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mm/mmap.c: use IS_ERR_VALUE to check return value of get_unmapped_area

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get_unmapped_area() returns an address or -errno on failure.  Historically
we have checked for the failure by offset_in_page() which is correct but
quite hard to read.  Newer code started using IS_ERR_VALUE which is much
easier to read.  Convert remaining users of offset_in_page as well.

[mhocko@suse.com: rewrite changelog]
[mhocko@kernel.org: fix mremap.c and uprobes.c sites also]
Link: http://lkml.kernel.org/r/20191012102512.28051-1-pugaowei@gmail.com
Signed-off-by: Gaowei Pu <pugaowei@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Gaowei Pu 2019-11-30 17:51:03 -08:00 committed by Linus Torvalds
parent 4e4a9eb921
commit ff68dac6d6
3 changed files with 8 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
kernel/events/uprobes.c
View File

@ -1457,7 +1457,7 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area)
/* Try to map as high as possible, this is only a hint. */ /* Try to map as high as possible, this is only a hint. */
area->vaddr = get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE, area->vaddr = get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE,
PAGE_SIZE, 0, 0); PAGE_SIZE, 0, 0);
if (area->vaddr & ~PAGE_MASK) { if (IS_ERR_VALUE(area->vaddr)) {
ret = area->vaddr; ret = area->vaddr;
goto fail; goto fail;
} }

9
mm/mmap.c
View File

@ -1417,7 +1417,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
* that it represents a valid section of the address space. * that it represents a valid section of the address space.
*/ */
addr = get_unmapped_area(file, addr, len, pgoff, flags); addr = get_unmapped_area(file, addr, len, pgoff, flags);
if (offset_in_page(addr)) if (IS_ERR_VALUE(addr))
return addr; return addr;
if (flags & MAP_FIXED_NOREPLACE) { if (flags & MAP_FIXED_NOREPLACE) {
@ -2981,15 +2981,16 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla
struct rb_node **rb_link, *rb_parent; struct rb_node **rb_link, *rb_parent;
pgoff_t pgoff = addr >> PAGE_SHIFT; pgoff_t pgoff = addr >> PAGE_SHIFT;
int error; int error;
unsigned long mapped_addr;
/* Until we need other flags, refuse anything except VM_EXEC. */ /* Until we need other flags, refuse anything except VM_EXEC. */
if ((flags & (~VM_EXEC)) != 0) if ((flags & (~VM_EXEC)) != 0)
return -EINVAL; return -EINVAL;
flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags; flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
error = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED); mapped_addr = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED);
if (offset_in_page(error)) if (IS_ERR_VALUE(mapped_addr))
return error; return mapped_addr;
error = mlock_future_check(mm, mm->def_flags, len); error = mlock_future_check(mm, mm->def_flags, len);
if (error) if (error)

4
mm/mremap.c
View File

@ -558,7 +558,7 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
ret = get_unmapped_area(vma->vm_file, new_addr, new_len, vma->vm_pgoff + ret = get_unmapped_area(vma->vm_file, new_addr, new_len, vma->vm_pgoff +
((addr - vma->vm_start) >> PAGE_SHIFT), ((addr - vma->vm_start) >> PAGE_SHIFT),
map_flags); map_flags);
if (offset_in_page(ret)) if (IS_ERR_VALUE(ret))
goto out1; goto out1;
ret = move_vma(vma, addr, old_len, new_len, new_addr, locked, uf, ret = move_vma(vma, addr, old_len, new_len, new_addr, locked, uf,
@ -706,7 +706,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
vma->vm_pgoff + vma->vm_pgoff +
((addr - vma->vm_start) >> PAGE_SHIFT), ((addr - vma->vm_start) >> PAGE_SHIFT),
map_flags); map_flags);
if (offset_in_page(new_addr)) { if (IS_ERR_VALUE(new_addr)) {
ret = new_addr; ret = new_addr;
goto out; goto out;
} }