remarkable-linux/include/linux/thread_info.h
Mark Rutland 907241dccb 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:

  affa219b60 ("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>
2016-09-24 09:35:06 +02:00

151 lines
3.5 KiB
C

/* thread_info.h: common low-level thread information accessors
*
* Copyright (C) 2002 David Howells (dhowells@redhat.com)
* - Incorporating suggestions made by Linus Torvalds
*/
#ifndef _LINUX_THREAD_INFO_H
#define _LINUX_THREAD_INFO_H
#include <linux/types.h>
#include <linux/bug.h>
struct timespec;
struct compat_timespec;
#ifdef CONFIG_THREAD_INFO_IN_TASK
struct thread_info {
unsigned long flags; /* low level flags */
};
#define INIT_THREAD_INFO(tsk) \
{ \
.flags = 0, \
}
#endif
#ifdef CONFIG_THREAD_INFO_IN_TASK
#define current_thread_info() ((struct thread_info *)current)
#endif
/*
* System call restart block.
*/
struct restart_block {
long (*fn)(struct restart_block *);
union {
/* For futex_wait and futex_wait_requeue_pi */
struct {
u32 __user *uaddr;
u32 val;
u32 flags;
u32 bitset;
u64 time;
u32 __user *uaddr2;
} futex;
/* For nanosleep */
struct {
clockid_t clockid;
struct timespec __user *rmtp;
#ifdef CONFIG_COMPAT
struct compat_timespec __user *compat_rmtp;
#endif
u64 expires;
} nanosleep;
/* For poll */
struct {
struct pollfd __user *ufds;
int nfds;
int has_timeout;
unsigned long tv_sec;
unsigned long tv_nsec;
} poll;
};
};
extern long do_no_restart_syscall(struct restart_block *parm);
#include <linux/bitops.h>
#include <asm/thread_info.h>
#ifdef __KERNEL__
#ifdef CONFIG_DEBUG_STACK_USAGE
# define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK | \
__GFP_ZERO)
#else
# define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK)
#endif
/*
* flag set/clear/test wrappers
* - pass TIF_xxxx constants to these functions
*/
static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
{
set_bit(flag, (unsigned long *)&ti->flags);
}
static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
{
clear_bit(flag, (unsigned long *)&ti->flags);
}
static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
{
return test_and_set_bit(flag, (unsigned long *)&ti->flags);
}
static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
{
return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
}
static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
{
return test_bit(flag, (unsigned long *)&ti->flags);
}
#define set_thread_flag(flag) \
set_ti_thread_flag(current_thread_info(), flag)
#define clear_thread_flag(flag) \
clear_ti_thread_flag(current_thread_info(), flag)
#define test_and_set_thread_flag(flag) \
test_and_set_ti_thread_flag(current_thread_info(), flag)
#define test_and_clear_thread_flag(flag) \
test_and_clear_ti_thread_flag(current_thread_info(), flag)
#define test_thread_flag(flag) \
test_ti_thread_flag(current_thread_info(), flag)
#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
static inline int arch_within_stack_frames(const void * const stack,
const void * const stackend,
const void *obj, unsigned long len)
{
return 0;
}
#endif
#ifdef CONFIG_HARDENED_USERCOPY
extern void __check_object_size(const void *ptr, unsigned long n,
bool to_user);
static __always_inline void check_object_size(const void *ptr, unsigned long n,
bool to_user)
{
if (!__builtin_constant_p(n))
__check_object_size(ptr, n, to_user);
}
#else
static inline void check_object_size(const void *ptr, unsigned long n,
bool to_user)
{ }
#endif /* CONFIG_HARDENED_USERCOPY */
#endif /* __KERNEL__ */
#endif /* _LINUX_THREAD_INFO_H */