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

native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc

Index: native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc b/native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc
index 049e53b4925afb050d387966848bd7260ad6804a..8f6bd2a7126314feb7e3a41a7ceb618ddc523a69 100644
--- a/native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc
+++ b/native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc
@@ -20,6 +20,7 @@
 
 #include "nacl_io/kernel_intercept.h"
 #include "nacl_io/kernel_wrap_real.h"
+#include "nacl_io/log.h"
 
 EXTERN_C_BEGIN
 
@@ -89,21 +90,37 @@ extern struct nacl_irt_memory __libnacl_irt_memory;
   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) {
@@ -128,7 +145,7 @@ int WRAP(seek)(int fd, off_t offset, int whence, off_t* new_offset) {
 }
 
 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) {
@@ -140,23 +157,23 @@ int WRAP(getdents)(int fd, dirent* buf, size_t count, size_t* nread) {
 }
 
 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) {
@@ -188,19 +205,19 @@ int WRAP(open)(const char* pathname, int oflag, mode_t cmode, int* newfd) {
 }
 
 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) {
@@ -211,48 +228,47 @@ int WRAP(getcwd)(char* pathname, size_t len) {
 }
 
 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() {
@@ -342,6 +358,7 @@ 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;
@@ -350,6 +367,7 @@ void kernel_wrap_init() {
 
 void kernel_wrap_uninit() {
   if (s_wrapped) {
+    LOG_TRACE("kernel_wrap_uninit");
     EXPAND_SYMBOL_LIST_OPERATION(USE_REAL)
     s_wrapped = false;
   }