mirror of
https://github.com/jart/cosmopolitan.git
synced 2024-05-18 03:22:40 +00:00
6e6fc38935
Commit bc6c183 introduced a bunch of discrepancies between what files
look like in the repo and what clang-format says they should look like.
However, there were already a few discrepancies prior to that. Most of
these discrepancies seemed to be unintentional, but a few of them were
load-bearing (e.g., a #include that violated header ordering needing
something to have been #defined by a 'later' #include.)
I opted to take what I hope is a relatively smooth-brained approach: I
reverted the .clang-format change, ran clang-format on the whole repo,
reapplied the .clang-format change, reran clang-format again, and then
reverted the commit that contained the first run. Thus the full effect
of this PR should only be to apply the changed formatting rules to the
repo, and from skimming the results, this seems to be the case.
My work can be checked by applying the short, manual commits, and then
rerunning the command listed in the autogenerated commits (those whose
messages I have prefixed auto:) and seeing if your results agree.
It might be that the other diffs should be fixed at some point but I'm
leaving that aside for now.
fd '\.c(c|pp)?$' --print0| xargs -0 clang-format -i
109 lines
4.9 KiB
C
109 lines
4.9 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
|
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2022 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. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#define ShouldUseMsabiAttribute() 1
|
|
#include "ape/sections.internal.h"
|
|
#include "libc/dce.h"
|
|
#include "libc/errno.h"
|
|
#include "libc/intrin/asmflag.h"
|
|
#include "libc/intrin/kprintf.h"
|
|
#include "libc/nt/enum/pageflags.h"
|
|
#include "libc/nt/memory.h"
|
|
#include "libc/nt/thunk/msabi.h"
|
|
#include "libc/runtime/runtime.h"
|
|
#include "libc/sysv/consts/nr.h"
|
|
#include "libc/sysv/consts/prot.h"
|
|
|
|
__msabi extern typeof(VirtualProtect) *const __imp_VirtualProtect;
|
|
|
|
__funline void __morph_mprotect(void *addr, size_t size, int prot, int ntprot) {
|
|
#ifdef __x86_64__
|
|
bool cf;
|
|
int ax, dx;
|
|
uint32_t op;
|
|
if (!IsWindows()) {
|
|
asm volatile(CFLAG_ASM("clc\n\t"
|
|
"syscall")
|
|
: CFLAG_CONSTRAINT(cf), "=a"(ax), "=d"(dx)
|
|
: "1"(__NR_mprotect), "D"(addr), "S"(size), "2"(prot)
|
|
: "rcx", "r8", "r9", "r10", "r11", "memory");
|
|
#ifndef NDEBUG
|
|
if (cf)
|
|
ax = -ax;
|
|
if (ax == -EPERM) {
|
|
kprintf("error: need pledge(prot_exec) permission to code morph\n");
|
|
}
|
|
if (ax < 0) {
|
|
kprintf("error: __morph_mprotect(%p, %#zx, %d) failed: errno=%d\n", addr,
|
|
size, prot, -ax);
|
|
}
|
|
#endif
|
|
} else {
|
|
__imp_VirtualProtect(addr, size, ntprot, &op);
|
|
}
|
|
#elif defined(__aarch64__)
|
|
register long r0 asm("x0") = (long)addr;
|
|
register long r1 asm("x1") = (long)size;
|
|
register long r2 asm("x2") = (long)prot;
|
|
register long r8 asm("x8") = (long)__NR_mprotect;
|
|
register long r16 asm("x16") = (long)__NR_mprotect;
|
|
asm volatile("svc\t0"
|
|
: "+r"(r0)
|
|
: "r"(r1), "r"(r2), "r"(r8), "r"(r16)
|
|
: "memory");
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* Begins code morphing executable.
|
|
*
|
|
* The following example
|
|
*
|
|
* #include <cosmo.h>
|
|
* #include <stdlib.h>
|
|
*
|
|
* privileged int main() { // privileged code is unmodifiable
|
|
* ShowCrashReports(); // print report if trapped
|
|
* __morph_begin(0); // make executable code R+W
|
|
* *(char *)exit = 0xCC; // turn exit() into an INT3 trap
|
|
* __morph_end(); // make executable code R+X
|
|
* exit(0); // won't actually exit
|
|
* }
|
|
*
|
|
* shows how the exit() function can be recompiled at runtime to become
|
|
* an int3 (x86-64) debugger trap. What makes it tricky is Cosmopolitan
|
|
* maintains a R^X invariant, in order to support OpenBSD. So when code
|
|
* wants to modify some part of the executable image in memory the vast
|
|
* majority of the code stops being executable during that time, unless
|
|
* it's been linked into a special privileged section of the binary. It
|
|
* is only possible to code morph from privileged functions. Privileged
|
|
* functions are also only allowed to call other privileged functions.
|
|
*/
|
|
privileged void __morph_begin(void) {
|
|
__morph_mprotect(__executable_start, __privileged_start - __executable_start,
|
|
PROT_READ | PROT_WRITE, kNtPageWritecopy);
|
|
}
|
|
|
|
/**
|
|
* Finishes code morphing executable.
|
|
*/
|
|
privileged void __morph_end(void) {
|
|
__morph_mprotect(__executable_start, __privileged_start - __executable_start,
|
|
PROT_READ | PROT_EXEC, kNtPageExecuteRead);
|
|
}
|