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path: root/arch/mips/kernel/probes-common.h
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2016-10-06MIPS: tracing: disable uprobe/kprobe on compact branch instructionsMarcin Nowakowski1-0/+2
Current instruction decoder for uprobe/kprobe handler only handles branches with delay slots. For compact branches the behaviour is rather unpredictable - and depending on the encoding of a compact branch instruction may result in one (or more) of: - executing an instruction that follows a branch which wasn't in a delay slot and shouldn't have been executed - incorrectly emulating a branch leading to a jump to a wrong location - unexpected branching out of the single-stepped code and never reaching the breakpoint that should terminate the probe handler Results of these actions are generally unpredictable, but can end up with a probed application or kernel crash, so disable placing probes on compact branches until they are handled properly. Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14336/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-06MIPS: tracing: move insn_has_delay_slot to a shared headerMarcin Nowakowski1-0/+81
Currently both kprobes and uprobes code have definitions of the insn_has_delay_slot method. Move it to a separate header as an inline method that each probe-specific method can later use. No functional change intended, although the methods slightly varied in the constraints they set for the methods - the uprobes one was chosen as it is slightly more specific when filtering opcode fields. Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14335/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>