selftests/bpf: Fix some incorrect inline asm codes

In one of upstream thread ([1]), there is a discussion about
the below inline asm code:

  if r1 == 0xdeadbeef goto +2;
  ...

In actual llvm backend, the above 0xdeadbeef will actually do
sign extension to 64bit value and then compare to register r1.

But the code itself does not imply the above semantics. It looks
like the comparision is between r1 and 0xdeadbeef. For example,
let us at a simple C code:
  $ cat t1.c
  int foo(long a) { return a == 0xdeadbeef ? 2 : 3; }
  $ clang --target=bpf -O2 -c t1.c && llvm-objdump -d t1.o
    ...
    w0 = 0x2
    r2 = 0xdeadbeef ll
    if r1 == r2 goto +0x1
    w0 = 0x3
    exit
It does try to compare r1 and 0xdeadbeef.

To address the above confusing inline asm issue, llvm backend ([2])
added some range checking for such insns and beyond. For the above
insn asm, the warning like below
  warning: immediate out of range, shall fit in int range
will be issued. If -Werror is in the compilation flags, the
error will be issued.

To avoid the above warning/error, the afore-mentioned inline asm
should be rewritten to

  if r1 == -559038737 goto +2;
  ...

Fix a few selftest cases like the above based on insn range checking
requirement in [2].

  [1] https://lore.kernel.org/bpf/[email protected]/
  [2] llvm/llvm-project#142989

Signed-off-by: Yonghong Song <[email protected]>

Author: Yonghong Song

tools/testing/selftests/bpf/progs/dummy_st_ops_success.c

@@ -19,7 +19,7 @@ int BPF_PROG(test_1, struct bpf_dummy_ops_state *state)
 	 */
 	asm volatile (
 		"if %[state] != 0 goto +2;"
-		"r0 = 0xf2f3f4f5;"
+		"r0 = -218893067;"
 		"exit;"
 	::[state]"p"(state));
 

tools/testing/selftests/bpf/progs/dynptr_fail.c

@@ -761,7 +761,7 @@ int dynptr_pruning_type_confusion(struct __sk_buff *ctx)
 		 *(u64 *)(r2 + 0) = r9;			\
 		 r3 = r10;				\
 		 r3 += -24;				\
-		 r9 = 0xeB9FeB9F;			\
+		 r9 = -341840993;			\
 		 *(u64 *)(r10 - 16) = r9;		\
 		 *(u64 *)(r10 - 24) = r9;		\
 		 r9 = 0;				\

tools/testing/selftests/bpf/progs/iters.c

@@ -774,7 +774,7 @@ __naked int delayed_read_mark(void)
 	"3:"
 		"r1 = r7;"
 		"r2 = 8;"
-		"r3 = 0xdeadbeef;"
+		"r3 = -559038737;"
 		"call %[bpf_probe_read_user];"
 		"goto 1b;"
 	"2:"

tools/testing/selftests/bpf/progs/verifier_and.c

@@ -99,7 +99,7 @@ __naked void known_subreg_with_unknown_reg(void)
 	call %[bpf_get_prandom_u32];			\
 	r0 <<= 32;					\
 	r0 += 1;					\
-	r0 &= 0xFFFF1234;				\
+	r0 &= -60876;					\
 	/* Upper bits are unknown but AND above masks out 1 zero'ing lower bits */\
 	if w0 < 1 goto l0_%=;				\
 	r1 = *(u32*)(r1 + 512);				\

tools/testing/selftests/bpf/progs/verifier_bounds.c

@@ -152,7 +152,7 @@ __naked void on_sign_extended_mov_test1(void)
 	call %[bpf_map_lookup_elem];			\
 	if r0 == 0 goto l0_%=;				\
 	/* r2 = 0xffff'ffff'ffff'ffff */		\
-	r2 = 0xffffffff;				\
+	r2 = -1;					\
 	/* r2 = 0xffff'ffff */				\
 	r2 >>= 32;					\
 	/* r0 = <oob pointer> */			\
@@ -183,7 +183,7 @@ __naked void on_sign_extended_mov_test2(void)
 	call %[bpf_map_lookup_elem];			\
 	if r0 == 0 goto l0_%=;				\
 	/* r2 = 0xffff'ffff'ffff'ffff */		\
-	r2 = 0xffffffff;				\
+	r2 = -1;					\
 	/* r2 = 0xfff'ffff */				\
 	r2 >>= 36;					\
 	/* r0 = <oob pointer> */			\

