[PATCH 17/34] mm: Update validate_mm() to use vma iterator
From: Liam R. Howlett
Date: Tue Apr 25 2023 - 10:12:46 EST
Use the vma iterator in the validation code and combine the code to
check the maple tree into the main validate_mm() function.
Introduce a new function vma_iter_dump_tree() to dump the maple tree in
hex layout.
Replace all calls to validate_mm_mt() with validate_mm().
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
include/linux/mmdebug.h | 14 ++++++
mm/debug.c | 9 ++++
mm/internal.h | 3 +-
mm/mmap.c | 101 ++++++++++++++++------------------------
4 files changed, 66 insertions(+), 61 deletions(-)
diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h
index b8728d11c9490..7c3e7b0b0e8fd 100644
--- a/include/linux/mmdebug.h
+++ b/include/linux/mmdebug.h
@@ -8,10 +8,12 @@
struct page;
struct vm_area_struct;
struct mm_struct;
+struct vma_iterator;
void dump_page(struct page *page, const char *reason);
void dump_vma(const struct vm_area_struct *vma);
void dump_mm(const struct mm_struct *mm);
+void vma_iter_dump_tree(const struct vma_iterator *vmi);
#ifdef CONFIG_DEBUG_VM
#define VM_BUG_ON(cond) BUG_ON(cond)
@@ -74,6 +76,17 @@ void dump_mm(const struct mm_struct *mm);
} \
unlikely(__ret_warn_once); \
})
+#define VM_WARN_ON_ONCE_MM(cond, mm) ({ \
+ static bool __section(".data.once") __warned; \
+ int __ret_warn_once = !!(cond); \
+ \
+ if (unlikely(__ret_warn_once && !__warned)) { \
+ dump_mm(mm); \
+ __warned = true; \
+ WARN_ON(1); \
+ } \
+ unlikely(__ret_warn_once); \
+})
#define VM_WARN_ON(cond) (void)WARN_ON(cond)
#define VM_WARN_ON_ONCE(cond) (void)WARN_ON_ONCE(cond)
@@ -90,6 +103,7 @@ void dump_mm(const struct mm_struct *mm);
#define VM_WARN_ON_ONCE_PAGE(cond, page) BUILD_BUG_ON_INVALID(cond)
#define VM_WARN_ON_FOLIO(cond, folio) BUILD_BUG_ON_INVALID(cond)
#define VM_WARN_ON_ONCE_FOLIO(cond, folio) BUILD_BUG_ON_INVALID(cond)
+#define VM_WARN_ON_ONCE_MM(cond, mm) BUILD_BUG_ON_INVALID(cond)
#define VM_WARN_ONCE(cond, format...) BUILD_BUG_ON_INVALID(cond)
#define VM_WARN(cond, format...) BUILD_BUG_ON_INVALID(cond)
#endif
diff --git a/mm/debug.c b/mm/debug.c
index c7b228097bd98..ee533a5ceb79d 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -268,4 +268,13 @@ void page_init_poison(struct page *page, size_t size)
if (page_init_poisoning)
memset(page, PAGE_POISON_PATTERN, size);
}
+
+void vma_iter_dump_tree(const struct vma_iterator *vmi)
+{
+#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
+ mas_dump(&vmi->mas);
+ mt_dump(vmi->mas.tree, mt_dump_hex);
+#endif /* CONFIG_DEBUG_VM_MAPLE_TREE */
+}
+
#endif /* CONFIG_DEBUG_VM */
diff --git a/mm/internal.h b/mm/internal.h
index 4c195920f5656..8d1a8bd001247 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1051,13 +1051,14 @@ static inline void vma_iter_store(struct vma_iterator *vmi,
printk("%lu > %lu\n", vmi->mas.index, vma->vm_start);
printk("store of vma %lu-%lu", vma->vm_start, vma->vm_end);
