fs/binfmt_elf.c: In function 'load_elf_binary':
fs/binfmt_elf.c:1002: warning: 'interp_map_addr' may be used uninitialized in this function
The compiler (gcc-4.1.0) is correct, but it failed to notice that we didn't
use the resulting value.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is using mmap()'s randomization functionality in such a way that
it maps the main executable of (specially compiled/linked -pie/-fpie)
ET_DYN binaries onto a random address (in cases in which mmap() is allowed
to perform a randomization).
Origin of this patch is in exec-shield
(http://people.redhat.com/mingo/exec-shield/)
[jkosina@suse.cz: pie randomization: fix BAD_ADDR macro]
Signed-off-by: Jan Kratochvil <honza@jikos.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
elf_core_dump() supports dumping arch specific ELF notes, via the #define
ELF_CORE_WRITE_EXTRA_NOTES. Currently the only user of this is the powerpc
spu coredump code.
There is a bug in the handling of foffset WRT the arch notes, which causes
us to erroneously increment foffset by the size of the arch notes, leaving
a block of zeroes in the file, and causing all subsequent data in the file
to be at <supposed position> + <arch note size>. eg:
LOAD 0x050000 0x00100000 0x00000000 0x20000 0x20000 R E 0x10000
Tells us we should have a chunk of data at 0x50000. The truth is the data
is at 0x90dbc = 0x50000 + 0x40dbc (the size of the arch notes).
This bug prevents gdb from reading the core file correctly.
The simplest fix is to simply remember the size of the arch notes, and add
it to foffset after we've written the arch notes. The only drawback is
that if the arch code doesn't write as many bytes as it said it would, we
end up with a broken core dump again. For now I think that's a reasonable
requirement.
Tested on a Cell blade, gdb no longer complains about the core file being
bogus.
While I'm here I should point out that the spu coredump code does not work
if we're dumping to a pipe - we'll have to wait for 23 to fix that.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When elf loader fails to map executable (due to memory shortage or because
binary is malformed), it can return 0. Normally, this is invisible because
process is killed with SIGKILL and it never returns to user space.
But if exec() is called from kernel thread (hotplug, whatever)
consequences are more interesting and vary depending on architecture.
i386. Nothing especially interesting, execve() just returns
with "success" :-)
x86_64. Fake zero frame is used on way to caller, RSP/RIP are loaded
with zeros, ergo... double fault.
ia64. Similar to i386, but r32...r95 are corrupted. Sometimes it
oopses due to return to zero PC, sometimes it sees NaT in
rXX and oopses due to NaT consumption.
Signed-off-by: Alexey Kuznetsov <alexey@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
linux/module.h
-> linux/elf.h
-> asm-i386/elf.h
-> linux/utsname.h
-> linux/sched.h
Noticeably cut the number of files which are rebuild upon touching sched.h
and cut down pulled junk from every module.h inclusion.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This bug was seen on ppc64, but it could have occurred on any
architecture with a page size of 64k or above. The problem is that in
fs/binfmt_elf.c:randomize_stack_top() randomizes the stack to within
0x7ff pages. On 4k page machines, this is 8MB; on 64k page boxes, this
is 128MB.
The problem is that the new binary layout (selected in
arch_pick_mmap_layout) places the mapping segment 128MB or the stack
rlimit away from the top of the process memory, whichever is larger. If
you chose an rlimit of less than 128MB (most defaults are in the 8Mb
range) then you can end up having your entire stack randomized away.
The fix is to make randomize_stack_top() only steal at most 8MB, which this
patch does. However, I have to point out that even with this, your stack
rlimit might not be exactly what you get if it's > 128MB, because you're
still losing the random offset of up to 8MB.
The true fix should be to leave an explicit gap for the randomization plus
a buffer when determining mmap_base, but that would involve fixing all the
architectures.
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes core dumps to include the vDSO vma, which is left out now.
It removes the special-case core writing macros, which were not doing the
right thing for the vDSO vma anyway. Instead, it uses VM_ALWAYSDUMP in the
vma; there is no need for the fixmap page to be installed. It handles the
CONFIG_COMPAT_VDSO case by making elf_core_dump use the fake vma from
get_gate_vma after real vmas in the same way the /proc/PID/maps code does.
This changes core dumps so they no longer include the non-PT_LOAD phdrs from
the vDSO. I made the change to add them in the first place, but in turned out
that nothing ever wanted them there since the advent of NT_AUXV. It's cleaner
to leave them out, and just let the phdrs inside the vDSO image speak for
themselves.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 59287c0913.
Hugh Dickins reports that it causes random failures on x86 with SuSE
10.2, and points out
"Isn't that randomization, anywhere from 0x10000 to ELF_ET_DYN_BASE,
sure to place the ET_DYN from time to time just where the comment
says it's trying to avoid? I assume that somehow results in the error
reported."
(where the comment in question is the existing comment in the source
code about mmap/brk clashes).
Suggested-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Marcus Meissner <meissner@suse.de>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Replace occurences of task->signal->session by a new process_session() helper
routine.
It will be useful for pid namespaces to abstract the session pid number.
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch changes struct file to use struct path instead of having
independent pointers to struct dentry and struct vfsmount, and converts all
users of f_{dentry,vfsmnt} in fs/ to use f_path.{dentry,mnt}.
Additionally, it adds two #define's to make the transition easier for users of
the f_dentry and f_vfsmnt.
Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Define elf_addr_t in linux/elf.h. The size of the type is determined using
ELF_CLASS. This allows us to remove the defines that today are spread all
over .c and .h files.
Signed-off-by: Magnus Damm <magnus@valinux.co.jp>
Cc: Daniel Jacobowitz <drow@false.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds SPU elf notes to the coredump. It creates a separate note
for each of /regs, /fpcr, /lslr, /decr, /decr_status, /mem, /signal1,
/signal1_type, /signal2, /signal2_type, /event_mask, /event_status,
/mbox_info, /ibox_info, /wbox_info, /dma_info, /proxydma_info, /object-id.
A new macro, ARCH_HAVE_EXTRA_NOTES, was created for architectures to
specify they have extra elf core notes.
A new macro, ELF_CORE_EXTRA_NOTES_SIZE, was created so the size of the
additional notes could be calculated and added to the notes phdr entry.
A new macro, ELF_CORE_WRITE_EXTRA_NOTES, was created so the new notes
would be written after the existing notes.
The SPU coredump code resides in spufs. Stub functions are provided in the
kernel which are hooked into the spufs code which does the actual work via
register_arch_coredump_calls().
A new set of __spufs_<file>_read/get() functions was provided to allow the
coredump code to read from the spufs files without having to lock the
SPU context for each file read from.
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Dwayne Grant McConnell <decimal@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
It is silly to use non-static variable for writting zeroes to the file.
And more seriously, foffset in core dump file dump function was incremented
too much, so some parts of core dump were shifted by size of few phdrs and
notes down, so although gdb was able to load that file, it did not make lot
of sense - in my test case data pages were shifted down by about 900 bytes.
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The file based core dump code was broken by pipe changes - a relative
llseek returns the absolute file position on success, not the relative
one, so dump_seek() always failed when invoked with non-zero current
position.
Only success/failure can be tested with relative lseek, we have to trust
kernel that on success we've got right file offset. With this fix in
place I have finally real core files instead of 1KB fragments...
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
[ Cleaned it up a bit while here - use SEEK_CUR instead of hardcoding 1 ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Using the infrastructure created in previous patches implement support to
pipe core dumps into programs.
This is done by overloading the existing core_pattern sysctl
with a new syntax:
|program
When the first character of the pattern is a '|' the kernel will instead
threat the rest of the pattern as a command to run. The core dump will be
written to the standard input of that program instead of to a file.
This is useful for having automatic core dump analysis without filling up
disks. The program can do some simple analysis and save only a summary of
the core dump.
The core dump proces will run with the privileges and in the name space of
the process that caused the core dump.
I also increased the core pattern size to 128 bytes so that longer command
lines fit.
Most of the changes comes from allowing core dumps without seeks. They are
fairly straight forward though.
One small incompatibility is that if someone had a core pattern previously
that started with '|' they will get suddenly new behaviour. I think that's
unlikely to be a real problem though.
Additional background:
> Very nice, do you happen to have a program that can accept this kind of
> input for crash dumps? I'm guessing that the embedded people will
> really want this functionality.
I had a cheesy demo/prototype. Basically it wrote the dump to a file again,
ran gdb on it to get a backtrace and wrote the summary to a shared directory.
Then there was a simple CGI script to generate a "top 10" crashes HTML
listing.
Unfortunately this still had the disadvantage to needing full disk space for a
dump except for deleting it afterwards (in fact it was worse because over the
pipe holes didn't work so if you have a holey address map it would require
more space).
Fortunately gdb seems to be happy to handle /proc/pid/fd/xxx input pipes as
cores (at least it worked with zsh's =(cat core) syntax), so it would be
likely possible to do it without temporary space with a simple wrapper that
calls it in the right way. I ran out of time before doing that though.
The demo prototype scripts weren't very good. If there is really interest I
can dig them out (they are currently on a laptop disk on the desk with the
laptop itself being in service), but I would recommend to rewrite them for any
serious application of this and fix the disk space problem.
Also to be really useful it should probably find a way to automatically fetch
the debuginfos (I cheated and just installed them in advance). If nobody else
does it I can probably do the rewrite myself again at some point.
My hope at some point was that desktops would support it in their builtin
crash reporters, but at least the KDE people I talked too seemed to be happy
with their user space only solution.
Alan sayeth:
I don't believe that piping as such as neccessarily the right model, but
the ability to intercept and processes core dumps from user space is asked
for by many enterprise users as well. They want to know about, capture,
analyse and process core dumps, often centrally and in automated form.
[akpm@osdl.org: loff_t != unsigned long]
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Create a new header file, fs/internal.h, for common definitions local to the
sources in the fs/ directory.
Move extern definitions that should be in header files from fs/*.c to
fs/internal.h or other main header files where they span directories.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
do_each_thread() is rcu-safe, and all tasks which use this ->mm must sleep
in wait_for_completion(&mm->core_done) at this point, so we can use RCU
locks.
Also, remove unneeded INIT_LIST_HEAD(new) before list_add(new, head).
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Andrew Morton
Jan Kratochvil
Michael Ellerman
Alexey Kuznetsov
Alexey Dobriyan
Randy Dunlap
Brian Pomerantz
James Bottomley
Andi Kleen
Alexey Dobriyan
Roland McGrath
Linus Torvalds
Cedric Le Goater
Josef "Jeff" Sipek
David Rientjes
Magnus Damm
Heiko Carstens
Marcus Meissner
Dwayne Grant McConnell
Petr Vandrovec
David Howells
Oleg Nesterov