Run 9-runqlat.bpf.c error

```
Loading BPF program...
libbpf: prog 'sched_switch': BPF program load failed: -EINVAL
libbpf: prog 'sched_switch': -- BEGIN PROG LOAD LOG --
0: R1=ctx() R10=fp0
; int BPF_PROG(sched_switch, bool preempt, struct task_struct *prev, struct task_struct *next)
0: (79) r2 = *(u64 *)(r1 +16)
func 'sched_switch' arg2 has btf_id 269 type STRUCT 'task_struct'
1: R1=ctx() R2_w=trusted_ptr_task_struct()
1: (79) r1 = *(u64 *)(r1 +8)
func 'sched_switch' arg1 has btf_id 269 type STRUCT 'task_struct'
2: R1_w=trusted_ptr_task_struct()
; return handle_switch(preempt, prev, next);
2: (85) call pc+2
caller:
R10=fp0
callee:
frame1: R1_w=trusted_ptr_task_struct() R2_w=trusted_ptr_task_struct() R10=fp0
5: frame1: R1_w=trusted_ptr_task_struct() R2_w=trusted_ptr_task_struct() R10=fp0
; static int handle_switch(bool preempt, struct task_struct *prev, struct task_struct *next)
5: (bf) r6 = r2 ; frame1: R2_w=trusted_ptr_task_struct() R6_w=trusted_ptr_task_struct()
6: (bf) r7 = r1 ; frame1: R1_w=trusted_ptr_task_struct() R7_w=trusted_ptr_task_struct()
; if (filter_cg && !bpf_current_task_under_cgroup(&cgroup_map, 0))
7: (18) r1 = 0xffff9d0e0238a000 ; frame1: R1_w=map_value(map=runqlat.rodata,ks=4,vs=12)
9: (71) r1 = *(u8 *)(r1 +0) ; frame1: R1_w=0
; if (filter_cg && !bpf_current_task_under_cgroup(&cgroup_map, 0))
10: (16) if w1 == 0x0 goto pc+5 ; frame1: R1_w=0
; if (filter_cg && !bpf_current_task_under_cgroup(&cgroup_map, 0))
16: (b7) r1 = 1 ; frame1: R1_w=1
; if (bpf_core_field_exists(t->__state))
17: (16) if w1 == 0x0 goto pc+10 ; frame1: R1_w=1
18: (b7) r1 = 24 ; frame1: R1_w=24
19: (bf) r3 = r7 ; frame1: R3_w=trusted_ptr_task_struct() R7=trusted_ptr_task_struct()
20: (0f) r3 += r1 ; frame1: R1_w=24 R3_w=trusted_ptr_task_struct(off=24)
21: (bf) r1 = r10 ; frame1: R1_w=fp0 R10=fp0
;
22: (07) r1 += -16 ; frame1: R1_w=fp-16
; return BPF_CORE_READ(t, __state);
23: (b4) w2 = 4 ; frame1: R2_w=4
24: (85) call bpf_probe_read_kernel#113 ; frame1: R0=scalar() fp-16=????mmmm
; return BPF_CORE_READ(t, __state);
25: (61) r1 = *(u32 *)(r10 -16) ; frame1: R1_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R10=fp0 fp-16=????mmmm
; if (get_task_state(prev) == TASK_RUNNING)
26: (55) if r1 != 0x0 goto pc+44 ; frame1: R1_w=0
27: (05) goto pc+9
; if (get_task_state(prev) == TASK_RUNNING)
37: (b7) r1 = 2468 ; frame1: R1_w=2468
38: (bf) r3 = r7 ; frame1: R3_w=trusted_ptr_task_struct() R7=trusted_ptr_task_struct()
39: (0f) r3 += r1 ; frame1: R1_w=2468 R3_w=trusted_ptr_task_struct(off=2468)
40: (bf) r1 = r10 ; frame1: R1_w=fp0 R10=fp0
;
41: (07) r1 += -16 ; frame1: R1_w=fp-16
; trace_enqueue(BPF_CORE_READ(prev, tgid), BPF_CORE_READ(prev, pid));
42: (b4) w2 = 4 ; frame1: R2_w=4
43: (85) call bpf_probe_read_kernel#113 ; frame1: R0=scalar() fp-16=????mmmm
44: (b7) r1 = 2464 ; frame1: R1_w=2464
45: (0f) r7 += r1 ; frame1: R1_w=2464 R7_w=trusted_ptr_task_struct(off=2464)
; trace_enqueue(BPF_CORE_READ(prev, tgid), BPF_CORE_READ(prev, pid));
46: (61) r8 = *(u32 *)(r10 -16) ; frame1: R8_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R10=fp0 fp-16=????mmmm
47: (bf) r1 = r10 ; frame1: R1_w=fp0 R10=fp0
;
48: (07) r1 += -16 ; frame1: R1_w=fp-16
; trace_enqueue(BPF_CORE_READ(prev, tgid), BPF_CORE_READ(prev, pid));
49: (b4) w2 = 4 ; frame1: R2_w=4
50: (bf) r3 = r7 ; frame1: R3_w=trusted_ptr_task_struct(off=2464) R7_w=trusted_ptr_task_struct(off=2464)
51: (85) call bpf_probe_read_kernel#113 ; frame1: R0_w=scalar() fp-16=????mmmm
; trace_enqueue(BPF_CORE_READ(prev, tgid), BPF_CORE_READ(prev, pid));
52: (61) r1 = *(u32 *)(r10 -16) ; frame1: R1_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R10=fp0 fp-16=????mmmm
53: (63) *(u32 *)(r10 -20) = r1 ; frame1: R1_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R10=fp0 fp-24=mmmm????
; if (!pid)
54: (16) if w1 == 0x0 goto pc+16 ; frame1: R1_w=scalar(smin=umin=umin32=1,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
; if (targ_tgid && targ_tgid != tgid)
55: (18) r1 = 0xffff9d0e0238a008 ; frame1: R1_w=map_value(map=runqlat.rodata,ks=4,vs=12,off=8)
57: (61) r2 = *(u32 *)(r1 +0) ; frame1: R1=map_value(map=runqlat.rodata,ks=4,vs=12,off=8) R2=0
; if (targ_tgid && targ_tgid != tgid)
58: (16) if w2 == 0x0 goto pc+2 ; frame1: R2=0
; ts = bpf_ktime_get_ns();
61: (85) call bpf_ktime_get_ns#5 ; frame1: R0_w=scalar()
; ts = bpf_ktime_get_ns();
62: (7b) *(u64 *)(r10 -16) = r0 ; frame1: R0_w=scalar() R10=fp0 fp-16_w=mmmmmmmm
63: (bf) r2 = r10 ; frame1: R2_w=fp0 R10=fp0
; ts = bpf_ktime_get_ns();
64: (07) r2 += -20 ; frame1: R2_w=fp-20
65: (bf) r3 = r10 ; frame1: R3_w=fp0 R10=fp0
66: (07) r3 += -16 ; frame1: R3_w=fp-16
; bpf_map_update_elem(&start, &pid, &ts, BPF_ANY);
67: (18) r1 = 0xffff8da68ce89c00 ; frame1: R1_w=map_ptr(map=start,ks=4,vs=8)
69: (b7) r4 = 0 ; frame1: R4_w=0
70: (85) call bpf_map_update_elem#2 ; frame1: R0=scalar()
71: (b7) r1 = 2464 ; frame1: R1_w=2464
72: (bf) r3 = r6 ; frame1: R3_w=trusted_ptr_task_struct() R6=trusted_ptr_task_struct()
73: (0f) r3 += r1 ; frame1: R1_w=2464 R3_w=trusted_ptr_task_struct(off=2464)
74: (bf) r7 = r10 ; frame1: R7_w=fp0 R10=fp0
; pid = BPF_CORE_READ(next, pid);
75: (07) r7 += -20 ; frame1: R7_w=fp-20
76: (bf) r1 = r7 ; frame1: R1_w=fp-20 R7_w=fp-20
77: (b4) w2 = 4 ; frame1: R2_w=4
78: (85) call bpf_probe_read_kernel#113 ; frame1: R0_w=scalar() fp-24=mmmm????
