From: "Liam R. Howlett" <[email protected]>
Start tracking the VMAs with the new maple tree structure in parallel with
the rb_tree. Add debug and trace events for maple tree operations and
duplicate the rb_tree that is created on forks into the maple tree.
The maple tree is added to the mm_struct including the mm_init struct,
added support in required mm/mmap functions, added tracking in kernel/fork
for process forking, and used to find the unmapped_area and checked
against what the rbtree finds.
This also moves the mmap_lock() in exit_mmap() since the oom reaper call
does walk the VMAs. Otherwise lockdep will be unhappy if oom happens.
Signed-off-by: Liam R. Howlett <[email protected]>
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
---
arch/x86/kernel/tboot.c | 1 +
drivers/firmware/efi/efi.c | 1 +
include/linux/mm.h | 2 +
include/linux/mm_types.h | 3 +
include/trace/events/mmap.h | 73 ++++++++
kernel/fork.c | 20 ++-
mm/init-mm.c | 2 +
mm/mmap.c | 323 +++++++++++++++++++++++++++++++++---
8 files changed, 396 insertions(+), 29 deletions(-)
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index f9af561c3cd4..859e8d2ea070 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -98,6 +98,7 @@ void __init tboot_probe(void)
static pgd_t *tboot_pg_dir;
static struct mm_struct tboot_mm = {
.mm_rb = RB_ROOT,
+ .mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, tboot_mm.mmap_lock),
.pgd = swapper_pg_dir,
.mm_users = ATOMIC_INIT(2),
.mm_count = ATOMIC_INIT(1),
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 5502e176d51b..92a765d8d3b6 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -55,6 +55,7 @@ static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
struct mm_struct efi_mm = {
.mm_rb = RB_ROOT,
+ .mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, efi_mm.mmap_lock),
.mm_users = ATOMIC_INIT(2),
.mm_count = ATOMIC_INIT(1),
.write_protect_seq = SEQCNT_ZERO(efi_mm.write_protect_seq),
diff --git a/include/linux/mm.h b/include/linux/mm.h
index b9316b2c11ce..d42dc897a913 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2574,6 +2574,8 @@ extern bool arch_has_descending_max_zone_pfns(void);
/* nommu.c */
extern atomic_long_t mmap_pages_allocated;
extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
+/* mmap.c */
+void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas);
/* interval_tree.c */
void vma_interval_tree_insert(struct vm_area_struct *node,
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 87eddd509de2..645715a4a89d 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -9,6 +9,7 @@
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/rbtree.h>
+#include <linux/maple_tree.h>
#include <linux/rwsem.h>
#include <linux/completion.h>
#include <linux/cpumask.h>
@@ -476,6 +477,7 @@ struct kioctx_table;
struct mm_struct {
struct {
struct vm_area_struct *mmap; /* list of VMAs */
+ struct maple_tree mm_mt;
struct rb_root mm_rb;
u64 vmacache_seqnum; /* per-thread vmacache */
#ifdef CONFIG_MMU
@@ -671,6 +673,7 @@ struct mm_struct {
unsigned long cpu_bitmap[];
};
+#define MM_MT_FLAGS (MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN)
extern struct mm_struct init_mm;
/* Pointer magic because the dynamic array size confuses some compilers. */
diff --git a/include/trace/events/mmap.h b/include/trace/events/mmap.h
index 4661f7ba07c0..216de5f03621 100644
--- a/include/trace/events/mmap.h
+++ b/include/trace/events/mmap.h
@@ -42,6 +42,79 @@ TRACE_EVENT(vm_unmapped_area,
__entry->low_limit, __entry->high_limit, __entry->align_mask,
__entry->align_offset)
);
+
+TRACE_EVENT(vma_mas_szero,
+ TP_PROTO(struct maple_tree *mt, unsigned long start,
+ unsigned long end),
+
+ TP_ARGS(mt, start, end),
+
+ TP_STRUCT__entry(
+ __field(struct maple_tree *, mt)
+ __field(unsigned long, start)
+ __field(unsigned long, end)
+ ),
+
+ TP_fast_assign(
+ __entry->mt = mt;
+ __entry->start = start;
+ __entry->end = end;
+ ),
+
+ TP_printk("mt_mod %p, (NULL), SNULL, %lu, %lu,",
+ __entry->mt,
+ (unsigned long) __entry->start,
+ (unsigned long) __entry->end
+ )
+);
+
+TRACE_EVENT(vma_store,
+ TP_PROTO(struct maple_tree *mt, struct vm_area_struct *vma),
+
+ TP_ARGS(mt, vma),
+
+ TP_STRUCT__entry(
+ __field(struct maple_tree *, mt)
+ __field(struct vm_area_struct *, vma)
+ __field(unsigned long, vm_start)
+ __field(unsigned long, vm_end)
+ ),
+
+ TP_fast_assign(
+ __entry->mt = mt;
+ __entry->vma = vma;
+ __entry->vm_start = vma->vm_start;
+ __entry->vm_end = vma->vm_end - 1;
+ ),
+
+ TP_printk("mt_mod %p, (%p), STORE, %lu, %lu,",
+ __entry->mt, __entry->vma,
+ (unsigned long) __entry->vm_start,
+ (unsigned long) __entry->vm_end
+ )
+);
+
+
+TRACE_EVENT(exit_mmap,
+ TP_PROTO(struct mm_struct *mm),
+
+ TP_ARGS(mm),
+
+ TP_STRUCT__entry(
+ __field(struct mm_struct *, mm)
+ __field(struct maple_tree *, mt)
+ ),
+
+ TP_fast_assign(
+ __entry->mm = mm;
+ __entry->mt = &mm->mm_mt;
+ ),
+
+ TP_printk("mt_mod %p, DESTROY\n",
+ __entry->mt
+ )
+);
+
#endif
/* This part must be outside protection */
diff --git a/kernel/fork.c b/kernel/fork.c
index 9796897560ab..bb985cc624fd 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -585,6 +585,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
int retval;
unsigned long charge;
LIST_HEAD(uf);
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
uprobe_start_dup_mmap();
if (mmap_write_lock_killable(oldmm)) {
@@ -616,6 +617,10 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
if (retval)
goto out;
+ retval = mas_expected_entries(&mas, oldmm->map_count);
+ if (retval)
+ goto out;
+
prev = NULL;
for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
struct file *file;
@@ -631,7 +636,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
*/
if (fatal_signal_pending(current)) {
retval = -EINTR;
- goto out;
+ goto loop_out;
}
if (mpnt->vm_flags & VM_ACCOUNT) {
unsigned long len = vma_pages(mpnt);
@@ -696,6 +701,11 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
rb_link = &tmp->vm_rb.rb_right;
rb_parent = &tmp->vm_rb;
+ /* Link the vma into the MT */
+ mas.index = tmp->vm_start;
+ mas.last = tmp->vm_end - 1;
+ mas_store(&mas, tmp);
+
mm->map_count++;
if (!(tmp->vm_flags & VM_WIPEONFORK))
retval = copy_page_range(tmp, mpnt);
