selftests/bpf: verifier/lwt converted to inline assembly

Test verifier/lwt automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-11-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

3 files changed, 236 insertions, 189 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c
index 632546912627..32e55c8e3e3b 100644
--- a/tools/testing/selftests/bpf/prog_tests/verifier.c
+++ b/tools/testing/selftests/bpf/prog_tests/verifier.c
@@ -33,6 +33,7 @@
 #include "verifier_ld_ind.skel.h"
 #include "verifier_leak_ptr.skel.h"
 #include "verifier_loops1.skel.h"
+#include "verifier_lwt.skel.h"
 #include "verifier_map_ptr.skel.h"
 #include "verifier_map_ret_val.skel.h"
 #include "verifier_masking.skel.h"
@@ -117,6 +118,7 @@ void test_verifier_jeq_infer_not_null(void)   { RUN(verifier_jeq_infer_not_null)
 void test_verifier_ld_ind(void)               { RUN(verifier_ld_ind); }
 void test_verifier_leak_ptr(void)             { RUN(verifier_leak_ptr); }
 void test_verifier_loops1(void)               { RUN(verifier_loops1); }
+void test_verifier_lwt(void)                  { RUN(verifier_lwt); }
 void test_verifier_map_ptr(void)              { RUN(verifier_map_ptr); }
 void test_verifier_map_ret_val(void)          { RUN(verifier_map_ret_val); }
 void test_verifier_masking(void)              { RUN(verifier_masking); }
diff --git a/tools/testing/selftests/bpf/progs/verifier_lwt.c b/tools/testing/selftests/bpf/progs/verifier_lwt.c
new file mode 100644
index 000000000000..5ab746307309
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_lwt.c
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Converted from tools/testing/selftests/bpf/verifier/lwt.c */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+SEC("lwt_in")
+__description("invalid direct packet write for LWT_IN")
+__failure __msg("cannot write into packet")
+__naked void packet_write_for_lwt_in(void)
+{
+	asm volatile ("					\
+	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
+	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
+	r0 = r2;					\
+	r0 += 8;					\
+	if r0 > r3 goto l0_%=;				\
+	*(u8*)(r2 + 0) = r2;				\
+l0_%=:	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
+	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
+	: __clobber_all);
+}
+
+SEC("lwt_out")
+__description("invalid direct packet write for LWT_OUT")
+__failure __msg("cannot write into packet")
+__naked void packet_write_for_lwt_out(void)
+{
+	asm volatile ("					\
+	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
+	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
+	r0 = r2;					\
+	r0 += 8;					\
+	if r0 > r3 goto l0_%=;				\
+	*(u8*)(r2 + 0) = r2;				\
+l0_%=:	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
+	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
+	: __clobber_all);
+}
+
+SEC("lwt_xmit")
+__description("direct packet write for LWT_XMIT")
+__success __retval(0)
+__naked void packet_write_for_lwt_xmit(void)
+{
+	asm volatile ("					\
+	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
+	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
+	r0 = r2;					\
+	r0 += 8;					\
+	if r0 > r3 goto l0_%=;				\
+	*(u8*)(r2 + 0) = r2;				\
+l0_%=:	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
+	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
+	: __clobber_all);
+}
+
+SEC("lwt_in")
+__description("direct packet read for LWT_IN")
+__success __retval(0)
+__naked void packet_read_for_lwt_in(void)
+{
+	asm volatile ("					\
+	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
+	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
+	r0 = r2;					\
+	r0 += 8;					\
+	if r0 > r3 goto l0_%=;				\
+	r0 = *(u8*)(r2 + 0);				\
+l0_%=:	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
+	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
+	: __clobber_all);
+}
+
+SEC("lwt_out")
+__description("direct packet read for LWT_OUT")
+__success __retval(0)
+__naked void packet_read_for_lwt_out(void)
+{
+	asm volatile ("					\
+	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
+	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
+	r0 = r2;					\
+	r0 += 8;					\
+	if r0 > r3 goto l0_%=;				\
+	r0 = *(u8*)(r2 + 0);				\
+l0_%=:	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
+	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
+	: __clobber_all);
+}
+
+SEC("lwt_xmit")
+__description("direct packet read for LWT_XMIT")
+__success __retval(0)
+__naked void packet_read_for_lwt_xmit(void)
+{
+	asm volatile ("					\
+	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
