Commit Graph

62 Commits

Author SHA1 Message Date
Rusty Lynch a528e21c23 [PATCH] kprobes/ia64: refuse inserting kprobe on slot 1
Without the ability to atomically write 16 bytes, we can not update the
middle slot of a bundle, slot 1, unless we stop the machine first.  This
patch will ensure the ability to robustly insert and remove a kprobe by
refusing to insert a kprobe on slot 1 until a mechanism is in place to
safely handle this case.

Signed-off-by: Rusty Lynch <rusty.lynch@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27 15:23:53 -07:00
Rusty Lynch 9508dbfe39 [PATCH] Return probe redesign: ia64 specific implementation
The following patch implements function return probes for ia64 using
the revised design.  With this new design we no longer need to do some
of the odd hacks previous required on the last ia64 return probe port
that I sent out for comments.

Note that this new implementation still does not resolve the problem noted
by Keith Owens where backtrace data is lost after a return probe is hit.

Changes include:
 * Addition of kretprobe_trampoline to act as a dummy function for instrumented
   functions to return to, and for the return probe infrastructure to place
   a kprobe on on, gaining control so that the return probe handler
   can be called, and so that the instruction pointer can be moved back
   to the original return address.
 * Addition of arch_init(), allowing a kprobe to be registered on
   kretprobe_trampoline
 * Addition of trampoline_probe_handler() which is used as the pre_handler
   for the kprobe inserted on kretprobe_implementation.  This is the function
   that handles the details for calling the return probe handler function
   and returning control back at the original return address
 * Addition of arch_prepare_kretprobe() which is setup as the pre_handler
   for a kprobe registered at the beginning of the target function by
   kernel/kprobes.c so that a return probe instance can be setup when
   a caller enters the target function.  (A return probe instance contains
   all the needed information for trampoline_probe_handler to do it's job.)
 * Hooks added to the exit path of a task so that we can cleanup any left-over
   return probe instances (i.e. if a task dies while inside a targeted function
   then the return probe instance was reserved at the beginning of the function
   but the function never returns so we need to mark the instance as unused.)

Signed-off-by: Rusty Lynch <rusty.lynch@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27 15:23:53 -07:00
Anil S Keshavamurthy 852caccc89 [PATCH] Kprobes/ia64: temporary disarming of reentrant probe
This patch includes IA64 architecture specific changes(ported form i386) to
support temporary disarming on reentrancy of probes.

In case of reentrancy we single step without calling user handler.

Signed-of-by: Anil S Keshavamurth <anil.s.keshavamurthy@intel.com>

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:25 -07:00
Keshavamurthy Anil S 89cb14c0dd [PATCH] Kprobes/IA64: check jprobe break before handling
Once the jprobe instrumented function returns, it executes a jprobe_break
which is a break instruction with __IA64_JPROBE_BREAK value.  The current
patch checks for this break value, before assuming that jprobe instrumented
function just completed.

The previous code was not checking for this value and that was a bug.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:24 -07:00
Anil S Keshavamurthy 708de8f11c [PATCH] Kprobes IA64: safe register kprobe
The current kprobes does not yet handle register kprobes on some of the
following kind of instruction which needs to be emulated in a special way.

1) mov r1=ip
2) chk -- Speculation check instruction

This patch attempts to fail register_kprobes() when user tries to insert
kprobes on the above kind of instruction.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:24 -07:00
Anil S Keshavamurthy 1674eafcbd [PATCH] Kprobes IA64: cmp ctype unc support
The current Kprobes when patching the original instruction with the break
instruction tries to retain the original qualifying predicate(qp), however
for cmp.crel.ctype where ctype == unc, which is a special instruction
always needs to be executed irrespective of qp.  Hence, if the instruction
we are patching is of this type, then we should not copy the original qp to
the break instruction, this is because we always want the break fault to
happen so that we can emulate the instruction.

This patch is based on the feedback given by David Mosberger

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:23 -07:00
Anil S Keshavamurthy a5403183d8 [PATCH] Kprobes IA64: arch_prepare_kprobes() cleanup
arch_prepare_kprobes() was doing lots of functionality
in just one single function. This patch
attempts to clean up arch_prepare_kprobes() by moving
specific sub task to the following (new)functions
1)valid_kprobe_addr() -->> validate the given kprobe address
2)get_kprobe_inst(slot..)->> Retrives the instruction for a given slot from the bundle
3)prepare_break_inst() -->> Prepares break instruction within the bundle
	3a)update_kprobe_inst_flag()-->>Updates the internal flags, required
			for proper emulation of the instruction at later
			point in time.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:23 -07:00
Rusty Lynch 13608d6433 [PATCH] Kprobes ia64 qp fix
Fix a bug where a kprobe still fires when the instruction is predicated
off.  So given the p6=0, and we have an instruction like:

(p6) move loc1=0

we should not be triggering the kprobe.  This is handled by carrying over
the qp section of the original instruction into the break instruction.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Rusty Lynch <Rusty.lynch@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:23 -07:00
Rusty Lynch 8bc76772ad [PATCH] Kprobes ia64 cleanup
A cleanup of the ia64 kprobes implementation such that all of the bundle
manipulation logic is concentrated in arch_prepare_kprobe().

With the current design for kprobes, the arch specific code only has a
chance to return failure inside the arch_prepare_kprobe() function.

This patch moves all of the work that was happening in arch_copy_kprobe()
and most of the work that was happening in arch_arm_kprobe() into
arch_prepare_kprobe().  By doing this we can add further robustness checks
in arch_arm_kprobe() and refuse to insert kprobes that will cause problems.

Signed-off-by: Rusty Lynch <Rusty.lynch@intel.com>
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:23 -07:00
Anil S Keshavamurthy cd2675bf65 [PATCH] Kprobes/IA64: support kprobe on branch/call instructions
This patch is required to support kprobe on branch/call instructions.

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:23 -07:00
Anil S Keshavamurthy b2761dc262 [PATCH] Kprobes/IA64: architecture specific JProbes support
This patch adds IA64 architecture specific JProbes support on top of Kprobes

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Rusty Lynch <Rusty.lynch@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:22 -07:00
Anil S Keshavamurthy fd7b231ff9 [PATCH] Kprobes/IA64: arch specific handling
This is an IA64 arch specific handling of Kprobes

Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Rusty Lynch <Rusty.lynch@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:22 -07:00