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Date: Thu, 16 Jul 2015 16:47:08 +0800
From: Baoquan He <bhe@...hat.com>
To: linux-kernel@...r.kernel.org, ncroxon@...hat.com,
dyoung@...hat.com, mhuang@...hat.com
Cc: Baoquan He <bhe@...hat.com>
Subject: [RHEL6.8 Patch 10/19] vmalloc: introduce remap_vmalloc_range_partial
Resolves: bz1097904
https://bugzilla.redhat.com/show_bug.cgi?id=1097904
This is back ported from upstream. There's a small conflict in
remap_vmalloc_range.
commit e69e9d4aee712a22665f008ae0550bb3d7c7f7c1
Author: HATAYAMA Daisuke <d.hatayama@...fujitsu.com>
Date: Wed Jul 3 15:02:18 2013 -0700
vmalloc: introduce remap_vmalloc_range_partial
We want to allocate ELF note segment buffer on the 2nd kernel in vmalloc
space and remap it to user-space in order to reduce the risk that memory
allocation fails on system with huge number of CPUs and so with huge ELF
note segment that exceeds 11-order block size.
Although there's already remap_vmalloc_range for the purpose of
remapping vmalloc memory to user-space, we need to specify user-space
range via vma.
Mmap on /proc/vmcore needs to remap range across multiple objects, so
the interface that requires vma to cover full range is problematic.
This patch introduces remap_vmalloc_range_partial that receives user-space
range as a pair of base address and size and can be used for mmap on
/proc/vmcore case.
remap_vmalloc_range is rewritten using remap_vmalloc_range_partial.
[akpm@...ux-foundation.org: use PAGE_ALIGNED()]
Signed-off-by: HATAYAMA Daisuke <d.hatayama@...fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
Cc: Vivek Goyal <vgoyal@...hat.com>
Cc: Atsushi Kumagai <kumagai-atsushi@....nes.nec.co.jp>
Cc: Lisa Mitchell <lisa.mitchell@...com>
Cc: Zhang Yanfei <zhangyanfei@...fujitsu.com>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Baoquan He <bhe@...hat.com>
---
include/linux/vmalloc.h | 4 +++
mm/vmalloc.c | 68 +++++++++++++++++++++++++++++++++----------------
2 files changed, 50 insertions(+), 22 deletions(-)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 56e82f6..1ecf5c7 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -68,6 +68,10 @@ extern void *vmap(struct page **pages, unsigned int count,
unsigned long flags, pgprot_t prot);
extern void vunmap(const void *addr);
+extern int remap_vmalloc_range_partial(struct vm_area_struct *vma,
+ unsigned long uaddr, void *kaddr,
+ unsigned long size);
+
extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
unsigned long pgoff);
void vmalloc_sync_all(void);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 2ae8618..ff148e0 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1477,10 +1477,9 @@ static void __vunmap(const void *addr, int deallocate_pages)
if (!addr)
return;
- if ((PAGE_SIZE-1) & (unsigned long)addr) {
- WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
+ if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
+ addr));
return;
- }
area = remove_vm_area(addr);
if (unlikely(!area)) {
@@ -2117,42 +2116,43 @@ finished:
}
/**
- * remap_vmalloc_range - map vmalloc pages to userspace
- * @vma: vma to cover (map full range of vma)
- * @addr: vmalloc memory
- * @pgoff: number of pages into addr before first page to map
+ * remap_vmalloc_range_partial - map vmalloc pages to userspace
+ * @vma: vma to cover
+ * @uaddr: target user address to start at
+ * @kaddr: virtual address of vmalloc kernel memory
+ * @size: size of map area
*
* Returns: 0 for success, -Exxx on failure
*
- * This function checks that addr is a valid vmalloc'ed area, and
- * that it is big enough to cover the vma. Will return failure if
- * that criteria isn't met.
+ * This function checks that @kaddr is a valid vmalloc'ed area,
+ * and that it is big enough to cover the range starting at
+ * @uaddr in @vma. Will return failure if that criteria isn't
+ * met.
*
* Similar to remap_pfn_range() (see mm/memory.c)
*/
-int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
- unsigned long pgoff)
+int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
+ void *kaddr, unsigned long size)
{
struct vm_struct *area;
- unsigned long uaddr = vma->vm_start;
- unsigned long usize = vma->vm_end - vma->vm_start;
- if ((PAGE_SIZE-1) & (unsigned long)addr)
+ size = PAGE_ALIGN(size);
+
+ if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
return -EINVAL;
- area = find_vm_area(addr);
+ area = find_vm_area(kaddr);
if (!area)
return -EINVAL;
if (!(area->flags & VM_USERMAP))
return -EINVAL;
- if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
+ if (kaddr + size > area->addr + area->size)
return -EINVAL;
- addr += pgoff << PAGE_SHIFT;
do {
- struct page *page = vmalloc_to_page(addr);
+ struct page *page = vmalloc_to_page(kaddr);
int ret;
ret = vm_insert_page(vma, uaddr, page);
@@ -2160,15 +2160,39 @@ int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
return ret;
uaddr += PAGE_SIZE;
- addr += PAGE_SIZE;
- usize -= PAGE_SIZE;
- } while (usize > 0);
+ kaddr += PAGE_SIZE;
+ size -= PAGE_SIZE;
+ } while (size > 0);
/* Prevent "things" like memory migration? VM_flags need a cleanup... */
vma->vm_flags |= VM_RESERVED;
return 0;
}
+EXPORT_SYMBOL(remap_vmalloc_range_partial);
+
+/**
+ * remap_vmalloc_range - map vmalloc pages to userspace
+ * @vma: vma to cover (map full range of vma)
+ * @addr: vmalloc memory
+ * @pgoff: number of pages into addr before first page to map
+ *
+ * Returns: 0 for success, -Exxx on failure
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * that it is big enough to cover the vma. Will return failure if
+ * that criteria isn't met.
+ *
+ * Similar to remap_pfn_range() (see mm/memory.c)
+ */
+int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
+ unsigned long pgoff)
+{
+ return remap_vmalloc_range_partial(vma, vma->vm_start,
+ addr + (pgoff << PAGE_SHIFT),
+ vma->vm_end - vma->vm_start);
+}
+
EXPORT_SYMBOL(remap_vmalloc_range);
/*
--
2.1.0
--
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