+	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
+	r0 = r2;					\
+	r0 += 8;					\
+	if r0 > r3 goto l0_%=;				\
+	r0 = *(u8*)(r2 + 0);				\
+l0_%=:	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
+	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
+	: __clobber_all);
+}
+
+SEC("lwt_xmit")
+__description("overlapping checks for direct packet access")
+__success __retval(0)
+__naked void checks_for_direct_packet_access(void)
+{
+	asm volatile ("					\
+	r2 = *(u32*)(r1 + %[__sk_buff_data]);		\
+	r3 = *(u32*)(r1 + %[__sk_buff_data_end]);	\
+	r0 = r2;					\
+	r0 += 8;					\
+	if r0 > r3 goto l0_%=;				\
+	r1 = r2;					\
+	r1 += 6;					\
+	if r1 > r3 goto l0_%=;				\
+	r0 = *(u16*)(r2 + 6);				\
+l0_%=:	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
+	  __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
+	: __clobber_all);
+}
+
+SEC("lwt_xmit")
+__description("make headroom for LWT_XMIT")
+__success __retval(0)
+__naked void make_headroom_for_lwt_xmit(void)
+{
+	asm volatile ("					\
+	r6 = r1;					\
+	r2 = 34;					\
+	r3 = 0;						\
+	call %[bpf_skb_change_head];			\
+	/* split for s390 to succeed */			\
+	r1 = r6;					\
+	r2 = 42;					\
+	r3 = 0;						\
+	call %[bpf_skb_change_head];			\
+	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm(bpf_skb_change_head)
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("invalid access of tc_classid for LWT_IN")
+__failure __msg("invalid bpf_context access")
+__failure_unpriv
+__naked void tc_classid_for_lwt_in(void)
+{
+	asm volatile ("					\
+	r0 = *(u32*)(r1 + %[__sk_buff_tc_classid]);	\
+	exit;						\
+"	:
+	: __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("invalid access of tc_classid for LWT_OUT")
+__failure __msg("invalid bpf_context access")
+__failure_unpriv
+__naked void tc_classid_for_lwt_out(void)
+{
+	asm volatile ("					\
+	r0 = *(u32*)(r1 + %[__sk_buff_tc_classid]);	\
+	exit;						\
+"	:
+	: __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
+	: __clobber_all);
+}
+
+SEC("socket")
+__description("invalid access of tc_classid for LWT_XMIT")
+__failure __msg("invalid bpf_context access")
+__failure_unpriv
+__naked void tc_classid_for_lwt_xmit(void)
+{
+	asm volatile ("					\
+	r0 = *(u32*)(r1 + %[__sk_buff_tc_classid]);	\
+	exit;						\
+"	:
+	: __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
+	: __clobber_all);
+}
+
+SEC("lwt_in")
+__description("check skb->tc_classid half load not permitted for lwt prog")
+__failure __msg("invalid bpf_context access")
+__naked void not_permitted_for_lwt_prog(void)
+{
+	asm volatile (
+	"r0 = 0;"
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	"r0 = *(u16*)(r1 + %[__sk_buff_tc_classid]);"
+#else
+	"r0 = *(u16*)(r1 + %[__imm_0]);"
+#endif
+	"exit;"
+	:
+	: __imm_const(__imm_0, offsetof(struct __sk_buff, tc_classid) + 2),
+	  __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
+	: __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/verifier/lwt.c b/tools/testing/selftests/bpf/verifier/lwt.c
deleted file mode 100644
index 5c8944d0b091..000000000000
--- a/tools/testing/selftests/bpf/verifier/lwt.c
+++ /dev/null
@@ -1,189 +0,0 @@
-{
-	"invalid direct packet write for LWT_IN",
-	.insns = {
-	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
-		    offsetof(struct __sk_buff, data)),
-	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
-		    offsetof(struct __sk_buff, data_end)),
-	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
-	BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
-	BPF_STX_MEM(BPF_B, BPF_REG_2, BPF_REG_2, 0),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.errstr = "cannot write into packet",
-	.result = REJECT,
-	.prog_type = BPF_PROG_TYPE_LWT_IN,
-},
-{
-	"invalid direct packet write for LWT_OUT",
-	.insns = {
-	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
-		    offsetof(struct __sk_buff, data)),
-	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
-		    offsetof(struct __sk_buff, data_end)),
-	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
-	BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
-	BPF_STX_MEM(BPF_B, BPF_REG_2, BPF_REG_2, 0),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.errstr = "cannot write into packet",
-	.result = REJECT,
-	.prog_type = BPF_PROG_TYPE_LWT_OUT,
-},
-{
-	"direct packet write for LWT_XMIT",
-	.insns = {
-	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
-		    offsetof(struct __sk_buff, data)),
-	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
