2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-27 22:53:55 +08:00
linux-next/include/linux/thread_info.h
Mark Rutland 48ac3c18cc fork: allow arch-override of VMAP stack alignment
In some cases, an architecture might wish its stacks to be aligned to a
boundary larger than THREAD_SIZE. For example, using an alignment of
double THREAD_SIZE can allow for stack overflows smaller than
THREAD_SIZE to be detected by checking a single bit of the stack
pointer.

This patch allows architectures to override the alignment of VMAP'd
stacks, by defining THREAD_ALIGN. Where not defined, this defaults to
THREAD_SIZE, as is the case today.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: linux-kernel@vger.kernel.org
2017-08-15 18:34:46 +01:00

154 lines
3.9 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>
#include <linux/restart_block.h>
#ifdef CONFIG_THREAD_INFO_IN_TASK
/*
* For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the
* definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels,
* including <asm/current.h> can cause a circular dependency on some platforms.
*/
#include <asm/current.h>
#define current_thread_info() ((struct thread_info *)current)
#endif
#include <linux/bitops.h>
/*
* For per-arch arch_within_stack_frames() implementations, defined in
* asm/thread_info.h.
*/
enum {
BAD_STACK = -1,
NOT_STACK = 0,
GOOD_FRAME,
GOOD_STACK,
};
#include <asm/thread_info.h>
#ifdef __KERNEL__
#ifndef THREAD_ALIGN
#define THREAD_ALIGN THREAD_SIZE
#endif
#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 */
extern void __compiletime_error("copy source size is too small")
__bad_copy_from(void);
extern void __compiletime_error("copy destination size is too small")
__bad_copy_to(void);
static inline void copy_overflow(int size, unsigned long count)
{
WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
}
static __always_inline bool
check_copy_size(const void *addr, size_t bytes, bool is_source)
{
int sz = __compiletime_object_size(addr);
if (unlikely(sz >= 0 && sz < bytes)) {
if (!__builtin_constant_p(bytes))
copy_overflow(sz, bytes);
else if (is_source)
__bad_copy_from();
else
__bad_copy_to();
return false;
}
check_object_size(addr, bytes, is_source);
return true;
}
#ifndef arch_setup_new_exec
static inline void arch_setup_new_exec(void) { }
#endif
#endif /* __KERNEL__ */
#endif /* _LINUX_THREAD_INFO_H */