diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h
index 772362adf471..053824b0a412 100644
--- a/include/linux/mmdebug.h
+++ b/include/linux/mmdebug.h
@@ -56,4 +56,10 @@ void dump_mm(const struct mm_struct *mm);
#define VIRTUAL_BUG_ON(cond) do { } while (0)
#endif
+#ifdef CONFIG_DEBUG_VM_PGFLAGS
+#define VM_BUG_ON_PGFLAGS(cond, page) VM_BUG_ON_PAGE(cond, page)
+#else
+#define VM_BUG_ON_PGFLAGS(cond, page) BUILD_BUG_ON_INVALID(cond)
+#endif
+
#endif
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 83161a22509c..12ab023b67f2 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -154,49 +154,80 @@ static inline int PageCompound(struct page *page)
return test_bit(PG_head, &page->flags) || PageTail(page);
}
+/*
+ * Page flags policies wrt compound pages
+ *
+ * PF_ANY:
+ * the page flag is relevant for small, head and tail pages.
+ *
+ * PF_HEAD:
+ * for compound page all operations related to the page flag applied to
+ * head page.
+ *
+ * PF_NO_TAIL:
+ * modifications of the page flag must be done on small or head pages,
+ * checks can be done on tail pages too.
+ *
+ * PF_NO_COMPOUND:
+ * the page flag is not relevant for compound pages.
+ */
+#define PF_ANY(page, enforce) page
+#define PF_HEAD(page, enforce) compound_head(page)
+#define PF_NO_TAIL(page, enforce) ({ \
+ VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \
+ compound_head(page);})
+#define PF_NO_COMPOUND(page, enforce) ({ \
+ VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \
+ page;})
+
/*
* Macros to create function definitions for page flags
*/
-#define TESTPAGEFLAG(uname, lname) \
-static inline int Page##uname(const struct page *page) \
- { return test_bit(PG_##lname, &page->flags); }
+#define TESTPAGEFLAG(uname, lname, policy) \
+static inline int Page##uname(struct page *page) \
+ { return test_bit(PG_##lname, &policy(page, 0)->flags); }
-#define SETPAGEFLAG(uname, lname) \
+#define SETPAGEFLAG(uname, lname, policy) \
static inline void SetPage##uname(struct page *page) \
- { set_bit(PG_##lname, &page->flags); }
+ { set_bit(PG_##lname, &policy(page, 1)->flags); }
-#define CLEARPAGEFLAG(uname, lname) \
+#define CLEARPAGEFLAG(uname, lname, policy) \
static inline void ClearPage##uname(struct page *page) \
- { clear_bit(PG_##lname, &page->flags); }
+ { clear_bit(PG_##lname, &policy(page, 1)->flags); }
-#define __SETPAGEFLAG(uname, lname) \
+#define __SETPAGEFLAG(uname, lname, policy) \
static inline void __SetPage##uname(struct page *page) \
- { __set_bit(PG_##lname, &page->flags); }
+ { __set_bit(PG_##lname, &policy(page, 1)->flags); }
-#define __CLEARPAGEFLAG(uname, lname) \
+#define __CLEARPAGEFLAG(uname, lname, policy) \
static inline void __ClearPage##uname(struct page *page) \
- { __clear_bit(PG_##lname, &page->flags); }
+ { __clear_bit(PG_##lname, &policy(page, 1)->flags); }
-#define TESTSETFLAG(uname, lname) \
+#define TESTSETFLAG(uname, lname, policy) \
static inline int TestSetPage##uname(struct page *page) \
- { return test_and_set_bit(PG_##lname, &page->flags); }
+ { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); }
-#define TESTCLEARFLAG(uname, lname) \
+#define TESTCLEARFLAG(uname, lname, policy) \
static inline int TestClearPage##uname(struct page *page) \
- { return test_and_clear_bit(PG_##lname, &page->flags); }
+ { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); }
-#define __TESTCLEARFLAG(uname, lname) \
+#define __TESTCLEARFLAG(uname, lname, policy) \
static inline int __TestClearPage##uname(struct page *page) \
- { return __test_and_clear_bit(PG_##lname, &page->flags); }
+ { return __test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); }
-#define PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \
- SETPAGEFLAG(uname, lname) CLEARPAGEFLAG(uname, lname)
+#define PAGEFLAG(uname, lname, policy) \
+ TESTPAGEFLAG(uname, lname, policy) \
+ SETPAGEFLAG(uname, lname, policy) \
+ CLEARPAGEFLAG(uname, lname, policy)
-#define __PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \
- __SETPAGEFLAG(uname, lname) __CLEARPAGEFLAG(uname, lname)
+#define __PAGEFLAG(uname, lname, policy) \
+ TESTPAGEFLAG(uname, lname, policy) \
+ __SETPAGEFLAG(uname, lname, policy) \
+ __CLEARPAGEFLAG(uname, lname, policy)
-#define TESTSCFLAG(uname, lname) \
- TESTSETFLAG(uname, lname) TESTCLEARFLAG(uname, lname)
+#define TESTSCFLAG(uname, lname, policy) \
+ TESTSETFLAG(uname, lname, policy) \
+ TESTCLEARFLAG(uname, lname, policy)
#define TESTPAGEFLAG_FALSE(uname) \
static inline int Page##uname(const struct page *page) { return 0; }
@@ -225,46 +256,48 @@ static inline int __TestClearPage##uname(struct page *page) { return 0; }
#define TESTSCFLAG_FALSE(uname) \
TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname)
+TESTPAGEFLAG(Locked, locked, PF_ANY)
+PAGEFLAG(Error, error, PF_ANY) TESTCLEARFLAG(Error, error, PF_ANY)
+PAGEFLAG(Referenced, referenced, PF_ANY) TESTCLEARFLAG(Referenced, referenced, PF_ANY)
+ __SETPAGEFLAG(Referenced, referenced, PF_ANY)
+PAGEFLAG(Dirty, dirty, PF_ANY) TESTSCFLAG(Dirty, dirty, PF_ANY)
+ __CLEARPAGEFLAG(Dirty, dirty, PF_ANY)
+PAGEFLAG(LRU, lru, PF_ANY) __CLEARPAGEFLAG(LRU, lru, PF_ANY)
+PAGEFLAG(Active, active, PF_ANY) __CLEARPAGEFLAG(Active, active, PF_ANY)
+ TESTCLEARFLAG(Active, active, PF_ANY)
+__PAGEFLAG(Slab, slab, PF_ANY)
+PAGEFLAG(Checked, checked, PF_ANY) /* Used by some filesystems */
+PAGEFLAG(Pinned, pinned, PF_ANY) TESTSCFLAG(Pinned, pinned, PF_ANY) /* Xen */
+PAGEFLAG(SavePinned, savepinned, PF_ANY); /* Xen */
+PAGEFLAG(Foreign, foreign, PF_ANY); /* Xen */
+PAGEFLAG(Reserved, reserved, PF_ANY) __CLEARPAGEFLAG(Reserved, reserved, PF_ANY)
+PAGEFLAG(SwapBacked, swapbacked, PF_ANY)
+ __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_ANY)
+ __SETPAGEFLAG(SwapBacked, swapbacked, PF_ANY)
-TESTPAGEFLAG(Locked, locked)
-PAGEFLAG(Error, error) TESTCLEARFLAG(Error, error)
-PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced)
- __SETPAGEFLAG(Referenced, referenced)
-PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty)
-PAGEFLAG(LRU, lru) __CLEARPAGEFLAG(LRU, lru)
-PAGEFLAG(Active, active) __CLEARPAGEFLAG(Active, active)
- TESTCLEARFLAG(Active, active)
-__PAGEFLAG(Slab, slab)
-PAGEFLAG(Checked, checked) /* Used by some filesystems */
-PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinned, pinned) /* Xen */
-PAGEFLAG(SavePinned, savepinned); /* Xen */
-PAGEFLAG(Foreign, foreign); /* Xen */
-PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved)
-PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked)
- __SETPAGEFLAG(SwapBacked, swapbacked)
-
-__PAGEFLAG(SlobFree, slob_free)
+__PAGEFLAG(SlobFree, slob_free, PF_ANY)
/*
* Private page markings that may be used by the filesystem that owns the page
* for its own purposes.
* - PG_private and PG_private_2 cause releasepage() and co to be invoked
*/
-PAGEFLAG(Private, private) __SETPAGEFLAG(Private, private)
- __CLEARPAGEFLAG(Private, private)
-PAGEFLAG(Private2, private_2) TESTSCFLAG(Private2, private_2)
-PAGEFLAG(OwnerPriv1, owner_priv_1) TESTCLEARFLAG(OwnerPriv1, owner_priv_1)
+PAGEFLAG(Private, private, PF_ANY) __SETPAGEFLAG(Private, private, PF_ANY)
+ __CLEARPAGEFLAG(Private, private, PF_ANY)
+PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY)
+PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY)
+ TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY)
/*
* Only test-and-set exist for PG_writeback. The unconditional operators are
* risky: they bypass page accounting.
