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bpf: Use proper type to calculate bpf_raw_tp_null_args.mask index

The calculation of the index used to access the mask field in 'struct
bpf_raw_tp_null_args' is done with 'int' type, which could overflow when
the tracepoint being attached has more than 8 arguments.

While none of the tracepoints mentioned in raw_tp_null_args[] currently
have more than 8 arguments, there do exist tracepoints that had more
than 8 arguments (e.g. iocost_iocg_forgive_debt), so use the correct
type for calculation and avoid Smatch static checker warning.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20250418074946.35569-1-shung-hsi.yu@suse.com

Closes: https://lore.kernel.org/r/843a3b94-d53d-42db-93d4-be10a4090146@stanley.mountain/

authored by

Shung-Hsi Yu and committed by
Andrii Nakryiko 53ebef53 5cffad0a

+2 -2
+2 -2
kernel/bpf/btf.c
··· 6829 6829 /* Is this a func with potential NULL args? */ 6830 6830 if (strcmp(tname, raw_tp_null_args[i].func)) 6831 6831 continue; 6832 - if (raw_tp_null_args[i].mask & (0x1 << (arg * 4))) 6832 + if (raw_tp_null_args[i].mask & (0x1ULL << (arg * 4))) 6833 6833 info->reg_type |= PTR_MAYBE_NULL; 6834 6834 /* Is the current arg IS_ERR? */ 6835 - if (raw_tp_null_args[i].mask & (0x2 << (arg * 4))) 6835 + if (raw_tp_null_args[i].mask & (0x2ULL << (arg * 4))) 6836 6836 ptr_err_raw_tp = true; 6837 6837 break; 6838 6838 }