linux-kernel - Re: Core file size?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <236282.74568.qm@web56515.mail.re3.yahoo.com>
Date:	Fri, 1 Dec 2006 07:47:34 -0800 (PST)
From:	linux err <linux_err@...oo.com>
To:	linux-kernel@...r.kernel.org
Subject: Re: Core file size?

This patch fixed it.

http://lkml.org/lkml/2005/6/13/204

The ELF core dump code has one use of off_t when
writing out segments.  Some
of the segments may be passed the 2GB limit of an
off_t, even on a 32-bit
system, so it's important to use loff_t instead.  This
fixes a corrupted
core dump in the bigcore test in GDB's testsuite.

Signed-off-by: Daniel Jacobowitz
<dan@...esourcery.com>

Index: linux-2.6.11/fs/binfmt_elf.c
===================================================================
--- linux-2.6.11.orig/fs/binfmt_elf.c	2005-06-09
16:38:17.000000000 -0400
+++ linux-2.6.11/fs/binfmt_elf.c	2005-06-10
00:10:52.000000000 -0400
@@ -1125,7 +1125,7 @@ static int dump_write(struct
file *file,
 	return file->f_op->write(file, addr, nr,
&file->f_pos) == nr;
 }
 
-static int dump_seek(struct file *file, off_t off)
+static int dump_seek(struct file *file, loff_t off)
 {
 	if (file->f_op->llseek) {
 		if (file->f_op->llseek(file, off, 0) != off)
-- 




--- Jesper Juhl <jesper.juhl@...il.com> wrote:

> On 30/11/06, linux err <linux_err@...oo.com> wrote:
> > Does anyone know what determines the size of a
> core
> > dump? I have a process running out of memory (it
> > allocates about 3GB) - but the size of core varies
> > (between 2-3GB) depending on how much the process
> > wrote on the allocated memory.
> >
> 
> Makes perfect sense. The core dump contains the
> memory of the process,
> so if the process has 3GB in use then the core file
> will be 3GB.
> 
> You can limit the size of core dumps with "ulimit
> -c"
> 
> 
> > Also, the time it takes to write the core (same
> size)
> > varies??
> >
> Could be many reasons for that. If the load on the
> machine varies the
> time to perform any given action will vary as well.
> 
> 
> > I briefly looked at elf_core_dump and
> get_user_pages()
> > in binfmt_elf.c. Is there any documentation on
> this?
> > Or anyone knows how it works?
> >
> http://x86.ddj.com/ftp/manuals/tools/elf.pdf
> http://en.wikipedia.org/wiki/Core_dump
> 
> 
> -- 
> Jesper Juhl <jesper.juhl@...il.com>
> Don't top-post 
> http://www.catb.org/~esr/jargon/html/T/top-post.html
> Plain text mails only, please     
> http://www.expita.com/nomime.html
> -
> To unsubscribe from this list: send the line
> "unsubscribe linux-kernel" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at 
> http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 



 
____________________________________________________________________________________
Do you Yahoo!?
Everyone is raving about the all-new Yahoo! Mail beta.
http://new.mail.yahoo.com
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/