*/
-TESTPAGEFLAG(Writeback, writeback) TESTSCFLAG(Writeback, writeback)
-PAGEFLAG(MappedToDisk, mappedtodisk)
+TESTPAGEFLAG(Writeback, writeback, PF_ANY) TESTSCFLAG(Writeback, writeback, PF_ANY)
+PAGEFLAG(MappedToDisk, mappedtodisk, PF_ANY)
/* PG_readahead is only used for reads; PG_reclaim is only for writes */
-PAGEFLAG(Reclaim, reclaim) TESTCLEARFLAG(Reclaim, reclaim)
-PAGEFLAG(Readahead, reclaim) TESTCLEARFLAG(Readahead, reclaim)
+PAGEFLAG(Reclaim, reclaim, PF_ANY) TESTCLEARFLAG(Reclaim, reclaim, PF_ANY)
+PAGEFLAG(Readahead, reclaim, PF_ANY) TESTCLEARFLAG(Readahead, reclaim, PF_ANY)
#ifdef CONFIG_HIGHMEM
/*
@@ -277,31 +310,32 @@ PAGEFLAG_FALSE(HighMem)
#endif
#ifdef CONFIG_SWAP
-PAGEFLAG(SwapCache, swapcache)
+PAGEFLAG(SwapCache, swapcache, PF_ANY)
#else
PAGEFLAG_FALSE(SwapCache)
#endif
-PAGEFLAG(Unevictable, unevictable) __CLEARPAGEFLAG(Unevictable, unevictable)
- TESTCLEARFLAG(Unevictable, unevictable)
+PAGEFLAG(Unevictable, unevictable, PF_ANY)
+ __CLEARPAGEFLAG(Unevictable, unevictable, PF_ANY)
+ TESTCLEARFLAG(Unevictable, unevictable, PF_ANY)
#ifdef CONFIG_MMU
-PAGEFLAG(Mlocked, mlocked) __CLEARPAGEFLAG(Mlocked, mlocked)
- TESTSCFLAG(Mlocked, mlocked) __TESTCLEARFLAG(Mlocked, mlocked)
+PAGEFLAG(Mlocked, mlocked, PF_ANY) __CLEARPAGEFLAG(Mlocked, mlocked, PF_ANY)
+ TESTSCFLAG(Mlocked, mlocked, PF_ANY) __TESTCLEARFLAG(Mlocked, mlocked, PF_ANY)
#else
PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked)
TESTSCFLAG_FALSE(Mlocked) __TESTCLEARFLAG_FALSE(Mlocked)
#endif
#ifdef CONFIG_ARCH_USES_PG_UNCACHED
-PAGEFLAG(Uncached, uncached)
+PAGEFLAG(Uncached, uncached, PF_ANY)
#else
PAGEFLAG_FALSE(Uncached)
#endif
#ifdef CONFIG_MEMORY_FAILURE
-PAGEFLAG(HWPoison, hwpoison)
-TESTSCFLAG(HWPoison, hwpoison)
+PAGEFLAG(HWPoison, hwpoison, PF_ANY)
+TESTSCFLAG(HWPoison, hwpoison, PF_ANY)
#define __PG_HWPOISON (1UL << PG_hwpoison)
#else
PAGEFLAG_FALSE(HWPoison)
@@ -309,10 +343,10 @@ PAGEFLAG_FALSE(HWPoison)
#endif
#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT)
-TESTPAGEFLAG(Young, young)
-SETPAGEFLAG(Young, young)
-TESTCLEARFLAG(Young, young)
-PAGEFLAG(Idle, idle)
+TESTPAGEFLAG(Young, young, PF_ANY)
+SETPAGEFLAG(Young, young, PF_ANY)
+TESTCLEARFLAG(Young, young, PF_ANY)
+PAGEFLAG(Idle, idle, PF_ANY)
#endif
/*
@@ -393,7 +427,7 @@ static inline void SetPageUptodate(struct page *page)
set_bit(PG_uptodate, &(page)->flags);
}
-CLEARPAGEFLAG(Uptodate, uptodate)
+CLEARPAGEFLAG(Uptodate, uptodate, PF_ANY)
int test_clear_page_writeback(struct page *page);
int __test_set_page_writeback(struct page *page, bool keep_write);
@@ -413,7 +447,7 @@ static inline void set_page_writeback_keepwrite(struct page *page)
test_set_page_writeback_keepwrite(page);
}
-__PAGEFLAG(Head, head) CLEARPAGEFLAG(Head, head)
+__PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY)
static inline void set_compound_head(struct page *page, struct page *head)
{
@@ -615,6 +649,10 @@ static inline int page_has_private(struct page *page)
return !!(page->flags & PAGE_FLAGS_PRIVATE);
}
+#undef PF_ANY
+#undef PF_HEAD
+#undef PF_NO_TAIL
+#undef PF_NO_COMPOUND
#endif /* !__GENERATING_BOUNDS_H */
#endif /* PAGE_FLAGS_H */
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index ee1ac1cc082c..8fbdef1980a5 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -580,6 +580,14 @@ config DEBUG_VM_RB
If unsure, say N.
+config DEBUG_VM_PGFLAGS
+ bool "Debug page-flags operations"
+ depends on DEBUG_VM
+ help
+ Enables extra validation on page flags operations.
+
+ If unsure, say N.
+
config DEBUG_VIRTUAL
bool "Debug VM translations"
depends on DEBUG_KERNEL && X86