mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 11:37:35 +00:00
f7ff77d865
- Invent iso8601us() for faster timestamps - Improve --strace descriptions of sigset_t - Rebuild the Landlock Make bootstrap binary - Introduce MODE=sysv for non-Windows builds - Permit OFD fcntl() locks under pledge(flock) - redbean can now protect your kernel from ddos - Have vfork() fallback to sys_fork() not fork() - Change kmalloc() to not die when out of memory - Improve documentation for some termios functions - Rewrite putenv() and friends to conform to POSIX - Fix linenoise + strace verbosity issue on Windows - Fix regressions in our ability to show backtraces - Change redbean SetHeader() to no-op if value is nil - Improve fcntl() so SQLite locks work in non-WAL mode - Remove some unnecessary work during fork() on Windows - Create redbean-based SSL reverse proxy for IPv4 TurfWar - Fix ape/apeinstall.sh warning when using non-bash shells - Add ProgramTrustedIp(), and IsTrustedIp() APIs to redbean - Support $PWD, $UID, $GID, and $EUID in command interpreter - Introduce experimental JTqFpD APE prefix for non-Windows builds - Invent blackhole daemon for firewalling IP addresses via UNIX named socket - Add ProgramTokenBucket(), AcquireToken(), and CountTokens() APIs to redbean
118 lines
5.5 KiB
C
118 lines
5.5 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 "ape/sections.internal.h"
|
|
#include "libc/calls/struct/sigset.h"
|
|
#include "libc/runtime/morph.h"
|
|
#include "libc/runtime/runtime.h"
|
|
#include "libc/runtime/symbols.internal.h"
|
|
|
|
/**
|
|
* Rewrites code in memory to hook function calls.
|
|
*
|
|
* We do this by searching each function for the nop instruction
|
|
* inserted by GCC when we use the -pg -mnop-mcount flags. There's no
|
|
* risk of corrupting data since the linker scripts won't mix code and
|
|
* data.
|
|
*
|
|
* Modules built with -O3 and without the profiling flags might have
|
|
* these same nop instructions, but that shouldn't be problematic since
|
|
* they're only there for the puposes of aligning jumps, and therefore
|
|
* aren't actually executed. However codebases that use huge function
|
|
* alignments with wide-nop slides could pose minor issues. Further note
|
|
* that Cosmopolitan sources are almost never intentionally written to
|
|
* use code alignment, since we've only seen a few cases where it helps.
|
|
*
|
|
* @see ape/ape.lds
|
|
*/
|
|
privileged noinstrument noasan int __hook(void *ifunc,
|
|
struct SymbolTable *symbols) {
|
|
int rc;
|
|
size_t i;
|
|
char *p, *pe;
|
|
intptr_t addr;
|
|
sigset_t mask;
|
|
uint64_t code, mcode;
|
|
intptr_t kMcount = (intptr_t)&mcount;
|
|
intptr_t kProgramCodeStart = (intptr_t)_ereal;
|
|
intptr_t kPrivilegedStart = (intptr_t)__privileged_addr;
|
|
if (!symbols) return -1;
|
|
__morph_begin(&mask);
|
|
for (i = 0; i < symbols->count; ++i) {
|
|
if (symbols->addr_base + symbols->symbols[i].x < kProgramCodeStart) {
|
|
continue;
|
|
}
|
|
if (symbols->addr_base + symbols->symbols[i].y >= kPrivilegedStart) {
|
|
break;
|
|
}
|
|
for (p = (char *)symbols->addr_base + symbols->symbols[i].x,
|
|
pe = (char *)symbols->addr_base + symbols->symbols[i].y;
|
|
p + 8 - 1 <= pe; ++p) {
|
|
code = ((uint64_t)(255 & p[7]) << 070 | (uint64_t)(255 & p[6]) << 060 |
|
|
(uint64_t)(255 & p[5]) << 050 | (uint64_t)(255 & p[4]) << 040 |
|
|
(uint64_t)(255 & p[3]) << 030 | (uint64_t)(255 & p[2]) << 020 |
|
|
(uint64_t)(255 & p[1]) << 010 | (uint64_t)(255 & p[0]) << 000);
|
|
|
|
/*
|
|
* Test for -mrecord-mcount (w/ -fpie or -fpic)
|
|
*
|
|
* nopw 0x00(%rax,%rax,1) ← morphed by package.com
|
|
* call *mcount(%rip) ← linked w/o -static
|
|
* addr32 call mcount ← relaxed w/ -static
|
|
* addr32 call mcount ← relaxed w/ -static
|
|
*
|
|
* Note that gcc refuses to insert the six byte nop.
|
|
*/
|
|
if ((code & 0x0000FFFFFFFFFFFF) == 0x0000441F0F66 ||
|
|
(code & 0x0000FFFFFFFFFFFF) ==
|
|
((((kMcount - ((intptr_t)&p[2] + 4)) << 16) | 0xE867) &
|
|
0x0000FFFFFFFFFFFF) ||
|
|
(code & 0x0000FFFFFFFFFFFF) ==
|
|
((((kMcount - ((intptr_t)&p[2] + 4)) << 16) | 0xFF15) &
|
|
0x0000FFFFFFFFFFFF)) {
|
|
p[0] = 0x67;
|
|
p[1] = 0xE8;
|
|
addr = (intptr_t)ifunc - ((intptr_t)&p[2] + 4);
|
|
p[2] = (addr & 0x000000ff) >> 000;
|
|
p[3] = (addr & 0x0000ff00) >> 010;
|
|
p[4] = (addr & 0x00ff0000) >> 020;
|
|
p[5] = (addr & 0xff000000) >> 030;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Test for -mnop-mcount (w/ -fno-pie)
|
|
*/
|
|
mcode = code & 0x000000FFFFFFFFFF;
|
|
if ((mcode == 0x00441F0F /* nopl 0x00(%eax,%eax,1) [canonical] */) ||
|
|
(mcode == 0x00041F0F67 /* nopl (%eax,%eax,1) [older gcc] */)) {
|
|
if (p[-1] != 0x66 /* nopw 0x0(%rax,%rax,1) [donotwant] */) {
|
|
p[0] = 0xE8 /* call Jvds */;
|
|
addr = (intptr_t)ifunc - ((intptr_t)&p[1] + 4);
|
|
p[1] = (addr & 0x000000ff) >> 000;
|
|
p[2] = (addr & 0x0000ff00) >> 010;
|
|
p[3] = (addr & 0x00ff0000) >> 020;
|
|
p[4] = (addr & 0xff000000) >> 030;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
__morph_end(&mask);
|
|
return 0;
|
|
}
|