Bug#200619: gcc: parisc: compiling dietlibc-dev with -Os causes segfault

[Matthias Klose <doko@cs.tu-berlin.de>]

[CC to jda]

Please can you recheck with a current gcc snapshot (from the
gcc-snapshot package) and attach the preprocessed source?


Gerrit Pape writes:
> Package: gcc
> 
> This applies to gcc_3.2.3-6 and gcc_3.3.1-0pre0 on hppa; gcc_3.0.4-16
> doesn't have this problem.
> 
> The dietlibc_0.22-2 builds with -Os by default on hppa, and this test
> program linked against the dietlibc dies with a segfault after fopen():
> 
> #include <stdio.h>
> int main() {
>   FILE *f;
>   fopen("foo", "a");
>   fclose(f);
>   return(0);
> }
> 
> If the dietlibc is built without -Os, the program works fine.
> 
> The bug is triggered by the following changes in
> dietlibc/libstdio/fdglue2.c (I attach fdglue2.c for reference):
> 
> diff -u -r1.10 -r1.11
> --- libstdio/fdglue2.c  9 Feb 2002 00:45:18 -0000       1.10
> +++ libstdio/fdglue2.c  4 Dec 2002 18:32:33 -0000       1.11
> @@ -1,5 +1,6 @@
>  #include <unistd.h>
>  #include <fcntl.h>
> +#include <sys/stat.h>
>  #include <errno.h>
>  #include "dietstdio.h"
>  #include <stdlib.h>
> @@ -23,7 +24,12 @@
>    tmp->bm=0;
>    tmp->bs=0;
>    tmp->buflen=BUFSIZE;
> -  tmp->flags=0;
> +  {
> +    struct stat st;
> +    fstat(fd,&st);
> +    tmp->flags=(S_ISFIFO(st.st_mode))?FDPIPE:0;
> +  }
> +  tmp->popen_kludge=0;
>    if (__stdio_atexit==0) {
>      __stdio_atexit=1;
>      atexit(__stdio_flushall);
>   
> The dietlibc compiled with revision 1.10 doesn't segfault, revision 1.11
> does.
> 
> The code changes look fine to me, and it works on other architectures,
> so I suppose it's a problem with gcc version >=3.2 on hppa optimizing
> the code.
> 
> I've a complete test environment on paer, and did run this through gdb
> several times.  If you need more details, just ask for it, I should be
> able to provide them.
> 
> Regards, Gerrit.
> #include <unistd.h>
> #include <fcntl.h>
> #include <sys/stat.h>
> #include <errno.h>
> #include "dietstdio.h"
> #include <stdlib.h>
> #include <pthread.h>
> 
> extern int __stdio_atexit;
> 
> FILE* __stdio_init_file_nothreads(int fd,int closeonerror);
> FILE* __stdio_init_file_nothreads(int fd,int closeonerror) {
>   FILE *tmp=(FILE*)malloc(sizeof(FILE));
>   if (!tmp) goto err_out;
>   tmp->buf=(char*)malloc(BUFSIZE);
>   if (!tmp->buf) {
>     free(tmp);
> err_out:
>     if (closeonerror) close(fd);
>     errno=ENOMEM;
>     return 0;
>   }
>   tmp->fd=fd;
>   tmp->bm=0;
>   tmp->bs=0;
>   tmp->buflen=BUFSIZE;
>   {
>     struct stat st;
>     fstat(fd,&st);
>     tmp->flags=(S_ISFIFO(st.st_mode))?FDPIPE:0;
>   }
>   tmp->popen_kludge=0;
>   if (__stdio_atexit==0) {
>     __stdio_atexit=1;
>     atexit(__stdio_flushall);
>   }
>   tmp->next=__stdio_root;
>   __stdio_root=tmp;
>   tmp->ungotten=0;
>   return tmp;
> }
> 
> FILE* __stdio_init_file(int fd,int closeonerror) __attribute__((weak,alias("__stdio_init_file_nothreads")));