Re: [PATCH 10/20] pseudo: Wrap renameat and opendir

[Saul Wold <sgw@linux.intel.com>]

On 02/07/2012 08:31 AM, Khem Raj wrote:
> On Tue, Feb 7, 2012 at 8:21 AM, Saul Wold<sgw@linux.intel.com>  wrote:
>> On 02/05/2012 10:40 PM, Khem Raj wrote:
>>>
>>> Signed-off-by: Khem Raj<raj.khem@gmail.com>
>>> ---
>>>   meta/recipes-devtools/pseudo/pseudo/opendir.patch  |   92 ++++++++
>>>   meta/recipes-devtools/pseudo/pseudo/renameat.patch |  227
>>> ++++++++++++++++++++
>>>   meta/recipes-devtools/pseudo/pseudo_1.2.bb         |    6 +-
>>>   3 files changed, 323 insertions(+), 2 deletions(-)
>>>   create mode 100644 meta/recipes-devtools/pseudo/pseudo/opendir.patch
>>>   create mode 100644 meta/recipes-devtools/pseudo/pseudo/renameat.patch
>>>
>>> diff --git a/meta/recipes-devtools/pseudo/pseudo/opendir.patch
>>> b/meta/recipes-devtools/pseudo/pseudo/opendir.patch
>>> new file mode 100644
>>> index 0000000..d20f717
>>> --- /dev/null
>>> +++ b/meta/recipes-devtools/pseudo/pseudo/opendir.patch
>>> @@ -0,0 +1,92 @@
>>> +commit 162f2692c399b93311652201a940fdaf9c9e6924
>>> +Author: Peter Seebach<peter.seebach@windriver.com>
>>> +Date:   Thu Feb 2 11:45:42 2012 -0600
>>> +
>>> +    Make opendir/closedir stash and forget directory names.
>>> +
>>> +    The dirfd(DIR *) interface allows you to get the fd for a DIR *,
>>> +    meaning you can use it with openat(), meaning you can need its
>>> +    path.  This causes a segfault.  Also gonna fix the base_path
>>> +    code not to segfault in that case, but first fix the underlying
>>> +    problem.
>>> +
>>
>>
>> Missing Upstream-Status: and Signed-off-by (yes I know we have an email
>> header).
>
> they are backports
>
Please update the patch!

Thanks
	Sau!

>>
>> Thanks
>>         Sau!
>>
>>> +diff --git a/ChangeLog.txt b/ChangeLog.txt
>>> +index 4de488c..9625b38 100644
>>> +--- a/ChangeLog.txt
>>> ++++ b/ChangeLog.txt
>>> +@@ -1,3 +1,7 @@
>>> ++2012-02-02:
>>> ++      * (seebs) stash dir name for DIR * from opendir using dirfd.
>>> ++      * (seebs) add closedir.
>>> ++
>>> + 2011-11-02:
>>> +       * (seebs) Call this 1.2 because the UNLOAD change is moderately
>>> +         significant, and so's the clone change.
>>> +diff --git a/ports/unix/guts/closedir.c b/ports/unix/guts/closedir.c
>>> +new file mode 100644
>>> +index 0000000..1085361
>>> +--- /dev/null
>>> ++++ b/ports/unix/guts/closedir.c
>>> +@@ -0,0 +1,20 @@
>>> ++/*
>>> ++ * Copyright (c) 2012 Wind River Systems; see
>>> ++ * guts/COPYRIGHT for information.
