Commit 0cd22afd authored by John Hubbard's avatar John Hubbard Committed by Linus Torvalds

mm/gup: fix a misnamed "write" argument, and a related bug

In several routines, the "flags" argument is incorrectly named "write".
Change it to "flags".

Also, in one place, the misnaming led to an actual bug:
"flags & FOLL_WRITE" is required, rather than just "flags".
(That problem was flagged by krobot, in v1 of this patch.)

Also, change the flags argument from int, to unsigned int.

You can see that this was a simple oversight, because the
calling code passes "flags" to the fifth argument:

gup_pgd_range():
    ...
    if (!gup_huge_pd(__hugepd(pgd_val(pgd)), addr,
		    PGDIR_SHIFT, next, flags, pages, nr))

...which, until this patch, the callees referred to as "write".

Also, change two lines to avoid checkpatch line length
complaints, and another line to fix another oversight
that checkpatch called out: missing "int" on pdshift.

Link: http://lkml.kernel.org/r/20191014184639.1512873-3-jhubbard@nvidia.com
Fixes: b798bec4 ("mm/gup: change write parameter to flags in fast walk")
Signed-off-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Reported-by: default avatarkbuild test robot <lkp@intel.com>
Suggested-by: default avatarKirill A. Shutemov <kirill@shutemov.name>
Suggested-by: default avatarIra Weiny <ira.weiny@intel.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: default avatarIra Weiny <ira.weiny@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6f24c8d3
......@@ -1973,7 +1973,8 @@ static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
}
static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
unsigned long end, unsigned int flags,
struct page **pages, int *nr)
{
unsigned long pte_end;
struct page *head, *page;
......@@ -1986,7 +1987,7 @@ static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
pte = READ_ONCE(*ptep);
if (!pte_access_permitted(pte, write))
if (!pte_access_permitted(pte, flags & FOLL_WRITE))
return 0;
/* hugepages are never "special" */
......@@ -2023,7 +2024,7 @@ static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
}
static int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
unsigned int pdshift, unsigned long end, int write,
unsigned int pdshift, unsigned long end, unsigned int flags,
struct page **pages, int *nr)
{
pte_t *ptep;
......@@ -2033,7 +2034,7 @@ static int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
ptep = hugepte_offset(hugepd, addr, pdshift);
do {
next = hugepte_addr_end(addr, end, sz);
if (!gup_hugepte(ptep, sz, addr, end, write, pages, nr))
if (!gup_hugepte(ptep, sz, addr, end, flags, pages, nr))
return 0;
} while (ptep++, addr = next, addr != end);
......@@ -2041,7 +2042,7 @@ static int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
}
#else
static inline int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
unsigned pdshift, unsigned long end, int write,
unsigned int pdshift, unsigned long end, unsigned int flags,
struct page **pages, int *nr)
{
return 0;
......@@ -2049,7 +2050,8 @@ static inline int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
#endif /* CONFIG_ARCH_HAS_HUGEPD */
static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
unsigned long end, unsigned int flags, struct page **pages, int *nr)
unsigned long end, unsigned int flags,
struct page **pages, int *nr)
{
struct page *head, *page;
int refs;
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment