lkml.org 
[lkml]   [2012]   [Jun]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:perf/core] uprobes: No need to re-check vma_address() in write_opcode()
Commit-ID:  eb2bf57bee42c7565032f93adaa211e2c9fcc52c
Gitweb: http://git.kernel.org/tip/eb2bf57bee42c7565032f93adaa211e2c9fcc52c
Author: Oleg Nesterov <oleg@redhat.com>
AuthorDate: Fri, 15 Jun 2012 17:43:47 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sat, 16 Jun 2012 09:10:47 +0200

uprobes: No need to re-check vma_address() in write_opcode()

write_opcode() is called by register_for_each_vma() and
uprobe_mmap() paths. In both cases the caller has already
verified this vaddr under mmap_sem, no need to re-check.

Note also that this check is wrong anyway, we should not
truncate loff_t returned by vma_address() if we do not trust
this mapping.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120615154347.GA9604@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/events/uprobes.c | 5 -----
1 files changed, 0 insertions(+), 5 deletions(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 2db1d94..14c71a2 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -211,7 +211,6 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
struct vm_area_struct *vma;
struct uprobe *uprobe;
unsigned long pgoff;
- loff_t addr;
int ret;
retry:
/* Read the page with vaddr into memory */
@@ -235,10 +234,6 @@ retry:
if (mapping != vma->vm_file->f_mapping)
goto put_out;

- addr = vma_address(vma, uprobe->offset);
- if (vaddr != (unsigned long)addr)
- goto put_out;
-
ret = -ENOMEM;
new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr);
if (!new_page)

\
 
 \ /
  Last update: 2012-06-18 12:21    [W:0.128 / U:0.604 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site