>>> ++ *
>>> ++ * static int
>>> ++ * wrap_closedir(DIR *dirp) {
>>> ++ *    int rc = -1;
>>> ++ */
>>> ++      if (!dirp) {
>>> ++              errno = EFAULT;
>>> ++              return -1;
>>> ++      }
>>> ++
>>> ++      int fd = dirfd(dirp);
>>> ++      pseudo_client_op(OP_CLOSE, 0, fd, -1, 0, 0);
>>> ++      rc = real_closedir(dirp);
>>> ++
>>> ++/*    return rc;
>>> ++ * }
>>> ++ */
>>> +diff --git a/ports/unix/guts/opendir.c b/ports/unix/guts/opendir.c
>>> +index 8eaa71f..e69717e 100644
>>> +--- a/ports/unix/guts/opendir.c
>>> ++++ b/ports/unix/guts/opendir.c
>>> +@@ -6,8 +6,25 @@
>>> +  * wrap_opendir(const char *path) {
>>> +  *    DIR * rc = NULL;
>>> +  */
>>> ++      struct stat buf;
>>> ++      int save_errno;
>>> +
>>> +       rc = real_opendir(path);
>>> ++      if (rc) {
>>> ++              int fd;
>>> ++              save_errno = errno;
>>> ++              fd = dirfd(rc);
>>> ++              if (real_fstat(fd,&buf) == -1) {
>>>
>>> ++                      pseudo_debug(1, "diropen (fd %d) succeeded, but
>>> fstat failed (%s).\n",
>>> ++                              fd, strerror(errno));
>>> ++                      pseudo_client_op_plain(OP_OPEN, PSA_READ, fd, -1,
>>> path, 0);
>>> ++              } else {
>>> ++                      pseudo_client_op_plain(OP_OPEN, PSA_READ, fd, -1,
>>> path,&buf);
>>> ++              }
>>> ++
>>> ++
>>> ++              errno = save_errno;
>>> ++      }
>>> +
>>> + /*    return rc;
>>> +  * }
>>> +diff --git a/ports/unix/wrapfuncs.in b/ports/unix/wrapfuncs.in
>>> +index e06e404..32250c4 100644
>>> +--- a/ports/unix/wrapfuncs.in
>>> ++++ b/ports/unix/wrapfuncs.in
>>> +@@ -21,6 +21,7 @@ long pathconf(const char *path, int name);
>>> + char *realpath(const char *name, char *resolved_name); /*
>>> version="GLIBC_2.3" */
>>> + int remove(const char *path); /* flags=AT_SYMLINK_NOFOLLOW */
>>> + DIR *opendir(const char *path);
>>> ++int closedir(DIR *dirp);
>>> + char *tempnam(const char *template, const char *pfx);
>>> + char *tmpnam(char *s);
>>> + int truncate(const char *path, off_t length);
>>> diff --git a/meta/recipes-devtools/pseudo/pseudo/renameat.patch
>>> b/meta/recipes-devtools/pseudo/pseudo/renameat.patch
>>> new file mode 100644
>>> index 0000000..74c8585
>>> --- /dev/null
>>> +++ b/meta/recipes-devtools/pseudo/pseudo/renameat.patch
>>> @@ -0,0 +1,227 @@
>>> +commit 795f2b44b7f692151556782f142a4a6e7d45d892
>>> +Author: Peter Seebach<peter.seebach@windriver.com>
>>> +Date:   Thu Feb 2 15:49:21 2012 -0600
>>> +
>>> +    Implement renameat()
>>> +
>>> +    After three long years, someone tried to use this.  This was
>>> impossibly
>>> +    hard back when pseudo was written, because there was only one dirfd
>>> +    provided for.  Thing is, now, the canonicalization happens in
>>> wrapfuncs,
>>> +    so a small tweak to makewrappers to recognize that oldpath should use
>>> +    olddirfd if it exists is enough to get us fully canonicalized paths
>>> +    when needed.
>>> +
>>> +    Also fix the crash if base_path gets called with an fd for which we
>>> have
>>> +    no path.
>>> +
>>> +diff --git a/ChangeLog.txt b/ChangeLog.txt
>>> +index 9625b38..25bd463 100644
>>> +--- a/ChangeLog.txt
>>> ++++ b/ChangeLog.txt
>>> +@@ -1,6 +1,9 @@
>>> + 2012-02-02:
>>> +       * (seebs) stash dir name for DIR * from opendir using dirfd.
>>> +       * (seebs) add closedir.
>>> ++      * (seebs) add initial pass at renameat()
>>> ++      * (seebs) in base_path, don't try to strlen the result if
>>> ++        fd_path() returns NULL.
>>> +
>>> + 2011-11-02:
>>> +       * (seebs) Call this 1.2 because the UNLOAD change is moderately
>>> +diff --git a/makewrappers b/makewrappers
>>> +index 20bbf2b..bf344d6 100755
>>> +--- a/makewrappers
>>> ++++ b/makewrappers
>>> +@@ -211,12 +211,13 @@ class Function:
>>> +         self.flags = '0'
>>> +         self.port = port
>>> +         self.directory = ''
>>> +-      self.version = 'NULL'
>>> ++        self.version = 'NULL'
>>> +         # On Darwin, some functions are SECRETLY converted to
>>> foo$INODE64
>>> +         # when called.  So we have to look those up for real_*
>>> +         self.inode64 = None
>>> +         self.real_func = None
>>> +         self.paths_to_munge = []
>>> ++        self.dirfds = {}
>>> +         self.hand_wrapped = None
>>> +         # used for the copyright date when creating stub functions
>>> +         self.date = datetime.date.today().year
>>> +@@ -239,6 +240,7 @@ class Function:
>>> +         # * If the arg has a name ending in 'path', we will canonicalize
>>> it.
>>> +         # * If the arg is named 'dirfd' or 'flags', it becomes the
>>> default
>>> +         #   values for the dirfd and flags arguments when
>>> canonicalizing.
>>> ++        # * If the name ends in dirfd, we do the same fancy stuff.
>>> +         # * Note that the "comments" field (/* ... */ after the decl)
>>> can
>>> +         #   override the dirfd/flags values.
>>> +         self.args = ArgumentList(bits.group(2))
>>> +@@ -246,7 +248,9 @@ class Function:
>>> +             # ignore varargs, they never get these special treatments
>>> +             if arg.vararg:
>>> +                 pass
>>> +-            elif arg.name == 'dirfd':
>>> ++            elif arg.name[-5:] == 'dirfd':
>>> ++                if len(arg.name)>    5:
>>> ++                    self.dirfds[arg.name[:-5]] = True
>>> +                 self.dirfd = 'dirfd'
>>> +             elif arg.name == 'flags':
>>> +                 self.flags = 'flags'
>>> +@@ -325,9 +329,13 @@ class Function:
>>> +         """create/allocate canonical paths"""
>>> +         alloc_paths = []
>>> +         for path in self.paths_to_munge:
>>> ++            prefix = path[:-4]
>>> ++          if not prefix in self.dirfds:
>>> ++                prefix = ''
>>> ++            print "for path %s: prefix<%s>" % ( path, prefix )
>>> +             alloc_paths.append(
>>> +-                "%s = pseudo_root_path(__func__, __LINE__, %s, %s, %s);"
>>> %
>>> +-                (path, self.dirfd, path, self.flags))
>>> ++                "%s = pseudo_root_path(__func__, __LINE__, %s%s, %s,
>>> %s);" %
>>> ++                (path, prefix, self.dirfd, path, self.flags))
>>> +         return "\n\t\t\t".join(alloc_paths)
>>> +
>>> +     def free_paths(self):
>>> +diff --git a/ports/unix/guts/renameat.c b/ports/unix/guts/renameat.c
>>> +index c8203b7..f13cd1e 100644
>>> +--- a/ports/unix/guts/renameat.c
>>> ++++ b/ports/unix/guts/renameat.c
>>> +@@ -1,15 +1,111 @@
>>> + /*
>>> +- * Copyright (c) 2008-2010 Wind River Systems; see
>>> ++ * Copyright (c) 2008-2012 Wind River Systems; see
>>> +  * guts/COPYRIGHT for information.
