Add memfd fexecve zipos support (#752)

This commit is contained in:
Gavin Hayes 2023-03-29 21:16:46 -04:00 committed by GitHub
parent ba42248575
commit 669b4c5f19
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GPG key ID: 4AEE18F83AFDEB23
5 changed files with 102 additions and 22 deletions

View file

@ -30,6 +30,7 @@
#include "libc/fmt/itoa.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/describeflags.internal.h"
#include "libc/intrin/safemacros.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/intrin/weaken.h"
#include "libc/str/str.h"
@ -125,9 +126,6 @@ static int fd_to_mem_fd(const int infd, char *path) {
int fd;
if (IsLinux()) {
fd = sys_memfd_create(__func__, MFD_CLOEXEC);
if ((fd != -1) && path) {
FormatInt32(stpcpy(path, "/proc/self/fd/"), fd);
}
} else if (IsFreebsd()) {
fd = sys_shm_open(SHM_ANON, O_CREAT | O_RDWR, 0);
} else {
@ -144,10 +142,22 @@ static int fd_to_mem_fd(const int infd, char *path) {
readRc = pread(infd, space, st.st_size, 0);
bool success = readRc != -1;
if (success && (st.st_size > 8) && IsAPEMagic(space)) {
success = ape_to_elf(space, st.st_size);
int flags = fcntl(fd, F_GETFD);
if (success = (flags != -1) &&
(fcntl(fd, F_SETFD, flags & (~FD_CLOEXEC)) != -1) &&
ape_to_elf(space, st.st_size)) {
const int newfd = fcntl(fd, F_DUPFD, 9001);
if (newfd != -1) {
close(fd);
fd = newfd;
}
}
}
const int e = errno;
if ((_weaken(munmap)(space, st.st_size) != -1) && success) {
if (path) {
FormatInt32(stpcpy(path, "COSMOPOLITAN_INIT_ZIPOS="), fd);
}
_unassert(readRc == st.st_size);
return fd;
} else if (!success) {
@ -182,6 +192,7 @@ int fexecve(int fd, char *const argv[], char *const envp[]) {
} else {
STRACE("fexecve(%d, %s, %s) → ...", fd, DescribeStringList(argv),
DescribeStringList(envp));
int savedErr = 0;
do {
if (!IsLinux() && !IsFreebsd()) {
rc = enosys();
@ -200,33 +211,36 @@ int fexecve(int fd, char *const argv[], char *const envp[]) {
if (rc == -1) {
break;
} else if (!memfdReq) {
rc = fexecve_impl(fd, argv, envp);
fexecve_impl(fd, argv, envp);
if (errno != ENOEXEC) {
break;
}
savedErr = ENOEXEC;
}
}
int newfd;
char *path = alloca(PATH_MAX);
BEGIN_CANCELLATION_POINT;
BLOCK_SIGNALS;
strace_enabled(-1);
newfd = fd_to_mem_fd(fd, NULL);
newfd = fd_to_mem_fd(fd, path);
strace_enabled(+1);
ALLOW_SIGNALS;
END_CANCELLATION_POINT;
if (newfd == -1) {
if (rc == -1) {
errno = ENOEXEC;
}
rc = -1;
break;
}
fexecve_impl(newfd, argv, envp);
if (rc == -1) {
errno = ENOEXEC;
size_t numenvs;
for (numenvs = 0; envp[numenvs];) ++numenvs;
const size_t desenvs = min(500, max(numenvs + 1, 2));
static _Thread_local char *envs[500];
memcpy(envs, envp, numenvs * sizeof(char *));
envs[numenvs] = path;
envs[numenvs + 1] = NULL;
fexecve_impl(newfd, argv, envs);
if (!savedErr) {
savedErr = errno;
}
rc = -1;
const int savedErr = errno;
BEGIN_CANCELLATION_POINT;
BLOCK_SIGNALS;
strace_enabled(-1);
@ -234,8 +248,11 @@ int fexecve(int fd, char *const argv[], char *const envp[]) {
strace_enabled(+1);
ALLOW_SIGNALS;
END_CANCELLATION_POINT;
errno = savedErr;
} while (0);
if (savedErr) {
errno = savedErr;
}
rc = -1;
}
STRACE("fexecve(%d) failed %d% m", fd, rc);
return rc;

