[NaCl SDK] nacl_io: Make IRT intercepts (and their test code) more robust.

native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <sys/types.h>  // Include something that will define __GLIBC__.
 
 // The entire file is wrapped in this #if. We do this so this .cc file can be
 // compiled, even on a non-newlib build.
 #if defined(__native_client__) && !defined(__GLIBC__) && !defined(__BIONIC__)
 
 #include "nacl_io/kernel_wrap.h"
 
 #include <dirent.h>
 #include <errno.h>
 #include <irt.h>
 #include <irt_dev.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <sys/time.h>
 
 #include "nacl_io/kernel_intercept.h"
 #include "nacl_io/kernel_wrap_real.h"
+#include "nacl_io/log.h"
 
 EXTERN_C_BEGIN
 
 // Macro to get the REAL function pointer
 #define REAL(name) __nacl_irt_##name##_real
 
 // Macro to get the WRAP function
 #define WRAP(name) __nacl_irt_##name##_wrap
 
 // Declare REAL function pointer.
@@ skipping 49 matching lines @@
   OP(dev_filename, link); \
   OP(dev_filename, rename); \
   OP(dev_filename, symlink); \
   OP(dev_filename, chmod); \
   OP(dev_filename, access); \
   OP(dev_filename, readlink); \
   OP(dev_filename, utimes); \
   OP(memory, mmap); \
   OP(memory, munmap);
 
+// Most kernal intercept functions (ki_*) return -1 and set errno accordingly.
+// However the IRT wrappers are expected to return errno on failure. Here we
+// check that the ki_ function actually set errno and fall back to EIO if it
+// didn't.
+#define RTN_ERRNO_IF(cond) \
+  if (cond) { \
+    int rtn = errno; \
+    if (rtn == 0) rtn = EIO; \
+    return rtn; \
+  }
+
+#define ERRNO_RTN(function_call) \

[binji, 2014/05/06 23:25:54]

make this consistent with the other kernel_wrap_* (it doesn't have it)

[Sam Clegg, 2014/05/07 00:29:03]

Done.

+  RTN_ERRNO_IF(function_call < 0); \
+  return 0;
 
 EXPAND_SYMBOL_LIST_OPERATION(DECLARE_REAL_PTR);
 
 int WRAP(close)(int fd) {
-  return (ki_close(fd) < 0) ? errno : 0;
+  ERRNO_RTN(ki_close(fd));

[binji, 2014/05/06 23:25:54]

do this stuff for kernel_wrap_bionic too

[Sam Clegg, 2014/05/07 00:29:03]

Done.

 }
 
 int WRAP(dup)(int fd, int* newfd) {
   *newfd = ki_dup(fd);
-  return (*newfd < 0) ? errno : 0;
+  RTN_ERRNO_IF(*newfd < 0);

[binji, 2014/05/06 23:29:52]

ERRNO_RTN

[Sam Clegg, 2014/05/07 00:29:03]

Done.

+  return 0;
 }
 
 int WRAP(dup2)(int fd, int newfd) {
   newfd = ki_dup2(fd, newfd);
-  return (newfd < 0) ? errno : 0;
+  RTN_ERRNO_IF(newfd < 0);

[binji, 2014/05/06 23:29:52]

ERRNO_RTN

[Sam Clegg, 2014/05/07 00:29:03]

Done.

+  return 0;
 }
 
 void WRAP(exit)(int status) {
   ki_exit(status);
 }
 
 int WRAP(read)(int fd, void* buf, size_t count, size_t* nread) {
   ssize_t signed_nread = ki_read(fd, buf, count);
   *nread = static_cast<size_t>(signed_nread);
   return (signed_nread < 0) ? errno : 0;

[binji, 2014/05/06 23:31:49]

missed some:
read, write, seek, getdents ...

[Sam Clegg, 2014/05/07 00:29:03]

Done.

 }
 
 int WRAP(write)(int fd, const void* buf, size_t count, size_t* nwrote) {
   ssize_t signed_nwrote = ki_write(fd, buf, count);
   *nwrote = static_cast<size_t>(signed_nwrote);
   return (signed_nwrote < 0) ? errno : 0;
 }
 
 int WRAP(seek)(int fd, off_t offset, int whence, off_t* new_offset) {
   *new_offset = ki_lseek(fd, offset, whence);
   return (*new_offset < 0) ? errno : 0;
 }
 
 int WRAP(fstat)(int fd, struct stat* buf) {
-  return (ki_fstat(fd, buf) < 0) ? errno : 0;
+  ERRNO_RTN(ki_fstat(fd, buf));
 }
 
 int WRAP(getdents)(int fd, dirent* buf, size_t count, size_t* nread) {
   int rtn = ki_getdents(fd, buf, count);
   if (rtn < 0)
     return errno;
   *nread = rtn;
   return 0;
 }
 
 int WRAP(fchdir)(int fd) {
-  return (ki_fchdir(fd) < 0) ? errno : 0;
+  ERRNO_RTN(ki_fchdir(fd));
 }
 
 int WRAP(fchmod)(int fd, mode_t mode) {
-  return (ki_fchmod(fd, mode) < 0) ? errno : 0;
+  ERRNO_RTN(ki_fchmod(fd, mode));
 }
 
 int WRAP(fsync)(int fd) {
-  return (ki_fsync(fd) < 0) ? errno : 0;
+  ERRNO_RTN(ki_fsync(fd));
 }
 
