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Add x86_64-linux-gnu emulator

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I wanted a tiny scriptable meltdown proof way to run userspace programs
and visualize how program execution impacts memory. It helps to explain
how things like Actually Portable Executable works. It can show you how
the GCC generated code is going about manipulating matrices and more. I
didn't feel fully comfortable with Qemu and Bochs because I'm not smart
enough to understand them. I wanted something like gVisor but with much
stronger levels of assurances. I wanted a single binary that'll run, on
all major operating systems with an embedded GPL barrier ZIP filesystem
that is tiny enough to transpile to JavaScript and run in browsers too.

https://justine.storage.googleapis.com/emulator625.mp4
This commit is contained in:
Justine Tunney 2020-08-25 04:23:25 -07:00
parent 467504308a
commit f4f4caab0e
1052 changed files with 65667 additions and 7825 deletions
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39
libc/zipos/open.c
View file

@ -23,10 +23,10 @@
#include "libc/calls/internal.h"
#include "libc/calls/struct/sigset.h"
#include "libc/calls/struct/stat.h"
#include "libc/conv/sizemultiply.h"
#include "libc/dce.h"
#include "libc/macros.h"
#include "libc/mem/mem.h"
#include "libc/nexgen32e/crc32.h"
#include "libc/runtime/rbx.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
@ -83,37 +83,39 @@ static int __zipos_inflate_tiny(struct ZiposHandle *h, uint8_t *data,
return undeflate(h->mem, h->size, data, size, &ds) != -1 ? 0 : eio();
}
static int __zipos_load(size_t cf, unsigned flags, int mode) {
static int __zipos_load(struct Zipos *zipos, size_t cf, unsigned flags,
int mode) {
int fd;
size_t lf;
struct ZiposHandle *h;
lf = ZIP_CFILE_OFFSET(&_base[0] + cf);
assert(ZIP_LFILE_MAGIC(&_base[0] + lf) == kZipLfileHdrMagic);
assert(ZIP_LFILE_COMPRESSIONMETHOD(&_base[0] + lf) == kZipCompressionNone ||
ZIP_LFILE_COMPRESSIONMETHOD(&_base[0] + lf) == kZipCompressionDeflate);
lf = ZIP_CFILE_OFFSET(zipos->map + cf);
assert(ZIP_LFILE_MAGIC(zipos->map + lf) == kZipLfileHdrMagic);
assert(ZIP_LFILE_COMPRESSIONMETHOD(zipos->map + lf) == kZipCompressionNone ||
ZIP_LFILE_COMPRESSIONMETHOD(zipos->map + lf) ==
kZipCompressionDeflate);
if ((fd = createfd()) == -1) return -1;
if (!(h = calloc(1, sizeof(*h)))) return -1;
h->cfile = cf;
if ((h->size = ZIP_LFILE_UNCOMPRESSEDSIZE(&_base[0] + lf))) {
if (ZIP_LFILE_COMPRESSIONMETHOD(&_base[0] + lf)) {
assert(ZIP_LFILE_COMPRESSEDSIZE(&_base[0] + lf));
if ((h->size = ZIP_LFILE_UNCOMPRESSEDSIZE(zipos->map + lf))) {
if (ZIP_LFILE_COMPRESSIONMETHOD(zipos->map + lf)) {
assert(ZIP_LFILE_COMPRESSEDSIZE(zipos->map + lf));
h->mapsize = ROUNDUP(h->size + FRAMESIZE, FRAMESIZE);
if ((h->map = mapanon(h->mapsize)) != MAP_FAILED) {
h->mem = h->map + FRAMESIZE / 2;
if ((IsTiny() ? __zipos_inflate_tiny : __zipos_inflate_fast)(
h, ZIP_LFILE_CONTENT(&_base[0] + lf),
ZIP_LFILE_COMPRESSEDSIZE(&_base[0] + lf)) == -1) {
h, ZIP_LFILE_CONTENT(zipos->map + lf),
ZIP_LFILE_COMPRESSEDSIZE(zipos->map + lf)) == -1) {
fd = -1;
}
} else {
fd = -1;
}
} else {
h->mem = ZIP_LFILE_CONTENT(&_base[0] + lf);
h->mem = ZIP_LFILE_CONTENT(zipos->map + lf);
}
}
if (!IsTiny() && fd != -1 &&
crc32_z(0, h->mem, h->size) != ZIP_LFILE_CRC32(&_base[0] + lf)) {
crc32_z(0, h->mem, h->size) != ZIP_LFILE_CRC32(zipos->map + lf)) {
fd = eio();
}
if (fd != -1) {
@ -136,12 +138,17 @@ int __zipos_open(const struct ZiposUri *name, unsigned flags, int mode) {
int fd;
ssize_t cf;
sigset_t oldmask;
struct Zipos *zipos;
assert((flags & O_ACCMODE) == O_RDONLY);
sigprocmask(SIG_BLOCK, &kSigsetFull, &oldmask);
if ((cf = __zipos_find(name)) != -1) {
fd = __zipos_load(cf, flags, mode);
if ((zipos = __zipos_get())) {
if ((cf = __zipos_find(zipos, name)) != -1) {
fd = __zipos_load(zipos, cf, flags, mode);
} else {
fd = enoent();
}
} else {
fd = enoent();
fd = enoexec();
}
sigprocmask(SIG_SETMASK, &oldmask, NULL);
return fd;