1 # This is a fork of the (for now) unmaintained Sys::Syscall 0.25,
2 # specifically the Debian libsys-syscall-perl 0.25-6 version to
3 # fix upstream regressions in 0.25.
5 # This license differs from the rest of public-inbox
7 # This module is Copyright (c) 2005 Six Apart, Ltd.
8 # Copyright (C) 2019-2020 all contributors <meta@public-inbox.org>
10 # All rights reserved.
12 # You may distribute under the terms of either the GNU General Public
13 # License or the Artistic License, as specified in the Perl README file.
14 package PublicInbox::Syscall;
16 use parent qw(Exporter);
17 use POSIX qw(ENOSYS SEEK_CUR);
20 # $VERSION = '0.25'; # Sys::Syscall version
21 our @EXPORT_OK = qw(epoll_ctl epoll_create epoll_wait
22 EPOLLIN EPOLLOUT EPOLLET
23 EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD
24 EPOLLONESHOT EPOLLEXCLUSIVE
25 signalfd SFD_NONBLOCK);
26 our %EXPORT_TAGS = (epoll => [qw(epoll_ctl epoll_create epoll_wait
28 EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD
29 EPOLLONESHOT EPOLLEXCLUSIVE)],
38 EPOLLEXCLUSIVE => (1 << 28),
39 EPOLLONESHOT => (1 << 30),
45 SFD_CLOEXEC => 02000000,
46 SFD_NONBLOCK => 00004000,
49 our $loaded_syscall = 0;
52 # props to Gaal for this!
53 return if $loaded_syscall++;
55 delete @INC{qw<syscall.ph asm/unistd.ph bits/syscall.ph
56 _h2ph_pre.ph sys/syscall.ph>};
58 $clean->(); # don't trust modules before us
59 my $rv = eval { require 'syscall.ph'; 1 } || eval { require 'sys/syscall.ph'; 1 };
60 $clean->(); # don't require modules after us trust us
72 our $no_deprecated = 0;
75 my $machine = (POSIX::uname())[-1];
76 # whether the machine requires 64-bit numbers to be on 8-byte
80 # if we're running on an x86_64 kernel, but a 32-bit process,
81 # we need to use the x32 or i386 syscall numbers.
82 if ($machine eq "x86_64" && $Config{ptrsize} == 4) {
83 $machine = $Config{cppsymbols} =~ /\b__ILP32__=1\b/ ? 'x32' : 'i386';
86 # Similarly for mips64 vs mips
87 if ($machine eq "mips64" && $Config{ptrsize} == 4) {
91 if ($machine =~ m/^i[3456]86$/) {
92 $SYS_epoll_create = 254;
94 $SYS_epoll_wait = 256;
96 } elsif ($machine eq "x86_64") {
97 $SYS_epoll_create = 213;
99 $SYS_epoll_wait = 232;
100 $SYS_signalfd4 = 289;
101 } elsif ($machine eq 'x32') {
102 $SYS_epoll_create = 1073742037;
103 $SYS_epoll_ctl = 1073742057;
104 $SYS_epoll_wait = 1073742056;
105 $SYS_signalfd4 = 1073742113;
106 } elsif ($machine =~ m/^parisc/) {
107 $SYS_epoll_create = 224;
108 $SYS_epoll_ctl = 225;
109 $SYS_epoll_wait = 226;
111 $SYS_signalfd4 = 309;
112 } elsif ($machine =~ m/^ppc64/) {
113 $SYS_epoll_create = 236;
114 $SYS_epoll_ctl = 237;
115 $SYS_epoll_wait = 238;
117 $SYS_signalfd4 = 313;
118 } elsif ($machine eq "ppc") {
119 $SYS_epoll_create = 236;
120 $SYS_epoll_ctl = 237;
121 $SYS_epoll_wait = 238;
123 $SYS_signalfd4 = 313;
124 } elsif ($machine =~ m/^s390/) {
125 $SYS_epoll_create = 249;
126 $SYS_epoll_ctl = 250;
127 $SYS_epoll_wait = 251;
129 $SYS_signalfd4 = 322;
130 } elsif ($machine eq "ia64") {
131 $SYS_epoll_create = 1243;
132 $SYS_epoll_ctl = 1244;
133 $SYS_epoll_wait = 1245;
135 $SYS_signalfd4 = 289;
136 } elsif ($machine eq "alpha") {
137 # natural alignment, ints are 32-bits
138 $SYS_epoll_create = 407;
139 $SYS_epoll_ctl = 408;
140 $SYS_epoll_wait = 409;
142 $SYS_signalfd4 = 484;
143 } elsif ($machine eq "aarch64") {
144 $SYS_epoll_create = 20; # (sys_epoll_create1)
