Re: 2.6.11-rc3: Kylix application no longer works?

[Pavel Machek <pavel@ucw.cz>]

Hi!

> > > > I wonder if reverting the patch will restore the old behaviour?
> > > 
> > > This seems to be minimal fix to get Kylix application back to the
> > > working state... Maybe it is good idea for 2.6.11?
> > > 
> > > Signed-off-by: Pavel Machek <pavel@suse.cz>
> > > 								Pavel
> > > 
> > > --- clean/fs/binfmt_elf.c	2005-02-03 22:27:19.000000000 +0100
> > > +++ linux/fs/binfmt_elf.c	2005-02-08 18:46:38.000000000 +0100
> > > @@ -803,11 +803,8 @@
> > >  				nbyte = ELF_MIN_ALIGN - nbyte;
> > >  				if (nbyte > elf_brk - elf_bss)
> > >  					nbyte = elf_brk - elf_bss;
> > > -				if (clear_user((void __user *) elf_bss + load_bias, nbyte)) {
> > > -					retval = -EFAULT;
> > > -					send_sig(SIGKILL, current, 0);
> > > -					goto out_free_dentry;
> > > -				}
> > > +				if (clear_user((void __user *) elf_bss + load_bias, nbyte))
> > > +					printk(KERN_ERR "Error clearing BSS, wrong ELF executable? (Kylix?!)\n");
> > 
> > do once or rate limit rather than log spamming.
> 
> We could just remove the printk and stick a comment over it.  If the
> application later tries to access the not-there pages then it'll just
> fault.
> 
> However I worry if there is some way in which we can leave unzeroed memory
> accessible to the application, although it's hard to see how that could
> happen.
> 
> Daniel, Pavel cruelly chopped you off the Cc when replying.  What's your
> diagnosis on the below?

Not me, my mailer did it :-). No, don't know what went wrong, and I
forwarded the message to Daniel; his reaction was:

>
> Elf file type is EXEC (Executable file)
> Entry point 0x80614b4
> There are 5 program headers, starting at offset 52
>
> Program Headers:
>   Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg
>Align
>   PHDR           0x000034 0x08048034 0x08048034 0x000a0 0x000a0 R E
>0x4
>   INTERP         0x0000d4 0x080480d4 0x080480d4 0x00013 0x00013 R
>0x1
>       [Requesting program interpreter: /lib/ld-linux.so.2]
>   LOAD           0x000000 0x08048000 0x08048000 0xb7354 0x1b7354 R E
>0x1000
>   LOAD           0x0b7354 0x08200354 0x08200354 0x1e3e4 0x1f648 RW
>0x1000
>   DYNAMIC        0x0d56a0 0x0821e6a0 0x0821e6a0 0x00098 0x00098 RW
>0x4

Looks fine but it's probably the first load segment: that's a megabyte
of blank space at the end...

that's all I can see.

								Pavel

-- 
People were complaining that M$ turns users into beta-testers...
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