diff mbox series

[bpf-next,v2,2/2] selftests/bpf: Add a selftest for checking subreg equality

Message ID 20230417222139.360607-1-yhs@fb.com (mailing list archive)
State Accepted
Commit 49859de997c3115b85544bce6b6ceab60a7fabc4
Delegated to: BPF
Headers show
Series [bpf-next,v2,1/2] bpf: Improve verifier u32 scalar equality checking | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-10 success Logs for test_maps on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-15 success Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-20 success Logs for test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-7 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-2 success Logs for build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-3 success Logs for build for aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-5 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-6 success Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-4 success Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-8 success Logs for test_maps on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-9 success Logs for test_maps on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-11 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-17 fail Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-18 success Logs for test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-19 success Logs for test_progs_no_alu32 on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-21 fail Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-22 fail Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-23 success Logs for test_progs_no_alu32_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-24 success Logs for test_progs_no_alu32_parallel on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-25 success Logs for test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-26 success Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-27 success Logs for test_progs_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-28 success Logs for test_progs_parallel on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-29 success Logs for test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-30 success Logs for test_progs_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-31 success Logs for test_verifier on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-32 success Logs for test_verifier on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-34 success Logs for test_verifier on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-35 success Logs for test_verifier on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-13 success Logs for test_progs on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-14 success Logs for test_progs on aarch64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-16 fail Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-33 success Logs for test_verifier on s390x with gcc
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/apply success Patch already applied to bpf-next

Commit Message

Yonghong Song April 17, 2023, 10:21 p.m. UTC 
Add a selftest to ensure subreg equality if source register
upper 32bit is 0. Without previous patch, the test will
fail verification.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 .../selftests/bpf/prog_tests/verifier.c       |  2 +
 .../selftests/bpf/progs/verifier_reg_equal.c  | 58 +++++++++++++++++++
 2 files changed, 60 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/progs/verifier_reg_equal.c

v1 -> v2:
  - Add some comments for the test
  - Add a negative test
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c
index 73dff693d411..25bc8958dbfe 100644
--- a/tools/testing/selftests/bpf/prog_tests/verifier.c
+++ b/tools/testing/selftests/bpf/prog_tests/verifier.c
@@ -31,6 +31,7 @@ 
 #include "verifier_meta_access.skel.h"
 #include "verifier_raw_stack.skel.h"
 #include "verifier_raw_tp_writable.skel.h"
+#include "verifier_reg_equal.skel.h"
 #include "verifier_ringbuf.skel.h"
 #include "verifier_spill_fill.skel.h"
 #include "verifier_stack_ptr.skel.h"
@@ -95,6 +96,7 @@  void test_verifier_masking(void)              { RUN(verifier_masking); }
 void test_verifier_meta_access(void)          { RUN(verifier_meta_access); }
 void test_verifier_raw_stack(void)            { RUN(verifier_raw_stack); }
 void test_verifier_raw_tp_writable(void)      { RUN(verifier_raw_tp_writable); }
+void test_verifier_reg_equal(void)            { RUN(verifier_reg_equal); }
 void test_verifier_ringbuf(void)              { RUN(verifier_ringbuf); }
 void test_verifier_spill_fill(void)           { RUN(verifier_spill_fill); }
 void test_verifier_stack_ptr(void)            { RUN(verifier_stack_ptr); }
diff --git a/tools/testing/selftests/bpf/progs/verifier_reg_equal.c b/tools/testing/selftests/bpf/progs/verifier_reg_equal.c
new file mode 100644
index 000000000000..dc1d8c30fb0e
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_reg_equal.c
@@ -0,0 +1,58 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+SEC("socket")
+__description("check w reg equal if r reg upper32 bits 0")
+__success
+__naked void subreg_equality_1(void)
+{
+	asm volatile ("					\
+	call %[bpf_ktime_get_ns];			\
+	*(u64 *)(r10 - 8) = r0;				\
+	r2 = *(u32 *)(r10 - 8);				\
+	/* At this point upper 4-bytes of r2 are 0,	\
+	 * thus insn w3 = w2 should propagate reg id,	\
+	 * and w2 < 9 comparison would also propagate	\
+	 * the range for r3.				\
+	 */						\
+	w3 = w2;					\
+	if w2 < 9 goto l0_%=;				\
+	exit;						\
+l0_%=:	if r3 < 9 goto l1_%=;				\
+	/* r1 read is illegal at this point */		\
+	r0 -= r1;					\
+l1_%=:	exit;						\
+"	:
+	: __imm(bpf_ktime_get_ns)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("check w reg not equal if r reg upper32 bits not 0")
+__failure __msg("R1 !read_ok")
+__naked void subreg_equality_2(void)
+{
+	asm volatile ("					\
+	call %[bpf_ktime_get_ns];			\
+	r2 = r0;					\
+	/* Upper 4-bytes of r2 may not be 0, thus insn	\
+	 * w3 = w2 should not propagate reg id,	and	\
+	 * w2 < 9 comparison should not propagate	\
+	 * the range for r3 either.			\
+	 */						\
+	w3 = w2;					\
+	if w2 < 9 goto l0_%=;				\
+	exit;						\
+l0_%=:	if r3 < 9 goto l1_%=;				\
+	/* r1 read is illegal at this point */		\
+	r0 -= r1;					\
+l1_%=:	exit;						\
+"	:
+	: __imm(bpf_ktime_get_ns)
+	: __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";