5.4-stable review patch. If anyone has any objections, please let me know.
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From: Andrii Nakryiko andriin@fb.com
[ Upstream commit 7a387bed47f7e80e257d966cd64a3e92a63e26a1 ]
Enhance scripts/bpf_helpers_doc.py to emit C header with BPF helper definitions (to be included from libbpf's bpf_helpers.h).
Signed-off-by: Andrii Nakryiko andriin@fb.com Signed-off-by: Alexei Starovoitov ast@kernel.org Stable-dep-of: e37243b65d52 ("bpf, scripts: Correct GPL license name") Signed-off-by: Sasha Levin sashal@kernel.org --- scripts/bpf_helpers_doc.py | 155 ++++++++++++++++++++++++++++++++++++- 1 file changed, 154 insertions(+), 1 deletion(-)
diff --git a/scripts/bpf_helpers_doc.py b/scripts/bpf_helpers_doc.py index 894cc58c1a034..15d3d83d6297c 100755 --- a/scripts/bpf_helpers_doc.py +++ b/scripts/bpf_helpers_doc.py @@ -391,6 +391,154 @@ SEE ALSO
print('')
+class PrinterHelpers(Printer): + """ + A printer for dumping collected information about helpers as C header to + be included from BPF program. + @helpers: array of Helper objects to print to standard output + """ + + type_fwds = [ + 'struct bpf_fib_lookup', + 'struct bpf_perf_event_data', + 'struct bpf_perf_event_value', + 'struct bpf_sock', + 'struct bpf_sock_addr', + 'struct bpf_sock_ops', + 'struct bpf_sock_tuple', + 'struct bpf_spin_lock', + 'struct bpf_sysctl', + 'struct bpf_tcp_sock', + 'struct bpf_tunnel_key', + 'struct bpf_xfrm_state', + 'struct pt_regs', + 'struct sk_reuseport_md', + 'struct sockaddr', + 'struct tcphdr', + + 'struct __sk_buff', + 'struct sk_msg_md', + 'struct xpd_md', + ] + known_types = { + '...', + 'void', + 'const void', + 'char', + 'const char', + 'int', + 'long', + 'unsigned long', + + '__be16', + '__be32', + '__wsum', + + 'struct bpf_fib_lookup', + 'struct bpf_perf_event_data', + 'struct bpf_perf_event_value', + 'struct bpf_sock', + 'struct bpf_sock_addr', + 'struct bpf_sock_ops', + 'struct bpf_sock_tuple', + 'struct bpf_spin_lock', + 'struct bpf_sysctl', + 'struct bpf_tcp_sock', + 'struct bpf_tunnel_key', + 'struct bpf_xfrm_state', + 'struct pt_regs', + 'struct sk_reuseport_md', + 'struct sockaddr', + 'struct tcphdr', + } + mapped_types = { + 'u8': '__u8', + 'u16': '__u16', + 'u32': '__u32', + 'u64': '__u64', + 's8': '__s8', + 's16': '__s16', + 's32': '__s32', + 's64': '__s64', + 'size_t': 'unsigned long', + 'struct bpf_map': 'void', + 'struct sk_buff': 'struct __sk_buff', + 'const struct sk_buff': 'const struct __sk_buff', + 'struct sk_msg_buff': 'struct sk_msg_md', + 'struct xdp_buff': 'struct xdp_md', + } + + def print_header(self): + header = '''\ +/* This is auto-generated file. See bpf_helpers_doc.py for details. */ + +/* Forward declarations of BPF structs */''' + + print(header) + for fwd in self.type_fwds: + print('%s;' % fwd) + print('') + + def print_footer(self): + footer = '' + print(footer) + + def map_type(self, t): + if t in self.known_types: + return t + if t in self.mapped_types: + return self.mapped_types[t] + print("") + print("Unrecognized type '%s', please add it to known types!" % t) + sys.exit(1) + + seen_helpers = set() + + def print_one(self, helper): + proto = helper.proto_break_down() + + if proto['name'] in self.seen_helpers: + return + self.seen_helpers.add(proto['name']) + + print('/*') + print(" * %s" % proto['name']) + print(" *") + if (helper.desc): + # Do not strip all newline characters: formatted code at the end of + # a section must be followed by a blank line. + for line in re.sub('\n$', '', helper.desc, count=1).split('\n'): + print(' *{}{}'.format(' \t' if line else '', line)) + + if (helper.ret): + print(' *') + print(' * Returns') + for line in helper.ret.rstrip().split('\n'): + print(' *{}{}'.format(' \t' if line else '', line)) + + print(' */') + print('static %s %s(*%s)(' % (self.map_type(proto['ret_type']), + proto['ret_star'], proto['name']), end='') + comma = '' + for i, a in enumerate(proto['args']): + t = a['type'] + n = a['name'] + if proto['name'] == 'bpf_get_socket_cookie' and i == 0: + t = 'void' + n = 'ctx' + one_arg = '{}{}'.format(comma, self.map_type(t)) + if n: + if a['star']: + one_arg += ' {}'.format(a['star']) + else: + one_arg += ' ' + one_arg += '{}'.format(n) + comma = ', ' + print(one_arg, end='') + + print(') = (void *) %d;' % len(self.seen_helpers)) + print('') + ###############################################################################
# If script is launched from scripts/ from kernel tree and can access @@ -405,6 +553,8 @@ Parse eBPF header file and generate documentation for eBPF helper functions. The RST-formatted output produced can be turned into a manual page with the rst2man utility. """) +argParser.add_argument('--header', action='store_true', + help='generate C header file') if (os.path.isfile(bpfh)): argParser.add_argument('--filename', help='path to include/uapi/linux/bpf.h', default=bpfh) @@ -417,5 +567,8 @@ headerParser = HeaderParser(args.filename) headerParser.run()
# Print formatted output to standard output. -printer = PrinterRST(headerParser.helpers) +if args.header: + printer = PrinterHelpers(headerParser.helpers) +else: + printer = PrinterRST(headerParser.helpers) printer.print_all()