 int WRAP(fdatasync)(int fd) {
-  return (ki_fdatasync(fd) < 0) ? errno : 0;
+  ERRNO_RTN(ki_fdatasync(fd));
 }
 
 int WRAP(ftruncate)(int fd, off_t length) {
-  return (ki_ftruncate(fd, length) < 0) ? errno : 0;
+  ERRNO_RTN(ki_ftruncate(fd, length));
 }
 
 int WRAP(isatty)(int fd, int* result) {
   *result = ki_isatty(fd);
   if (*result == 0)
     return errno;
   return 0;
 }
 
 int WRAP(mmap)(void** addr, size_t length, int prot, int flags, int fd,
@@ skipping 11 matching lines @@
   ki_munmap(addr, length);
   return REAL(munmap)(addr, length);
 }
 
 int WRAP(open)(const char* pathname, int oflag, mode_t cmode, int* newfd) {
   *newfd = ki_open(pathname, oflag);
   return (*newfd < 0) ? errno : 0;
 }
 
 int WRAP(stat)(const char* pathname, struct stat* buf) {
-  return (ki_stat(pathname, buf) < 0) ? errno : 0;
+  ERRNO_RTN(ki_stat(pathname, buf));
 }
 
 int WRAP(mkdir)(const char* pathname, mode_t mode) {
-  return (ki_mkdir(pathname, mode) < 0) ? errno : 0;
+  ERRNO_RTN(ki_mkdir(pathname, mode));
 }
 
 int WRAP(rmdir)(const char* pathname) {
-  return (ki_rmdir(pathname) < 0) ? errno : 0;
+  ERRNO_RTN(ki_rmdir(pathname));
 }
 
 int WRAP(chdir)(const char* pathname) {
-  return (ki_chdir(pathname) < 0) ? errno : 0;
+  ERRNO_RTN(ki_chdir(pathname));
 }
 
 int WRAP(getcwd)(char* pathname, size_t len) {
   char* rtn = ki_getcwd(pathname, len);
   if (NULL == rtn)
     return errno;
   return 0;
 }
 
 int WRAP(unlink)(const char* pathname) {
-  return (ki_unlink(pathname) < 0) ? errno : 0;
+  ERRNO_RTN(ki_unlink(pathname));
 }
 
 int WRAP(truncate)(const char* pathname, off_t length) {
-  return (ki_truncate(pathname, length) < 0) ? errno : 0;
+  ERRNO_RTN(ki_truncate(pathname, length));
 }
 
 int WRAP(lstat)(const char* pathname, struct stat* buf) {
-  return (ki_lstat(pathname, buf) < 0) ? errno : 0;
+  ERRNO_RTN(ki_lstat(pathname, buf));
 }
 
 int WRAP(link)(const char* pathname, const char* newpath) {
-  return (ki_link(pathname, newpath) < 0) ? errno : 0;
+  ERRNO_RTN(ki_link(pathname, newpath));
 }
 
 int WRAP(rename)(const char* pathname, const char* newpath) {
-  return (ki_rename(pathname, newpath) < 0) ? errno : 0;
+  ERRNO_RTN(ki_rename(pathname, newpath));
 }
 
 int WRAP(symlink)(const char* pathname, const char* newpath) {
-  return (ki_symlink(pathname, newpath) < 0) ? errno : 0;
+  ERRNO_RTN(ki_symlink(pathname, newpath));
 }
 
 int WRAP(chmod)(const char* pathname, mode_t mode) {
-  return (ki_chmod(pathname, mode) < 0) ? errno : 0;
+  ERRNO_RTN(ki_chmod(pathname, mode));
 }
 
 int WRAP(access)(const char* pathname, int amode) {
-  return (ki_access(pathname, amode) < 0) ? errno : 0;
+  ERRNO_RTN(ki_access(pathname, amode));
 }
 
 int WRAP(readlink)(const char* pathname, char *buf,
                    size_t count, size_t *nread) {
   int rtn = ki_readlink(pathname, buf, count);
-  if (rtn < 0)
-    return errno;
+  RTN_ERRNO_IF(rtn < 0);
   *nread = rtn;
   return 0;
 }
 
 int WRAP(utimes)(const char* pathname, const struct timeval times[2]) {
-  return (ki_utimes(pathname, times) < 0) ? errno : 0;
+  ERRNO_RTN(ki_utimes(pathname, times));
 }
 
 static void assign_real_pointers() {
   static bool assigned = false;
   if (!assigned) {
     __libnacl_irt_dev_filename_init();
     EXPAND_SYMBOL_LIST_OPERATION(ASSIGN_REAL_PTR)
     assigned = true;
   }
 }
@@ skipping 69 matching lines @@
 
 int _real_write(int fd, const void* buf, size_t count, size_t* nwrote) {
   CHECK_REAL(write);
   return REAL(write)(fd, buf, count, nwrote);
 }
 
 static bool s_wrapped = false;
 
 void kernel_wrap_init() {
   if (!s_wrapped) {
+    LOG_TRACE("kernel_wrap_init");
     assign_real_pointers();
     EXPAND_SYMBOL_LIST_OPERATION(USE_WRAP)
     s_wrapped = true;
   }
 }
 
 void kernel_wrap_uninit() {
   if (s_wrapped) {
+    LOG_TRACE("kernel_wrap_uninit");
     EXPAND_SYMBOL_LIST_OPERATION(USE_REAL)
     s_wrapped = false;
   }
 }
 
 EXTERN_C_END
 
 #endif  // defined(__native_client__) && !defined(__GLIBC__) ...