Commit e5ae3728 authored by Christophe Leroy's avatar Christophe Leroy Committed by Linus Torvalds
Browse files

mm: make generic arch_is_kernel_initmem_freed() do what it says 

Commit 7a5da02d ("locking/lockdep: check for freed initmem in
static_obj()") added arch_is_kernel_initmem_freed() which is supposed to
report whether an object is part of already freed init memory.

For the time being, the generic version of
arch_is_kernel_initmem_freed() always reports 'false', allthough
free_initmem() is generically called on all architectures.

Therefore, change the generic version of arch_is_kernel_initmem_freed()
to check whether free_initmem() has been called.  If so, then check if a
given address falls into init memory.

To ease the use of system_state, move it out of line into its only
caller which is lockdep.c

Link: https://lkml.kernel.org/r/1d40783e676e07858be97d881f449ee7ea8adfb1.1633001016.git.christophe.leroy@csgroup.eu


Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d2635f20

include/asm-generic/sections.h

+0 −14
Original line number Diff line number Diff line
@@ -80,20 +80,6 @@ static inline int arch_is_kernel_data(unsigned long addr) 
}

#endif



/*

 * Check if an address is part of freed initmem. This is needed on architectures

 * with virt == phys kernel mapping, for code that wants to check if an address

 * is part of a static object within [_stext, _end]. After initmem is freed,

 * memory can be allocated from it, and such allocations would then have

 * addresses within the range [_stext, _end].

 */

#ifndef arch_is_kernel_initmem_freed

static inline int arch_is_kernel_initmem_freed(unsigned long addr)

{

	return 0;

}

#endif



/**

 * memory_contains - checks if an object is contained within a memory region

 * @begin: virtual address of the beginning of the memory region

kernel/locking/lockdep.c

+15 −0
Original line number Diff line number Diff line
@@ -788,6 +788,21 @@ static int very_verbose(struct lock_class *class) 
 * Is this the address of a static object:

 */

#ifdef __KERNEL__

/*

 * Check if an address is part of freed initmem. After initmem is freed,

 * memory can be allocated from it, and such allocations would then have

 * addresses within the range [_stext, _end].

 */

#ifndef arch_is_kernel_initmem_freed

static int arch_is_kernel_initmem_freed(unsigned long addr)

{

	if (system_state < SYSTEM_FREEING_INITMEM)

		return 0;



	return init_section_contains((void *)addr, 1);

}

#endif



static int static_obj(const void *obj)

{

	unsigned long start = (unsigned long) &_stext,