fn read_inferior_memory()

in reverie-ptrace/src/task.rs [1916:1944]

• 17 lines of code
• 5 McCabe index (conditional complexity)

    fn read_inferior_memory(&self, addr: u64, mut size: usize) -> Result<Vec<u8>, TraceError> {
        let task = self.assume_stopped();

        // NB: dont' trust size to be sane blindly.
        if size > 0x8000 {
            size = 0x8000;
        }

        let mut res = vec![0; size];
        if let Some(addr) = Addr::from_raw(addr as usize) {
            let nb = task.read(addr, &mut res)?;
            res.resize(nb, 0);
        }

        // There could be a software breakpoint within the address requested,
        // we should return the orignal contents without the breakpoint insn.
        // This is *not* documented in gdb remote protocol, however, both
        // gdbserver and rr does this. see:
        // rr: https://github.com/rr-debugger/rr/blob/master/src/GdbServer.cc#L561
        // gdbserver: https://github.com/bminor/binutils-gdb/blob/master/gdbserver/mem-break.cc#L1914
        for (bkpt, saved_insn) in self.breakpoints.iter() {
            if (addr..addr + res.len() as u64).contains(bkpt) {
                // This abuses bkpt insn 0xcc is single byte.
                res[*bkpt as usize - addr as usize] = *saved_insn as u8;
            }
        }

        Ok(res)
    }