View file

@ -18,6 +18,7 @@
*/
#include "libc/calls/calls.h"
#include "libc/calls/metalfile.internal.h"
#include "libc/fmt/conv.h"
#include "libc/intrin/cmpxchg.h"
#include "libc/intrin/promises.internal.h"
#include "libc/intrin/strace.internal.h"
@ -59,7 +60,7 @@ static void __zipos_munmap_unneeded(const uint8_t *base, const uint8_t *cdir,
* @threadsafe
*/
struct Zipos *__zipos_get(void) {
int fd;
int fd = -1;
ssize_t size;
const char *msg;
static bool once;
@ -67,10 +68,17 @@ struct Zipos *__zipos_get(void) {
const char *progpath;
static struct Zipos zipos;
uint8_t *map, *base, *cdir;
if (!once && PLEDGED(RPATH)) {
progpath = getenv("COSMOPOLITAN_INIT_ZIPOS");
if (progpath) {
fd = atoi(progpath);
}
if (!once && ((fd != -1) || PLEDGED(RPATH))) {
__zipos_lock();
progpath = GetProgramExecutableName();
if ((fd = open(progpath, O_RDONLY)) != -1) {
if (fd == -1) {
progpath = GetProgramExecutableName();
fd = open(progpath, O_RDONLY);
}
if (fd != -1) {
if ((size = getfiledescriptorsize(fd)) != -1ul &&
(map = mmap(0, size, PROT_READ, MAP_SHARED, fd, 0)) != MAP_FAILED) {
if ((base = FindEmbeddedApe(map, size))) {

View file

@ -128,3 +128,14 @@ TEST(fexecve, ziposAPE) {
EXITS(42);
close(fd);
}
TEST(fexecve, ziposAPEHasZipos) {
if (!IsLinux() && !IsFreebsd()) return;
int fd = open("/zip/zipread.com", O_RDONLY);
SPAWN(fork);
ASSERT_NE(-1, fd);
if (fd == -1 && errno == ENOSYS) _Exit(42);
fexecve(fd, (char *const[]){0}, (char *const[]){0});
EXITS(42);
close(fd);
}

View file

@ -19,7 +19,8 @@ TEST_LIBC_CALLS_BINS = \
$(TEST_LIBC_CALLS_COMS) \
$(TEST_LIBC_CALLS_COMS:%=%.dbg) \
o/$(MODE)/test/libc/calls/life-nomod.com \
o/$(MODE)/test/libc/calls/life-classic.com
o/$(MODE)/test/libc/calls/life-classic.com \
o/$(MODE)/test/libc/calls/zipread.com
TEST_LIBC_CALLS_TESTS = \
$(TEST_LIBC_CALLS_SRCS_TEST:%.c=o/$(MODE)/%.com.ok)
@ -95,6 +96,7 @@ o/$(MODE)/test/libc/calls/fexecve_test.com.dbg: \
o/$(MODE)/test/libc/mem/prog/life.elf.zip.o \
o/$(MODE)/tool/build/echo.zip.o \
o/$(MODE)/test/libc/calls/life-nomod.com.zip.o \
o/$(MODE)/test/libc/calls/zipread.com.zip.o \
$(LIBC_TESTMAIN) \
$(CRT) \
$(APE_NO_MODIFY_SELF)
@ -102,7 +104,8 @@ o/$(MODE)/test/libc/calls/fexecve_test.com.dbg: \
o/$(MODE)/test/libc/calls/tiny64.elf.zip.o \
o/$(MODE)/test/libc/calls/life-nomod.com.zip.o \
o/$(MODE)/test/libc/calls/life-classic.com.zip.o: private \
o/$(MODE)/test/libc/calls/life-classic.com.zip.o \
o/$(MODE)/test/libc/calls/zipread.com.zip.o: private \
ZIPOBJ_FLAGS += \
-B

41
test/libc/calls/zipread.c Normal file
View file

@ -0,0 +1,41 @@
/*-*- 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 2023 Gavin Arthur Hayes
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/calls/calls.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/o.h"
STATIC_YOINK("zip_uri_support");
int main(int argc, char *argv[]) {
int fd = open("/zip/life.elf", O_RDONLY);
if (fd != -1) {
uint8_t buf[4] = {0};
ssize_t readres = read(fd, buf, sizeof(buf));
if (readres == sizeof(buf)) {
if (memcmp(buf,
"\x7F"
"ELF",
sizeof(buf)) == 0) {
return 42;
}
}
close(fd);
}
return 1;
}