ICEBP assembly instruction
问题 As a workaround with x86 instructions, I used an opcode looks like .byte 0xf1, 0xc1 and tried to execute that inside gdb. the disassembly of that line shows f1 icebp So, when first byte which is F1 is fetched it is recognized as an instruction called icebp . This is known to be an undocumented instruction. The only thing I found in the SDM, is a footnote in INT sections saying The mnemonic ICEBP has also been used for the instruction with opcode F1 Continuing with gdb, it says Cannot access