selftests: bpf: add zero extend checks for ALU32 and/or/xor [Linux 5.2]

selftests: bpf: add zero extend checks for ALU32 and/or/xor [Linux 5.2]

This Linux kernel change "selftests: bpf: add zero extend checks for ALU32 and/or/xor" is included in the Linux 5.2 release. This change is authored by Björn Töpel <bjorn.topel [at] gmail.com> on Wed May 22 11:23:23 2019 +0200. The commit for this change in Linux stable tree is 00d8304 (patch).

selftests: bpf: add zero extend checks for ALU32 and/or/xor

Add three tests to test_verifier/basic_instr that make sure that the
high 32-bits of the destination register is cleared after an ALU32
and/or/xor.

Signed-off-by: Björn Töpel <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>

There are 39 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 tools/testing/selftests/bpf/verifier/basic_instr.c | 39 ++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/tools/testing/selftests/bpf/verifier/basic_instr.c b/tools/testing/selftests/bpf/verifier/basic_instr.c
index ed91a7b..4d84408 100644
--- a/tools/testing/selftests/bpf/verifier/basic_instr.c
+++ b/tools/testing/selftests/bpf/verifier/basic_instr.c
@@ -132,3 +132,42 @@
    .prog_type = BPF_PROG_TYPE_SCHED_CLS,
    .result = ACCEPT,
 },
+{
+   "and32 reg zero extend check",
+   .insns = {
+   BPF_MOV64_IMM(BPF_REG_0, -1),
+   BPF_MOV64_IMM(BPF_REG_2, -2),
+   BPF_ALU32_REG(BPF_AND, BPF_REG_0, BPF_REG_2),
+   BPF_ALU64_IMM(BPF_RSH, BPF_REG_0, 32),
+   BPF_EXIT_INSN(),
+   },
+   .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+   .result = ACCEPT,
+   .retval = 0,
+},
+{
+   "or32 reg zero extend check",
+   .insns = {
+   BPF_MOV64_IMM(BPF_REG_0, -1),
+   BPF_MOV64_IMM(BPF_REG_2, -2),
+   BPF_ALU32_REG(BPF_OR, BPF_REG_0, BPF_REG_2),
+   BPF_ALU64_IMM(BPF_RSH, BPF_REG_0, 32),
+   BPF_EXIT_INSN(),
+   },
+   .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+   .result = ACCEPT,
+   .retval = 0,
+},
+{
+   "xor32 reg zero extend check",
+   .insns = {
+   BPF_MOV64_IMM(BPF_REG_0, -1),
+   BPF_MOV64_IMM(BPF_REG_2, 0),
+   BPF_ALU32_REG(BPF_XOR, BPF_REG_0, BPF_REG_2),
+   BPF_ALU64_IMM(BPF_RSH, BPF_REG_0, 32),
+   BPF_EXIT_INSN(),
+   },
+   .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+   .result = ACCEPT,
+   .retval = 0,
+},

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