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authorJohn Hubbard <jhubbard@nvidia.com>2019-10-18 20:19:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-10-19 06:32:32 -0400
commit0cd22afdcea21fa16bb5b0d3e0508ca42072d0bd (patch)
treeeb856e14bac0ae8fb696c04d44c748cac9135f79
parent6f24c8d30d08f270b54f4c2cb9b08dfccbe59c57 (diff)
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: b798bec4741b ("mm/gup: change write parameter to flags in fast walk") Signed-off-by: John Hubbard <jhubbard@nvidia.com> Reported-by: kbuild test robot <lkp@intel.com> Suggested-by: Kirill A. Shutemov <kirill@shutemov.name> Suggested-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Ira 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/gup.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/mm/gup.c b/mm/gup.c
index 23a9f9c9d377..8f236a335ae9 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -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;