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51c9c08439
Current infrastructure of kprobe uses the unconditional trap instruction to probe a running kernel. Optprobe allows kprobe to replace the trap with a branch instruction to a detour buffer. Detour buffer contains instructions to create an in memory pt_regs. Detour buffer also has a call to optimized_callback() which in turn call the pre_handler(). After the execution of the pre-handler, a call is made for instruction emulation. The NIP is determined in advanced through dummy instruction emulation and a branch instruction is created to the NIP at the end of the trampoline. To address the limitation of branch instruction in POWER architecture, detour buffer slot is allocated from a reserved area. For the time being, 64KB is reserved in memory for this purpose. Instructions which can be emulated using analyse_instr() are the candidates for optimization. Before optimization ensure that the address range between the detour buffer allocated and the instruction being probed is within +/- 32MB. Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> |
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| .. | ||
| alloc.c | ||
| checksum_32.S | ||
| checksum_64.S | ||
| checksum_wrappers.c | ||
| code-patching.c | ||
| copy_32.S | ||
| copypage_64.S | ||
| copypage_power7.S | ||
| copyuser_64.S | ||
| copyuser_power7.S | ||
| crtsavres.S | ||
| div64.S | ||
| feature-fixups-test.S | ||
| feature-fixups.c | ||
| hweight_64.S | ||
| ldstfp.S | ||
| locks.c | ||
| Makefile | ||
| mem_64.S | ||
| memcmp_64.S | ||
| memcpy_64.S | ||
| memcpy_power7.S | ||
| rheap.c | ||
| sstep.c | ||
| string_64.S | ||
| string.S | ||
| usercopy_64.c | ||
| vmx-helper.c | ||
| xor_vmx.c | ||