6 +21,7 @@ $(OUTPUT)/tm-vmx-unavail: CFLAGS += -pthread -m64
$(OUTPUT)/tm-resched-dscr: ../pmu/lib.c
$(OUTPUT)/tm-unavailable: CFLAGS += -O0 -pthread -m64 -Wno-error=uninitialized
-mvsx
$(OUTPUT)/tm-trap: CFLAGS += -O0 -pthread -m64
+$(OUTPUT)/tm-signal-context-force-tm: CFLAGS += -pthread -m64
SIGNAL_CONTEXT_CHK_TESTS := $(patsubst
%,$(OUTPUT)/%,$(SIGNAL_CONTEXT_CHK_TESTS))
$(SIGNAL_CONTEXT_CHK_TESTS): tm-signal.S
diff --git a/tools/testing/selftests/powerpc/tm/tm-signal-context-force-tm.c
b/tools/testing/selftests/powerpc/tm/tm-signal-context-force-tm.c
new file mode 100644
index ..31717625f318
--- /dev/null
+++ b/tools/te