; tsp = bpf_map_lookup_elem(&start, &pid);
79: (18) r1 = 0xffff8da68ce89c00 ; frame1: R1_w=map_ptr(map=start,ks=4,vs=8)
81: (bf) r2 = r7 ; frame1: R2_w=fp-20 R7_w=fp-20
82: (85) call bpf_map_lookup_elem#1 ; frame1: R0=map_value_or_null(id=1,map=start,ks=4,vs=8)
83: (bf) r8 = r0 ; frame1: R0=map_value_or_null(id=1,map=start,ks=4,vs=8) R8_w=map_value_or_null(id=1,map=start,ks=4,vs=8)
; if (!tsp)
84: (15) if r8 == 0x0 goto pc+129 ; frame1: R8_w=map_value(map=start,ks=4,vs=8)
; delta = bpf_ktime_get_ns() - *tsp;
85: (85) call bpf_ktime_get_ns#5 ; frame1: R0_w=scalar()
86: (bf) r7 = r0 ; frame1: R0_w=scalar(id=2) R7_w=scalar(id=2)
; delta = bpf_ktime_get_ns() - *tsp;
87: (79) r1 = *(u64 *)(r8 +0) ; frame1: R1_w=scalar() R8_w=map_value(map=start,ks=4,vs=8)
; delta = bpf_ktime_get_ns() - *tsp;
88: (1f) r7 -= r1 ; frame1: R1_w=scalar() R7_w=scalar()
; if (delta < 0)
89: (c5) if r7 s< 0x0 goto pc+119 ; frame1: R7_w=scalar(smin=0,umax=0x7fffffffffffffff,var_off=(0x0; 0x7fffffffffffffff))
; if (targ_per_process)
90: (18) r1 = 0xffff9d0e0238a001 ; frame1: R1_w=map_value(map=runqlat.rodata,ks=4,vs=12,off=1)
92: (71) r1 = *(u8 *)(r1 +0) ; frame1: R1=0
; if (targ_per_process)
93: (16) if w1 == 0x0 goto pc+8 ; frame1: R1=0
; else if (targ_per_thread)
102: (18) r1 = 0xffff9d0e0238a002 ; frame1: R1_w=map_value(map=runqlat.rodata,ks=4,vs=12,off=2)
104: (71) r1 = *(u8 *)(r1 +0) ; frame1: R1_w=0
; else if (targ_per_thread)
105: (16) if w1 == 0x0 goto pc+109 ; frame1: R1_w=0
; else if (targ_per_pidns)
215: (18) r1 = 0xffff9d0e0238a003 ; frame1: R1_w=map_value(map=runqlat.rodata,ks=4,vs=12,off=3)
217: (71) r1 = *(u8 *)(r1 +0) ; frame1: R1_w=0
; else if (targ_per_pidns)
218: (16) if w1 == 0x0 goto pc+29 ; frame1: R1_w=0
; inum = BPF_CORE_READ(upid.ns, ns.inum);
248: (b4) w1 = -1 ; frame1: R1_w=0xffffffff
249: (05) goto pc-143
;
107: (63) *(u32 *)(r10 -24) = r1 ; frame1: R1=0xffffffff R10=fp0 fp-24=mmmm0xffffffff
108: (bf) r2 = r10 ; frame1: R2_w=fp0 R10=fp0
;
109: (07) r2 += -24 ; frame1: R2_w=fp-24
; val = bpf_map_lookup_elem(map, key);
110: (18) r1 = 0xffff8da68ce89000 ; frame1: R1_w=map_ptr(map=hists,ks=4,vs=120)
112: (85) call bpf_map_lookup_elem#1 ; frame1: R0_w=map_value_or_null(id=3,map=hists,ks=4,vs=120)
113: (bf) r8 = r0 ; frame1: R0_w=map_value_or_null(id=3,map=hists,ks=4,vs=120) R8_w=map_value_or_null(id=3,map=hists,ks=4,vs=120)
; if (val)
114: (55) if r8 != 0x0 goto pc+17 ; frame1: R8_w=0
115: (bf) r2 = r10 ; frame1: R2_w=fp0 R10=fp0
; err = bpf_map_update_elem(map, key, init, BPF_NOEXIST);
116: (07) r2 += -24 ; frame1: R2_w=fp-24
117: (18) r1 = 0xffff8da68ce89000 ; frame1: R1_w=map_ptr(map=hists,ks=4,vs=120)
119: (18) r3 = 0xffff8da58c334310 ; frame1: R3_w=map_value(map=runqlat.bss,ks=4,vs=120)
121: (b7) r4 = 1 ; frame1: R4_w=1
122: (85) call bpf_map_update_elem#2 ; frame1: R0=scalar()
; if (err && err != -EEXIST)
123: (15) if r0 == 0x0 goto pc+1 ; frame1: R0=scalar(umin=1)
124: (55) if r0 != 0xffffffef goto pc+84 ; frame1: R0=-17
125: (bf) r2 = r10 ; frame1: R2_w=fp0 R10=fp0
; return bpf_map_lookup_elem(map, key);
126: (07) r2 += -24 ; frame1: R2_w=fp-24
127: (18) r1 = 0xffff8da68ce89000 ; frame1: R1_w=map_ptr(map=hists,ks=4,vs=120)
129: (85) call bpf_map_lookup_elem#1 ; frame1: R0_w=map_value_or_null(id=4,map=hists,ks=4,vs=120)
130: (bf) r8 = r0 ; frame1: R0_w=map_value_or_null(id=4,map=hists,ks=4,vs=120) R8_w=map_value_or_null(id=4,map=hists,ks=4,vs=120)
; if (!histp)
131: (15) if r8 == 0x0 goto pc+77 ; frame1: R8_w=map_value(map=hists,ks=4,vs=120)
; if (!histp->comm[0])
132: (71) r1 = *(u8 *)(r8 +104) ; frame1: R1_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff)) R8=map_value(map=hists,ks=4,vs=120)
; if (!histp->comm[0])
133: (56) if w1 != 0x0 goto pc+7 ; frame1: R1_w=0
134: (bf) r1 = r8 ; frame1: R1_w=map_value(map=hists,ks=4,vs=120) R8=map_value(map=hists,ks=4,vs=120)
135: (07) r1 += 104 ; frame1: R1_w=map_value(map=hists,ks=4,vs=120,off=104)
136: (b7) r2 = 3008 ; frame1: R2_w=3008
137: (0f) r6 += r2 ; frame1: R2_w=3008 R6_w=trusted_ptr_task_struct(off=3008)
; bpf_probe_read_kernel_str(&histp->comm, sizeof(histp->comm),
138: (b4) w2 = 16 ; frame1: R2_w=16
139: (bf) r3 = r6 ; frame1: R3_w=trusted_ptr_task_struct(off=3008) R6_w=trusted_ptr_task_struct(off=3008)
140: (85) call bpf_probe_read_kernel_str#115 ; frame1: R0=scalar(smin=smin32=-4095,smax=smax32=16)
; if (targ_ms)
141: (18) r1 = 0xffff9d0e0238a004 ; frame1: R1_w=map_value(map=runqlat.rodata,ks=4,vs=12,off=4)
143: (71) r2 = *(u8 *)(r1 +0) ; frame1: R1_w=map_value(map=runqlat.rodata,ks=4,vs=12,off=4) R2_w=0
144: (b7) r1 = 1000 ; frame1: R1_w=1000
145: (16) if w2 == 0x0 goto pc+1 ; frame1: R2_w=0
;
147: (3f) r7 /= r1 ; frame1: R1_w=1000 R7_w=scalar()
; u32 hi = v >> 32;
148: (bf) r2 = r7 ; frame1: R2_w=scalar(id=5) R7_w=scalar(id=5)
149: (77) r2 >>= 32 ; frame1: R2_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
; if (hi)
150: (16) if w2 == 0x0 goto pc+27 178: frame1: R0=scalar(smin=smin32=-4095,smax=smax32=16) R1=1000 R2=0 R6=trusted_ptr_task_struct(off=3008) R7=scalar(id=5) R8=map_value(map=hists,ks=4,vs=120) R10=fp0 fp-16=mmmmmmmm fp-24=mmmmmmmm
178: (b4) w2 = 1 ; frame1: R2_w=1
179: (b4) w3 = 1 ; frame1: R3_w=1
; return log2(v);
180: (26) if w7 > 0xffff goto pc+1 ; frame1: R7=scalar(id=5,smax=0x7fffffff0000ffff,umax=0xffffffff0000ffff,smin32=0,smax32=umax32=0xffff,var_off=(0x0; 0xffffffff0000ffff))
181: (b4) w3 = 0 ; frame1: R3_w=0
; r = (v > 0xFFFF) << 4; v >>= r;
182: (64) w3 <<= 4 ; frame1: R3_w=0
; r = (v > 0xFFFF) << 4; v >>= r;
183: (7c) w7 >>= w3 ; frame1: R3_w=0 R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=0xffff,var_off=(0x0; 0xffff))
184: (b4) w1 = 1 ; frame1: R1_w=1
185: (26) if w7 > 0xff goto pc+1 ; frame1: R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff))
186: (b4) w1 = 0 ; frame1: R1=0
; shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
187: (64) w1 <<= 3 ; frame1: R1_w=0
; shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
