[PATCH 3/3] thread_info: include <current.h> for THREAD_INFO_IN_TASK

From	Mark Rutland <mark.rutland@arm.com>
Newsgroups	linux.kernel
Subject	[PATCH 3/3] thread_info: include <current.h> for THREAD_INFO_IN_TASK
Date	2016-10-19 20:40 +0200
Message-ID	<su3Wq-53C-37@gated-at.bofh.it> (permalink)
References	<su3Wq-53C-35@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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When CONFIG_THREAD_INFO_IN_TASK is selected, the current_thread_info()
macro relies on current having been defined prior to its use. However,
not all users of current_thread_info() include <asm/current.h>, and thus
current is not guaranteed to be defined.

When CONFIG_THREAD_INFO_IN_TASK is not selected, it's possible that
get_current() / current are based upon current_thread_info(), and
<asm/current.h> includes <asm/thread_info.h>. Thus always including
<asm/current.h> would result in circular dependences on some platforms.

To ensure both cases work, this patch includes <asm/current.h>, but only
when CONFIG_THREAD_INFO_IN_TASK is selected.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Kees Cook <keescook@chromium.org> 
---
 include/linux/thread_info.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index c75c6ab..ef1f4b0 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -12,6 +12,7 @@
 #include <linux/restart_block.h>
 
 #ifdef CONFIG_THREAD_INFO_IN_TASK
+#include <asm/current.h>
 #define current_thread_info() ((struct thread_info *)current)
 #endif
 
-- 
1.9.1

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[PATCH 3/3] thread_info: include <current.h> for THREAD_INFO_IN_TASK Mark Rutland <mark.rutland@arm.com> - 2016-10-19 20:40 +0200
  Re: [PATCH 3/3] thread_info: include <current.h> for  THREAD_INFO_IN_TASK Heiko Carstens <heiko.carstens@de.ibm.com> - 2016-10-20 12:30 +0200
    Re: [PATCH 3/3] thread_info: include <current.h> for  THREAD_INFO_IN_TASK Mark Rutland <mark.rutland@arm.com> - 2016-10-24 12:00 +0200

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