linux.git/fs/binfmt_elf.c, branch v2.6.35

coredump: pass mm->flags as a coredump parameter for consistency

2010-03-06T19:26:46+00:00

Pass mm->flags as a coredump parameter for consistency.

 ---
1787         if (mm->core_state || !get_dumpable(mm)) {  <- (1)
1788                 up_write(&mm->mmap_sem);
1789                 put_cred(cred);
1790                 goto fail;
1791         }
1792
[...]
1798         if (get_dumpable(mm) == 2) {    /* Setuid core dump mode */ <-(2)
1799                 flag = O_EXCL;          /* Stop rewrite attacks */
1800                 cred->fsuid = 0;        /* Dump root private */
1801         }
 ---

Since dumpable bits are not protected by lock, there is a chance to change
these bits between (1) and (2).

To solve this issue, this patch copies mm->flags to
coredump_params.mm_flags at the beginning of do_coredump() and uses it
instead of get_dumpable() while dumping core.

This copy is also passed to binfmt->core_dump, since elf*_core_dump() uses
dump_filter bits in mm->flags.

[akpm@linux-foundation.org: fix merge]
Signed-off-by: Masami Hiramatsu 
Acked-by: Roland McGrath 
Cc: Hidehiro Kawai 
Cc: Oleg Nesterov 
Cc: Ingo Molnar 
Reviewed-by: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

elf coredump: add extended numbering support

2010-03-06T19:26:46+00:00

The current ELF dumper implementation can produce broken corefiles if
program headers exceed 65535.  This number is determined by the number of
vmas which the process have.  In particular, some extreme programs may use
more than 65535 vmas.  (If you google max_map_count, you can find some
users facing this problem.) This kind of program never be able to generate
correct coredumps.

This patch implements ``extended numbering'' that uses sh_info field of
the first section header instead of e_phnum field in order to represent
upto 4294967295 vmas.

This is supported by
AMD64-ABI(http://www.x86-64.org/documentation.html) and
Solaris(http://docs.sun.com/app/docs/doc/817-1984/).
Of course, we are preparing patches for gdb and binutils.

Signed-off-by: Daisuke HATAYAMA 
Cc: "Luck, Tony" 
Cc: Jeff Dike 
Cc: David Howells 
Cc: Greg Ungerer 
Cc: Roland McGrath 
Cc: Oleg Nesterov 
Cc: Ingo Molnar 
Cc: Alexander Viro 
Cc: Andi Kleen 
Cc: Alan Cox 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

elf coredump: make offset calculation process and writing process explicit

2010-03-06T19:26:46+00:00

By the next patch, elf_core_dump() and elf_fdpic_core_dump() will support
extended numbering and so will produce the corefiles with section header
table in a special case.

The problem is the process of writing a file header offset of the section
header table into e_shoff field of the ELF header.  ELF header is
positioned at the beginning of the corefile, while section header at the
end.  So, we need to take which of the following ways:

 1. Seek backward to retry writing operation for ELF header
    after writing process for a whole part

 2. Make offset calculation process and writing process
    totally sequential

The clause 1.  is not always possible: one cannot assume that file system
supports seek function.  Consider the no_llseek case.

Therefore, this patch adopts the clause 2.

Signed-off-by: Daisuke HATAYAMA 
Cc: "Luck, Tony" 
Cc: Jeff Dike 
Cc: David Howells 
Cc: Greg Ungerer 
Cc: Roland McGrath 
Cc: Oleg Nesterov 
Cc: Ingo Molnar 
Cc: Alexander Viro 
Cc: Andi Kleen 
Cc: Alan Cox 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

elf coredump: replace ELF_CORE_EXTRA_* macros by functions

2010-03-06T19:26:45+00:00

elf_core_dump() and elf_fdpic_core_dump() use #ifdef and the corresponding
macro for hiding _multiline_ logics in functions.  This patch removes
#ifdef and replaces ELF_CORE_EXTRA_* by corresponding functions.  For
architectures not implemeonting ELF_CORE_EXTRA_*, we use weak functions in
order to reduce a range of modification.

This cleanup is for my next patches, but I think this cleanup itself is
worth doing regardless of my firnal purpose.

Signed-off-by: Daisuke HATAYAMA 
Cc: "Luck, Tony" 
Cc: Jeff Dike 
Cc: David Howells 
Cc: Greg Ungerer 
Cc: Roland McGrath 
Cc: Oleg Nesterov 
Cc: Ingo Molnar 
Cc: Alexander Viro 
Cc: Andi Kleen 
Cc: Alan Cox 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

coredump: move dump_write() and dump_seek() into a header file

2010-03-06T19:26:45+00:00

My next patch will replace ELF_CORE_EXTRA_* macros by functions, putting
them into other newly created *.c files.  Then, each files will contain
dump_write(), where each pair of binfmt_*.c and elfcore.c should be the
same.  So, this patch moves them into a header file with dump_seek().
Also, the patch deletes confusing DUMP_WRITE macros in each files.

Signed-off-by: Daisuke HATAYAMA 
Cc: "Luck, Tony" 
Cc: Jeff Dike 
Cc: David Howells 
Cc: Greg Ungerer 
Cc: Roland McGrath 
Cc: Oleg Nesterov 
Cc: Ingo Molnar 
Cc: Alexander Viro 
Cc: Andi Kleen 
Cc: Alan Cox 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Split 'flush_old_exec' into two functions

2010-01-29T16:22:01+00:00

'flush_old_exec()' is the point of no return when doing an execve(), and
it is pretty badly misnamed.  It doesn't just flush the old executable
environment, it also starts up the new one.

Which is very inconvenient for things like setting up the new
personality, because we want the new personality to affect the starting
of the new environment, but at the same time we do _not_ want the new
personality to take effect if flushing the old one fails.

As a result, the x86-64 '32-bit' personality is actually done using this
insane "I'm going to change the ABI, but I haven't done it yet" bit
(TIF_ABI_PENDING), with SET_PERSONALITY() not actually setting the
personality, but just the "pending" bit, so that "flush_thread()" can do
the actual personality magic.

This patch in no way changes any of that insanity, but it does split the
'flush_old_exec()' function up into a preparatory part that can fail
(still called flush_old_exec()), and a new part that will actually set
up the new exec environment (setup_new_exec()).  All callers are changed
to trivially comply with the new world order.

Signed-off-by: H. Peter Anvin 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds

mm: introduce coredump parameter structure

2009-12-17T23:45:31+00:00

Introduce coredump parameter data structure (struct coredump_params) to
simplify binfmt->core_dump() arguments.

Signed-off-by: Masami Hiramatsu 
Suggested-by: Ingo Molnar 
Cc: Hidehiro Kawai 
Cc: Oleg Nesterov 
Cc: Roland McGrath 
Cc: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

elf: kill USE_ELF_CORE_DUMP

2009-12-16T15:20:12+00:00

Currently all architectures but microblaze unconditionally define
USE_ELF_CORE_DUMP.  The microblaze omission seems like an error to me, so
let's kill this ifdef and make sure we are the same everywhere.

Signed-off-by: Christoph Hellwig 
Acked-by: Hugh Dickins 
Cc: 
Cc: Michal Simek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tree-wide: fix assorted typos all over the place

2009-12-04T14:39:55+00:00

That is "success", "unknown", "through", "performance", "[re|un]mapping"
, "access", "default", "reasonable", "[con]currently", "temperature"
, "channel", "[un]used", "application", "example","hierarchy", "therefore"
, "[over|under]flow", "contiguous", "threshold", "enough" and others.

Signed-off-by: André Goddard Rosa 
Signed-off-by: Jiri Kosina

elf: clean up fill_note_info()

2009-09-24T14:21:01+00:00

Introduce a helper function elf_note_info_init() to help fill_note_info()
to do initializations, also fix the potential memory leaks.

[akpm@linux-foundation.org: remove NUM_NOTES]
Signed-off-by: WANG Cong 
Cc: Alexander Viro 
Cc: David Howells 
Cc: Roland McGrath 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds