Messages in this thread | | | Date | Fri, 20 Mar 2015 11:30:01 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH 1/5] x86: change THREAD_INFO definition to not depend on KERNEL_STACK_OFFSET |
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On Thu, Mar 19, 2015 at 06:17:45PM +0100, Denys Vlasenko wrote: > This changes THREAD_INFO definition and all its callsites > so that they do not count stack position from > (top of stack - KERNEL_STACK_OFFSET), but from top of stack. > > Semi-mysterious expressions THREAD_INFO(%rsp,RIP) - "why RIP??" > are now replaced by more logical THREAD_INFO(%rsp,SIZEOF_PTREGS) - > "calculate thread_info's address using information that > rsp is SIZEOF_PTREGS bytes below top of stack". > > While at it, replace "(off)-THREAD_SIZE(reg)" with equivalent > "((off)-THREAD_SIZE)(reg)". The form without parentheses > falsely looks like we invoke THREAD_SIZE() macro. > > Improve comment atop THREAD_INFO macro definition. > > This patch does not change generated code (verified by objdump). > > Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> > CC: Linus Torvalds <torvalds@linux-foundation.org> > CC: Steven Rostedt <rostedt@goodmis.org> > CC: Ingo Molnar <mingo@kernel.org> > CC: Borislav Petkov <bp@alien8.de> > CC: "H. Peter Anvin" <hpa@zytor.com> > CC: Andy Lutomirski <luto@amacapital.net> > CC: Oleg Nesterov <oleg@redhat.com> > CC: Frederic Weisbecker <fweisbec@gmail.com> > CC: Alexei Starovoitov <ast@plumgrid.com> > CC: Will Drewry <wad@chromium.org> > CC: Kees Cook <keescook@chromium.org> > CC: x86@kernel.org > CC: linux-kernel@vger.kernel.org
Acked-by: Borislav Petkov <bp@suse.de>
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply. --
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