Commit-ID: 907241dccb4ce5d9413cf3c030b32b0cfc184914
Gitweb: http://git.kernel.org/tip/907241dccb4ce5d9413cf3c030b32b0cfc184914
Author: Mark Rutland <mark.rutl...@arm.com>
AuthorDate: Fri, 23 Sep 2016 18:24:07 +0100
Committer: Ingo Molnar <mi...@kernel.org>
CommitDate: Sat, 24 Sep 2016 09:35:06 +0200
thread_info: Use unsigned long for flags
The generic THREAD_INFO_IN_TASK definition of thread_info::flags is a
u32, matching x86 prior to the introduction of THREAD_INFO_IN_TASK.
However, common helpers like test_ti_thread_flag() implicitly assume
that thread_info::flags has at least the size and alignment of unsigned
long, and relying on padding and alignment provided by other elements of
task_struct is somewhat fragile. Additionally, some architectures use
more that 32 bits for thread_info::flags, and others may need to in
future.
With THREAD_INFO_IN_TASK, task struct follows thread_info with a long
field, and thus we no longer save any space as we did back in commit:
affa219b60a11b32 ("x86: change thread_info's flag field back to 32 bits")
Given all this, it makes more sense for the generic thread_info::flags
to be an unsigned long.
In fact given <linux/thread_info.h> contains/uses the helpers mentioned
above, BE arches *must* use unsigned long (or something of the same size)
today, or they wouldn't work.
Make it so.
Signed-off-by: Mark Rutland <mark.rutl...@arm.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Andy Lutomirski <l...@kernel.org>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Brian Gerst <brge...@gmail.com>
Cc: Denys Vlasenko <dvlas...@redhat.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Josh Poimboeuf <jpoim...@redhat.com>
Cc: Kees Cook <keesc...@chromium.org>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Link:
http://lkml.kernel.org/r/1474651447-30447-1-git-send-email-mark.rutl...@arm.com
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
include/linux/thread_info.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index e2d0fd8..45f004e 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -15,7 +15,7 @@ struct compat_timespec;
#ifdef CONFIG_THREAD_INFO_IN_TASK
struct thread_info {
- u32 flags; /* low level flags */
+ unsigned long flags; /* low level flags */
};
#define INIT_THREAD_INFO(tsk) \