printk("into slot %lu-%lu", vmi->mas.index, vmi->mas.last);
- mt_dump(vmi->mas.tree, mt_dump_hex);
+ vma_iter_dump_tree(vmi);
}
if (WARN_ON(vmi->mas.node != MAS_START && vmi->mas.last < vma->vm_start)) {
printk("%lu < %lu\n", vmi->mas.last, vma->vm_start);
printk("store of vma %lu-%lu", vma->vm_start, vma->vm_end);
printk("into slot %lu-%lu", vmi->mas.index, vmi->mas.last);
mt_dump(vmi->mas.tree, mt_dump_hex);
+ vma_iter_dump_tree(vmi);
}
#endif
diff --git a/mm/mmap.c b/mm/mmap.c
index 1554f90d497ef..d34a41791ddb2 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -299,62 +299,44 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
return origbrk;
}
-#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
-extern void mt_validate(struct maple_tree *mt);
-extern void mt_dump(const struct maple_tree *mt, enum mt_dump_format fmt);
-
-/* Validate the maple tree */
-static void validate_mm_mt(struct mm_struct *mm)
-{
- struct maple_tree *mt = &mm->mm_mt;
- struct vm_area_struct *vma_mt;
-
- MA_STATE(mas, mt, 0, 0);
-
- mt_validate(&mm->mm_mt);
- mas_for_each(&mas, vma_mt, ULONG_MAX) {
- if ((vma_mt->vm_start != mas.index) ||
- (vma_mt->vm_end - 1 != mas.last)) {
- pr_emerg("issue in %s\n", current->comm);
- dump_stack();
- dump_vma(vma_mt);
- pr_emerg("mt piv: %p %lu - %lu\n", vma_mt,
- mas.index, mas.last);
- pr_emerg("mt vma: %p %lu - %lu\n", vma_mt,
- vma_mt->vm_start, vma_mt->vm_end);
-
- mt_dump(mas.tree, mt_dump_hex);
- if (vma_mt->vm_end != mas.last + 1) {
- pr_err("vma: %p vma_mt %lu-%lu\tmt %lu-%lu\n",
- mm, vma_mt->vm_start, vma_mt->vm_end,
- mas.index, mas.last);
- mt_dump(mas.tree, mt_dump_hex);
- }
- VM_BUG_ON_MM(vma_mt->vm_end != mas.last + 1, mm);
- if (vma_mt->vm_start != mas.index) {
- pr_err("vma: %p vma_mt %p %lu - %lu doesn't match\n",
- mm, vma_mt, vma_mt->vm_start, vma_mt->vm_end);
- mt_dump(mas.tree, mt_dump_hex);
- }
- VM_BUG_ON_MM(vma_mt->vm_start != mas.index, mm);
- }
- }
-}
-
+#if defined(CONFIG_DEBUG_VM)
static void validate_mm(struct mm_struct *mm)
{
int bug = 0;
int i = 0;
struct vm_area_struct *vma;
- MA_STATE(mas, &mm->mm_mt, 0, 0);
+ VMA_ITERATOR(vmi, mm, 0);
- validate_mm_mt(mm);
+#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
+ mt_validate(&mm->mm_mt);
+#endif
- mas_for_each(&mas, vma, ULONG_MAX) {
+ for_each_vma(vmi, vma) {
#ifdef CONFIG_DEBUG_VM_RB
struct anon_vma *anon_vma = vma->anon_vma;
struct anon_vma_chain *avc;
+#endif
+ unsigned long vmi_start, vmi_end;
+ bool warn = 0;
+
+ vmi_start = vma_iter_addr(&vmi);
+ vmi_end = vma_iter_end(&vmi);
+ if (VM_WARN_ON_ONCE_MM(vma->vm_end != vmi_end, mm))
+ warn = 1;
+
+ if (VM_WARN_ON_ONCE_MM(vma->vm_start != vmi_start, mm))
+ warn = 1;
+
+ if (warn) {
+ pr_emerg("issue in %s\n", current->comm);
+ dump_stack();
+ dump_vma(vma);
+ pr_emerg("tree range: %px start %lx end %lx\n", vma,
+ vmi_start, vmi_end - 1);
+ vma_iter_dump_tree(&vmi);
+ }
+#ifdef CONFIG_DEBUG_VM_RB
if (anon_vma) {
anon_vma_lock_read(anon_vma);
