The patch titled
Subject: revert "Revert "mm/vmalloc: modify struct vmap_area to reduce its size""
has been added to the -mm tree. Its filename is
revert-revert-mm-vmalloc-modify-struct-vmap_area-to-reduce-its-size.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/revert-revert-mm-vmalloc-modify-struct-vmap_area-to-reduce-its-size.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/revert-revert-mm-vmalloc-modify-struct-vmap_area-to-reduce-its-size.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: revert "Revert "mm/vmalloc: modify struct vmap_area to reduce its size""
Revert linux-next's bdbfb1d52d5e5 ("Revert "mm/vmalloc: modify struct
vmap_area to reduce its size"").
Numerous reports of kernel crashes due to this. We can't figure out what
it's for or why it's in -next.
Link: http://lkml.kernel.org/r/20200722144650.GA19628@pc636
Link: http://lkml.kernel.org/r/CA+G9fYuj3bHUMz8XQztbmTgF0c5+rZ5-FkUjFyvEftej2jLT+Q@xxxxxxxxxxxxxx
Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Cc: Uladzislau Rezki <urezki@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Pengfei Li <lpf.vector@xxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Yafang Shao <laoar.shao@xxxxxxxxx>
Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@xxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Joerg Roedel <jroedel@xxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Dennis Zhou <dennis@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/vmalloc.h | 20 +++++++++++++-------
mm/vmalloc.c | 24 ++++++++++--------------
2 files changed, 23 insertions(+), 21 deletions(-)
--- a/include/linux/vmalloc.h~revert-revert-mm-vmalloc-modify-struct-vmap_area-to-reduce-its-size
+++ a/include/linux/vmalloc.h
@@ -67,15 +67,21 @@ struct vmap_area {
unsigned long va_start;
unsigned long va_end;
- /*
- * Largest available free size in subtree.
- */
- unsigned long subtree_max_size;
- unsigned long flags;
struct rb_node rb_node; /* address sorted rbtree */
struct list_head list; /* address sorted list */
- struct llist_node purge_list; /* "lazy purge" list */
- struct vm_struct *vm;
+
+ /*
+ * The following three variables can be packed, because
+ * a vmap_area object is always one of the three states:
+ * 1) in "free" tree (root is vmap_area_root)
+ * 2) in "busy" tree (root is free_vmap_area_root)
+ * 3) in purge list (head is vmap_purge_list)
+ */
+ union {
+ unsigned long subtree_max_size; /* in "free" tree */
+ struct vm_struct *vm; /* in "busy" tree */
+ struct llist_node purge_list; /* in purge list */
+ };
};
/*
--- a/mm/vmalloc.c~revert-revert-mm-vmalloc-modify-struct-vmap_area-to-reduce-its-size
+++ a/mm/vmalloc.c
@@ -408,7 +408,6 @@ EXPORT_SYMBOL(vmalloc_to_pfn);
#define DEBUG_AUGMENT_PROPAGATE_CHECK 0
#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
-#define VM_VM_AREA 0x04
static DEFINE_SPINLOCK(vmap_area_lock);
static DEFINE_SPINLOCK(free_vmap_area_lock);
@@ -1220,7 +1219,7 @@ retry:
va->va_start = addr;
va->va_end = addr + size;
- va->flags = 0;
+ va->vm = NULL;
spin_lock(&vmap_area_lock);
@@ -1995,7 +1994,6 @@ void __init vmalloc_init(void)
if (WARN_ON_ONCE(!va))
continue;
- va->flags = VM_VM_AREA;
va->va_start = (unsigned long)tmp->addr;
va->va_end = va->va_start + tmp->size;
va->vm = tmp;
@@ -2040,7 +2038,6 @@ static void setup_vmalloc_vm(struct vm_s
unsigned long flags, const void *caller)
{
spin_lock(&vmap_area_lock);
- va->flags |= VM_VM_AREA;
setup_vmalloc_vm_locked(vm, va, flags, caller);
spin_unlock(&vmap_area_lock);
}
@@ -2141,10 +2138,10 @@ struct vm_struct *find_vm_area(const voi
struct vmap_area *va;
va = find_vmap_area((unsigned long)addr);
- if (va && va->flags & VM_VM_AREA)
- return va->vm;
+ if (!va)
+ return NULL;
- return NULL;
+ return va->vm;
}
/**
@@ -2165,11 +2162,10 @@ struct vm_struct *remove_vm_area(const v
spin_lock(&vmap_area_lock);
va = __find_vmap_area((unsigned long)addr);
- if (va && va->flags & VM_VM_AREA) {
+ if (va && va->vm) {
struct vm_struct *vm = va->vm;
va->vm = NULL;
- va->flags &= ~VM_VM_AREA;
spin_unlock(&vmap_area_lock);
kasan_free_shadow(vm);
@@ -2835,7 +2831,7 @@ long vread(char *buf, char *addr, unsign
if (!count)
break;
- if (!(va->flags & VM_VM_AREA))
+ if (!va->vm)
continue;
vm = va->vm;
@@ -2915,7 +2911,7 @@ long vwrite(char *buf, char *addr, unsig
if (!count)
break;
- if (!(va->flags & VM_VM_AREA))
+ if (!va->vm)
continue;
vm = va->vm;
@@ -3506,10 +3502,10 @@ static int s_show(struct seq_file *m, vo
va = list_entry(p, struct vmap_area, list);
/*
- * s_show can encounter race with remove_vm_area, !VM_VM_AREA on
- * behalf of vmap area is being tear down or vm_map_ram allocation.
+ * s_show can encounter race with remove_vm_area, !vm on behalf
+ * of vmap area is being tear down or vm_map_ram allocation.
*/
- if (!(va->flags & VM_VM_AREA)) {
+ if (!va->vm) {
seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
(void *)va->va_start, (void *)va->va_end,
va->va_end - va->va_start);
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
mm-close-race-between-munmap-and-expand_upwards-downwards-fix.patch
mm-hugetlb-avoid-hardcoding-while-checking-if-cma-is-enabled-fix.patch
io-mapping-indicate-mapping-failure-fix.patch
mm-fix-kthread_use_mm-vs-tlb-invalidate-fix.patch
mm.patch
mm-handle-page-mapping-better-in-dump_page-fix.patch
mm-memcg-percpu-account-percpu-memory-to-memory-cgroups-fix.patch
mm-memcg-percpu-account-percpu-memory-to-memory-cgroups-fix-fix.patch
mm-thp-replace-http-links-with-https-ones-fix.patch
mm-vmstat-add-events-for-thp-migration-without-split-fix.patch
mmhwpoison-rework-soft-offline-for-in-use-pages-fix.patch
mm-vmstat-fix-proc-sys-vm-stat_refresh-generating-false-warnings-fix-2.patch
linux-next-rejects.patch
revert-revert-mm-vmalloc-modify-struct-vmap_area-to-reduce-its-size.patch
mm-migrate-clear-__gfp_reclaim-to-make-the-migration-callback-consistent-with-regular-thp-allocations-fix.patch
mm-madvise-introduce-process_madvise-syscall-an-external-memory-hinting-api-fix.patch
mm-madvise-introduce-process_madvise-syscall-an-external-memory-hinting-api-fix-2.patch
kernel-forkc-export-kernel_thread-to-modules.patch
