blob: 600b9ee146125eba0b4fae7f54fb03ba9876f7bf [file] [log] [blame]
From 907241dccb4ce5d9413cf3c030b32b0cfc184914 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland@arm.com>
Date: Fri, 23 Sep 2016 18:24:07 +0100
Subject: [PATCH] thread_info: Use unsigned long for flags
commit 907241dccb4ce5d9413cf3c030b32b0cfc184914 upstream.
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.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1474651447-30447-1-git-send-email-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index e2d0fd81b1ba..45f004e9cc59 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) \
--
2.15.0