[lkml]   [2011]   [Dec]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v5 4/9] x86-64: Remove kernel.vsyscall64 sysctl
Andy Lutomirski <luto <at> MIT.EDU> writes:

> It's unnecessary overhead in code that's supposed to be highly
> optimized. Removing it allows us to remove one of the two syscall
> instructions in the vsyscall page.
> The only sensible use for it is for UML users, and it doesn't fully
> address inconsistent vsyscall results on UML. The real fix for UML
> is to stop using vsyscalls entirely.

UML is not the only use case for this. Anybody who wants to be able to
trace _all_ system calls (for debugging, ptrace-based sandboxing, or a
number of other purposes) needs this.

We either need this back, or need another way to make it possible to
trace these system calls.

Apologies for the late reply, I didn't notice this change until it got
into my distribution's kernel.

--Matthew Maurer

 \ /
  Last update: 2011-12-05 19:33    [W:0.163 / U:10.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site