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d1d4388201
It hasn't been helpful enough to be justify the maintenance burden. What actually does help is mprotect(), kprintf(), --ftrace and --strace which can always be counted upon to work correctly. We aren't losing much with this change. Support for ASAN on AARCH64 was never implemented. Applying ASAN to the core libc runtimes was disabled many months ago. If there is some way to have an ASAN runtime for user programs that is less invasive we can potentially consider reintroducing support. But now is premature.
85 lines
4.1 KiB
C
85 lines
4.1 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/calls/struct/itimerval.h"
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#include "libc/calls/struct/itimerval.internal.h"
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#include "libc/dce.h"
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#include "libc/intrin/describeflags.internal.h"
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#include "libc/intrin/strace.internal.h"
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#include "libc/sysv/errfuns.h"
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#include "libc/time.h"
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/**
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* Schedules delivery of one-shot or intermittent interrupt signal, e.g.
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*
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* Raise SIGALRM every 1.5s:
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*
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* sigaction(SIGALRM,
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* &(struct sigaction){.sa_handler = OnSigalrm},
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* NULL);
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* setitimer(ITIMER_REAL,
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* &(const struct itimerval){{1, 500000},
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* {1, 500000}},
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* NULL);
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*
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* Single-shot alarm to interrupt connect() after 50ms:
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*
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* sigaction(SIGALRM,
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* &(struct sigaction){.sa_handler = OnSigalrm,
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* .sa_flags = SA_RESETHAND},
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* NULL);
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* setitimer(ITIMER_REAL,
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* &(const struct itimerval){{0, 0}, {0, 50000}},
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* NULL);
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* if (connect(...) == -1 && errno == EINTR) { ... }
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*
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* Disarm existing timer:
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*
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* setitimer(ITIMER_REAL, &(const struct itimerval){0}, NULL);
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*
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* If the goal is to use alarms to interrupt blocking i/o routines, e.g.
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* read(), connect(), etc. then it's important to install the signal
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* handler using sigaction() rather than signal(), because the latter
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* sets the `SA_RESTART` flag.
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*
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* Timers are not inherited across fork.
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*
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* @param which can be ITIMER_REAL, ITIMER_VIRTUAL, etc.
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* @param newvalue specifies the interval ({0,0} means one-shot) and
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* duration ({0,0} means disarm) in microseconds ∈ [0,999999] and
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* if this parameter is NULL, we'll polyfill getitimer() behavior
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* @param out_opt_old may receive remainder of previous op (if any)
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* @return 0 on success or -1 w/ errno
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* @asyncsignalsafe
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*/
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int setitimer(int which, const struct itimerval *newvalue,
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struct itimerval *oldvalue) {
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int rc;
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if (!IsWindows()) {
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if (newvalue) {
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rc = sys_setitimer(which, newvalue, oldvalue);
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} else {
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rc = sys_getitimer(which, oldvalue);
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}
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} else {
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rc = sys_setitimer_nt(which, newvalue, oldvalue);
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}
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STRACE("setitimer(%s, %s, [%s]) → %d% m", DescribeItimer(which),
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DescribeItimerval(0, newvalue), DescribeItimerval(rc, oldvalue), rc);
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return rc;
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}
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