As opt_hard_wire_dead_code_branches() was changed to react to
accumulated branch prediction flags for conditional jumps,
add tests for various possible predictions.
Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/verifier.c | 2 +
.../selftests/bpf/progs/verifier_dead_code.c | 63 +++++++++++++++++++
2 files changed, 65 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/verifier_dead_code.c
diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c
index 75f7a2ce334b..efd42c07f58a 100644
--- a/tools/testing/selftests/bpf/prog_tests/verifier.c
+++ b/tools/testing/selftests/bpf/prog_tests/verifier.c
@@ -26,6 +26,7 @@
#include "verifier_ctx.skel.h"
#include "verifier_ctx_sk_msg.skel.h"
#include "verifier_d_path.skel.h"
+#include "verifier_dead_code.skel.h"
#include "verifier_direct_packet_access.skel.h"
#include "verifier_direct_stack_access_wraparound.skel.h"
#include "verifier_div0.skel.h"
@@ -154,6 +155,7 @@ void test_verifier_const_or(void) { RUN(verifier_const_or); }
void test_verifier_ctx(void) { RUN(verifier_ctx); }
void test_verifier_ctx_sk_msg(void) { RUN(verifier_ctx_sk_msg); }
void test_verifier_d_path(void) { RUN(verifier_d_path); }
+void test_verifier_dead_code(void) { RUN(verifier_dead_code); }
void test_verifier_direct_packet_access(void) { RUN(verifier_direct_packet_access); }
void test_verifier_direct_stack_access_wraparound(void) { RUN(verifier_direct_stack_access_wraparound); }
void test_verifier_div0(void) { RUN(verifier_div0); }
diff --git a/tools/testing/selftests/bpf/progs/verifier_dead_code.c b/tools/testing/selftests/bpf/progs/verifier_dead_code.c
new file mode 100644
index 000000000000..b2eed6be0d42
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_dead_code.c
@@ -0,0 +1,63 @@
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+SEC("socket")
+__xlated("0: r1 = 1")
+__xlated("1: r0 = 42")
+__xlated("2: r0 = 24")
+__xlated("3: exit")
+__success
+__retval(24)
+__naked void cond_always_false(void)
+{
+ asm volatile (
+ "r1 = 1;"
+ "r0 = 42;"
+ "if r1 != 1 goto +1;"
+ "r0 = 24;"
+ "exit;"
+ ::: __clobber_all
+ );
+}
+
+SEC("socket")
+__xlated("0: r1 = 2")
+__xlated("1: r0 = 42")
+__xlated("2: exit")
+__success
+__retval(42)
+__naked void cond_always_true(void)
+{
+ asm volatile (
+ "r1 = 2;"
+ "r0 = 42;"
+ "if r1 != 1 goto +1;"
+ "r0 = 24;"
+ "exit;"
+ ::: __clobber_all
+ );
+}
+
+SEC("socket")
+__xlated("0: call")
+__xlated("1: r1 = r0")
+__xlated("2: r0 = 42")
+__xlated("3: if r1 != 0x1 goto pc+1")
+__xlated("4: r0 = 24")
+__xlated("5: exit")
+__success
+__naked void cond_unknown(void)
+{
+ asm volatile (
+ "call %[bpf_get_prandom_u32];"
+ "r1 = r0;"
+ "r0 = 42;"
+ "if r1 != 1 goto +1;"
+ "r0 = 24;"
+ "exit;"
+ :
+ : __imm(bpf_get_prandom_u32)
+ : __clobber_all
+ );
+}
--
2.47.0
