Subject: Re: [PATCH] ftrace: unify arch_syscall_addr() implementations
Newsgroups: gmane.linux.kernel
Date: 2010-01-23 01:38:38 GMT (2 years, 2 weeks, 5 days, 8 hours and 6 minutes ago)
From: Heiko Carstens <heiko.carstens <at> de.ibm.com> Date: Fri, 22 Jan 2010 17:37:00 +0100 > On Fri, Jan 22, 2010 at 09:36:17AM -0500, Steven Rostedt wrote: >> I would not be too sure. s390 is very strange, and I would definitely >> want to get an Ack from the arch maintainers first. > > It's not a typo. The syscall table on s390 contains always 32 bit pointers > since we know that the address of the function to be called is (way) below > 4GB. So this saves us a few bytes. > In addition this makes syscall patching done by some security modules a > bit more difficult, since they would need to store a 64 bit pointer. > That's because we make sure that module addresses are always above 4GB. Sparc64 is the same way.