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

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>

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index c747610..ece7e13 100644 (file)
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -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. */
                area->vaddr = get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE,
                                                PAGE_SIZE, 0, 0);
-               if (area->vaddr & ~PAGE_MASK) {
+               if (IS_ERR_VALUE(area->vaddr)) {
                        ret = area->vaddr;
                        goto fail;
                }

diff --git a/mm/mmap.c b/mm/mmap.c
index 311b08f..b9d0c2f 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1417,7 +1417,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
         * that it represents a valid section of the address space.
         */
        addr = get_unmapped_area(file, addr, len, pgoff, flags);
-       if (offset_in_page(addr))
+       if (IS_ERR_VALUE(addr))
                return addr;
 
        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;
        pgoff_t pgoff = addr >> PAGE_SHIFT;
        int error;
+       unsigned long mapped_addr;
 
        /* Until we need other flags, refuse anything except VM_EXEC. */
        if ((flags & (~VM_EXEC)) != 0)
                return -EINVAL;
        flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
 
-       error = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED);
-       if (offset_in_page(error))
-               return error;
+       mapped_addr = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED);
+       if (IS_ERR_VALUE(mapped_addr))
+               return mapped_addr;
 
        error = mlock_future_check(mm, mm->def_flags, len);
        if (error)

diff --git a/mm/mremap.c b/mm/mremap.c
index 1fc8a29..122938d 100644 (file)
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -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 +
                                ((addr - vma->vm_start) >> PAGE_SHIFT),
                                map_flags);
-       if (offset_in_page(ret))
+       if (IS_ERR_VALUE(ret))
                goto out1;
 
        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 +
                                        ((addr - vma->vm_start) >> PAGE_SHIFT),
                                        map_flags);
-               if (offset_in_page(new_addr)) {
+               if (IS_ERR_VALUE(new_addr)) {
                        ret = new_addr;
                        goto out;
                }