]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
x86/asm/entry/64: Change the THREAD_INFO() definition to not depend on KERNEL_STACK_O...
authorDenys Vlasenko <dvlasenk@redhat.com>
Thu, 19 Mar 2015 17:17:45 +0000 (18:17 +0100)
committerIngo Molnar <mingo@kernel.org>
Tue, 24 Mar 2015 18:42:37 +0000 (19:42 +0100)
commitb3fe8ba320ace38cee6859b4c015d81627254ddb
tree5d831988166280490c4593f4505dacfca46e54c4
parenta76c7f4604937bc781bfc411ef92c59474ddadda
x86/asm/entry/64: Change the THREAD_INFO() definition to not depend on KERNEL_STACK_OFFSET

This changes the 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>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1426785469-15125-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/ia32/ia32entry.S
arch/x86/include/asm/thread_info.h
arch/x86/kernel/entry_64.S