implement zipos mmap

libc/runtime/mmap.c

@@ -50,6 +50,7 @@
 #include "libc/sysv/consts/prot.h"
 #include "libc/sysv/errfuns.h"
 #include "libc/thread/thread.h"
+#include "libc/zipos/zipos.internal.h"
 
 #define MAP_ANONYMOUS_linux   0x00000020
 #define MAP_ANONYMOUS_openbsd 0x00001000
@@ -485,6 +486,9 @@ static noasan inline void *Mmap(void *addr, size_t size, int prot, int flags,
 void *mmap(void *addr, size_t size, int prot, int flags, int fd, int64_t off) {
   void *res;
   size_t toto;
+  if (__isfdkind(fd, kFdZip)) {
+    return _weaken(__zipos_mmap)(addr, size, prot, flags, (struct ZiposHandle *)(intptr_t)g_fds.p[fd].handle, off);
+  }
 #if defined(SYSDEBUG) && (_KERNTRACE || _NTTRACE)
   if (IsWindows()) {
     STRACE("mmap(%p, %'zu, %s, %s, %d, %'ld) → ...", addr, size,

libc/zipos/mmap.c

@@ -0,0 +1,58 @@
+/*-*- 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 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/calls/calls.h"
+#include "libc/calls/struct/iovec.h"
+#include "libc/dce.h"
+#include "libc/intrin/likely.h"
+#include "libc/intrin/strace.internal.h"
+#include "libc/sysv/consts/map.h"
+#include "libc/sysv/consts/prot.h"
+#include "libc/sysv/errfuns.h"
+#include "libc/zipos/zipos.internal.h"
+
+#define IP(X)      (intptr_t)(X)
+#define VIP(X)     (void *)IP(X)
+
+void *__zipos_mmap(void *addr, size_t size, int prot, int flags, struct ZiposHandle *h, int64_t off) {
+  if (VERY_UNLIKELY(!!(flags & MAP_ANONYMOUS))) {
+    STRACE("fd anonymous mismatch");
+    return VIP(einval());
+  }
+
+  if (VERY_UNLIKELY(!(!!(prot & PROT_WRITE) ^ !!(flags & MAP_SHARED)))) {
+    STRACE("PROT_WRITE and MAP_SHARED on zipos");
+    return VIP(eacces());
+  }
+
+  const int tempProt = !IsXnu() ? prot | PROT_WRITE : PROT_WRITE;
+  void *outAddr = mmap(addr, size, tempProt, flags | MAP_ANONYMOUS, -1, 0);
+  if (outAddr == MAP_FAILED) {
+    return MAP_FAILED;
+  }
+  const int64_t beforeOffset = __zipos_lseek(h, 0, SEEK_CUR);
+  if ((beforeOffset == -1) || (__zipos_read(h, &(struct iovec){outAddr, size}, 1, off) == -1)) {
+    munmap(outAddr, size);
+    return MAP_FAILED;
+  }
+  __zipos_lseek(h, beforeOffset, SEEK_SET);
+  if(prot != tempProt) {
+    mprotect(outAddr, size, prot);
+  }
+  return outAddr;
+}

libc/zipos/open.c

@@ -48,7 +48,7 @@
 static char *mapend;
 static size_t maptotal;
 
-static void *__zipos_mmap(size_t mapsize) {
+static void *__zipos_mmap_space(size_t mapsize) {
   char *start;
   size_t offset;
   _unassert(mapsize);
@@ -78,7 +78,7 @@ StartOver:
     ph = &h->next;
   }
   if (!h) {
-    h = __zipos_mmap(mapsize);
+    h = __zipos_mmap_space(mapsize);
   }
   __zipos_unlock();
   if (IsAsan()) {

libc/zipos/zipos.S

@@ -34,6 +34,7 @@
 	.yoink	__zipos_read
 	.yoink	__zipos_stat
 	.yoink	__zipos_notat
+	.yoink	__zipos_mmap
 
 //	TODO(jart): why does corruption happen when zip has no assets?
 	.yoink	.cosmo

libc/zipos/zipos.internal.h

@@ -48,6 +48,7 @@ ssize_t __zipos_write(struct ZiposHandle *, const struct iovec *, size_t,
 int64_t __zipos_lseek(struct ZiposHandle *, int64_t, unsigned) _Hide;
 int __zipos_fcntl(int, int, uintptr_t) _Hide;
 int __zipos_notat(int, const char *) _Hide;
+void *__zipos_mmap(void *, uint64_t, int32_t, int32_t, struct ZiposHandle *, int64_t) _Hide;
 
 #ifdef _NOPL0
 #define __zipos_lock()   _NOPL0("__threadcalls", __zipos_lock)

test/libc/runtime/mmap_test.c

@@ -46,6 +46,8 @@
 #include "libc/x/xspawn.h"
 #include "third_party/xed/x86.h"
 
+STATIC_YOINK("zip_uri_support");
+
 char testlib_enable_tmp_setup_teardown;
 
 void SetUpOnce(void) {
@@ -219,6 +221,17 @@ TEST(isheap, mallocOffset) {
   ASSERT_TRUE(_isheap(p + 100000));
 }
 
+TEST(mmap, ziposMapFiles) {
+  int fd;
+  const char *lifepath = "/zip/life.elf";
+  void *p;
+
+  ASSERT_NE(-1, (fd = open(lifepath, O_RDONLY), "%s", lifepath));
+  ASSERT_NE(NULL, (p = mmap(NULL, 0x00010000, PROT_READ, MAP_SHARED, fd, 0)));
+  EXPECT_STREQN("ELF", ((const char *)p)+1, 3);
+  close(fd);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // NON-SHARED READ-ONLY FILE MEMORY
 

test/libc/runtime/test.mk

@@ -51,6 +51,7 @@ o/$(MODE)/test/libc/runtime/runtime.pkg:			\
 
 o/$(MODE)/test/libc/runtime/%.com.dbg:				\
 		$(TEST_LIBC_RUNTIME_DEPS)			\
+		o/$(MODE)/test/libc/mem/prog/life.elf.zip.o			\
 		o/$(MODE)/test/libc/runtime/%.o			\
 		o/$(MODE)/test/libc/runtime/runtime.pkg		\
 		$(LIBC_TESTMAIN)				\