Commit 33e5d769 authored by David Howells's avatar David Howells Committed by Linus Torvalds
Browse files

nommu: fix a number of issues with the per-MM VMA patch 



Fix a number of issues with the per-MM VMA patch:

 (1) Make mmap_pages_allocated an atomic_long_t, just in case this is used on
     a NOMMU system with more than 2G pages.  Makes no difference on a 32-bit
     system.

 (2) Report vma->vm_pgoff * PAGE_SIZE as a 64-bit value, not a 32-bit value,
     lest it overflow.

 (3) Move the allocation of the vm_area_struct slab back for fork.c.

 (4) Use KMEM_CACHE() for both vm_area_struct and vm_region slabs.

 (5) Use BUG_ON() rather than if () BUG().

 (6) Make the default validate_nommu_regions() a static inline rather than a
     #define.

 (7) Make free_page_series()'s objection to pages with a refcount != 1 more
     informative.

 (8) Adjust the __put_nommu_region() banner comment to indicate that the
     semaphore must be held for writing.

 (9) Limit the number of warnings about munmaps of non-mmapped regions.

Reported-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5482415a

fs/proc/meminfo.c

+1 −1
Original line number Diff line number Diff line
@@ -120,7 +120,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v) 
		K(i.freeram-i.freehigh),

#endif

#ifndef CONFIG_MMU

		K((unsigned long) atomic_read(&mmap_pages_allocated)),

		K((unsigned long) atomic_long_read(&mmap_pages_allocated)),

#endif

		K(i.totalswap),

		K(i.freeswap),

fs/proc/task_nommu.c

+2 −2
Original line number Diff line number Diff line
@@ -136,14 +136,14 @@ static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma) 
	}



	seq_printf(m,

		   "%08lx-%08lx %c%c%c%c %08lx %02x:%02x %lu %n",

		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",

		   vma->vm_start,

		   vma->vm_end,

		   flags & VM_READ ? 'r' : '-',

		   flags & VM_WRITE ? 'w' : '-',

		   flags & VM_EXEC ? 'x' : '-',

		   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',

		   vma->vm_pgoff << PAGE_SHIFT,

		   (unsigned long long) vma->vm_pgoff << PAGE_SHIFT,

		   MAJOR(dev), MINOR(dev), ino, &len);



	if (file) {

include/linux/mm.h

+1 −1
Original line number Diff line number Diff line
@@ -1079,7 +1079,7 @@ static inline void setup_per_cpu_pageset(void) {} 
#endif



/* nommu.c */

extern atomic_t mmap_pages_allocated;

extern atomic_long_t mmap_pages_allocated;



/* prio_tree.c */

void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);

kernel/fork.c

+1 −0
Original line number Diff line number Diff line
@@ -1488,6 +1488,7 @@ void __init proc_caches_init(void) 
	mm_cachep = kmem_cache_create("mm_struct",

			sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,

			SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);

	vm_area_cachep = KMEM_CACHE(vm_area_struct, SLAB_PANIC);

	mmap_init();

}

mm/mmap.c

+0 −3
Original line number Diff line number Diff line
@@ -2481,7 +2481,4 @@ void mm_drop_all_locks(struct mm_struct *mm) 
 */

void __init mmap_init(void)

{

	vm_area_cachep = kmem_cache_create("vm_area_struct",

			sizeof(struct vm_area_struct), 0,

			SLAB_PANIC, NULL);

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE