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 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 POSIX qw(ENOSYS SEEK_CUR);
20 use vars qw(@ISA @EXPORT_OK %EXPORT_TAGS $VERSION);
24 @EXPORT_OK = qw(epoll_ctl epoll_create epoll_wait
25 EPOLLIN EPOLLOUT EPOLLET
26 EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD
27 EPOLLONESHOT EPOLLEXCLUSIVE
28 signalfd SFD_NONBLOCK);
29 %EXPORT_TAGS = (epoll => [qw(epoll_ctl epoll_create epoll_wait
31 EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD
32 EPOLLONESHOT EPOLLEXCLUSIVE)],
35 use constant EPOLLIN => 1;
36 use constant EPOLLOUT => 4;
37 # use constant EPOLLERR => 8;
38 # use constant EPOLLHUP => 16;
39 # use constant EPOLLRDBAND => 128;
40 use constant EPOLLEXCLUSIVE => (1 << 28);
41 use constant EPOLLONESHOT => (1 << 30);
42 use constant EPOLLET => (1 << 31);
43 use constant EPOLL_CTL_ADD => 1;
44 use constant EPOLL_CTL_DEL => 2;
45 use constant EPOLL_CTL_MOD => 3;
47 SFD_CLOEXEC => 02000000,
48 SFD_NONBLOCK => 00004000,
52 our $loaded_syscall = 0;
55 # props to Gaal for this!
56 return if $loaded_syscall++;
58 delete @INC{qw<syscall.ph asm/unistd.ph bits/syscall.ph
59 _h2ph_pre.ph sys/syscall.ph>};
61 $clean->(); # don't trust modules before us
62 my $rv = eval { require 'syscall.ph'; 1 } || eval { require 'sys/syscall.ph'; 1 };
63 $clean->(); # don't require modules after us trust us
75 our $no_deprecated = 0;
78 my $machine = (POSIX::uname())[-1];
79 # whether the machine requires 64-bit numbers to be on 8-byte
83 # if we're running on an x86_64 kernel, but a 32-bit process,
84 # we need to use the i386 syscall numbers.
85 if ($machine eq "x86_64" && $Config{ptrsize} == 4) {
89 # Similarly for mips64 vs mips
90 if ($machine eq "mips64" && $Config{ptrsize} == 4) {
94 if ($machine =~ m/^i[3456]86$/) {
95 $SYS_epoll_create = 254;
97 $SYS_epoll_wait = 256;
99 } elsif ($machine eq "x86_64") {
100 $SYS_epoll_create = 213;
101 $SYS_epoll_ctl = 233;
102 $SYS_epoll_wait = 232;
103 $SYS_signalfd4 = 289;
104 } elsif ($machine =~ m/^parisc/) {
105 $SYS_epoll_create = 224;
106 $SYS_epoll_ctl = 225;
107 $SYS_epoll_wait = 226;
109 $SYS_signalfd4 = 309;
110 } elsif ($machine =~ m/^ppc64/) {
111 $SYS_epoll_create = 236;
112 $SYS_epoll_ctl = 237;
113 $SYS_epoll_wait = 238;
115 $SYS_signalfd4 = 313;
116 } elsif ($machine eq "ppc") {
117 $SYS_epoll_create = 236;
118 $SYS_epoll_ctl = 237;
119 $SYS_epoll_wait = 238;
121 $SYS_signalfd4 = 313;
122 } elsif ($machine =~ m/^s390/) {
123 $SYS_epoll_create = 249;
124 $SYS_epoll_ctl = 250;
125 $SYS_epoll_wait = 251;
127 $SYS_signalfd4 = 322;
128 } elsif ($machine eq "ia64") {
129 $SYS_epoll_create = 1243;
130 $SYS_epoll_ctl = 1244;
131 $SYS_epoll_wait = 1245;
133 $SYS_signalfd4 = 289;
134 } elsif ($machine eq "alpha") {
135 # natural alignment, ints are 32-bits
136 $SYS_epoll_create = 407;
137 $SYS_epoll_ctl = 408;
138 $SYS_epoll_wait = 409;
140 $SYS_signalfd4 = 484;
141 } elsif ($machine eq "aarch64") {
142 $SYS_epoll_create = 20; # (sys_epoll_create1)
144 $SYS_epoll_wait = 22; # (sys_epoll_pwait)
148 } elsif ($machine =~ m/arm(v\d+)?.*l/) {
150 $SYS_epoll_create = 250;
151 $SYS_epoll_ctl = 251;
152 $SYS_epoll_wait = 252;
154 $SYS_signalfd4 = 355;
155 } elsif ($machine =~ m/^mips64/) {
156 $SYS_epoll_create = 5207;
157 $SYS_epoll_ctl = 5208;
158 $SYS_epoll_wait = 5209;
160 $SYS_signalfd4 = 5283;
161 } elsif ($machine =~ m/^mips/) {
162 $SYS_epoll_create = 4248;
163 $SYS_epoll_ctl = 4249;
164 $SYS_epoll_wait = 4250;
166 $SYS_signalfd4 = 4324;
168 # as a last resort, try using the *.ph files which may not
169 # exist or may be wrong
171 $SYS_epoll_create = eval { &SYS_epoll_create; } || 0;
172 $SYS_epoll_ctl = eval { &SYS_epoll_ctl; } || 0;
173 $SYS_epoll_wait = eval { &SYS_epoll_wait; } || 0;
175 # Note: do NOT add new syscalls to depend on *.ph, here.
176 # Better to miss syscalls (so we can fallback to IO::Poll)
177 # than to use wrong ones, since the names are not stable
178 # (at least not on FreeBSD), if the actual numbers are.
182 *epoll_wait = \&epoll_wait_mod8;
183 *epoll_ctl = \&epoll_ctl_mod8;
185 *epoll_wait = \&epoll_wait_mod4;
186 *epoll_ctl = \&epoll_ctl_mod4;
190 elsif ($^O eq "freebsd") {
191 if ($ENV{FREEBSD_SENDFILE}) {
192 # this is still buggy and in development
196 ############################################################################
198 ############################################################################
200 sub epoll_defined { return $SYS_epoll_create ? 1 : 0; }
203 syscall($SYS_epoll_create, $no_deprecated ? 0 : ($_[0]||100)+0);
207 # ARGS: (epfd, op, fd, events_mask)
209 syscall($SYS_epoll_ctl, $_[0]+0, $_[1]+0, $_[2]+0, pack("LLL", $_[3], $_[2], 0));
212 syscall($SYS_epoll_ctl, $_[0]+0, $_[1]+0, $_[2]+0, pack("LLLL", $_[3], 0, $_[2], 0));
216 # ARGS: (epfd, maxevents, timeout (milliseconds), arrayref)
217 # arrayref: values modified to be [$fd, $event]
218 our $epoll_wait_events;
219 our $epoll_wait_size = 0;
220 sub epoll_wait_mod4 {
221 # resize our static buffer if requested size is bigger than we've ever done
222 if ($_[1] > $epoll_wait_size) {
223 $epoll_wait_size = $_[1];
224 $epoll_wait_events = "\0" x 12 x $epoll_wait_size;
226 my $ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0);
228 @{$_[3]->[$_]}[1,0] = unpack("LL", substr($epoll_wait_events, 12*$_, 8));
233 sub epoll_wait_mod8 {
234 # resize our static buffer if requested size is bigger than we've ever done
235 if ($_[1] > $epoll_wait_size) {
236 $epoll_wait_size = $_[1];
237 $epoll_wait_events = "\0" x 16 x $epoll_wait_size;
240 if ($no_deprecated) {
241 $ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0, undef);
243 $ct = syscall($SYS_epoll_wait, $_[0]+0, $epoll_wait_events, $_[1]+0, $_[2]+0);
246 # 16 byte epoll_event structs, with format:
247 # 4 byte mask [idx 1]
248 # 4 byte padding (we put it into idx 2, useless)
249 # 8 byte data (first 4 bytes are fd, into idx 0)
250 @{$_[3]->[$_]}[1,2,0] = unpack("LLL", substr($epoll_wait_events, 16*$_, 12));
256 my ($fd, $signos, $flags) = @_;
257 if ($SYS_signalfd4) {
258 # Not sure if there's a way to get pack/unpack to get the
259 # contents of POSIX::SigSet to a buffer, but prepping the
260 # bitmap like one would for select() works:
262 vec($buf, $_ - 1, 1) = 1 for @$signos;
264 syscall($SYS_signalfd4, $fd, $buf, 8, $flags|SFD_CLOEXEC);
275 This is free software. IT COMES WITHOUT WARRANTY OF ANY KIND.
279 Brad Fitzpatrick <brad@danga.com>