linux-stable.git/kernel/kprobes.c, branch linux-2.6.24.y

kprobes: support kretprobe blacklist

2007-10-16T16:43:10+00:00

Introduce architecture dependent kretprobe blacklists to prohibit users
from inserting return probes on the function in which kprobes can be
inserted but kretprobes can not.

This patch also removes "__kprobes" mark from "__switch_to" on x86_64 and
registers "__switch_to" to the blacklist on x86-64, because that mark is to
prohibit user from inserting only kretprobe.

Signed-off-by: Masami Hiramatsu 
Cc: Prasanna S Panchamukhi 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

x86: optimize page faults like all other achitectures and kill notifier cruft

2007-10-16T16:42:50+00:00

x86(-64) are the last architectures still using the page fault notifier
cruft for the kprobes page fault hook.  This patch converts them to the
proper direct calls, and removes the now unused pagefault notifier bits
aswell as the cruft in kprobes.c that was related to this mess.

I know Andi didn't really like this, but all other architecture maintainers
agreed the direct calls are much better and besides the obvious cruft
removal a common way of dealing with kprobes across architectures is
important aswell.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix sparc64]
Signed-off-by: Christoph Hellwig 
Cc: Andi Kleen 
Cc: 
Cc: Prasanna S Panchamukhi 
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fix compilation with gcc 4.2

2007-08-11T22:47:42+00:00

gcc-4.2 is a lot more picky about its symbol handling.  EXPORT_SYMBOL no
longer works on symbols that are undefined or defined with static scope.

For example, with CONFIG_PROFILE off, I see:

  kernel/profile.c:206: error: __ksymtab_profile_event_unregister causes a section type conflict
  kernel/profile.c:205: error: __ksymtab_profile_event_register causes a section type conflict

This patch moves the EXPORTs inside the #ifdef CONFIG_PROFILE, so we
only try to export symbols that are defined.

Also, in kernel/kprobes.c there's an EXPORT_SYMBOL_GPL() for
jprobes_return, which if CONFIG_JPROBES is undefined is a static
inline and gives the same error.

And in drivers/acpi/resources/rsxface.c, there's an
ACPI_EXPORT_SYMBOPL() for a static symbol. If it's static, it's not
accessible from outside the compilation unit, so should bot be exported.

These three changes allow building a zx1_defconfig kernel with gcc 4.2
on IA64.

[akpm@linux-foundation.org: export jpobe_return properly]
Signed-off-by: Peter Chubb 
Cc: Prasanna S Panchamukhi 
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: "Luck, Tony" 
Cc: Len Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

jprobes: make jprobes a little safer for users

2007-07-19T17:04:44+00:00

I realise jprobes are a razor-blades-included type of interface, but that
doesn't mean we can't try and make them safer to use.  This guy I know once
wrote code like this:

struct jprobe jp = { .kp.symbol_name = "foo", .entry = "jprobe_foo" };

And then his kernel exploded. Oops.

This patch adds an arch hook, arch_deref_entry_point() (I don't like it
either) which takes the void * in a struct jprobe, and gives back the text
address that it represents.

We can then use that in register_jprobe() to check that the entry point we're
passed is actually in the kernel text, rather than just some random value.

Signed-off-by: Michael Ellerman 
Cc: Prasanna S Panchamukhi 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: David S. Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Kprobes: The ON/OFF knob thru debugfs

2007-05-08T18:15:19+00:00

This patch provides a debugfs knob to turn kprobes on/off

o A new file /debug/kprobes/enabled indicates if kprobes is enabled or
  not (default enabled)
o Echoing 0 to this file will disarm all installed probes
o Any new probe registration when disabled will register the probe but
  not arm it. A message will be printed out in such a case.
o When a value 1 is echoed to the file, all probes (including ones
  registered in the intervening period) will be enabled
o Unregistration will happen irrespective of whether probes are globally
  enabled or not.
o Update Documentation/kprobes.txt to reflect these changes. While there
  also update the doc to make it current.

We are also looking at providing sysrq key support to tie to the disabling
feature provided by this patch.

[akpm@linux-foundation.org: Use bool like a bool!]
[akpm@linux-foundation.org: add printk facility levels]
[cornelia.huck@de.ibm.com: Add the missing arch_trampoline_kprobe() for s390]
Signed-off-by: Ananth N Mavinakayanahalli 
Signed-off-by: Srinivasa DS 
Signed-off-by: Cornelia Huck 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kprobes: kretprobes simplifications

2007-05-08T18:15:19+00:00

 - consolidate duplicate code in all arch_prepare_kretprobe instances
   into common code
 - replace various odd helpers that use hlist_for_each_entry to get
   the first elemenet of a list with either a hlist_for_each_entry_save
   or an opencoded access to the first element in the caller
 - inline add_rp_inst into it's only remaining caller
 - use kretprobe_inst_table_head instead of opencoding it

Signed-off-by: Christoph Hellwig 
Cc: Prasanna S Panchamukhi 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kprobes: codingstyle cleanups

2007-05-08T18:15:19+00:00

Remove superflous braces and fix indentation aswell as comments.

Signed-off-by: Christoph Hellwig 
Cc: Prasanna S Panchamukhi 
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kprobes: use hlist_for_each_entry

2007-05-08T18:15:19+00:00

Signed-off-by: Christoph Hellwig 
Cc: Prasanna S Panchamukhi 
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Simplify kallsyms_lookup()

2007-05-08T18:15:08+00:00

Several kallsyms_lookup() pass dummy arguments but only need, say, module's
name.  Make kallsyms_lookup() accept NULLs where possible.

Also, makes picture clearer about what interfaces are needed for all symbol
resolving business.

Signed-off-by: Alexey Dobriyan 
Cc: Rusty Russell 
Acked-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

move die notifier handling to common code

2007-05-08T18:15:04+00:00

This patch moves the die notifier handling to common code.  Previous
various architectures had exactly the same code for it.  Note that the new
code is compiled unconditionally, this should be understood as an appel to
the other architecture maintainer to implement support for it aswell (aka
sprinkling a notify_die or two in the proper place)

arm had a notifiy_die that did something totally different, I renamed it to
arm_notify_die as part of the patch and made it static to the file it's
declared and used at.  avr32 used to pass slightly less information through
this interface and I brought it into line with the other architectures.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix vmalloc_sync_all bustage]
[bryan.wu@analog.com: fix vmalloc_sync_all in nommu]
Signed-off-by: Christoph Hellwig 
Cc: 
Cc: Russell King 
Signed-off-by: Bryan Wu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds