tools/bpftool: Fix compilation warnings in 32-bit mode

Fix few compilation warnings in bpftool when compiling in 32-bit mode.
Abstract away u64 to pointer conversion into a helper function.

Signed-off-by: Andrii Nakryiko <[e-mail]>
Signed-off-by: Alexei Starovoitov <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

tools/bpf/bpftool/btf_dumper.c

···
 	if (!info->btf_id || !info->nr_func_info ||
 	    btf__get_from_id(info->btf_id, &prog_btf))
 		goto print;
-	finfo = (struct bpf_func_info *)info->func_info;
+	finfo = u64_to_ptr(info->func_info);
 	func_type = btf__type_by_id(prog_btf, finfo->type_id);
 	if (!func_type || !btf_is_func(func_type))
 		goto print;

tools/bpf/bpftool/link.c

···
 	switch (info->type) {
 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
 		jsonw_string_field(json_wtr, "tp_name",
-				   (const char *)info->raw_tracepoint.tp_name);
+				   u64_to_ptr(info->raw_tracepoint.tp_name));
 		break;
 	case BPF_LINK_TYPE_TRACING:
 		err = get_prog_info(info->prog_id, &prog_info);
···
 	switch (info->type) {
 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
 		printf("\n\ttp '%s'  ",
-		       (const char *)info->raw_tracepoint.tp_name);
+		       (const char *)u64_to_ptr(info->raw_tracepoint.tp_name));
 		break;
 	case BPF_LINK_TYPE_TRACING:
 		err = get_prog_info(info->prog_id, &prog_info);

tools/bpf/bpftool/main.h

···
 /* Make sure we do not use kernel-only integer typedefs */
 #pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
 
-#define ptr_to_u64(ptr)	((__u64)(unsigned long)(ptr))
+static inline __u64 ptr_to_u64(const void *ptr)
+{
+	return (__u64)(unsigned long)ptr;
+}
+
+static inline void *u64_to_ptr(__u64 ptr)
+{
+	return (void *)(unsigned long)ptr;
+}
 
 #define NEXT_ARG()	({ argc--; argv++; if (argc < 0) usage(); })
 #define NEXT_ARGP()	({ (*argc)--; (*argv)++; if (*argc < 0) usage(); })

tools/bpf/bpftool/prog.c

···
 			p_info("no instructions returned");
 			return -1;
 		}
-		buf = (unsigned char *)(info->jited_prog_insns);
+		buf = u64_to_ptr(info->jited_prog_insns);
 		member_len = info->jited_prog_len;
 	} else {	/* DUMP_XLATED */
 		if (info->xlated_prog_len == 0 || !info->xlated_prog_insns) {
 			p_err("error retrieving insn dump: kernel.kptr_restrict set?");
 			return -1;
 		}
-		buf = (unsigned char *)info->xlated_prog_insns;
+		buf = u64_to_ptr(info->xlated_prog_insns);
 		member_len = info->xlated_prog_len;
 	}
 
···
 		return -1;
 	}
 
-	func_info = (void *)info->func_info;
+	func_info = u64_to_ptr(info->func_info);
 
 	if (info->nr_line_info) {
 		prog_linfo = bpf_prog_linfo__new(info);
···
 
 		n = write(fd, buf, member_len);
 		close(fd);
-		if (n != member_len) {
+		if (n != (ssize_t)member_len) {
 			p_err("error writing output file: %s",
 			      n < 0 ? strerror(errno) : "short write");
 			return -1;
···
 			__u32 i;
 			if (info->nr_jited_ksyms) {
 				kernel_syms_load(&dd);
-				ksyms = (__u64 *) info->jited_ksyms;
+				ksyms = u64_to_ptr(info->jited_ksyms);
 			}
 
 			if (json_output)
 				jsonw_start_array(json_wtr);
 
-			lens = (__u32 *) info->jited_func_lens;
+			lens = u64_to_ptr(info->jited_func_lens);
 			for (i = 0; i < info->nr_jited_func_lens; i++) {
 				if (ksyms) {
 					sym = kernel_syms_search(&dd, ksyms[i]);
···
 	} else {
 		kernel_syms_load(&dd);
 		dd.nr_jited_ksyms = info->nr_jited_ksyms;
-		dd.jited_ksyms = (__u64 *) info->jited_ksyms;
+		dd.jited_ksyms = u64_to_ptr(info->jited_ksyms);
 		dd.btf = btf;
 		dd.func_info = func_info;
 		dd.finfo_rec_size = info->func_info_rec_size;
···
 		goto out;
 	}
 
-	func_info = (struct bpf_func_info *)(info_linear->info.func_info);
+	func_info = u64_to_ptr(info_linear->info.func_info);
 	t = btf__type_by_id(btf, func_info[0].type_id);
 	if (!t) {
 		p_err("btf %d doesn't have type %d",