>>> +  *
>>> +  * static int
>>> +  * wrap_renameat(int olddirfd, const char *oldpath, int newdirfd, const
>>> char *newpath) {
>>> +  *    int rc = -1;
>>> +  */
>>> ++      pseudo_msg_t *msg;
>>> ++      struct stat oldbuf, newbuf;
>>> ++      int oldrc, newrc;
>>> ++      int save_errno;
>>> ++      int old_db_entry = 0;
>>> +
>>> +-      pseudo_diag("help! unimplemented renameat [%s ->    %s].\n",
>>> oldpath, newpath);
>>> ++      pseudo_debug(2, "renameat: %d,%s->%d,%s\n",
>>> ++              olddirfd, oldpath ? oldpath : "<nil>",
>>> ++              newdirfd, newpath ? newpath : "<nil>");
>>> ++
>>> ++#ifdef PSEUDO_NO_REAL_AT_FUNCTIONS
>>> ++      if (olddirfd != AT_FDCWD || newdirfd != AT_FDCWD) {
>>> ++              errno = ENOSYS;
>>> ++              return -1;
>>> ++      }
>>> ++#endif
>>> ++
>>> ++      if (!oldpath || !newpath) {
>>> ++              errno = EFAULT;
>>> ++              return -1;
>>> ++      }
>>> ++
>>> ++      save_errno = errno;
>>> ++
>>> ++#ifdef PSEUDO_NO_REAL_AT_FUNCTIONS
>>> ++      newrc = real_lstat(newpath,&newbuf);
>>> ++      oldrc = real_lstat(oldpath,&oldbuf);
>>> ++#else
>>> ++      oldrc = real___fxstatat(_STAT_VER, olddirfd, oldpath,&oldbuf,
>>> AT_SYMLINK_NOFOLLOW);
>>> ++      newrc = real___fxstatat(_STAT_VER, newdirfd, newpath,&newbuf,
>>> AT_SYMLINK_NOFOLLOW);
>>>
>>> ++#endif
>>> ++
>>> ++      errno = save_errno;
>>> ++
>>> ++      /* newpath must be removed. */
>>> ++      /* as with unlink, we have to mark that the file may get deleted
>>> */
>>> ++      msg = pseudo_client_op_plain(OP_MAY_UNLINK, 0, -1, newdirfd,
>>> newpath, newrc ? NULL :&newbuf);
>>> ++      if (msg&&    msg->result == RESULT_SUCCEED)
>>>
>>> ++              old_db_entry = 1;
>>> +       rc = real_renameat(olddirfd, oldpath, newdirfd, newpath);
>>> ++      save_errno = errno;
>>> ++      if (old_db_entry) {
>>> ++              if (rc == -1) {
>>> ++                      /* since we failed, that wasn't really unlinked --
>>> put
>>> ++                       * it back.
>>> ++                       */
>>> ++                      pseudo_client_op_plain(OP_CANCEL_UNLINK, 0, -1,
>>> newdirfd, newpath,&newbuf);
>>> ++              } else {
>>> ++                      /* confirm that the file was removed */
>>> ++                      pseudo_client_op_plain(OP_DID_UNLINK, 0, -1,
>>> newdirfd, newpath,&newbuf);
>>> ++              }
>>> ++      }
>>> ++      if (rc == -1) {
>>> ++              /* and we're done. */
>>> ++              errno = save_errno;
>>> ++              return rc;
>>> ++      }
>>> ++      save_errno = errno;
>>> ++      /* nothing to do for a "rename" of a link to itself */
>>> ++      if (newrc != -1&&    oldrc != -1&&
>>> ++          newbuf.st_dev == oldbuf.st_dev&&
>>> ++          newbuf.st_ino == oldbuf.st_ino) {
>>> ++              return rc;
>>> ++        }
>>> ++
>>> ++      /* rename(3) is not mv(1).  rename(file, dir) fails; you must
>>> provide
>>> ++       * the corrected path yourself.  You can rename over a directory
>>> only
>>> ++       * if the source is a directory.  Symlinks are simply removed.
>>> ++       *
>>> ++       * If we got here, the real rename call succeeded.  That means
>>> newpath
>>> ++       * has been unlinked and oldpath has been linked to it.
>>> ++       *
>>> ++       * There are a ton of special cases to error check.  I don't check
>>> ++       * for any of them, because in every such case, the underlying
>>> rename
>>> ++       * failed, and there is nothing to do.
