cosmopolitan/libc/zipos/get.c
Justine Tunney ae638c0850 Fix bugs and make improvements
- Get clone() working on FreeBSD
- Increase some Python build quotas
- Add more atomic builtins to chibicc
- Fix ASAN poisoning of alloca() memory
- Make MODE= mandatory link path tinier
- Improve the examples folder a little bit
- Start working on some more resource limits
- Make the linenoise auto-complete UI as good as GNU readline
- Update compile.com, avoiding AVX codegen on non-AVX systems
- Make sure empty path to syscalls like opendir raises ENOENT
- Correctly polyfill ENOENT vs. ENOTDIR on the New Technology
- Port bestline's paredit features to //third_party/linenoise
- Remove workarounds for RHEL 5.0 bugs that were fixed in 5.1
2022-04-20 10:05:34 -07:00

120 lines
4.6 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/bits/safemacros.internal.h"
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/calls/sigbits.h"
#include "libc/calls/strace.internal.h"
#include "libc/calls/struct/stat.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/intrin/kprintf.h"
#include "libc/intrin/spinlock.h"
#include "libc/limits.h"
#include "libc/macros.internal.h"
#include "libc/mem/alloca.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/auxv.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/prot.h"
#include "libc/sysv/consts/sig.h"
#include "libc/zip.h"
#include "libc/zipos/zipos.internal.h"
static uint64_t __zipos_get_min_offset(const uint8_t *base,
const uint8_t *cdir) {
uint64_t i, n, c, r, o;
c = GetZipCdirOffset(cdir);
n = GetZipCdirRecords(cdir);
for (r = c, i = 0; i < n; ++i, c += ZIP_CFILE_HDRSIZE(base + c)) {
o = GetZipCfileOffset(base + c);
if (o < r) r = o;
}
return r;
}
static void __zipos_munmap_unneeded(const uint8_t *base, const uint8_t *cdir,
const uint8_t *map) {
uint64_t n;
n = __zipos_get_min_offset(base, cdir);
n += base - map;
n = ROUNDDOWN(n, FRAMESIZE);
if (n) munmap(map, n);
}
/**
* Returns pointer to zip central directory of current executable.
* @asyncsignalsafe (TODO: verify this)
* @threadsafe
*/
struct Zipos *__zipos_get(void) {
int fd;
char *path;
ssize_t size;
static bool once;
sigset_t neu, old;
struct Zipos *res;
const char *progpath;
static struct Zipos zipos;
uint8_t *map, *base, *cdir;
_Alignas(64) static char lock;
_spinlock(&lock);
if (!once) {
sigfillset(&neu);
if (!IsWindows()) {
sys_sigprocmask(SIG_BLOCK, &neu, &old);
}
progpath = GetProgramExecutableName();
if ((fd = open(progpath, O_RDONLY)) != -1) {
if ((size = getfiledescriptorsize(fd)) != SIZE_MAX &&
(map = mmap(0, size, PROT_READ, MAP_SHARED, fd, 0)) != MAP_FAILED) {
if ((base = FindEmbeddedApe(map, size))) {
size -= base - map;
} else {
base = map;
}
if ((cdir = GetZipCdir(base, size))) {
__zipos_munmap_unneeded(base, cdir, map);
zipos.map = base;
zipos.cdir = cdir;
STRACE("__zipos_get(%#s)", progpath);
} else {
munmap(map, size);
STRACE("__zipos_get(%#s) → eocd not found", progpath);
}
}
close(fd);
} else {
STRACE("__zipos_get(%#s) → open failed %m", progpath);
}
if (!IsWindows()) {
sigprocmask(SIG_SETMASK, &old, 0);
}
once = true;
}
if (zipos.cdir) {
res = &zipos;
} else {
res = 0;
}
_spunlock(&lock);
return res;
}