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authorOleg Nesterov <oleg@redhat.com>2012-07-29 20:22:12 +0200
committerIngo Molnar <mingo@kernel.org>2012-07-30 11:27:18 +0200
commitf403072c6108e15f319a4a5036b650c77760522c (patch)
tree196781f30871635b7c8fc702a7566b5ed09e525c /kernel
parent35d56ca9d401d9d0ac8d91e4db1485af5f38f6fd (diff)
downloadop-kernel-dev-f403072c6108e15f319a4a5036b650c77760522c.zip
op-kernel-dev-f403072c6108e15f319a4a5036b650c77760522c.tar.gz
uprobes: Don't recheck vma/f_mapping in write_opcode()
write_opcode() rechecks valid_vma() and ->f_mapping, this is pointless. The caller, register_for_each_vma() or uprobe_mmap(), has already done these checks under mmap_sem. To clarify, uprobe_mmap() checks valid_vma() only, but we can rely on build_probe_list(vm_file->f_mapping->host). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182212.GA20304@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/uprobes.c19
1 files changed, 1 insertions, 18 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index f935327..a2b32a5 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -206,33 +206,16 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
unsigned long vaddr, uprobe_opcode_t opcode)
{
struct page *old_page, *new_page;
- struct address_space *mapping;
void *vaddr_old, *vaddr_new;
struct vm_area_struct *vma;
- struct uprobe *uprobe;
int ret;
+
retry:
/* Read the page with vaddr into memory */
ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma);
if (ret <= 0)
return ret;
- ret = -EINVAL;
-
- /*
- * We are interested in text pages only. Our pages of interest
- * should be mapped for read and execute only. We desist from
- * adding probes in write mapped pages since the breakpoints
- * might end up in the file copy.
- */
- if (!valid_vma(vma, is_swbp_insn(&opcode)))
- goto put_out;
-
- uprobe = container_of(auprobe, struct uprobe, arch);
- mapping = uprobe->inode->i_mapping;
- if (mapping != vma->vm_file->f_mapping)
- goto put_out;
-
ret = -ENOMEM;
new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr);
if (!new_page)
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