tools/testing/selftests/bpf/progs/verifier_direct_packet_access.c

@@ -485,7 +485,7 @@ __naked void test20_x_pkt_ptr_1(void)
 	asm volatile ("					\
 	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
 	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
-	r0 = 0xffffffff;				\
+	r0 = -1;					\
 	*(u64*)(r10 - 8) = r0;				\
 	r0 = *(u64*)(r10 - 8);				\
 	r0 &= 0x7fff;					\
@@ -515,7 +515,7 @@ __naked void test21_x_pkt_ptr_2(void)
 	r0 = r2;					\
 	r0 += 8;					\
 	if r0 > r3 goto l0_%=;				\
-	r4 = 0xffffffff;				\
+	r4 = -1;					\
 	*(u64*)(r10 - 8) = r4;				\
 	r4 = *(u64*)(r10 - 8);				\
 	r4 &= 0x7fff;					\
@@ -548,7 +548,7 @@ __naked void test22_x_pkt_ptr_3(void)
 	r3 = *(u64*)(r10 - 16);				\
 	if r0 > r3 goto l0_%=;				\
 	r2 = *(u64*)(r10 - 8);				\
-	r4 = 0xffffffff;				\
+	r4 = -1;					\
 	lock *(u64 *)(r10 - 8) += r4;			\
 	r4 = *(u64*)(r10 - 8);				\
 	r4 >>= 49;					\
@@ -605,7 +605,7 @@ __naked void test24_x_pkt_ptr_5(void)
 	asm volatile ("					\
 	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
 	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
-	r0 = 0xffffffff;				\
+	r0 = -1;					\
 	*(u64*)(r10 - 8) = r0;				\
 	r0 = *(u64*)(r10 - 8);				\
 	r0 &= 0xff;					\

tools/testing/selftests/bpf/progs/verifier_ldsx.c

@@ -50,7 +50,7 @@ __success __success_unpriv __retval(-1)
 __naked void ldsx_s32(void)
 {
 	asm volatile (
-	"r1 = 0xfffffffe;"
+	"r1 = -2;"
 	"*(u64 *)(r10 - 8) = r1;"
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 	"r0 = *(s32 *)(r10 - 8);"

tools/testing/selftests/bpf/progs/verifier_masking.c

@@ -171,7 +171,7 @@ __success __success_unpriv __retval(0)
 __naked void test_out_of_bounds_9(void)
 {
 	asm volatile ("					\
-	r1 = 0xffffffff;				\
+	r1 = -1;					\
 	w2 = %[__imm_0];				\
 	r2 -= r1;					\
 	r2 |= r1;					\
@@ -191,7 +191,7 @@ __success __success_unpriv __retval(0)
 __naked void test_out_of_bounds_10(void)
 {
 	asm volatile ("					\
-	r1 = 0xffffffff;				\
+	r1 = -1;					\
 	w2 = %[__imm_0];				\
 	r2 -= r1;					\
 	r2 |= r1;					\

tools/testing/selftests/bpf/progs/verifier_movsx.c

@@ -64,7 +64,7 @@ __success __success_unpriv __retval(-1)
 __naked void mov64sx_s32(void)
 {
 	asm volatile ("					\
-	r0 = 0xfffffffe;				\
+	r0 = -2;					\
 	r0 = (s32)r0;					\
 	r0 >>= 1;					\
 	exit;						\

tools/testing/selftests/bpf/progs/verifier_or_jmp32_k.c

@@ -11,7 +11,7 @@ __msg("R0 invalid mem access 'scalar'")
 __naked void or_jmp32_k(void)
 {
 	asm volatile ("					\
-	r0 = 0xffffffff;				\
+	r0 = -1;					\
 	r0 /= 1;					\
 	r1 = 0;						\
 	w1 = -1;					\