188: (7c) w7 >>= w1 ; frame1: R1_w=0 R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=255,var_off=(0x0; 0xff))
; shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
189: (4c) w1 |= w3 ; frame1: R1_w=0 R3=0
190: (b4) w3 = 1 ; frame1: R3_w=1
; shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
191: (26) if w7 > 0xf goto pc+1 ; frame1: R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=15,var_off=(0x0; 0xf))
192: (b4) w3 = 0 ; frame1: R3_w=0
; shift = (v > 0xF) << 2; v >>= shift; r |= shift;
193: (64) w3 <<= 2 ; frame1: R3_w=0
; shift = (v > 0xF) << 2; v >>= shift; r |= shift;
194: (4c) w1 |= w3 ; frame1: R1_w=0 R3_w=0
; shift = (v > 0xF) << 2; v >>= shift; r |= shift;
195: (7c) w7 >>= w3 ; frame1: R3_w=0 R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=15,var_off=(0x0; 0xf))
196: (26) if w7 > 0x3 goto pc+1 ; frame1: R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=3,var_off=(0x0; 0x3))
197: (b4) w2 = 0 ; frame1: R2=0
; shift = (v > 0x3) << 1; v >>= shift; r |= shift;
198: (64) w2 <<= 1 ; frame1: R2_w=0
; shift = (v > 0x3) << 1; v >>= shift; r |= shift;
199: (4c) w1 |= w2 ; frame1: R1_w=0 R2_w=0
; shift = (v > 0x3) << 1; v >>= shift; r |= shift;
200: (7c) w7 >>= w2 ; frame1: R2_w=0 R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=3,var_off=(0x0; 0x3))
; r |= (v >> 1);
201: (74) w7 >>= 1 ; frame1: R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=1,var_off=(0x0; 0x1))
; r |= (v >> 1);
202: (4c) w1 |= w7 ; frame1: R1_w=scalar() R7_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=1,var_off=(0x0; 0x1))
; if (slot >= MAX_SLOTS)
203: (a6) if w1 < 0x19 goto pc+1 205: frame1: R0=scalar(smin=smin32=-4095,smax=smax32=16) R1=scalar(smax=0x7fffffff00000018,umax=0xffffffff00000018,smin32=0,smax32=umax32=24,var_off=(0x0; 0xffffffff0000001f)) R2=0 R3=0 R6=trusted_ptr_task_struct(off=3008) R7=scalar(smin=smin32=0,smax=umax=smax32=umax32=1,var_off=(0x0; 0x1)) R8=map_value(map=hists,ks=4,vs=120) R10=fp0 fp-16=mmmmmmmm fp-24=mmmmmmmm
; __sync_fetch_and_add(&histp->slots[slot], 1);
205: (67) r1 <<= 2 ; frame1: R1_w=scalar(smax=0x7ffffffc00000060,umax=0xfffffffc00000060,smin32=0,smax32=umax32=96,var_off=(0x0; 0xfffffffc0000007c))
206: (0f) r8 += r1
math between map_value pointer and register with unbounded min value is not allowed
processed 382 insns (limit 1000000) max_states_per_insn 4 total_states 32 peak_states 28 mark_read 5
-- END PROG LOAD LOG --
libbpf: prog 'sched_switch': failed to load: -EINVAL
libbpf: failed to load object 'runqlat.bpf.o'
Failed to load BPF object: -22
```

When I load the program, it's show that the `slot` is unbounded.
How can I fix it?

Start by reproducing the load failure from 9-runqlat.bpf.c and inspect the libbpf verifier output at the sched_switch and handle_switch paths. Determine why the program is rejected with -EINVAL, then rerun the tool to confirm that the BPF program loads successfully.

Written by the indexing model from the issue text.