| Message ID | 20250330121718.175815-2-bhe@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/gup: Minor fix, cleanup and improvements | expand |
在 2025/3/30 14:17, Baoquan He 写道: > Not like fault_in_writeable() or fault_in_writeable(), in fault_in_readable()? In the above, one of the 2 fault_in_writeable should be fault_in_readable() ? Zhu Yanjun > fault_in_safe_writeable() local variable 'start' is increased page > by page to loop till the whole address range is handled. However, > it mistakenly calcalates the size of handled range with 'uaddr - start'. > > Fix it here. > > Signed-off-by: Baoquan He <bhe@redhat.com> > --- > mm/gup.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/gup.c b/mm/gup.c > index 855ab860f88b..73777b1de679 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -2207,8 +2207,8 @@ size_t fault_in_safe_writeable(const char __user *uaddr, size_t size) > } while (start != end); > mmap_read_unlock(mm); > > - if (size > (unsigned long)uaddr - start) > - return size - ((unsigned long)uaddr - start); > + if (size > start - (unsigned long)uaddr) > + return size - (start - (unsigned long)uaddr); > return 0; > } > EXPORT_SYMBOL(fault_in_safe_writeable);
On 03/30/25 at 09:43pm, Zhu Yanjun wrote: > 在 2025/3/30 14:17, Baoquan He 写道: > > Not like fault_in_writeable() or fault_in_writeable(), in > fault_in_readable()? > > In the above, one of the 2 fault_in_writeable should be fault_in_readable() > ? You are right, I will fix it in v2. Thanks. > > fault_in_safe_writeable() local variable 'start' is increased page > > by page to loop till the whole address range is handled. However, > > it mistakenly calcalates the size of handled range with 'uaddr - start'. > > > > Fix it here. > > > > Signed-off-by: Baoquan He <bhe@redhat.com> > > --- > > mm/gup.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/mm/gup.c b/mm/gup.c > > index 855ab860f88b..73777b1de679 100644 > > --- a/mm/gup.c > > +++ b/mm/gup.c > > @@ -2207,8 +2207,8 @@ size_t fault_in_safe_writeable(const char __user *uaddr, size_t size) > > } while (start != end); > > mmap_read_unlock(mm); > > - if (size > (unsigned long)uaddr - start) > > - return size - ((unsigned long)uaddr - start); > > + if (size > start - (unsigned long)uaddr) > > + return size - (start - (unsigned long)uaddr); > > return 0; > > } > > EXPORT_SYMBOL(fault_in_safe_writeable); > >
diff --git a/mm/gup.c b/mm/gup.c index 855ab860f88b..73777b1de679 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2207,8 +2207,8 @@ size_t fault_in_safe_writeable(const char __user *uaddr, size_t size) } while (start != end); mmap_read_unlock(mm); - if (size > (unsigned long)uaddr - start) - return size - ((unsigned long)uaddr - start); + if (size > start - (unsigned long)uaddr) + return size - (start - (unsigned long)uaddr); return 0; } EXPORT_SYMBOL(fault_in_safe_writeable);
Not like fault_in_writeable() or fault_in_writeable(), in fault_in_safe_writeable() local variable 'start' is increased page by page to loop till the whole address range is handled. However, it mistakenly calcalates the size of handled range with 'uaddr - start'. Fix it here. Signed-off-by: Baoquan He <bhe@redhat.com> --- mm/gup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)