linux-toradex.git/fs/exec.c, branch v3.10.2

perf: Disable monitoring on setuid processes for regular users

2013-06-26T09:40:18+00:00

There was a a bug in setup_new_exec(), whereby
the test to disabled perf monitoring was not
correct because the new credentials for the
process were not yet committed and therefore
the get_dumpable() test was never firing.

The patch fixes the problem by moving the
perf_event test until after the credentials
are committed.

Signed-off-by: Stephane Eranian 
Tested-by: Jiri Olsa 
Acked-by: Peter Zijlstra 
Cc: 
Signed-off-by: Ingo Molnar

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2013-05-02T00:51:54+00:00

Pull VFS updates from Al Viro,

Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).

7kloc removed.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
  don't bother with deferred freeing of fdtables
  proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
  proc: Make the PROC_I() and PDE() macros internal to procfs
  proc: Supply a function to remove a proc entry by PDE
  take cgroup_open() and cpuset_open() to fs/proc/base.c
  ppc: Clean up scanlog
  ppc: Clean up rtas_flash driver somewhat
  hostap: proc: Use remove_proc_subtree()
  drm: proc: Use remove_proc_subtree()
  drm: proc: Use minor->index to label things, not PDE->name
  drm: Constify drm_proc_list[]
  zoran: Don't print proc_dir_entry data in debug
  reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
  proc: Supply an accessor for getting the data from a PDE's parent
  airo: Use remove_proc_subtree()
  rtl8192u: Don't need to save device proc dir PDE
  rtl8187se: Use a dir under /proc/net/r8180/
  proc: Add proc_mkdir_data()
  proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
  proc: Move PDE_NET() to fs/proc/proc_net.c
  ...

exec: do not abuse ->cred_guard_mutex in threadgroup_lock()

2013-05-01T00:04:07+00:00

threadgroup_lock() takes signal->cred_guard_mutex to ensure that
thread_group_leader() is stable.  This doesn't look nice, the scope of
this lock in do_execve() is huge.

And as Dave pointed out this can lead to deadlock, we have the
following dependencies:

	do_execve:		cred_guard_mutex -> i_mutex
	cgroup_mount:		i_mutex -> cgroup_mutex
	attach_task_by_pid:	cgroup_mutex -> cred_guard_mutex

Change de_thread() to take threadgroup_change_begin() around the
switch-the-leader code and change threadgroup_lock() to avoid
->cred_guard_mutex.

Note that de_thread() can't sleep with ->group_rwsem held, this can
obviously deadlock with the exiting leader if the writer is active, so it
does threadgroup_change_end() before schedule().

Reported-by: Dave Jones 
Acked-by: Tejun Heo 
Acked-by: Li Zefan 
Signed-off-by: Oleg Nesterov 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

set_task_comm: kill the pointless memset() + wmb()

2013-05-01T00:04:07+00:00

set_task_comm() does memset() + wmb() before strlcpy().  This buys
nothing and to add to the confusion, the comment is wrong.

- We do not need memset() to be "safe from non-terminating string
  reads", the final char is always zero and we never change it.

- wmb() is paired with nothing, it cannot prevent from printing
  the mixture of the old/new data unless the reader takes the lock.

Signed-off-by: Oleg Nesterov 
Cc: Andi Kleen 
Cc: John Stultz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: allow arch code to control the user page table ceiling

2013-04-29T22:54:34+00:00

On architectures where a pgd entry may be shared between user and kernel
(e.g.  ARM+LPAE), freeing page tables needs a ceiling other than 0.
This patch introduces a generic USER_PGTABLES_CEILING that arch code can
override.  It is the responsibility of the arch code setting the ceiling
to ensure the complete freeing of the page tables (usually in
pgd_free()).

[catalin.marinas@arm.com: commit log; shift_arg_pages(), asm-generic/pgtables.h changes]
Signed-off-by: Hugh Dickins 
Signed-off-by: Catalin Marinas 
Cc: Russell King 
Cc: 	[3.3+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

new helper: read_code()

2013-04-29T19:40:23+00:00

switch binfmts that use ->read() to that (and to kernel_read()
in several cases in binfmt_flat - sure, it's nommu, but still,
doing ->read() into kmalloc'ed buffer...)

Signed-off-by: Al Viro

coredump: remove redundant defines for dumpable states

2013-02-28T03:10:11+00:00

The existing SUID_DUMP_* defines duplicate the newer SUID_DUMPABLE_*
defines introduced in 54b501992dd2 ("coredump: warn about unsafe
suid_dumpable / core_pattern combo").  Remove the new ones, and use the
prior values instead.

Signed-off-by: Kees Cook 
Reported-by: Chen Gang 
Cc: Alexander Viro 
Cc: Alan Cox 
Cc: "Eric W. Biederman" 
Cc: Doug Ledford 
Cc: Serge Hallyn 
Cc: James Morris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs/exec.c: make bprm_mm_init() static

2013-02-26T07:46:13+00:00

There is only one user of bprm_mm_init, and it's inside the same file.

Signed-off-by: Yuanhan Liu 
Signed-off-by: Andrew Morton 
Signed-off-by: Al Viro

new helper: file_inode(file)

2013-02-23T04:31:31+00:00

Signed-off-by: Al Viro

fs/exec.c: work around icc miscompilation

2013-01-11T22:54:55+00:00

The tricky problem is this check:

	if (i++ >= max)

icc (mis)optimizes this check as:

	if (++i > max)

The check now becomes a no-op since max is MAX_ARG_STRINGS (0x7FFFFFFF).

This is "allowed" by the C standard, assuming i++ never overflows,
because signed integer overflow is undefined behavior.  This
optimization effectively reverts the previous commit 362e6663ef23
("exec.c, compat.c: fix count(), compat_count() bounds checking") that
tries to fix the check.

This patch simply moves ++ after the check.

Signed-off-by: Xi Wang 
Cc: Jason Baron 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds