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authorLinus Torvalds <torvalds@linux-foundation.org>2016-05-28 01:57:31 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-28 01:57:31 +0300
commit5d22fc25d4fc8096d2d7df27ea1893d4e055e764 (patch)
tree464a86dc3d004dd334e37a8fe7e7b42f8511581e /mm/mmap.c
parent287980e49ffc0f6d911601e7e352a812ed27768e (diff)
downloadlinux-5d22fc25d4fc8096d2d7df27ea1893d4e055e764.tar.xz
mm: remove more IS_ERR_VALUE abuses
The do_brk() and vm_brk() return value was "unsigned long" and returned the starting address on success, and an error value on failure. The reasons are entirely historical, and go back to it basically behaving like the mmap() interface does. However, nobody actually wanted that interface, and it causes totally pointless IS_ERR_VALUE() confusion. What every single caller actually wants is just the simpler integer return of zero for success and negative error number on failure. So just convert to that much clearer and more common calling convention, and get rid of all the IS_ERR_VALUE() uses wrt vm_brk(). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
-rw-r--r--mm/mmap.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index d3d9a94ca031..de2c1769cc68 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -168,7 +168,7 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma)
return next;
}
-static unsigned long do_brk(unsigned long addr, unsigned long len);
+static int do_brk(unsigned long addr, unsigned long len);
SYSCALL_DEFINE1(brk, unsigned long, brk)
{
@@ -224,7 +224,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
goto out;
/* Ok, looks good - let it rip. */
- if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk)
+ if (do_brk(oldbrk, newbrk-oldbrk) < 0)
goto out;
set_brk:
@@ -2625,7 +2625,7 @@ static inline void verify_mm_writelocked(struct mm_struct *mm)
* anonymous maps. eventually we may be able to do some
* brk-specific accounting here.
*/
-static unsigned long do_brk(unsigned long addr, unsigned long len)
+static int do_brk(unsigned long addr, unsigned long len)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma, *prev;
@@ -2636,7 +2636,7 @@ static unsigned long do_brk(unsigned long addr, unsigned long len)
len = PAGE_ALIGN(len);
if (!len)
- return addr;
+ return 0;
flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
@@ -2703,13 +2703,13 @@ out:
if (flags & VM_LOCKED)
mm->locked_vm += (len >> PAGE_SHIFT);
vma->vm_flags |= VM_SOFTDIRTY;
- return addr;
+ return 0;
}
-unsigned long vm_brk(unsigned long addr, unsigned long len)
+int vm_brk(unsigned long addr, unsigned long len)
{
struct mm_struct *mm = current->mm;
- unsigned long ret;
+ int ret;
bool populate;
if (down_write_killable(&mm->mmap_sem))
@@ -2718,7 +2718,7 @@ unsigned long vm_brk(unsigned long addr, unsigned long len)
ret = do_brk(addr, len);
populate = ((mm->def_flags & VM_LOCKED) != 0);
up_write(&mm->mmap_sem);
- if (populate)
+ if (populate && !ret)
mm_populate(addr, len);
return ret;
}