146 $SYS_epoll_wait = 22; # (sys_epoll_pwait)
150 } elsif ($machine =~ m/arm(v\d+)?.*l/) {
152 $SYS_epoll_create = 250;
153 $SYS_epoll_ctl = 251;
154 $SYS_epoll_wait = 252;
156 $SYS_signalfd4 = 355;
157 } elsif ($machine =~ m/^mips64/) {
158 $SYS_epoll_create = 5207;
159 $SYS_epoll_ctl = 5208;
160 $SYS_epoll_wait = 5209;
162 $SYS_signalfd4 = 5283;
163 } elsif ($machine =~ m/^mips/) {
164 $SYS_epoll_create = 4248;
165 $SYS_epoll_ctl = 4249;
166 $SYS_epoll_wait = 4250;
168 $SYS_signalfd4 = 4324;
170 # as a last resort, try using the *.ph files which may not
171 # exist or may be wrong
173 $SYS_epoll_create = eval { &SYS_epoll_create; } || 0;
174 $SYS_epoll_ctl = eval { &SYS_epoll_ctl; } || 0;
175 $SYS_epoll_wait = eval { &SYS_epoll_wait; } || 0;
177 # Note: do NOT add new syscalls to depend on *.ph, here.
178 # Better to miss syscalls (so we can fallback to IO::Poll)
179 # than to use wrong ones, since the names are not stable
180 # (at least not on FreeBSD), if the actual numbers are.
184 *epoll_wait = \&epoll_wait_mod8;
185 *epoll_ctl = \&epoll_ctl_mod8;
187 *epoll_wait = \&epoll_wait_mod4;
188 *epoll_ctl = \&epoll_ctl_mod4;
192 elsif ($^O eq "freebsd") {
193 if ($ENV{FREEBSD_SENDFILE}) {
194 # this is still buggy and in development
198 ############################################################################
200 ############################################################################
202 sub epoll_defined { return $SYS_epoll_create ? 1 : 0; }
205 syscall($SYS_epoll_create, $no_deprecated ? 0 : ($_[0]||100)+0);
209 # ARGS: (epfd, op, fd, events_mask)
211 syscall($SYS_epoll_ctl, $_[0]+0, $_[1]+0, $_[2]+0, pack("LLL", $_[3], $_[2], 0));
214 syscall($SYS_epoll_ctl, $_[0]+0, $_[1]+0, $_[2]+0, pack("LLLL", $_[3], 0, $_[2], 0));
218 # ARGS: (epfd, maxevents, timeout (milliseconds), arrayref)
219 # arrayref: values modified to be [$fd, $event]
220 our $epoll_wait_events;
221 our $epoll_wait_size = 0;
222 sub epoll_wait_mod4 {
223 # resize our static buffer if requested size is bigger than we've ever done
224 if ($_[1] > $epoll_wait_size) {
225 $epoll_wait_size = $_[1];
226 $epoll_wait_events = "\0" x 12 x $epoll_wait_size;
228 my $ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0);
230 @{$_[3]->[$_]}[1,0] = unpack("LL", substr($epoll_wait_events, 12*$_, 8));
235 sub epoll_wait_mod8 {
236 # resize our static buffer if requested size is bigger than we've ever done
237 if ($_[1] > $epoll_wait_size) {
238 $epoll_wait_size = $_[1];
239 $epoll_wait_events = "\0" x 16 x $epoll_wait_size;
242 if ($no_deprecated) {
243 $ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0, undef);
245 $ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0);
248 # 16 byte epoll_event structs, with format:
249 # 4 byte mask [idx 1]
250 # 4 byte padding (we put it into idx 2, useless)
251 # 8 byte data (first 4 bytes are fd, into idx 0)
252 @{$_[3]->[$_]}[1,2,0] = unpack("LLL", substr($epoll_wait_events, 16*$_, 12));
258 my ($fd, $signos, $flags) = @_;
259 if ($SYS_signalfd4) {
260 # Not sure if there's a way to get pack/unpack to get the
261 # contents of POSIX::SigSet to a buffer, but prepping the
262 # bitmap like one would for select() works:
264 vec($buf, $_ - 1, 1) = 1 for @$signos;
266 syscall($SYS_signalfd4, $fd, $buf, 8, $flags|SFD_CLOEXEC);
277 This is free software. IT COMES WITHOUT WARRANTY OF ANY KIND.
281 Brad Fitzpatrick <brad@danga.com>