linux-toradex.git/kernel/ptrace.c, branch v2.6.20.17

[PATCH] pidspace: is_init()

2006-09-29T16:18:12+00:00

This is an updated version of Eric Biederman's is_init() patch.
(http://lkml.org/lkml/2006/2/6/280).  It applies cleanly to 2.6.18-rc3 and
replaces a few more instances of ->pid == 1 with is_init().

Further, is_init() checks pid and thus removes dependency on Eric's other
patches for now.

Eric's original description:

	There are a lot of places in the kernel where we test for init
	because we give it special properties.  Most  significantly init
	must not die.  This results in code all over the kernel test
	->pid == 1.

	Introduce is_init to capture this case.

	With multiple pid spaces for all of the cases affected we are
	looking for only the first process on the system, not some other
	process that has pid == 1.

Signed-off-by: Eric W. Biederman 
Signed-off-by: Sukadev Bhattiprolu 
Cc: Dave Hansen 
Cc: Serge Hallyn 
Cc: Cedric Le Goater 
Cc: 
Acked-by: Paul Mackerras 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] NOMMU: Check that access_process_vm() has a valid target

2006-09-27T15:26:14+00:00

Check that access_process_vm() is accessing a valid mapping in the target
process.

This limits ptrace() accesses and accesses through /proc//maps to only
those regions actually mapped by a program.

Signed-off-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] sched: cleanup, remove task_t, convert to struct task_struct

2006-07-03T22:27:11+00:00

cleanup: remove task_t and convert all the uses to struct task_struct. I
introduced it for the scheduler anno and it was a mistake.

Conversion was mostly scripted, the result was reviewed and all
secondary whitespace and style impact (if any) was fixed up by hand.

Signed-off-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] coredump: kill ptrace related stuff

2006-06-26T16:58:27+00:00

With this patch zap_process() sets SIGNAL_GROUP_EXIT while sending SIGKILL to
the thread group.  This means that a TASK_TRACED task

	1. Will be awakened by signal_wake_up(1)

	2. Can't sleep again via ptrace_notify()

	3. Can't go to do_signal_stop() after return
	   from ptrace_stop() in get_signal_to_deliver()

So we can remove all ptrace related stuff from coredump path.

Signed-off-by: Oleg Nesterov 
Cc: "Eric W. Biederman" 
Cc: Roland McGrath 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] proc: Cleanup proc_fd_access_allowed

2006-06-26T16:58:26+00:00

In process of getting proc_fd_access_allowed to work it has developed a few
warts.  In particular the special case that always allows introspection and
the special case to allow inspection of kernel threads.

The special case for introspection is needed for /proc/self/mem.

The special case for kernel threads really should be overridable
by security modules.

So consolidate these checks into ptrace.c:may_attach().

The check to always allow introspection is trivial.

The check to allow access to kernel threads, and zombies is a little
trickier.  mem_read and mem_write already verify an mm exists so it isn't
needed twice.  proc_fd_access_allowed only doesn't want a check to verify
task->mm exits, s it prevents all access to kernel threads.  So just move
the task->mm check into ptrace_attach where it is needed for practical
reasons.

I did a quick audit and none of the security modules in the kernel seem to
care if they are passed a task without an mm into security_ptrace.  So the
above move should be safe and it allows security modules to come up with
more restrictive policy.

Signed-off-by: Eric W. Biederman 
Cc: Stephen Smalley 
Cc: Chris Wright 
Cc: James Morris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ptrace_attach: fix possible deadlock schenario with irqs

2006-05-11T18:08:49+00:00

Eric Biederman points out that we can't take the task_lock while holding
tasklist_lock for writing, because another CPU that holds the task lock
might take an interrupt that then tries to take tasklist_lock for writing.

Which would be a nasty deadlock, with one CPU spinning forever in an
interrupt handler (although admittedly you need to really work at
triggering it ;)

Since the ptrace_attach() code is special and very unusual, just make it
be extra careful, and use trylock+repeat to avoid the possible deadlock.

Cc: Oleg Nesterov 
Cc: Eric W. Biederman 
Cc: Roland McGrath 
Signed-off-by: Linus Torvalds

Fix ptrace_attach()/ptrace_traceme()/de_thread() race

2006-05-07T17:49:33+00:00

This holds the task lock (and, for ptrace_attach, the tasklist_lock)
over the actual attach event, which closes a race between attacking to a
thread that is either doing a PTRACE_TRACEME or getting de-threaded.

Thanks to Oleg Nesterov for reminding me about this, and Chris Wright
for noticing a lost return value in my first version.

Signed-off-by: Linus Torvalds

[PATCH] fix non-leader exec under ptrace

2006-04-14T15:59:13+00:00

This reverts most of commit 30e0fca6c1d7d26f3f2daa4dd2b12c51dadc778a.
It broke the case of non-leader MT exec when ptraced.
I think the bug it was intended to fix was already addressed by commit
788e05a67c343fa22f2ae1d3ca264e7f15c25eaf.

Signed-off-by: Roland McGrath 
Acked-by: Oleg Nesterov 
Signed-off-by: Linus Torvalds

BUG_ON() Conversion in kernel/ptrace.c

2006-04-02T11:43:40+00:00

this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn 
Signed-off-by: Adrian Bunk

[PATCH] don't use REMOVE_LINKS/SET_LINKS for reparenting

2006-03-29T02:36:41+00:00

There are places where kernel uses REMOVE_LINKS/SET_LINKS while changing
process's ->parent.  Use add_parent/remove_parent instead, they don't abuse
of global process list.

Signed-off-by: Oleg Nesterov 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds