From: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Date: Fri, 1 Oct 2021 15:03:48 +0200
Subject: bpf/tests: Add test of LDX_MEM with operand aliasing
Patch-mainline: v5.16-rc1
Git-commit: 7bceeb95726b105bd4241c9635acc0836df675d4
References: jsc#PED-1377
This patch adds a set of tests of BPF_LDX_MEM where both operand registers
are the same register. Mainly testing 32-bit JITs that may load a 64-bit
value in two 32-bit loads, and must not overwrite the address register.
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211001130348.3670534-11-johan.almbladh@anyfinetworks.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
lib/test_bpf.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 58 insertions(+)
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -11133,6 +11133,64 @@ static struct bpf_test tests[] = {
{},
{ { 0, 2 } },
},
+ /* BPF_LDX_MEM with operand aliasing */
+ {
+ "LDX_MEM_B: operand register aliasing",
+ .u.insns_int = {
+ BPF_ST_MEM(BPF_B, R10, -8, 123),
+ BPF_MOV64_REG(R0, R10),
+ BPF_LDX_MEM(BPF_B, R0, R0, -8),
+ BPF_EXIT_INSN(),
+ },
+ INTERNAL,
+ { },
+ { { 0, 123 } },
+ .stack_depth = 8,
+ },
+ {
+ "LDX_MEM_H: operand register aliasing",
+ .u.insns_int = {
+ BPF_ST_MEM(BPF_H, R10, -8, 12345),
+ BPF_MOV64_REG(R0, R10),
+ BPF_LDX_MEM(BPF_H, R0, R0, -8),
+ BPF_EXIT_INSN(),
+ },
+ INTERNAL,
+ { },
+ { { 0, 12345 } },
+ .stack_depth = 8,
+ },
+ {
+ "LDX_MEM_W: operand register aliasing",
+ .u.insns_int = {
+ BPF_ST_MEM(BPF_W, R10, -8, 123456789),
+ BPF_MOV64_REG(R0, R10),
+ BPF_LDX_MEM(BPF_W, R0, R0, -8),
+ BPF_EXIT_INSN(),
+ },
+ INTERNAL,
+ { },
+ { { 0, 123456789 } },
+ .stack_depth = 8,
+ },
+ {
+ "LDX_MEM_DW: operand register aliasing",
+ .u.insns_int = {
+ BPF_LD_IMM64(R1, 0x123456789abcdefULL),
+ BPF_STX_MEM(BPF_DW, R10, R1, -8),
+ BPF_MOV64_REG(R0, R10),
+ BPF_LDX_MEM(BPF_DW, R0, R0, -8),
+ BPF_ALU64_REG(BPF_SUB, R0, R1),
+ BPF_MOV64_REG(R1, R0),
+ BPF_ALU64_IMM(BPF_RSH, R1, 32),
+ BPF_ALU64_REG(BPF_OR, R0, R1),
+ BPF_EXIT_INSN(),
+ },
+ INTERNAL,
+ { },
+ { { 0, 0 } },
+ .stack_depth = 8,
+ },
/*
* Register (non-)clobbering tests for the case where a JIT implements
* complex ALU or ATOMIC operations via function calls. If so, the