@@ -704,10 +714,12 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
tmp->vm_ops->open(tmp);
if (retval)
- goto out;
+ goto loop_out;
}
/* a new mm has just been created */
retval = arch_dup_mmap(oldmm, mm);
+loop_out:
+ mas_destroy(&mas);
out:
mmap_write_unlock(mm);
flush_tlb_mm(oldmm);
@@ -723,7 +735,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
fail_nomem:
retval = -ENOMEM;
vm_unacct_memory(charge);
- goto out;
+ goto loop_out;
}
static inline int mm_alloc_pgd(struct mm_struct *mm)
@@ -1107,6 +1119,8 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
{
mm->mmap = NULL;
mm->mm_rb = RB_ROOT;
+ mt_init_flags(&mm->mm_mt, MM_MT_FLAGS);
+ mt_set_external_lock(&mm->mm_mt, &mm->mmap_lock);
mm->vmacache_seqnum = 0;
atomic_set(&mm->mm_users, 1);
atomic_set(&mm->mm_count, 1);
diff --git a/mm/init-mm.c b/mm/init-mm.c
index fbe7844d0912..b912b0f2eced 100644
--- a/mm/init-mm.c
+++ b/mm/init-mm.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/mm_types.h>
#include <linux/rbtree.h>
+#include <linux/maple_tree.h>
#include <linux/rwsem.h>
#include <linux/spinlock.h>
#include <linux/list.h>
@@ -29,6 +30,7 @@
*/
struct mm_struct init_mm = {
.mm_rb = RB_ROOT,
+ .mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, init_mm.mmap_lock),
.pgd = swapper_pg_dir,
.mm_users = ATOMIC_INIT(2),
.mm_count = ATOMIC_INIT(1),
diff --git a/mm/mmap.c b/mm/mmap.c
index d7e120ad5825..e777da0132f6 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -381,7 +381,70 @@ static int browse_rb(struct mm_struct *mm)
}
return bug ? -1 : i;
}
+#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
+extern void mt_validate(struct maple_tree *mt);
+extern void mt_dump(const struct maple_tree *mt);
+/* 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, *vma = mm->mmap;
+
+ MA_STATE(mas, mt, 0, 0);
+ mas_for_each(&mas, vma_mt, ULONG_MAX) {
+ if (xa_is_zero(vma_mt))
+ continue;
+
+ if (!vma)
+ break;
+
+ if ((vma != vma_mt) ||
+ (vma->vm_start != vma_mt->vm_start) ||
+ (vma->vm_end != vma_mt->vm_end) ||
+ (vma->vm_start != mas.index) ||
+ (vma->vm_end - 1 != mas.last)) {
+ pr_emerg("issue in %s\n", current->comm);
+ dump_stack();
+#ifdef CONFIG_DEBUG_VM
+ dump_vma(vma_mt);
+ pr_emerg("and next in rb\n");
+ dump_vma(vma->vm_next);
+#endif
+ pr_emerg("mt piv: %px %lu - %lu\n", vma_mt,
+ mas.index, mas.last);
+ pr_emerg("mt vma: %px %lu - %lu\n", vma_mt,
+ vma_mt->vm_start, vma_mt->vm_end);
+ pr_emerg("rb vma: %px %lu - %lu\n", vma,
+ vma->vm_start, vma->vm_end);
+ pr_emerg("rb->next = %px %lu - %lu\n", vma->vm_next,
+ vma->vm_next->vm_start, vma->vm_next->vm_end);
+
+ mt_dump(mas.tree);
+ if (vma_mt->vm_end != mas.last + 1) {
+ pr_err("vma: %px 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);
+ }
+ VM_BUG_ON_MM(vma_mt->vm_end != mas.last + 1, mm);
+ if (vma_mt->vm_start != mas.index) {
+ pr_err("vma: %px vma_mt %px %lu - %lu doesn't match\n",
+ mm, vma_mt, vma_mt->vm_start, vma_mt->vm_end);
+ mt_dump(mas.tree);
+ }
+ VM_BUG_ON_MM(vma_mt->vm_start != mas.index, mm);
+ }
+ VM_BUG_ON(vma != vma_mt);
+ vma = vma->vm_next;
+
+ }
+ VM_BUG_ON(vma);
+ mt_validate(&mm->mm_mt);
+}
+#else
+#define validate_mm_mt(root) do { } while (0)
+#endif
static void validate_mm_rb(struct rb_root *root, struct vm_area_struct *ignore)
{
struct rb_node *nd;
@@ -436,6 +499,7 @@ static void validate_mm(struct mm_struct *mm)
}
#else
#define validate_mm_rb(root, ignore) do { } while (0)
+#define validate_mm_mt(root) do { } while (0)
#define validate_mm(mm) do { } while (0)
#endif
@@ -680,6 +744,56 @@ static void __vma_link_file(struct vm_area_struct *vma)
}
}
+/*
+ * vma_mas_store() - Store a VMA in the maple tree.
+ * @vma: The vm_area_struct
+ * @mas: The maple state
+ *
+ * Efficient way to store a VMA in the maple tree when the @mas has already
+ * walked to the correct location.
+ *
+ * Note: the end address is inclusive in the maple tree.
+ */
+inline void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas)
+{
+ trace_vma_store(mas->tree, vma);
+ mas_set_range(mas, vma->vm_start, vma->vm_end - 1);
+ mas_store_prealloc(mas, vma);
+}
+
+/*
+ * vma_mas_remove() - Remove a VMA from the maple tree.
+ * @vma: The vm_area_struct
+ * @mas: The maple state
+ *
+ * Efficient way to remove a VMA from the maple tree when the @mas has already
+ * been established and points to the correct location.
+ * Note: the end address is inclusive in the maple tree.
+ */
+static inline void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas)
+{
+ trace_vma_mas_szero(mas->tree, vma->vm_start, vma->vm_end - 1);
+ mas->index = vma->vm_start;
+ mas->last = vma->vm_end - 1;
+ mas_store_prealloc(mas, NULL);
+}
+
+/*
+ * vma_mas_szero() - Set a given range to zero. Used when modifying a
+ * vm_area_struct start or end.
+ *
+ * @mm: The struct_mm
+ * @start: The start address to zero
+ * @end: The end address to zero.
+ */
+static inline void vma_mas_szero(struct ma_state *mas, unsigned long start,
+ unsigned long end)
+{
+ trace_vma_mas_szero(mas->tree, start, end - 1);
+ mas_set_range(mas, start, end - 1);
+ mas_store_prealloc(mas, NULL);
+}
+
static void
__vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
struct vm_area_struct *prev, struct rb_node **rb_link,
@@ -689,17 +803,22 @@ __vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
__vma_link_rb(mm, vma, rb_link, rb_parent);
}
-static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
+static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
struct vm_area_struct *prev, struct rb_node **rb_link,
struct rb_node *rb_parent)
{
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
struct address_space *mapping = NULL;
+ if (mas_preallocate(&mas, vma, GFP_KERNEL))
+ return -ENOMEM;
+
if (vma->vm_file) {
mapping = vma->vm_file->f_mapping;
i_mmap_lock_write(mapping);
}
+ vma_mas_store(vma, &mas);
__vma_link(mm, vma, prev, rb_link, rb_parent);
__vma_link_file(vma);
@@ -708,13 +827,15 @@ static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma,
mm->map_count++;
validate_mm(mm);
+ return 0;
}
/*
* Helper for vma_adjust() in the split_vma insert case: insert a vma into the
* mm's list and rbtree. It has already been inserted into the interval tree.
