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 <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
And here's a port of the powerpc patch to get rid of the notifier
chain completely to s390. It's ontop of Martins patch as that one
is in mainline already.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Running a probe on s390 with a probe address that is not 4 byte aligned
results in a Kernel BUG. The problem is that the stura instruction used
by swap_instruction requires the destination address to be 4 byte aligned.
As stura only writes 4 bytes, aligning to the next 4 byte aligned address
results in the breakpoint instruction being stored past the probe address.
The fix is to align the address backward (to the previous 4 byte aligned
address) and writing the two byte breakpoint instruction in the appropriate
bytes.
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Wilder <dwilder@us.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
The illegal operation handler calls the die notifier with DIE_BPT to
let kprobes pick up its breakpoint. If kprobes does not find its
breakpoint it returns NOTIFY_STOP instead of NOTIFY_DONE.
Since we use stop_machine_run on s390 to arm/disarm the kprobes
breakpoints the race that kprobe_handler tries to solve by checking
for the kprobes breakpoints does not exist. Removing the check makes
BUG_ON working again.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Set read-only flag in the page table entries for the kernel image text
section. This will catch all instruction caused corruptions withing the
text section.
Instruction replacement via kprobes still works, since it bypasses now
dynamic address translation.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
kretprobe_trampoline_holder() is in kprobes section but used to
register a kprobe in arch_init_kprobes(). Hence register_kprobe()
and therefore arch_init_kprobes() will fail.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When we are unregistering a kprobe-booster, we can't release its
instruction buffer immediately on the preemptive kernel, because some
processes might be preempted on the buffer. The freeze_processes() and
thaw_processes() functions can clean most of processes up from the buffer.
There are still some non-frozen threads who have the PF_NOFREEZE flag. If
those threads are sleeping (not preempted) at the known place outside the
buffer, we can ensure safety of freeing.
However, the processing of this check routine takes a long time. So, this
patch introduces the garbage collection mechanism of insn_slot. It also
introduces the "dirty" flag to free_insn_slot because of efficiency.
The "clean" instruction slots (dirty flag is cleared) are released
immediately. But the "dirty" slots which are used by boosted kprobes, are
marked as garbages. collect_garbage_slots() will be invoked to release
"dirty" slots if there are more than INSNS_PER_PAGE garbage slots or if
there are no unused slots.
Cc: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "bibo,mao" <bibo.mao@intel.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Yumiko Sugita <yumiko.sugita.yf@hitachi.com>
Cc: Satoshi Oshima <soshima@redhat.com>
Cc: Hideo Aoki <haoki@redhat.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
kprobe_flush_task() possibly calls kfree function during holding
kretprobe_lock spinlock, if kfree function is probed by kretprobe that will
incur spinlock deadlock. This patch moves kfree function out scope of
kretprobe_lock.
Signed-off-by: bibo, mao <bibo.mao@intel.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Michael Grundy <grundym@us.ibm.com>
Signed-off-by: David Wilder <dwilder@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
