From e2f9797b3c7396065ca3bc9f223225ca63c1e2bd Mon Sep 17 00:00:00 2001 From: Johan Almbladh Date: Fri, 1 Oct 2021 15:03:43 +0200 Subject: bpf/tests: Add more tests for ALU and ATOMIC register clobbering This patch expands the register-clobbering-during-function-call tests to cover more all ALU32/64 MUL, DIV and MOD operations and all ATOMIC operations. In short, if a JIT implements a complex operation with a call to an external function, it must make sure to save and restore all its caller-saved registers that may be clobbered by the call. Signed-off-by: Johan Almbladh Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20211001130348.3670534-6-johan.almbladh@anyfinetworks.com --- lib/test_bpf.c | 267 ++++++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 197 insertions(+), 70 deletions(-) (limited to 'lib/test_bpf.c') diff --git a/lib/test_bpf.c b/lib/test_bpf.c index c7db90112ef0..201f34060eef 100644 --- a/lib/test_bpf.c +++ b/lib/test_bpf.c @@ -3744,76 +3744,6 @@ static struct bpf_test tests[] = { { }, { { 0, -1 } } }, - { - /* - * Register (non-)clobbering test, in the case where a 32-bit - * JIT implements complex ALU64 operations via function calls. - * If so, the function call must be invisible in the eBPF - * registers. The JIT must then save and restore relevant - * registers during the call. The following tests check that - * the eBPF registers retain their values after such a call. - */ - "INT: Register clobbering, R1 updated", - .u.insns_int = { - BPF_ALU32_IMM(BPF_MOV, R0, 0), - BPF_ALU32_IMM(BPF_MOV, R1, 123456789), - BPF_ALU32_IMM(BPF_MOV, R2, 2), - BPF_ALU32_IMM(BPF_MOV, R3, 3), - BPF_ALU32_IMM(BPF_MOV, R4, 4), - BPF_ALU32_IMM(BPF_MOV, R5, 5), - BPF_ALU32_IMM(BPF_MOV, R6, 6), - BPF_ALU32_IMM(BPF_MOV, R7, 7), - BPF_ALU32_IMM(BPF_MOV, R8, 8), - BPF_ALU32_IMM(BPF_MOV, R9, 9), - BPF_ALU64_IMM(BPF_DIV, R1, 123456789), - BPF_JMP_IMM(BPF_JNE, R0, 0, 10), - BPF_JMP_IMM(BPF_JNE, R1, 1, 9), - BPF_JMP_IMM(BPF_JNE, R2, 2, 8), - BPF_JMP_IMM(BPF_JNE, R3, 3, 7), - BPF_JMP_IMM(BPF_JNE, R4, 4, 6), - BPF_JMP_IMM(BPF_JNE, R5, 5, 5), - BPF_JMP_IMM(BPF_JNE, R6, 6, 4), - BPF_JMP_IMM(BPF_JNE, R7, 7, 3), - BPF_JMP_IMM(BPF_JNE, R8, 8, 2), - BPF_JMP_IMM(BPF_JNE, R9, 9, 1), - BPF_ALU32_IMM(BPF_MOV, R0, 1), - BPF_EXIT_INSN(), - }, - INTERNAL, - { }, - { { 0, 1 } } - }, - { - "INT: Register clobbering, R2 updated", - .u.insns_int = { - BPF_ALU32_IMM(BPF_MOV, R0, 0), - BPF_ALU32_IMM(BPF_MOV, R1, 1), - BPF_ALU32_IMM(BPF_MOV, R2, 2 * 123456789), - BPF_ALU32_IMM(BPF_MOV, R3, 3), - BPF_ALU32_IMM(BPF_MOV, R4, 4), - BPF_ALU32_IMM(BPF_MOV, R5, 5), - BPF_ALU32_IMM(BPF_MOV, R6, 6), - BPF_ALU32_IMM(BPF_MOV, R7, 7), - BPF_ALU32_IMM(BPF_MOV, R8, 8), - BPF_ALU32_IMM(BPF_MOV, R9, 9), - BPF_ALU64_IMM(BPF_DIV, R2, 123456789), - BPF_JMP_IMM(BPF_JNE, R0, 0, 10), - BPF_JMP_IMM(BPF_JNE, R1, 1, 9), - BPF_JMP_IMM(BPF_JNE, R2, 2, 8), - BPF_JMP_IMM(BPF_JNE, R3, 3, 7), - BPF_JMP_IMM(BPF_JNE, R4, 4, 6), - BPF_JMP_IMM(BPF_JNE, R5, 5, 5), - BPF_JMP_IMM(BPF_JNE, R6, 6, 4), - BPF_JMP_IMM(BPF_JNE, R7, 7, 3), - BPF_JMP_IMM(BPF_JNE, R8, 8, 2), - BPF_JMP_IMM(BPF_JNE, R9, 9, 1), - BPF_ALU32_IMM(BPF_MOV, R0, 1), - BPF_EXIT_INSN(), - }, - INTERNAL, - { }, - { { 0, 1 } } - }, { /* * Test 32-bit JITs that implement complex ALU64 operations as @@ -10586,6 +10516,203 @@ static struct bpf_test tests[] = { {}, { { 0, 2 } }, }, + /* + * Register (non-)clobbering tests for the case where a JIT implements + * complex ALU or ATOMIC operations via function calls. If so, the + * function call must be transparent to the eBPF registers. The JIT + * must therefore save and restore relevant registers across the call. + * The following tests check that the eBPF registers retain their + * values after such an operation. Mainly intended for complex ALU + * and atomic operation, but we run it for all. You never know... + * + * Note that each operations should be tested twice with different + * destinations, to check preservation for all registers. + */ +#define BPF_TEST_CLOBBER_ALU(alu, op, dst, src) \ + { \ + #alu "_" #op " to " #dst ": no clobbering", \ + .u.insns_int = { \ + BPF_ALU64_IMM(BPF_MOV, R0, R0), \ + BPF_ALU64_IMM(BPF_MOV, R1, R1), \ + BPF_ALU64_IMM(BPF_MOV, R2, R2), \ + BPF_ALU64_IMM(BPF_MOV, R3, R3), \ + BPF_ALU64_IMM(BPF_MOV, R4, R4), \ + BPF_ALU64_IMM(BPF_MOV, R5, R5), \ + BPF_ALU64_IMM(BPF_MOV, R6, R6), \ + BPF_ALU64_IMM(BPF_MOV, R7, R7), \ + BPF_ALU64_IMM(BPF_MOV, R8, R8), \ + BPF_ALU64_IMM(BPF_MOV, R9, R9), \ + BPF_##alu(BPF_ ##op, dst, src), \ + BPF_ALU32_IMM(BPF_MOV, dst, dst), \ + BPF_JMP_IMM(BPF_JNE, R0, R0, 10), \ + BPF_JMP_IMM(BPF_JNE, R1, R1, 9), \ + BPF_JMP_IMM(BPF_JNE, R2, R2, 8), \ + BPF_JMP_IMM(BPF_JNE, R3, R3, 7), \ + BPF_JMP_IMM(BPF_JNE, R4, R4, 6), \ + BPF_JMP_IMM(BPF_JNE, R5, R5, 5), \ + BPF_JMP_IMM(BPF_JNE, R6, R6, 4), \ + BPF_JMP_IMM(BPF_JNE, R7, R7, 3), \ + BPF_JMP_IMM(BPF_JNE, R8, R8, 2), \ + BPF_JMP_IMM(BPF_JNE, R9, R9, 1), \ + BPF_ALU64_IMM(BPF_MOV, R0, 1), \ + BPF_EXIT_INSN(), \ + }, \ + INTERNAL, \ + { }, \ + { { 0, 1 } } \ + } + /* ALU64 operations, register clobbering */ + BPF_TEST_CLOBBER_ALU(ALU64_IMM, AND, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, AND, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, OR, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, OR, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, XOR, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, XOR, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, LSH, R8, 12), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, LSH, R9, 12), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, RSH, R8, 12), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, RSH, R9, 12), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, ARSH, R8, 12), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, ARSH, R9, 12), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, ADD, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, ADD, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, SUB, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, SUB, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, MUL, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, MUL, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, DIV, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, DIV, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, MOD, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU64_IMM, MOD, R9, 123456789), + /* ALU32 immediate operations, register clobbering */ + BPF_TEST_CLOBBER_ALU(ALU32_IMM, AND, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, AND, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, OR, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, OR, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, XOR, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, XOR, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, LSH, R8, 12), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, LSH, R9, 12), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, RSH, R8, 12), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, RSH, R9, 12), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, ARSH, R8, 12), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, ARSH, R9, 12), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, ADD, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, ADD, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, SUB, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, SUB, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, MUL, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, MUL, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, DIV, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, DIV, R9, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, MOD, R8, 123456789), + BPF_TEST_CLOBBER_ALU(ALU32_IMM, MOD, R9, 123456789), + /* ALU64 register operations, register clobbering */ + BPF_TEST_CLOBBER_ALU(ALU64_REG, AND, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, AND, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, OR, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, OR, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, XOR, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, XOR, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, LSH, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, LSH, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, RSH, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, RSH, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, ARSH, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, ARSH, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, ADD, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, ADD, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, SUB, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, SUB, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, MUL, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, MUL, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, DIV, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, DIV, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, MOD, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU64_REG, MOD, R9, R1), + /* ALU32 register operations, register clobbering */ + BPF_TEST_CLOBBER_ALU(ALU32_REG, AND, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, AND, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, OR, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, OR, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, XOR, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, XOR, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, LSH, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, LSH, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, RSH, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, RSH, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, ARSH, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, ARSH, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, ADD, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, ADD, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, SUB, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, SUB, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, MUL, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, MUL, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, DIV, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, DIV, R9, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, MOD, R8, R1), + BPF_TEST_CLOBBER_ALU(ALU32_REG, MOD, R9, R1), +#undef BPF_TEST_CLOBBER_ALU +#define BPF_TEST_CLOBBER_ATOMIC(width, op) \ + { \ + "Atomic_" #width " " #op ": no clobbering", \ + .u.insns_int = { \ + BPF_ALU64_IMM(BPF_MOV, R0, 0), \ + BPF_ALU64_IMM(BPF_MOV, R1, 1), \ + BPF_ALU64_IMM(BPF_MOV, R2, 2), \ + BPF_ALU64_IMM(BPF_MOV, R3, 3), \ + BPF_ALU64_IMM(BPF_MOV, R4, 4), \ + BPF_ALU64_IMM(BPF_MOV, R5, 5), \ + BPF_ALU64_IMM(BPF_MOV, R6, 6), \ + BPF_ALU64_IMM(BPF_MOV, R7, 7), \ + BPF_ALU64_IMM(BPF_MOV, R8, 8), \ + BPF_ALU64_IMM(BPF_MOV, R9, 9), \ + BPF_ST_MEM(width, R10, -8, \ + (op) == BPF_CMPXCHG ? 0 : \ + (op) & BPF_FETCH ? 1 : 0), \ + BPF_ATOMIC_OP(width, op, R10, R1, -8), \ + BPF_JMP_IMM(BPF_JNE, R0, 0, 10), \ + BPF_JMP_IMM(BPF_JNE, R1, 1, 9), \ + BPF_JMP_IMM(BPF_JNE, R2, 2, 8), \ + BPF_JMP_IMM(BPF_JNE, R3, 3, 7), \ + BPF_JMP_IMM(BPF_JNE, R4, 4, 6), \ + BPF_JMP_IMM(BPF_JNE, R5, 5, 5), \ + BPF_JMP_IMM(BPF_JNE, R6, 6, 4), \ + BPF_JMP_IMM(BPF_JNE, R7, 7, 3), \ + BPF_JMP_IMM(BPF_JNE, R8, 8, 2), \ + BPF_JMP_IMM(BPF_JNE, R9, 9, 1), \ + BPF_ALU64_IMM(BPF_MOV, R0, 1), \ + BPF_EXIT_INSN(), \ + }, \ + INTERNAL, \ + { }, \ + { { 0, 1 } }, \ + .stack_depth = 8, \ + } + /* 64-bit atomic operations, register clobbering */ + BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_ADD), + BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_AND), + BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_OR), + BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_XOR), + BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_ADD | BPF_FETCH), + BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_AND | BPF_FETCH), + BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_OR | BPF_FETCH), + BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_XOR | BPF_FETCH), + BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_XCHG), + BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_CMPXCHG), + /* 32-bit atomic operations, register clobbering */ + BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_ADD), + BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_AND), + BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_OR), + BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_XOR), + BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_ADD | BPF_FETCH), + BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_AND | BPF_FETCH), + BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_OR | BPF_FETCH), + BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_XOR | BPF_FETCH), + BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_XCHG), + BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_CMPXCHG), +#undef BPF_TEST_CLOBBER_ATOMIC /* Checking that ALU32 src is not zero extended in place */ #define BPF_ALU32_SRC_ZEXT(op) \ { \ -- cgit v1.2.3-59-g8ed1b