linux-toradex.git/kernel/kprobes.c, branch v2.6.16.9

[PATCH] Kprobes: Fix deadlock in function-return probes

2006-02-03T16:32:00+00:00

When two function-return probes are inserted on kfree()[1] and the second
on say, sys_link()[2], and later [2] is unregistered, we have a deadlock as
kfree is called with the kretprobe_lock held and the function-return probe
on kfree will also try to grab the same lock.

However, we can move the kfree() during unregistration to outside the
spinlock as we are sure that no instances from the free list will be used
after synchronized_sched() returns during the unregistration process.
Thanks to Masami Hiramatsu for spotting this.

Signed-off-by: Ananth N Mavinakayanahalli 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] kernel/kprobes.c: fix a warning #ifndef ARCH_SUPPORTS_KRETPROBES

2006-02-03T16:32:00+00:00

kernel/kprobes.c:353: warning: 'pre_handler_kretprobe' defined but not used

Signed-off-by: Adrian Bunk 
Acked-by: Ananth N Mavinakayanahalli 
Acked-by: "Keshavamurthy, Anil S" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] kprobes: fix unloading of self probed module

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

When a kprobes modules is written in such a way that probes are inserted on
itself, then unload of that moudle was not possible due to reference
couning on the same module.

The below patch makes a check and incrementes the module refcount only if
it is not a self probed module.

We need to allow modules to probe themself for kprobes performance
measurements

This patch has been tested on several x86_64, ppc64 and IA64 architectures.

Signed-off-by: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Kprobes: conversion from kcalloc to kzalloc

2006-01-10T16:01:41+00:00

Signed-of-by: Anil S Keshavamurthy 

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

[PATCH] kprobes: fix build breakage

2006-01-10T16:01:40+00:00

The following patch (against 2.6.15-rc5-mm3) fixes a kprobes build break
due to changes introduced in the kprobe locking in 2.6.15-rc5-mm3.  In
addition, the patch reverts back the open-coding of kprobe_mutex.

Signed-off-by: Ananth N Mavinakayanahalli 
Acked-by: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] kprobes: arch_remove_kprobe

2006-01-10T16:01:40+00:00

Currently arch_remove_kprobes() is only implemented/required for x86_64 and
powerpc.  All other architecture like IA64, i386 and sparc64 implementes a
dummy function which is being called from arch independent kprobes.c file.

This patch removes the dummy functions and replaces it with
#define arch_remove_kprobe(p, s)	do { } while(0)

Signed-off-by: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] kprobes-changed-from-using-spinlock-to-mutex fix

2006-01-10T16:01:40+00:00

Based on some feedback from Oleg Nesterov, I have made few changes to
previously posted patch.

Signed-off-by: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] kprobes: changed from using spinlock to mutex

2006-01-10T16:01:40+00:00

Since Kprobes runtime exception handlers is now lock free as this code path is
now using RCU to walk through the list, there is no need for the
register/unregister{_kprobe} to use spin_{lock/unlock}_isr{save/restore}.  The
serialization during registration/unregistration is now possible using just a
mutex.

In the above process, this patch also fixes a minor memory leak for x86_64 and
powerpc.

Signed-off-by: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] kprobes: enable funcions only for required arch

2006-01-10T16:01:39+00:00

Kernel/kprobes.c defines get_insn_slot() and free_insn_slot() which are
currently required _only_ for x86_64 and powerpc (which has no-exec support).

FYI, get{free}_insn_slot() functions manages the memory page which is mapped
as executable, required for instruction emulation.

This patch moves those two functions under __ARCH_WANT_KPROBES_INSN_SLOT and
defines __ARCH_WANT_KPROBES_INSN_SLOT in arch specific kprobes.h file.

Signed-off-by: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] kprobes: increment kprobe missed count for multiprobes

2005-12-12T16:57:45+00:00

When multiple probes are registered at the same address and if due to some
recursion (probe getting triggered within a probe handler), we skip calling
pre_handlers and just increment nmissed field.

The below patch make sure it walks the list for multiple probes case.
Without the below patch we get incorrect results of nmissed count for
multiple probe case.

Signed-off-by: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds