The kernel implements readlink of /proc/pid/exe by getting the file from
the first executable VMA. Then the path to the file is reconstructed and
reported as the result.
Because of the VMA walk the code is slightly different on nommu systems.
This patch avoids separate /proc/pid/exe code on nommu systems. Instead of
walking the VMAs to find the first executable file-backed VMA we store a
reference to the exec'd file in the mm_struct.
That reference would prevent the filesystem holding the executable file
from being unmounted even after unmapping the VMAs. So we track the number
of VM_EXECUTABLE VMAs and drop the new reference when the last one is
unmapped. This avoids pinning the mounted filesystem.
[akpm@linux-foundation.org: improve comments]
[yamamoto@valinux.co.jp: fix dup_mmap]
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: David Howells <dhowells@redhat.com>
Cc:"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I have not yet seen anyone saying he has a reasonable use case for using
BINFMT_FLAT modular on his embedded device.
Considering that fs/binfmt_flat.c even lacks a MODULE_LICENSE() I really doubt
there is any, and this patch therefore makes BINFMT_FLAT a bool.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Bryan Wu <cooloney.lkml@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The warning issued by fs/binfmt_flat.c when the format handler is given a
non-FLAT and non-script executable is annoying to say the least when working
with FDPIC ELF objects. If you build a kernel that supports both FLAT and
FDPIC ELFs on no-mmu, every time you execute an FDPIC ELF, the kernel spits
out this message. While I understand a lot of newcomers to the no-mmu world
screw up generation of FLAT binaries, this warning is not usable for systems
that support more than just FLAT.
Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Bernd Schmidt <bernds_cb1@t-online.de>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix this lot:
fs/binfmt_flat.c: In function `decompress_exec':
fs/binfmt_flat.c:293: warning: label `out' defined but not used
fs/binfmt_flat.c: In function `load_flat_file':
fs/binfmt_flat.c:462: warning: unsigned int format, long int arg (arg 3)
fs/binfmt_flat.c:462: warning: unsigned int format, long int arg (arg 4)
fs/binfmt_flat.c:518: warning: comparison of distinct pointer types lacks a cast
fs/binfmt_flat.c:549: warning: passing arg 1 of `ksize' makes pointer from integer without a cast
fs/binfmt_flat.c:601: warning: passing arg 1 of `ksize' makes pointer from integer without a cast
fs/binfmt_flat.c: In function `load_flat_binary':
fs/binfmt_flat.c:116: warning: 'dummy' might be used uninitialized in this function
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For some time /proc/sys/kernel/core_pattern has been able to set its output
destination as a pipe, allowing a user space helper to receive and
intellegently process a core. This infrastructure however has some
shortcommings which can be enhanced. Specifically:
1) The coredump code in the kernel should ignore RLIMIT_CORE limitation
when core_pattern is a pipe, since file system resources are not being
consumed in this case, unless the user application wishes to save the core,
at which point the app is restricted by usual file system limits and
restrictions.
2) The core_pattern code should be able to parse and pass options to the
user space helper as an argv array. The real core limit of the uid of the
crashing proces should also be passable to the user space helper (since it
is overridden to zero when called).
3) Some miscellaneous bugs need to be cleaned up (specifically the
recognition of a recursive core dump, should the user mode helper itself
crash. Also, the core dump code in the kernel should not wait for the user
mode helper to exit, since the same context is responsible for writing to
the pipe, and a read of the pipe by the user mode helper will result in a
deadlock.
This patch:
Remove the check of RLIMIT_CORE if core_pattern is a pipe. In the event that
core_pattern is a pipe, the entire core will be fed to the user mode helper.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Cc: <martin.pitt@ubuntu.com>
Cc: <wwoods@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add minimum support for the Blackfin relocations, since we don't have
enough space in each reloc. The idea is to store a value with one
relocation so that subsequent ones can access it.
Actually, this patch is required for Blackfin. Currently if BINFMT_FLAT is
enabled, git-tree kernel will fail to compile.
Signed-off-by: Bernd Schmidt <bernd.schmidt@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Cc: David McCullough <davidm@snapgear.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Miles Bader <miles.bader@necel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Report the correct errno for out of memory debug output in binfmt_flat.c
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
remap() the region we get from mmap() to mark the fact that we are
using all of the available slack space. Any slack space is used
to form a simple brk region, and potentially more stack space than
requested at load time.
Any searches of the vma chain may well fail looking for
stack (and especially arg) addresses if the remaping is not done.
The simplest example is /proc/<pid>/cmdline, since the args
are pretty much always at the top of the data/bss/stack region.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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>
binfmt_flat.c calls set_personality with PER_LINUX as the personality.
On the arm architecture this results in the program running in 26bit
usermode. PER_LINUX_32BIT should be used instead. This doesn't affect
other architectures that use binfmt_flat.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Bernd Schmidt points out that binfmt_flat is now leaving the exec file open
while the application runs. This offsets all the application's fd numbers.
We should have closed the file within exec(), not at exit()-time.
But there doesn't seem to be a lot of point in doing all this just to avoid
going over RLIMIT_NOFILE by one fd for a few microseconds. So take the EMFILE
checking out again. This will cause binfmt_flat to again fail LTP's
exec-should-return-EMFILE-when-fdtable-is-full test. That test appears to be
wrong anyway - Open Group specs say nothing about exec() returning EMFILE.
Cc: Bernd Schmidt <bernd.schmidt@analog.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In binfmt_flat.c, the flat binary loader should check file descriptor table
and install the fd on the file.
Convert the function to single-exit and fix this bug.
Signed-off-by: "Luke Yang" <luke.adi@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Modify the initial trace output (which is based on flags in the binary
header) so that it is not done until after the magic number check. This
may well not be a flat format binary, so the flags could be invalid.
(Prime example, running a script).
Changes prompted by patches from Stuart Hughs.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
)
From: Adrian Bunk <bunk@stusta.de>
- create one common dump_thread() prototype in kernel.h
- dump_thread() is only used in fs/binfmt_aout.c and can therefore be
removed on all architectures where CONFIG_BINFMT_AOUT is not
available
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
How is anon_rss initialized? In dup_mmap, and by mm_alloc's memset; but
that's not so good if an mm_counter_t is a special type. And how is rss
initialized? By set_mm_counter, all over the place. Come on, we just need to
initialize them both at once by set_mm_counter in mm_init (which follows the
memcpy when forking).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use MAP_PRIVATE when calling mmap to get memory for the code region.
The flat loader was using MAP_SHARED, but underlying changes to the
MMUless mmap means this is now wrong.
Signed-off-by: Greg Ungerer <gerg@uclinux.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make sure that binfmt_flat passes the correct flags into do_mmap(). nommu's
validate_mmap_request() will simple return -EINVAL if we try and pass it a
flags value of zero.
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Matt Helsley
Adrian Bunk
Mike Frysinger
David Howells
Andrew Morton
Neil Horman
Bernd Schmidt
Greg Ungerer
Josef "Jeff" Sipek
Jörn Engel
Malcolm Parsons
Andrew Morton
Luke Yang
Hugh Dickins
Yoshinori Sato
Linus Torvalds