linux.git/kernel/ptrace.c, branch v2.6.17.10

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

[PATCH] fix zap_thread's ptrace related problems

2006-02-15T19:05:43+00:00

1. The tracee can go from ptrace_stop() to do_signal_stop()
   after __ptrace_unlink(p).

2. It is unsafe to __ptrace_unlink(p) while p->parent may wait
   for tasklist_lock in ptrace_detach().

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

[PATCH] compound page: no access_process_vm check

2006-02-15T00:09:33+00:00

The PageCompound check before access_process_vm's set_page_dirty_lock is no
longer necessary, so remove it.  But leave the PageCompound checks in
bio_set_pages_dirty, dio_bio_complete and nfs_free_user_pages: at least some
of those were introduced as a little optimization on hugetlb pages.

Signed-off-by: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] move capable() to capability.h

2006-01-12T02:42:13+00:00

- Move capable() from sched.h to capability.h;

- Use  where capable() is used
	(in include/, block/, ipc/, kernel/, a few drivers/,
	mm/, security/, & sound/;
	many more drivers/ to go)

Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] use ptrace_get_task_struct in various places

2006-01-09T04:13:51+00:00

The ptrace_get_task_struct() helper that I added as part of the ptrace
consolidation is useful in variety of places that currently opencode it.
Switch them to the common helpers.

Add a ptrace_traceme() helper that needs to be explicitly called, and simplify
the ptrace_get_task_struct() interface.  We don't need the request argument
now, and we return the task_struct directly, using ERR_PTR() for error
returns.  It's a bit more code in the callers, but we have two sane routines
that do one thing well now.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Fix crash when ptrace poking hugepage areas

2005-11-30T03:47:03+00:00

set_page_dirty() will not cope with being handed a page * which is part of
a compound page, but not the master page in that compound page.  This case
can occur via access_process_vm() if you attemp to write to another
process's hugepage memory area using ptrace() (causing an oops or hang).

This patch fixes the bug by only calling set_page_dirty() from
access_process_vm() if the page is not a compound page.  We already use a
similar fix in bio_set_pages_dirty() for the case of direct io to
hugepages.

Signed-off-by: David Gibson 
Acked-by: William Irwin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds