Subject: [merged] blackfin-ptrace-call-find_vma-with-the-mmap_sem-held.patch removed from -mm tree
To: davidlohr@xxxxxx,realmz6@xxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 09 Jun 2014 12:39:58 -0700
The patch titled
Subject: blackfin/ptrace: call find_vma with the mmap_sem held
has been removed from the -mm tree. Its filename was
blackfin-ptrace-call-find_vma-with-the-mmap_sem-held.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Davidlohr Bueso <davidlohr@xxxxxx>
Subject: blackfin/ptrace: call find_vma with the mmap_sem held
Performing vma lookups without taking the mm->mmap_sem is asking for
trouble. While doing the search, the vma in question can be modified or
even removed before returning to the caller. Take the lock (shared) in
order to avoid races while iterating through the vmacache and/or rbtree.
Signed-off-by: Davidlohr Bueso <davidlohr@xxxxxx>
Cc: Steven Miao <realmz6@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/blackfin/kernel/ptrace.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff -puN arch/blackfin/kernel/ptrace.c~blackfin-ptrace-call-find_vma-with-the-mmap_sem-held arch/blackfin/kernel/ptrace.c
--- a/arch/blackfin/kernel/ptrace.c~blackfin-ptrace-call-find_vma-with-the-mmap_sem-held
+++ a/arch/blackfin/kernel/ptrace.c
@@ -117,6 +117,7 @@ put_reg(struct task_struct *task, unsign
int
is_user_addr_valid(struct task_struct *child, unsigned long start, unsigned long len)
{
+ bool valid;
struct vm_area_struct *vma;
struct sram_list_struct *sraml;
@@ -124,9 +125,12 @@ is_user_addr_valid(struct task_struct *c
if (start + len < start)
return -EIO;
+ down_read(&child->mm->mmap_sem);
vma = find_vma(child->mm, start);
- if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
- return 0;
+ valid = vma && start >= vma->vm_start && start + len <= vma->vm_end;
+ up_read(&child->mm->mmap_sem);
+ if (valid)
+ return 0;
for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
if (start >= (unsigned long)sraml->addr
_
Patches currently in -mm which might be from davidlohr@xxxxxx are
origin.patch
m68k-call-find_vma-with-the-mmap_sem-held-in-sys_cacheflush.patch
linux-next.patch
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