list_for_each_entry(avc, &vma->anon_vma_chain, same_vma)
@@ -365,16 +347,15 @@ static void validate_mm(struct mm_struct *mm)
i++;
}
if (i != mm->map_count) {
- pr_emerg("map_count %d mas_for_each %d\n", mm->map_count, i);
+ pr_emerg("map_count %d vma iterator %d\n", mm->map_count, i);
bug = 1;
}
VM_BUG_ON_MM(bug, mm);
}
-#else /* !CONFIG_DEBUG_VM_MAPLE_TREE */
-#define validate_mm_mt(root) do { } while (0)
+#else /* !CONFIG_DEBUG_VM */
#define validate_mm(mm) do { } while (0)
-#endif /* CONFIG_DEBUG_VM_MAPLE_TREE */
+#endif /* CONFIG_DEBUG_VM */
/*
* vma has some anon_vma assigned, and is already inserted on that
@@ -2234,7 +2215,7 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
struct vm_area_struct *new;
int err;
- validate_mm_mt(vma->vm_mm);
+ validate_mm(vma->vm_mm);
WARN_ON(vma->vm_start >= addr);
WARN_ON(vma->vm_end <= addr);
@@ -2292,7 +2273,7 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
/* Success. */
if (new_below)
vma_next(vmi);
- validate_mm_mt(vma->vm_mm);
+ validate_mm(vma->vm_mm);
return 0;
out_free_mpol:
@@ -2301,7 +2282,7 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
vma_iter_free(vmi);
out_free_vma:
vm_area_free(new);
- validate_mm_mt(vma->vm_mm);
+ validate_mm(vma->vm_mm);
return err;
}
@@ -2936,7 +2917,7 @@ int do_vma_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
arch_unmap(mm, start, end);
ret = do_vmi_align_munmap(vmi, vma, mm, start, end, uf, downgrade);
- validate_mm_mt(mm);
+ validate_mm(mm);
return ret;
}
@@ -2958,7 +2939,7 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
struct mm_struct *mm = current->mm;
struct vma_prepare vp;
- validate_mm_mt(mm);
+ validate_mm(mm);
/*
* Check against address space limits by the changed size
* Note: This happens *after* clearing old mappings in some code paths.
@@ -3199,7 +3180,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
bool faulted_in_anon_vma = true;
VMA_ITERATOR(vmi, mm, addr);
- validate_mm_mt(mm);
+ validate_mm(mm);
/*
* If anonymous vma has not yet been faulted, update new pgoff
* to match new location, to increase its chance of merging.
@@ -3258,7 +3239,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
goto out_vma_link;
*need_rmap_locks = false;
}
- validate_mm_mt(mm);
+ validate_mm(mm);
return new_vma;
out_vma_link:
@@ -3274,7 +3255,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
out_free_vma:
vm_area_free(new_vma);
out:
- validate_mm_mt(mm);
+ validate_mm(mm);
return NULL;
}
@@ -3411,7 +3392,7 @@ static struct vm_area_struct *__install_special_mapping(
int ret;
struct vm_area_struct *vma;
- validate_mm_mt(mm);
+ validate_mm(mm);
vma = vm_area_alloc(mm);
if (unlikely(vma == NULL))
return ERR_PTR(-ENOMEM);
@@ -3434,12 +3415,12 @@ static struct vm_area_struct *__install_special_mapping(
perf_event_mmap(vma);
- validate_mm_mt(mm);
+ validate_mm(mm);
return vma;
out:
vm_area_free(vma);
- validate_mm_mt(mm);
+ validate_mm(mm);
return ERR_PTR(ret);
}
--
2.39.2