*/
-static void __insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
+static void __insert_vm_struct(struct mm_struct *mm, struct ma_state *mas,
+ struct vm_area_struct *vma)
{
struct vm_area_struct *prev;
struct rb_node **rb_link, *rb_parent;
@@ -722,7 +843,10 @@ static void __insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
if (find_vma_links(mm, vma->vm_start, vma->vm_end,
&prev, &rb_link, &rb_parent))
BUG();
- __vma_link(mm, vma, prev, rb_link, rb_parent);
+
+ vma_mas_store(vma, mas);
+ __vma_link_list(mm, vma, prev);
+ __vma_link_rb(mm, vma, rb_link, rb_parent);
mm->map_count++;
}
@@ -756,10 +880,13 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
bool start_changed = false, end_changed = false;
long adjust_next = 0;
int remove_next = 0;
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
+ struct vm_area_struct *exporter = NULL, *importer = NULL;
- if (next && !insert) {
- struct vm_area_struct *exporter = NULL, *importer = NULL;
+ validate_mm(mm);
+ validate_mm_mt(mm);
+ if (next && !insert) {
if (end >= next->vm_end) {
/*
* vma expands, overlapping all the next, and
@@ -842,6 +969,12 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
again:
vma_adjust_trans_huge(orig_vma, start, end, adjust_next);
+ if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
+ if (exporter && exporter->anon_vma)
+ unlink_anon_vmas(importer);
+ return -ENOMEM;
+ }
+
if (file) {
mapping = file->f_mapping;
root = &mapping->i_mmap;
@@ -882,17 +1015,28 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
}
if (start != vma->vm_start) {
+ unsigned long old_start = vma->vm_start;
vma->vm_start = start;
+ if (old_start < start)
+ vma_mas_szero(&mas, old_start, start);
start_changed = true;
}
if (end != vma->vm_end) {
+ unsigned long old_end = vma->vm_end;
vma->vm_end = end;
+ if (old_end > end)
+ vma_mas_szero(&mas, end, old_end);
end_changed = true;
}
+
+ if (end_changed || start_changed)
+ vma_mas_store(vma, &mas);
+
vma->vm_pgoff = pgoff;
if (adjust_next) {
next->vm_start += adjust_next;
next->vm_pgoff += adjust_next >> PAGE_SHIFT;
+ vma_mas_store(next, &mas);
}
if (file) {
@@ -906,6 +1050,8 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
/*
* vma_merge has merged next into vma, and needs
* us to remove next before dropping the locks.
+ * Since we have expanded over this vma, the maple tree will
+ * have overwritten by storing the value
*/
if (remove_next != 3)
__vma_unlink(mm, next, next);
@@ -928,7 +1074,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
* us to insert it before dropping the locks
* (it may either follow vma or precede it).
*/
- __insert_vm_struct(mm, insert);
+ __insert_vm_struct(mm, &mas, insert);
} else {
if (start_changed)
vma_gap_update(vma);
@@ -1025,6 +1171,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
uprobe_mmap(insert);
validate_mm(mm);
+ validate_mm_mt(mm);
return 0;
}
@@ -1178,6 +1325,7 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
struct vm_area_struct *area, *next;
int err;
+ validate_mm_mt(mm);
/*
* We later require that vma->vm_flags == vm_flags,
* so this tests vma->vm_flags & VM_SPECIAL, too.
@@ -1253,6 +1401,7 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
khugepaged_enter_vma_merge(area, vm_flags);
return area;
}
+ validate_mm_mt(mm);
return NULL;
}
@@ -1732,6 +1881,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
struct rb_node **rb_link, *rb_parent;
unsigned long charged = 0;
+ validate_mm_mt(mm);
/* Check against address space limit. */
if (!may_expand_vm(mm, vm_flags, len >> PAGE_SHIFT)) {
unsigned long nr_pages;
@@ -1846,7 +1996,14 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
goto free_vma;
}
- vma_link(mm, vma, prev, rb_link, rb_parent);
+ if (vma_link(mm, vma, prev, rb_link, rb_parent)) {
+ error = -ENOMEM;
+ if (file)
+ goto unmap_and_free_vma;
+ else
+ goto free_vma;
+ }
+
/* Once vma denies write, undo our temporary denial count */
unmap_writable:
if (file && vm_flags & VM_SHARED)
@@ -1879,6 +2036,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
vma_set_page_prot(vma);
+ validate_mm_mt(mm);
return addr;
unmap_and_free_vma:
@@ -1895,6 +2053,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
unacct_error:
if (charged)
vm_unacct_memory(charged);
+ validate_mm_mt(mm);
return error;
}
@@ -1911,12 +2070,19 @@ static unsigned long unmapped_area(struct vm_unmapped_area_info *info)
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long length, low_limit, high_limit, gap_start, gap_end;
+ unsigned long gap;
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
/* Adjust search length to account for worst case alignment overhead */
length = info->length + info->align_mask;
if (length < info->length)
return -ENOMEM;
+ mas_empty_area(&mas, info->low_limit, info->high_limit - 1,
+ length);
+ gap = mas.index;
+ gap += (info->align_offset - gap) & info->align_mask;
+
/* Adjust search limits by the desired length */
if (info->high_limit < length)
return -ENOMEM;
@@ -1998,20 +2164,31 @@ static unsigned long unmapped_area(struct vm_unmapped_area_info *info)
VM_BUG_ON(gap_start + info->length > info->high_limit);
VM_BUG_ON(gap_start + info->length > gap_end);
+
+ VM_BUG_ON(gap != gap_start);
return gap_start;
}
static unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info)
{
struct mm_struct *mm = current->mm;
- struct vm_area_struct *vma;
+ struct vm_area_struct *vma = NULL;
unsigned long length, low_limit, high_limit, gap_start, gap_end;
+ unsigned long gap;
+
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
+ validate_mm_mt(mm);
/* Adjust search length to account for worst case alignment overhead */
length = info->length + info->align_mask;
if (length < info->length)
return -ENOMEM;
+ mas_empty_area_rev(&mas, info->low_limit, info->high_limit - 1,
+ length);
+ gap = mas.last + 1 - info->length;
+ gap -= (gap - info->align_offset) & info->align_mask;
+
/*
* Adjust search limits by the desired length.
* See implementation comment at top of unmapped_area().
