lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 25 Aug 2020 15:30:05 +0200 From: peterz@...radead.org To: Masami Hiramatsu <mhiramat@...nel.org> Cc: "Eddy_Wu@...ndmicro.com" <Eddy_Wu@...ndmicro.com>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, "x86@...nel.org" <x86@...nel.org>, "David S. Miller" <davem@...emloft.net> Subject: Re: x86/kprobes: kretprobe fails to triggered if kprobe at function entry is not optimized (trigger by int3 breakpoint) On Tue, Aug 25, 2020 at 10:15:55PM +0900, Masami Hiramatsu wrote: > > damn... one last problem is dangling instances.. so close. > > We can apparently unregister a kretprobe while there's still active > > kretprobe_instance's out referencing it. > > Yeah, kretprobe already provided the per-instance data (as far as > I know, only systemtap depends on it). We need to provide it for > such users. > But if we only have one lock, we can avoid checking NMI because > we can check the recursion with trylock. It is needed only if the > kretprobe uses per-instance data. Or we can just pass a dummy > instance on the stack. I think it is true in general, you can unregister a rp while tasks are preempted. Anyway,. I think I have a solution, just need to talk to paulmck for a bit. > > Ignoring that issue for the moment, the below seems to actually work. > > OK, this looks good to me too. > I'll make a series to rewrite kretprobe based on this patch, OK? Please, I'll send the fix along when I have it.
Powered by blists - more mailing lists