Messages in this thread | ![/](/images/icornerl.gif) | | From | Heiko Carstens <> | Subject | [PATCH v2 0/3] kprobes: add new dma insn slot cache for s390 | Date | Fri, 23 Aug 2013 13:04:11 +0200 |
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The current kpropes insn caches allocate memory areas for insn slots with module_alloc(). The assumption is that the kernel image and module area are both within the same +/- 2GB memory area.
This however is not true for s390 where the kernel image resides within the first 2GB (DMA memory area), but the module area is far away in the vmalloc area, usually somewhere close below the 4TB area.
For new pc relative instructions s390 needs insn slots that are within +/- 2GB of each area. That way we can patch displacements of pc-relative instructions within the insn slots just like x86 and powerpc.
The module area works already with the normal insn slot allocator, however there is currently no way to get insn slots that are within the first 2GB on s390 (aka DMA area).
Therefore this patch set modifies the kprobes insn slot cache code in order to allow to specify a custom allocator for the insn slot cache pages. In addition architecure can now have private insn slot caches withhout the need to modify common code.
Patch 1 unifies and simplifies the current insn and optinsn caches implementation. This is a preparation which allows to add more insn caches in a simple way.
Patch 2 adds the possibility to specify a custom allocator.
Patch 3 makes s390 use the new insn slot mechanisms and adds support for pc-relative instructions with long displacements.
v1->v2: add possibility to specifiy a custom allocator and move the new dmainsn cache into s390 code and leave common code alone.
Heiko Carstens (3): kprobes: unify insn caches kprobes: allow to specify custum allocator for insn caches s390/kprobes: add support for pc-relative long displacement instructions
arch/s390/include/asm/kprobes.h | 4 +- arch/s390/kernel/kprobes.c | 144 +++++++++++++++++++++++++++++++++++++-- include/linux/kprobes.h | 34 +++++++-- kernel/kprobes.c | 95 +++++++++++--------------- 4 files changed, 209 insertions(+), 68 deletions(-)
-- 1.7.10.4
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