@@ -2097,6 +2274,32 @@ static unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info)
VM_BUG_ON(gap_end < info->low_limit);
VM_BUG_ON(gap_end < gap_start);
+
+ if (gap != gap_end) {
+ pr_err("%s: %px Gap was found: mt %lu gap_end %lu\n", __func__,
+ mm, gap, gap_end);
+ pr_err("window was %lu - %lu size %lu\n", info->high_limit,
+ info->low_limit, length);
+ pr_err("mas.min %lu max %lu mas.last %lu\n", mas.min, mas.max,
+ mas.last);
+ pr_err("mas.index %lu align mask %lu offset %lu\n", mas.index,
+ info->align_mask, info->align_offset);
+ pr_err("rb_find_vma find on %lu => %px (%px)\n", mas.index,
+ find_vma(mm, mas.index), vma);
+#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
+ mt_dump(&mm->mm_mt);
+#endif
+ {
+ struct vm_area_struct *dv = mm->mmap;
+
+ while (dv) {
+ printk("vma %px %lu-%lu\n", dv, dv->vm_start, dv->vm_end);
+ dv = dv->vm_next;
+ }
+ }
+ VM_BUG_ON(gap != gap_end);
+ }
+
return gap_end;
}
@@ -2302,7 +2505,6 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
vmacache_update(addr, vma);
return vma;
}
-
EXPORT_SYMBOL(find_vma);
/*
@@ -2375,7 +2577,9 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
struct vm_area_struct *next;
unsigned long gap_addr;
int error = 0;
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
+ validate_mm_mt(mm);
if (!(vma->vm_flags & VM_GROWSUP))
return -EFAULT;
@@ -2399,9 +2603,14 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
/* Check that both stack segments have the same anon_vma? */
}
+ if (mas_preallocate(&mas, vma, GFP_KERNEL))
+ return -ENOMEM;
+
/* We must make sure the anon_vma is allocated. */
- if (unlikely(anon_vma_prepare(vma)))
+ if (unlikely(anon_vma_prepare(vma))) {
+ mas_destroy(&mas);
return -ENOMEM;
+ }
/*
* vma->vm_start/vm_end cannot change under us because the caller
@@ -2438,6 +2647,8 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
vm_stat_account(mm, vma->vm_flags, grow);
anon_vma_interval_tree_pre_update_vma(vma);
vma->vm_end = address;
+ /* Overwrite old entry in mtree. */
+ vma_mas_store(vma, &mas);
anon_vma_interval_tree_post_update_vma(vma);
if (vma->vm_next)
vma_gap_update(vma->vm_next);
@@ -2452,6 +2663,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
anon_vma_unlock_write(vma->anon_vma);
khugepaged_enter_vma_merge(vma, vma->vm_flags);
validate_mm(mm);
+ validate_mm_mt(mm);
return error;
}
#endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */
@@ -2465,7 +2677,9 @@ int expand_downwards(struct vm_area_struct *vma,
struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *prev;
int error = 0;
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
+ validate_mm(mm);
address &= PAGE_MASK;
if (address < mmap_min_addr)
return -EPERM;
@@ -2479,9 +2693,14 @@ int expand_downwards(struct vm_area_struct *vma,
return -ENOMEM;
}
+ if (mas_preallocate(&mas, vma, GFP_KERNEL))
+ return -ENOMEM;
+
/* We must make sure the anon_vma is allocated. */
- if (unlikely(anon_vma_prepare(vma)))
+ if (unlikely(anon_vma_prepare(vma))) {
+ mas_destroy(&mas);
return -ENOMEM;
+ }
/*
* vma->vm_start/vm_end cannot change under us because the caller
@@ -2519,6 +2738,8 @@ int expand_downwards(struct vm_area_struct *vma,
anon_vma_interval_tree_pre_update_vma(vma);
vma->vm_start = address;
vma->vm_pgoff -= grow;
+ /* Overwrite old entry in mtree. */
+ vma_mas_store(vma, &mas);
anon_vma_interval_tree_post_update_vma(vma);
vma_gap_update(vma);
spin_unlock(&mm->page_table_lock);
@@ -2652,14 +2873,17 @@ static void unmap_region(struct mm_struct *mm,
* vma list as we go..
*/
static bool
-detach_vmas_to_be_unmapped(struct mm_struct *mm, struct vm_area_struct *vma,
- struct vm_area_struct *prev, unsigned long end)
+detach_vmas_to_be_unmapped(struct mm_struct *mm, struct ma_state *mas,
+ struct vm_area_struct *vma, struct vm_area_struct *prev,
+ unsigned long end)
{
struct vm_area_struct **insertion_point;
struct vm_area_struct *tail_vma = NULL;
insertion_point = (prev ? &prev->vm_next : &mm->mmap);
vma->vm_prev = NULL;
+ mas_set_range(mas, vma->vm_start, end - 1);
+ mas_store_prealloc(mas, NULL);
do {
vma_rb_erase(vma, &mm->mm_rb);
if (vma->vm_flags & VM_LOCKED)
@@ -2700,6 +2924,7 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
{
struct vm_area_struct *new;
int err;
+ validate_mm_mt(mm);
if (vma->vm_ops && vma->vm_ops->may_split) {
err = vma->vm_ops->may_split(vma, addr);
@@ -2752,6 +2977,7 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
mpol_put(vma_policy(new));
out_free_vma:
vm_area_free(new);
+ validate_mm_mt(mm);
return err;
}
@@ -2778,6 +3004,8 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
{
unsigned long end;
struct vm_area_struct *vma, *prev, *last;
+ int error = -ENOMEM;
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
if ((offset_in_page(start)) || start > TASK_SIZE || len > TASK_SIZE-start)
return -EINVAL;
@@ -2798,6 +3026,9 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
vma = find_vma_intersection(mm, start, end);
if (!vma)
return 0;
+
+ if (mas_preallocate(&mas, vma, GFP_KERNEL))
+ return -ENOMEM;
prev = vma->vm_prev;
/*
@@ -2808,7 +3039,6 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
* places tmp vma above, and higher split_vma places tmp vma below.
*/
if (start > vma->vm_start) {
- int error;
/*
* Make sure that map_count on return from munmap() will
@@ -2816,20 +3046,20 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
* its limit temporarily, to help free resources as expected.
*/
if (end < vma->vm_end && mm->map_count >= sysctl_max_map_count)
- return -ENOMEM;
+ goto map_count_exceeded;
error = __split_vma(mm, vma, start, 0);
if (error)
- return error;
+ goto split_failed;
prev = vma;
}
/* Does it split the last one? */
last = find_vma(mm, end);
if (last && end > last->vm_start) {
- int error = __split_vma(mm, last, end, 1);
+ error = __split_vma(mm, last, end, 1);
if (error)
- return error;
+ goto split_failed;
}
vma = vma_next(mm, prev);
@@ -2843,13 +3073,13 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
* split, despite we could. This is unlikely enough
* failure that it's not worth optimizing it for.
*/
- int error = userfaultfd_unmap_prep(vma, start, end, uf);
+ error = userfaultfd_unmap_prep(vma, start, end, uf);
if (error)
- return error;
+ goto userfaultfd_error;
}
/* Detach vmas from rbtree */
- if (!detach_vmas_to_be_unmapped(mm, vma, prev, end))
+ if (!detach_vmas_to_be_unmapped(mm, &mas, vma, prev, end))
downgrade = false;
if (downgrade)
@@ -2861,6 +3091,12 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
remove_vma_list(mm, vma);
return downgrade ? 1 : 0;
+
+map_count_exceeded:
+split_failed:
+userfaultfd_error:
+ mas_destroy(&mas);
+ return error;
}
int do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
@@ -3000,6 +3236,7 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla
pgoff_t pgoff = addr >> PAGE_SHIFT;
int error;
unsigned long mapped_addr;
+ validate_mm_mt(mm);
/* Until we need other flags, refuse anything except VM_EXEC. */
if ((flags & (~VM_EXEC)) != 0)
@@ -3049,7 +3286,9 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla
vma->vm_pgoff = pgoff;
vma->vm_flags = flags;
vma->vm_page_prot = vm_get_page_prot(flags);
- vma_link(mm, vma, prev, rb_link, rb_parent);
+ if(vma_link(mm, vma, prev, rb_link, rb_parent))
+ goto no_vma_link;
+
out:
perf_event_mmap(vma);
mm->total_vm += len >> PAGE_SHIFT;
@@ -3057,7 +3296,12 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla
if (flags & VM_LOCKED)
mm->locked_vm += (len >> PAGE_SHIFT);
vma->vm_flags |= VM_SOFTDIRTY;
+ validate_mm_mt(mm);
return 0;
+
+no_vma_link:
+ vm_area_free(vma);
+ return -ENOMEM;
}
int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
@@ -3103,6 +3347,7 @@ void exit_mmap(struct mm_struct *mm)
/* mm's last user has gone, and its about to be pulled down */
mmu_notifier_release(mm);
+ mmap_write_lock(mm);
if (unlikely(mm_is_oom_victim(mm))) {
/*
* Manually reap the mm to free as much memory as possible.
