On Wed, May 13, 2020 at 01:45:27PM -0300, Luis Machado wrote: > On 5/13/20 12:09 PM, Luis Machado wrote: > > Let me think about this for a bit. I'm trying to factor in the > > /proc/<pid>/maps contents. If debuggers know which pages have PROT_MTE > > set, then we can teach the tools not to PEEK/POKE tags from/to those > > memory ranges, which simplifies the error handling a bit. > > I was checking the output of /proc/<pid>/maps and it doesn't seem to contain > flags against which i can match PROT_MTE. It seems /proc/<pid>/smaps is the > one that contains the flags (mt) for MTE. Am i missing something? You are right, the smaps is the one with the MTE information. > Is this the only place debuggers can check for PROT_MTE? If so, that's > unfortunate. /proc/<pid>/smaps doesn't seem to be convenient for parsing. We can't change 'maps' as it's a pretty standard format with rwxp properties only. If you don't want to check any /proc file, just attempt to read the tags and check the ptrace return code. The downside is that you can't easily probe if a process is using MTE or not. But is this piece of information relevant? The gdb user should know what to look for (well, it's been a while since I used a debugger ;)). -- Catalin
