[RTEMS Project] #1394: scandir() fails due to MAXNAMELEN is incorrect

[RTEMS trac]

#1394: scandir() fails due to MAXNAMELEN is incorrect
--------------------+-----------------------
 Reporter:  daniel  |       Owner:  chrisj
     Type:  defect  |      Status:  assigned
 Priority:  normal  |   Milestone:  4.11
Component:  Newlib  |     Version:  4.10
 Severity:  normal  |  Resolution:
 Keywords:          |
--------------------+-----------------------

Old description:

> I have been trying to use scandir() however the newlib one does not work
> due to MAXNAMLEN and NAMLEN differ. scandir in libcsupport seems to have
> a fix for this, however my libcsupport_a-scandir.o is empty, I'm guessing
> because HAVE_SCANDIR is defined.
>
> It is used in scandir() (newlib-1.17.0/newlib/libc/posix/scandir.c:117)
> by the macro DIRSIZ. Where DIRSIZ uses the MAXNAMELEN define which is set
> incorrectly. It does not match the sizeof(struct dirent) which makes the
> DIRSIZ return a negative number, then malloc(DIRSIZ(d)) will try to
> allocate 4GB which fail.
>
> My guess is that MAXNAMELEN should be defined in
> newlib-1.17.0/newlib/libc/sys/rtems/sys/dirent.h or
> newlib-1.17.0/newlib/libc/sys/rtems/include/limits.h or in a new file.
>
> I tried to run the code below on my FAT filesystem, taken directly from
> the scandir(3) man page.
>
>       /* print files in current directory in reverse order */
>       #include <dirent.h>
>       main(){
>           struct dirent **namelist;
>           int n;
>
>           n = scandir(".", &namelist, 0, NULL);
>           if (n < 0)
>               perror("scandir");
>           else {
>               while(n--) {
>                   printf("%s\n", namelist[n]->d_name);
>                   free(namelist[n]);
>               }
>               free(namelist);
>           }
>       }

New description:

 I have been trying to use scandir() however the newlib one does not work
 due to MAXNAMLEN and NAMLEN differ. scandir in libcsupport seems to have a
 fix for this, however my libcsupport_a-scandir.o is empty, I'm guessing
 because HAVE_SCANDIR is defined.

 It is used in scandir() (newlib-1.17.0/newlib/libc/posix/scandir.c:117) by
 the macro DIRSIZ. Where DIRSIZ uses the MAXNAMELEN define which is set
 incorrectly. It does not match the sizeof(struct dirent) which makes the
 DIRSIZ return a negative number, then malloc(DIRSIZ(d)) will try to
 allocate 4GB which fail.

 My guess is that MAXNAMELEN should be defined in
 newlib-1.17.0/newlib/libc/sys/rtems/sys/dirent.h or
 newlib-1.17.0/newlib/libc/sys/rtems/include/limits.h or in a new file.

 I tried to run the code below on my FAT filesystem, taken directly from
 the scandir(3) man page.

       /* print files in current directory in reverse order */
       #include <dirent.h>
       main(){
           struct dirent **namelist;
           int n;

           n = scandir(".", &namelist, 0, NULL);
           if (n < 0)
               perror("scandir");
           else {
               while(n--) {
                   printf("%s\n", namelist[n]->d_name);
                   free(namelist[n]);
               }
               free(namelist);
           }
       }

--

Comment (by gedare):

 Attached patch should work but I haven't tested it yet.

--
Ticket URL: <http://devel.rtems.org/ticket/1394#comment:5>
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