selftests/bpf: verifier/bpf_get_stack converted to inline assembly

Test verifier/bpf_get_stack automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Author: eddyz87

tools/testing/selftests/bpf/prog_tests/verifier.c

@@ -10,6 +10,7 @@
 #include "verifier_bounds_deduction.skel.h"
 #include "verifier_bounds_deduction_non_const.skel.h"
 #include "verifier_bounds_mix_sign_unsign.skel.h"
+#include "verifier_bpf_get_stack.skel.h"
 #include "verifier_cfg.skel.h"
 #include "verifier_cgroup_inv_retcode.skel.h"
 #include "verifier_cgroup_skb.skel.h"
@@ -87,6 +88,7 @@ void test_verifier_bounds(void)               { RUN(verifier_bounds); }
 void test_verifier_bounds_deduction(void)     { RUN(verifier_bounds_deduction); }
 void test_verifier_bounds_deduction_non_const(void)     { RUN(verifier_bounds_deduction_non_const); }
 void test_verifier_bounds_mix_sign_unsign(void) { RUN(verifier_bounds_mix_sign_unsign); }
+void test_verifier_bpf_get_stack(void)        { RUN(verifier_bpf_get_stack); }
 void test_verifier_cfg(void)                  { RUN(verifier_cfg); }
 void test_verifier_cgroup_inv_retcode(void)   { RUN(verifier_cgroup_inv_retcode); }
 void test_verifier_cgroup_skb(void)           { RUN(verifier_cgroup_skb); }

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

@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Converted from tools/testing/selftests/bpf/verifier/bpf_get_stack.c */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+#define MAX_ENTRIES 11
+
+struct test_val {
+	unsigned int index;
+	int foo[MAX_ENTRIES];
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 1);
+	__type(key, int);
+	__type(value, struct test_val);
+} map_array_48b SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 1);
+	__type(key, long long);
+	__type(value, struct test_val);
+} map_hash_48b SEC(".maps");
+
+SEC("tracepoint")
+__description("bpf_get_stack return R0 within range")
+__success
+__naked void stack_return_r0_within_range(void)
+{
+	asm volatile ("					\
+	r6 = r1;					\
+	r1 = 0;						\
+	*(u64*)(r10 - 8) = r1;				\
+	r2 = r10;					\
+	r2 += -8;					\
+	r1 = %[map_hash_48b] ll;			\
+	call %[bpf_map_lookup_elem];			\
+	if r0 == 0 goto l0_%=;				\
+	r7 = r0;					\
+	r9 = %[__imm_0];				\
+	r1 = r6;					\
+	r2 = r7;					\
+	r3 = %[__imm_0];				\
+	r4 = 256;					\
+	call %[bpf_get_stack];				\
+	r1 = 0;						\
+	r8 = r0;					\
+	r8 <<= 32;					\
+	r8 s>>= 32;					\
+	if r1 s> r8 goto l0_%=;				\
+	r9 -= r8;					\
+	r2 = r7;					\
+	r2 += r8;					\
+	r1 = r9;					\
+	r1 <<= 32;					\
+	r1 s>>= 32;					\
+	r3 = r2;					\
+	r3 += r1;					\
+	r1 = r7;					\
+	r5 = %[__imm_0];				\
+	r1 += r5;					\
+	if r3 >= r1 goto l0_%=;				\
+	r1 = r6;					\
+	r3 = r9;					\
+	r4 = 0;						\
+	call %[bpf_get_stack];				\
+l0_%=:	exit;						\
+"	:
+	: __imm(bpf_get_stack),
+	  __imm(bpf_map_lookup_elem),
+	  __imm_addr(map_hash_48b),
+	  __imm_const(__imm_0, sizeof(struct test_val) / 2)
+	: __clobber_all);
+}
+
+SEC("iter/task")
+__description("bpf_get_task_stack return R0 range is refined")
+__success
+__naked void return_r0_range_is_refined(void)
+{
+	asm volatile ("					\
+	r6 = *(u64*)(r1 + 0);				\
+	r6 = *(u64*)(r6 + 0);		/* ctx->meta->seq */\
+	r7 = *(u64*)(r1 + 8);		/* ctx->task */\
+	r1 = %[map_array_48b] ll;	/* fixup_map_array_48b */\
+	r2 = 0;						\
+	*(u64*)(r10 - 8) = r2;				\
+	r2 = r10;					\
+	r2 += -8;					\
+	call %[bpf_map_lookup_elem];			\
+	if r0 != 0 goto l0_%=;				\
+	r0 = 0;						\
+	exit;						\
+l0_%=:	if r7 != 0 goto l1_%=;				\
+	r0 = 0;						\
+	exit;						\
+l1_%=:	r1 = r7;					\
+	r2 = r0;					\
+	r9 = r0;			/* keep buf for seq_write */\
+	r3 = 48;					\
+	r4 = 0;						\
+	call %[bpf_get_task_stack];			\
+	if r0 s> 0 goto l2_%=;				\
+	r0 = 0;						\
+	exit;						\
+l2_%=:	r1 = r6;					\
+	r2 = r9;					\
+	r3 = r0;					\
+	call %[bpf_seq_write];				\
+	r0 = 0;						\
+	exit;						\
+"	:
+	: __imm(bpf_get_task_stack),
+	  __imm(bpf_map_lookup_elem),
+	  __imm(bpf_seq_write),
+	  __imm_addr(map_array_48b)
+	: __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";