-		    offsetof(struct __sk_buff, data_end)),
-	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
-	BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
-	BPF_STX_MEM(BPF_B, BPF_REG_2, BPF_REG_2, 0),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.result = ACCEPT,
-	.prog_type = BPF_PROG_TYPE_LWT_XMIT,
-},
-{
-	"direct packet read for LWT_IN",
-	.insns = {
-	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
-		    offsetof(struct __sk_buff, data)),
-	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
-		    offsetof(struct __sk_buff, data_end)),
-	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
-	BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
-	BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_2, 0),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.result = ACCEPT,
-	.prog_type = BPF_PROG_TYPE_LWT_IN,
-},
-{
-	"direct packet read for LWT_OUT",
-	.insns = {
-	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
-		    offsetof(struct __sk_buff, data)),
-	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
-		    offsetof(struct __sk_buff, data_end)),
-	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
-	BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
-	BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_2, 0),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.result = ACCEPT,
-	.prog_type = BPF_PROG_TYPE_LWT_OUT,
-},
-{
-	"direct packet read for LWT_XMIT",
-	.insns = {
-	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
-		    offsetof(struct __sk_buff, data)),
-	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
-		    offsetof(struct __sk_buff, data_end)),
-	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
-	BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1),
-	BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_2, 0),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.result = ACCEPT,
-	.prog_type = BPF_PROG_TYPE_LWT_XMIT,
-},
-{
-	"overlapping checks for direct packet access",
-	.insns = {
-	BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
-		    offsetof(struct __sk_buff, data)),
-	BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
-		    offsetof(struct __sk_buff, data_end)),
-	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
-	BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 4),
-	BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
-	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 6),
-	BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 1),
-	BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_2, 6),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.result = ACCEPT,
-	.prog_type = BPF_PROG_TYPE_LWT_XMIT,
-},
-{
-	"make headroom for LWT_XMIT",
-	.insns = {
-	BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
-	BPF_MOV64_IMM(BPF_REG_2, 34),
-	BPF_MOV64_IMM(BPF_REG_3, 0),
-	BPF_EMIT_CALL(BPF_FUNC_skb_change_head),
-	/* split for s390 to succeed */
-	BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
-	BPF_MOV64_IMM(BPF_REG_2, 42),
-	BPF_MOV64_IMM(BPF_REG_3, 0),
-	BPF_EMIT_CALL(BPF_FUNC_skb_change_head),
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-	BPF_EXIT_INSN(),
-	},
-	.result = ACCEPT,
-	.prog_type = BPF_PROG_TYPE_LWT_XMIT,
-},
-{
-	"invalid access of tc_classid for LWT_IN",
-	.insns = {
-	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
-		    offsetof(struct __sk_buff, tc_classid)),
-	BPF_EXIT_INSN(),
-	},
-	.result = REJECT,
-	.errstr = "invalid bpf_context access",
-},
-{
-	"invalid access of tc_classid for LWT_OUT",
-	.insns = {
-	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
-		    offsetof(struct __sk_buff, tc_classid)),
-	BPF_EXIT_INSN(),
-	},
-	.result = REJECT,
-	.errstr = "invalid bpf_context access",
-},
-{
-	"invalid access of tc_classid for LWT_XMIT",
-	.insns = {
-	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
-		    offsetof(struct __sk_buff, tc_classid)),
-	BPF_EXIT_INSN(),
-	},
-	.result = REJECT,
-	.errstr = "invalid bpf_context access",
-},
-{
-	"check skb->tc_classid half load not permitted for lwt prog",
-	.insns = {
-	BPF_MOV64_IMM(BPF_REG_0, 0),
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-	BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
-		    offsetof(struct __sk_buff, tc_classid)),
-#else
-	BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
-		    offsetof(struct __sk_buff, tc_classid) + 2),
-#endif
-	BPF_EXIT_INSN(),
-	},
-	.result = REJECT,
-	.errstr = "invalid bpf_context access",
-	.prog_type = BPF_PROG_TYPE_LWT_IN,
-},