0acb5f6456
Operations which write to memory and special purpose registers should be restricted on systems with integrity guarantees (such as Secure Boot) and, optionally, to avoid self-destructive behaviors. Add a config option, XMON_DEFAULT_RO_MODE, to set default xmon behavior. The kernel cmdline options xmon=ro and xmon=rw override this default. The following xmon operations are affected: memops: disable memmove disable memset disable memzcan memex: no-op'd mwrite super_regs: no-op'd write_spr bpt_cmds: disable proc_call: disable Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf> Reviewed-by: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>