@@ -3120,9 +3365,7 @@ void exit_mmap(struct mm_struct *mm)
set_bit(MMF_OOM_SKIP, &mm->flags);
}
- mmap_write_lock(mm);
arch_exit_mmap(mm);
-
vma = mm->mmap;
if (!vma) {
/* Can happen if dup_mmap() received an OOM */
@@ -3146,7 +3389,9 @@ void exit_mmap(struct mm_struct *mm)
vma = remove_vma(vma);
cond_resched();
}
- mm->mmap = NULL;
+
+ trace_exit_mmap(mm);
+ __mt_destroy(&mm->mm_mt);
mmap_write_unlock(mm);
vm_unacct_memory(nr_accounted);
}
@@ -3159,10 +3404,25 @@ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
{
struct vm_area_struct *prev;
struct rb_node **rb_link, *rb_parent;
+ unsigned long start = vma->vm_start;
+ struct vm_area_struct *overlap = NULL;
if (find_vma_links(mm, vma->vm_start, vma->vm_end,
&prev, &rb_link, &rb_parent))
return -ENOMEM;
+
+ overlap = mt_find(&mm->mm_mt, &start, vma->vm_end - 1);
+ if (overlap) {
+
+ pr_err("Found vma ending at %lu\n", start - 1);
+ pr_err("vma : %lu => %lu-%lu\n", (unsigned long)overlap,
+ overlap->vm_start, overlap->vm_end - 1);
+#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
+ mt_dump(&mm->mm_mt);
+#endif
+ BUG();
+ }
+
if ((vma->vm_flags & VM_ACCOUNT) &&
security_vm_enough_memory_mm(mm, vma_pages(vma)))
return -ENOMEM;
@@ -3184,7 +3444,9 @@ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
}
- vma_link(mm, vma, prev, rb_link, rb_parent);
+ if (vma_link(mm, vma, prev, rb_link, rb_parent))
+ return -ENOMEM;
+
return 0;
}
@@ -3202,7 +3464,9 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
struct vm_area_struct *new_vma, *prev;
struct rb_node **rb_link, *rb_parent;
bool faulted_in_anon_vma = true;
+ unsigned long index = addr;
+ validate_mm_mt(mm);
/*
* If anonymous vma has not yet been faulted, update new pgoff
* to match new location, to increase its chance of merging.
@@ -3214,6 +3478,8 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
if (find_vma_links(mm, addr, addr + len, &prev, &rb_link, &rb_parent))
return NULL; /* should never get here */
+ if (mt_find(&mm->mm_mt, &index, addr+len - 1))
+ BUG();
new_vma = vma_merge(mm, prev, addr, addr + len, vma->vm_flags,
vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
vma->vm_userfaultfd_ctx, anon_vma_name(vma));
@@ -3257,6 +3523,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
vma_link(mm, new_vma, prev, rb_link, rb_parent);
*need_rmap_locks = false;
}
+ validate_mm_mt(mm);
return new_vma;
out_free_mempol:
@@ -3264,6 +3531,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
out_free_vma:
vm_area_free(new_vma);
out:
+ validate_mm_mt(mm);
return NULL;
}
@@ -3400,6 +3668,7 @@ static struct vm_area_struct *__install_special_mapping(
int ret;
struct vm_area_struct *vma;
+ validate_mm_mt(mm);
vma = vm_area_alloc(mm);
if (unlikely(vma == NULL))
return ERR_PTR(-ENOMEM);
@@ -3422,10 +3691,12 @@ static struct vm_area_struct *__install_special_mapping(
perf_event_mmap(vma);
+ validate_mm_mt(mm);
return vma;
out:
vm_area_free(vma);
+ validate_mm_mt(mm);
return ERR_PTR(ret);
}
--
2.35.1
Hi Liam,
On Wed, 4 May 2022 01:07:52 +0000 Liam Howlett <[email protected]> wrote:
> From: "Liam R. Howlett" <[email protected]>
>
> Start tracking the VMAs with the new maple tree structure in parallel with
> the rb_tree. Add debug and trace events for maple tree operations and
> duplicate the rb_tree that is created on forks into the maple tree.
>
> The maple tree is added to the mm_struct including the mm_init struct,
> added support in required mm/mmap functions, added tracking in kernel/fork
> for process forking, and used to find the unmapped_area and checked
> against what the rbtree finds.
>
> This also moves the mmap_lock() in exit_mmap() since the oom reaper call
> does walk the VMAs. Otherwise lockdep will be unhappy if oom happens.
>
> Signed-off-by: Liam R. Howlett <[email protected]>
> Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
> ---
> arch/x86/kernel/tboot.c | 1 +
> drivers/firmware/efi/efi.c | 1 +
> include/linux/mm.h | 2 +
> include/linux/mm_types.h | 3 +
> include/trace/events/mmap.h | 73 ++++++++
> kernel/fork.c | 20 ++-
> mm/init-mm.c | 2 +
> mm/mmap.c | 323 +++++++++++++++++++++++++++++++++---
> 8 files changed, 396 insertions(+), 29 deletions(-)
>
[...]
> diff --git a/mm/mmap.c b/mm/mmap.c
> index d7e120ad5825..e777da0132f6 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
[...]
> @@ -680,6 +744,56 @@ static void __vma_link_file(struct vm_area_struct *vma)
> }
> }
>
> +/*
> + * vma_mas_store() - Store a VMA in the maple tree.
> + * @vma: The vm_area_struct
> + * @mas: The maple state
> + *
> + * Efficient way to store a VMA in the maple tree when the @mas has already
> + * walked to the correct location.
> + *
> + * Note: the end address is inclusive in the maple tree.
> + */
> +inline void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas)
> +{
> + trace_vma_store(mas->tree, vma);
> + mas_set_range(mas, vma->vm_start, vma->vm_end - 1);
> + mas_store_prealloc(mas, vma);
> +}
> +
> +/*
> + * vma_mas_remove() - Remove a VMA from the maple tree.
> + * @vma: The vm_area_struct
> + * @mas: The maple state
> + *
> + * Efficient way to remove a VMA from the maple tree when the @mas has already
> + * been established and points to the correct location.
> + * Note: the end address is inclusive in the maple tree.