>>> ++       * The only tricky part is that, because we used to ignore
>>> symlinks,
>>> ++       * we may have to rename or remove directory trees even though in
>>> ++       * theory rename can never destroy a directory tree.
>>> ++       */
>>> ++      if (!old_db_entry) {
>>> ++              /* create an entry under the old name, which will then be
>>> ++               * renamed; this way, children would get renamed too, if
>>> there
>>> ++               * were any.
>>> ++               */
>>> ++              if (newrc == 0) {
>>> ++                      if (newbuf.st_dev != oldbuf.st_dev) {
>>> ++                              oldbuf.st_dev = newbuf.st_dev;
>>> ++                              oldbuf.st_ino = newbuf.st_ino;
>>> ++                      }
>>> ++              }
>>> ++              pseudo_debug(1, "creating new '%s' [%llu] to rename\n",
>>> ++                      oldpath, (unsigned long long) oldbuf.st_ino);
>>> ++              pseudo_client_op_plain(OP_LINK, 0, -1, olddirfd,
>>> oldpath,&oldbuf);
>>> ++      }
>>> ++      /* special case: use 'fd' for olddirfd, because
>>> ++       * we know it has no other meaning for RENAME
>>> ++       */
>>> ++      pseudo_client_op_plain(OP_RENAME, 0, olddirfd, newdirfd,
>>> newpath,&oldbuf, oldpath);
>>>
>>> +
>>> ++      errno = save_errno;
>>> + /*    return rc;
>>> +  * }
>>> +  */
>>> +diff --git a/pseudo_client.c b/pseudo_client.c
>>> +index 48607c2..4a30420 100644
>>> +--- a/pseudo_client.c
>>> ++++ b/pseudo_client.c
>>> +@@ -988,6 +988,8 @@ base_path(int dirfd, const char *path, int
>>> leave_last) {
>>> +               if (dirfd != -1&&    dirfd != AT_FDCWD) {
>>>
>>> +                       if (dirfd>= 0) {
>>> +                               basepath = fd_path(dirfd);
>>> ++                      }
>>> ++                      if (basepath) {
>>> +                               baselen = strlen(basepath);
>>> +                       } else {
>>> +                               pseudo_diag("got *at() syscall for unknown
>>> directory, fd %d\n", dirfd);
>>> +@@ -1128,7 +1130,10 @@ pseudo_client_op(pseudo_op_t op, int access, int
>>> fd, int dirfd, const char *path
>>> +       if (path) {
>>> +               pseudo_debug(2, " %s", path);
>>> +       }
>>> +-      if (fd != -1) {
>>> ++      /* for OP_RENAME in renameat, "fd" is also used for the
>>> ++       * second dirfd.
>>> ++       */
>>> ++      if (fd != -1&&    op != OP_RENAME) {
>>>
>>> +               pseudo_debug(2, " [fd %d]", fd);
>>> +       }
>>> +       if (buf) {
>>> diff --git a/meta/recipes-devtools/pseudo/pseudo_1.2.bb
>>> b/meta/recipes-devtools/pseudo/pseudo_1.2.bb
>>> index f2ebc22..04bcbce 100644
>>> --- a/meta/recipes-devtools/pseudo/pseudo_1.2.bb
>>> +++ b/meta/recipes-devtools/pseudo/pseudo_1.2.bb
>>> @@ -1,10 +1,12 @@
>>>   require pseudo.inc
>>>
>>> -PR = "r4"
>>> +PR = "r5"
>>>
>>>   SRC_URI =
>>> "http://www.yoctoproject.org/downloads/${BPN}/${BPN}-${PV}.tar.bz2 \
>>>              file://oe-config.patch \
>>> -           file://static_sqlite.patch"
>>> +           file://static_sqlite.patch \
>>> +           file://opendir.patch \
>>> +           file://renameat.patch"
>>>
>>>   SRC_URI[md5sum] = "a2819084bab7e991f06626d02cf55048"
>>>   SRC_URI[sha256sum] =
>>> "4749a22df687f44d24c26e97170d4781a1bd52d5ee092364a40877e4d96ff058"
>