> + */
> +static inline void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas)
> +{
> + trace_vma_mas_szero(mas->tree, vma->vm_start, vma->vm_end - 1);
> + mas->index = vma->vm_start;
> + mas->last = vma->vm_end - 1;
> + mas_store_prealloc(mas, NULL);
> +}
Above two functions were defined in internal.h in v8[1], but moved to mmap.c in
this version. As mmap.c is compiled when CONFIG_MMU, build fails when the
config is not set as below:
.../mm/nommu.c: In function 'add_vma_to_mm':
.../mm/nommu.c:575:2: error: implicit declaration of function 'vma_mas_store'; did you mean 'mas_store'? [-Werror=implicit-function-declaration]
575 | vma_mas_store(vma, &mas);
| ^~~~~~~~~~~~~
| mas_store
.../mm/nommu.c: In function 'delete_vma_from_mm':
.../mm/nommu.c:599:2: error: implicit declaration of function 'vma_mas_remove' [-Werror=implicit-function-declaration]
599 | vma_mas_remove(vma, &mas);
| ^~~~~~~~~~~~~~
Was there a reason to move these definitions? I confirmed moving the
definition back to internal.h fixes this issue, but I'm unsure if that's the
right solution.
[1] https://lore.kernel.org/linux-mm/[email protected]/
Thanks,
SJ
[...]
* Liam R. Howlett <[email protected]> [220510 08:50]:
> * SeongJae Park <[email protected]> [220510 03:37]:
> > Hi Liam,
> >
> > On Wed, 4 May 2022 01:07:52 +0000 Liam Howlett <[email protected]> wrote:
> >
> > > From: "Liam R. Howlett" <[email protected]>
> > >
> > > Start tracking the VMAs with the new maple tree structure in parallel with
> > > the rb_tree. Add debug and trace events for maple tree operations and
> > > duplicate the rb_tree that is created on forks into the maple tree.
> > >
> > > The maple tree is added to the mm_struct including the mm_init struct,
> > > added support in required mm/mmap functions, added tracking in kernel/fork
> > > for process forking, and used to find the unmapped_area and checked
> > > against what the rbtree finds.
> > >
> > > This also moves the mmap_lock() in exit_mmap() since the oom reaper call
> > > does walk the VMAs. Otherwise lockdep will be unhappy if oom happens.
> > >
> > > Signed-off-by: Liam R. Howlett <[email protected]>
> > > Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
> > > ---
> > > arch/x86/kernel/tboot.c | 1 +
> > > drivers/firmware/efi/efi.c | 1 +
> > > include/linux/mm.h | 2 +
> > > include/linux/mm_types.h | 3 +
> > > include/trace/events/mmap.h | 73 ++++++++
> > > kernel/fork.c | 20 ++-
> > > mm/init-mm.c | 2 +
> > > mm/mmap.c | 323 +++++++++++++++++++++++++++++++++---
> > > 8 files changed, 396 insertions(+), 29 deletions(-)
> > >
> > [...]
> > > diff --git a/mm/mmap.c b/mm/mmap.c
> > > index d7e120ad5825..e777da0132f6 100644
> > > --- a/mm/mmap.c
> > > +++ b/mm/mmap.c
> > [...]
> > > @@ -680,6 +744,56 @@ static void __vma_link_file(struct vm_area_struct *vma)
> > > }
> > > }
> > >
> > > +/*
> > > + * vma_mas_store() - Store a VMA in the maple tree.
> > > + * @vma: The vm_area_struct
> > > + * @mas: The maple state
> > > + *
> > > + * Efficient way to store a VMA in the maple tree when the @mas has already
> > > + * walked to the correct location.
> > > + *
> > > + * Note: the end address is inclusive in the maple tree.
> > > + */
> > > +inline void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas)
> > > +{
> > > + trace_vma_store(mas->tree, vma);
> > > + mas_set_range(mas, vma->vm_start, vma->vm_end - 1);
> > > + mas_store_prealloc(mas, vma);
> > > +}
> > > +
> > > +/*
> > > + * vma_mas_remove() - Remove a VMA from the maple tree.
> > > + * @vma: The vm_area_struct
> > > + * @mas: The maple state
> > > + *
> > > + * Efficient way to remove a VMA from the maple tree when the @mas has already
> > > + * been established and points to the correct location.
> > > + * Note: the end address is inclusive in the maple tree.
> > > + */
> > > +static inline void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas)
> > > +{
> > > + trace_vma_mas_szero(mas->tree, vma->vm_start, vma->vm_end - 1);
> > > + mas->index = vma->vm_start;
> > > + mas->last = vma->vm_end - 1;
> > > + mas_store_prealloc(mas, NULL);
> > > +}
> >
> > Above two functions were defined in internal.h in v8[1], but moved to mmap.c in
> > this version. As mmap.c is compiled when CONFIG_MMU, build fails when the
> > config is not set as below:
> >
> > .../mm/nommu.c: In function 'add_vma_to_mm':
> > .../mm/nommu.c:575:2: error: implicit declaration of function 'vma_mas_store'; did you mean 'mas_store'? [-Werror=implicit-function-declaration]
> > 575 | vma_mas_store(vma, &mas);
> > | ^~~~~~~~~~~~~
> > | mas_store
> > .../mm/nommu.c: In function 'delete_vma_from_mm':
> > .../mm/nommu.c:599:2: error: implicit declaration of function 'vma_mas_remove' [-Werror=implicit-function-declaration]
> > 599 | vma_mas_remove(vma, &mas);
> > | ^~~~~~~~~~~~~~
> >
> > Was there a reason to move these definitions? I confirmed moving the
> > definition back to internal.h fixes this issue, but I'm unsure if that's the
> > right solution.
> >
> > [1] https://lore.kernel.org/linux-mm/[email protected]/
> >
>
> I moved the functions as they were dropped elsewhere for cleanup. I did
> check my m68k buildroot, but the buildroot seems to have not pulled the
> new code - it clones the repo externally. I just changed the branch to
> use mm-unstable and that is indeed failing as you see above. Your fix
> is correct - and I believe it also means I need to leave the damon
> change the way it is now.
>
I recall now that I wanted to have the function traced. Moving it to
the c file allowed me to add tracepoints pretty easily. Having it in
the header does not work as it will redefine the tracepoints many times
and cause a bit of a mess. I don't love putting the tracepoint as is in
another function but I think I will have to move to this method. On the
plus side, the open-coded modifications to the maple tree may be able to
use the tracepoints then.
* SeongJae Park <[email protected]> [220510 03:37]:
> Hi Liam,
>
> On Wed, 4 May 2022 01:07:52 +0000 Liam Howlett <[email protected]> wrote:
>
> > From: "Liam R. Howlett" <[email protected]>
> >
> > Start tracking the VMAs with the new maple tree structure in parallel with
> > the rb_tree. Add debug and trace events for maple tree operations and
> > duplicate the rb_tree that is created on forks into the maple tree.
> >
> > The maple tree is added to the mm_struct including the mm_init struct,
> > added support in required mm/mmap functions, added tracking in kernel/fork
> > for process forking, and used to find the unmapped_area and checked
> > against what the rbtree finds.
> >
> > This also moves the mmap_lock() in exit_mmap() since the oom reaper call
> > does walk the VMAs. Otherwise lockdep will be unhappy if oom happens.
> >
> > Signed-off-by: Liam R. Howlett <[email protected]>
> > Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
> > ---
> > arch/x86/kernel/tboot.c | 1 +
> > drivers/firmware/efi/efi.c | 1 +
> > include/linux/mm.h | 2 +
> > include/linux/mm_types.h | 3 +
> > include/trace/events/mmap.h | 73 ++++++++
> > kernel/fork.c | 20 ++-
> > mm/init-mm.c | 2 +
> > mm/mmap.c | 323 +++++++++++++++++++++++++++++++++---
> > 8 files changed, 396 insertions(+), 29 deletions(-)
> >
> [...]
> > diff --git a/mm/mmap.c b/mm/mmap.c
> > index d7e120ad5825..e777da0132f6 100644
> > --- a/mm/mmap.c
> > +++ b/mm/mmap.c
> [...]
> > @@ -680,6 +744,56 @@ static void __vma_link_file(struct vm_area_struct *vma)
> > }
> > }
> >
> > +/*
> > + * vma_mas_store() - Store a VMA in the maple tree.
> > + * @vma: The vm_area_struct
> > + * @mas: The maple state
> > + *
> > + * Efficient way to store a VMA in the maple tree when the @mas has already
> > + * walked to the correct location.
> > + *
> > + * Note: the end address is inclusive in the maple tree.
> > + */
> > +inline void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas)
> > +{
> > + trace_vma_store(mas->tree, vma);
> > + mas_set_range(mas, vma->vm_start, vma->vm_end - 1);
> > + mas_store_prealloc(mas, vma);
> > +}
> > +
> > +/*
> > + * vma_mas_remove() - Remove a VMA from the maple tree.
> > + * @vma: The vm_area_struct
> > + * @mas: The maple state
> > + *
> > + * Efficient way to remove a VMA from the maple tree when the @mas has already
> > + * been established and points to the correct location.
> > + * Note: the end address is inclusive in the maple tree.
> > + */
> > +static inline void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas)
> > +{
> > + trace_vma_mas_szero(mas->tree, vma->vm_start, vma->vm_end - 1);
> > + mas->index = vma->vm_start;
> > + mas->last = vma->vm_end - 1;
> > + mas_store_prealloc(mas, NULL);
> > +}
>
> Above two functions were defined in internal.h in v8[1], but moved to mmap.c in
> this version. As mmap.c is compiled when CONFIG_MMU, build fails when the
> config is not set as below:
>
> .../mm/nommu.c: In function 'add_vma_to_mm':
> .../mm/nommu.c:575:2: error: implicit declaration of function 'vma_mas_store'; did you mean 'mas_store'? [-Werror=implicit-function-declaration]
> 575 | vma_mas_store(vma, &mas);
> | ^~~~~~~~~~~~~
> | mas_store
> .../mm/nommu.c: In function 'delete_vma_from_mm':
> .../mm/nommu.c:599:2: error: implicit declaration of function 'vma_mas_remove' [-Werror=implicit-function-declaration]
> 599 | vma_mas_remove(vma, &mas);
> | ^~~~~~~~~~~~~~
>
> Was there a reason to move these definitions? I confirmed moving the
> definition back to internal.h fixes this issue, but I'm unsure if that's the
> right solution.
>
> [1] https://lore.kernel.org/linux-mm/[email protected]/
>
I moved the functions as they were dropped elsewhere for cleanup. I did
check my m68k buildroot, but the buildroot seems to have not pulled the
new code - it clones the repo externally. I just changed the branch to
use mm-unstable and that is indeed failing as you see above. Your fix
is correct - and I believe it also means I need to leave the damon
change the way it is now.
Thanks for catching this. I will send a fix to change this back after
testing.
Liam
On Wed, May 04, 2022 at 01:07:52AM +0000, Liam Howlett wrote:
> From: "Liam R. Howlett" <[email protected]>
>
> Start tracking the VMAs with the new maple tree structure in parallel with
> the rb_tree. Add debug and trace events for maple tree operations and
> duplicate the rb_tree that is created on forks into the maple tree.
>
> The maple tree is added to the mm_struct including the mm_init struct,
> added support in required mm/mmap functions, added tracking in kernel/fork
> for process forking, and used to find the unmapped_area and checked
> against what the rbtree finds.
>
> This also moves the mmap_lock() in exit_mmap() since the oom reaper call
> does walk the VMAs. Otherwise lockdep will be unhappy if oom happens.
>
> Signed-off-by: Liam R. Howlett <[email protected]>
> Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
...
> @@ -2479,9 +2693,14 @@ int expand_downwards(struct vm_area_struct *vma,
> return -ENOMEM;
> }
>
> + if (mas_preallocate(&mas, vma, GFP_KERNEL))
We have thousands of leaks reports here from kmemleak while running some
syscall fuzzers on today's linux-next tree.
unreferenced object 0xffff0803c0063d00 (size 256):
comm "trinity-c25", pid 177739, jiffies 4297781293 (age 354.988s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
slab_post_alloc_hook
kmem_cache_alloc_bulk
mas_alloc_nodes
mas_preallocate
mas_preallocate at lib/maple_tree.c:5579
expand_downwards
expand_downwards at mm/mmap.c:2094
expand_stack
do_page_fault
do_translation_fault
do_mem_abort
el1_abort
el1h_64_sync_handler
el1h_64_sync
handle_futex_death
exit_robust_list
futex_exit_release
exit_mm_release
> + return -ENOMEM;
> +
> /* We must make sure the anon_vma is allocated. */
> - if (unlikely(anon_vma_prepare(vma)))
> + if (unlikely(anon_vma_prepare(vma))) {
> + mas_destroy(&mas);
> return -ENOMEM;
> + }
>
> /*
> * vma->vm_start/vm_end cannot change under us because the caller
* Qian Cai <[email protected]> [220512 13:01]:
> On Wed, May 04, 2022 at 01:07:52AM +0000, Liam Howlett wrote:
> > From: "Liam R. Howlett" <[email protected]>
> >
> > Start tracking the VMAs with the new maple tree structure in parallel with
> > the rb_tree. Add debug and trace events for maple tree operations and
> > duplicate the rb_tree that is created on forks into the maple tree.
> >
> > The maple tree is added to the mm_struct including the mm_init struct,
> > added support in required mm/mmap functions, added tracking in kernel/fork
> > for process forking, and used to find the unmapped_area and checked
> > against what the rbtree finds.
> >
> > This also moves the mmap_lock() in exit_mmap() since the oom reaper call
> > does walk the VMAs. Otherwise lockdep will be unhappy if oom happens.
> >
> > Signed-off-by: Liam R. Howlett <[email protected]>
> > Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
> ...
> > @@ -2479,9 +2693,14 @@ int expand_downwards(struct vm_area_struct *vma,
> > return -ENOMEM;
> > }
> >
> > + if (mas_preallocate(&mas, vma, GFP_KERNEL))
>
> We have thousands of leaks reports here from kmemleak while running some
> syscall fuzzers on today's linux-next tree.
Thanks for the report. Yes, this is mine. I am testing a fix now.
>
> unreferenced object 0xffff0803c0063d00 (size 256):
> comm "trinity-c25", pid 177739, jiffies 4297781293 (age 354.988s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> backtrace:
> slab_post_alloc_hook
> kmem_cache_alloc_bulk
> mas_alloc_nodes
> mas_preallocate
> mas_preallocate at lib/maple_tree.c:5579
> expand_downwards
> expand_downwards at mm/mmap.c:2094
> expand_stack
> do_page_fault
> do_translation_fault
> do_mem_abort
> el1_abort
> el1h_64_sync_handler
> el1h_64_sync
> handle_futex_death
> exit_robust_list
> futex_exit_release
> exit_mm_release
>
> > + return -ENOMEM;
> > +
> > /* We must make sure the anon_vma is allocated. */
> > - if (unlikely(anon_vma_prepare(vma)))
> > + if (unlikely(anon_vma_prepare(vma))) {
> > + mas_destroy(&mas);
> > return -ENOMEM;
> > + }
> >
> > /*
> > * vma->vm_start/vm_end cannot change under us because the caller
On Wed, May 04, 2022 at 01:07:52AM +0000, Liam Howlett wrote:
> From: "Liam R. Howlett" <[email protected]>
>
> Start tracking the VMAs with the new maple tree structure in parallel with
> the rb_tree. Add debug and trace events for maple tree operations and
> duplicate the rb_tree that is created on forks into the maple tree.
>
> The maple tree is added to the mm_struct including the mm_init struct,
> added support in required mm/mmap functions, added tracking in kernel/fork
> for process forking, and used to find the unmapped_area and checked
> against what the rbtree finds.
>
> This also moves the mmap_lock() in exit_mmap() since the oom reaper call
> does walk the VMAs. Otherwise lockdep will be unhappy if oom happens.
>
> Signed-off-by: Liam R. Howlett <[email protected]>
> Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
...
> @@ -842,6 +969,12 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
> again:
> vma_adjust_trans_huge(orig_vma, start, end, adjust_next);
>
> + if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
> + if (exporter && exporter->anon_vma)
> + unlink_anon_vmas(importer);
> + return -ENOMEM;
> + }
> +
> if (file) {
> mapping = file->f_mapping;
> root = &mapping->i_mmap;
Running a syscall fuzzer for a while could still trigger some memory leak reports.
unreferenced object 0xffff4021439c6100 (size 256):
comm "trinity-c32", pid 1329067, jiffies 4301918356 (age 231692.944s)
hex dump (first 32 bytes):
00 61 9c 43 21 40 ff ff 1c b1 65 1d 02 40 ff ff [email protected]..@..
ff 2f 42 97 ff ff 00 00 ff 2f 43 97 ff ff 00 00 ./B....../C.....
backtrace:
[<ffffd4be60434e28>] slab_post_alloc_hook+0x98/0xf0
[<ffffd4be6043a2e0>] kmem_cache_alloc_bulk+0x26c/0x4ac
[<ffffd4be60d549c8>] mas_alloc_nodes+0x1e8/0x500
[<ffffd4be60d7cc68>] mas_preallocate+0xc8/0x210
[<ffffd4be603607a0>] __vma_adjust+0x27c/0x1290
__vma_adjust at mm/mmap.c:762
[<ffffd4be60361b0c>] vma_merge+0x358/0x650
[<ffffd4be60370e20>] mprotect_fixup+0x160/0x530
[<ffffd4be60371544>] do_mprotect_pkey.constprop.0+0x354/0x710
[<ffffd4be60371978>] __arm64_sys_mprotect+0x78/0x130
[<ffffd4be5fc43a24>] invoke_syscall+0x74/0x260
[<ffffd4be5fc43db8>] el0_svc_common.constprop.0+0x1a8/0x260
[<ffffd4be5fc43f1c>] do_el0_svc+0xac/0xe0
[<ffffd4be62d68144>] el0_svc+0x84/0x1c0
[<ffffd4be62d687dc>] el0t_64_sync_handler+0xbc/0x140
[<ffffd4be5fc12548>] el0t_64_sync+0x18c/0x190
* Qian Cai <[email protected]> [220606 08:26]:
> On Wed, May 04, 2022 at 01:07:52AM +0000, Liam Howlett wrote:
> > From: "Liam R. Howlett" <[email protected]>
> >
> > Start tracking the VMAs with the new maple tree structure in parallel with
> > the rb_tree. Add debug and trace events for maple tree operations and
> > duplicate the rb_tree that is created on forks into the maple tree.
> >
> > The maple tree is added to the mm_struct including the mm_init struct,
> > added support in required mm/mmap functions, added tracking in kernel/fork
> > for process forking, and used to find the unmapped_area and checked
> > against what the rbtree finds.
> >
> > This also moves the mmap_lock() in exit_mmap() since the oom reaper call
> > does walk the VMAs. Otherwise lockdep will be unhappy if oom happens.
> >
> > Signed-off-by: Liam R. Howlett <[email protected]>
> > Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
> ...
> > @@ -842,6 +969,12 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
> > again:
> > vma_adjust_trans_huge(orig_vma, start, end, adjust_next);
> >
> > + if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
> > + if (exporter && exporter->anon_vma)
> > + unlink_anon_vmas(importer);
> > + return -ENOMEM;
> > + }
> > +
> > if (file) {
> > mapping = file->f_mapping;
> > root = &mapping->i_mmap;
>
> Running a syscall fuzzer for a while could still trigger some memory leak reports.
>
> unreferenced object 0xffff4021439c6100 (size 256):
> comm "trinity-c32", pid 1329067, jiffies 4301918356 (age 231692.944s)
> hex dump (first 32 bytes):
> 00 61 9c 43 21 40 ff ff 1c b1 65 1d 02 40 ff ff [email protected]..@..
> ff 2f 42 97 ff ff 00 00 ff 2f 43 97 ff ff 00 00 ./B....../C.....
> backtrace:
> [<ffffd4be60434e28>] slab_post_alloc_hook+0x98/0xf0
> [<ffffd4be6043a2e0>] kmem_cache_alloc_bulk+0x26c/0x4ac
> [<ffffd4be60d549c8>] mas_alloc_nodes+0x1e8/0x500
> [<ffffd4be60d7cc68>] mas_preallocate+0xc8/0x210
> [<ffffd4be603607a0>] __vma_adjust+0x27c/0x1290
> __vma_adjust at mm/mmap.c:762
I assume this is 5.18.0-next-20220603? The line number seems to be
correct.
> [<ffffd4be60361b0c>] vma_merge+0x358/0x650
> [<ffffd4be60370e20>] mprotect_fixup+0x160/0x530
> [<ffffd4be60371544>] do_mprotect_pkey.constprop.0+0x354/0x710
> [<ffffd4be60371978>] __arm64_sys_mprotect+0x78/0x130
This must be on arm64 then.
> [<ffffd4be5fc43a24>] invoke_syscall+0x74/0x260
> [<ffffd4be5fc43db8>] el0_svc_common.constprop.0+0x1a8/0x260
> [<ffffd4be5fc43f1c>] do_el0_svc+0xac/0xe0
> [<ffffd4be62d68144>] el0_svc+0x84/0x1c0
> [<ffffd4be62d687dc>] el0t_64_sync_handler+0xbc/0x140
> [<ffffd4be5fc12548>] el0t_64_sync+0x18c/0x190
Does your fuzzer create a reproducer at all? It would be helpful a lot
since I cannot see my bug right now.
Thanks,
Liam
On Mon, Jun 06, 2022 at 04:16:27PM +0000, Liam Howlett wrote:
> Does your fuzzer create a reproducer at all? It would be helpful a lot
> since I cannot see my bug right now.
The same reproducer that running it over the weekend.
$ trinity -C 160