diff options
| author |   Oleg Nesterov <oleg@redhat.com> | 2012-06-15 17:43:42 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2012-06-16 09:10:45 +0200 |
| commit | d436615e60c386095dac4a9bf72b08868d2a7564 (patch) | |
| tree | d69e29a80512f13cb1ce3f302cd865fd35709ddf /kernel | |
| parent | uprobes: Document uprobe_register() vs uprobe_mmap() race (diff) | |
| download | linux-dev-d436615e60c386095dac4a9bf72b08868d2a7564.tar.xz linux-dev-d436615e60c386095dac4a9bf72b08868d2a7564.zip | |
uprobes: Copy_insn() shouldn't depend on mm/vma/vaddr
1. copy_insn() doesn't need "addr", it can use uprobe->offset.
Remove this argument.
2. Change copy_insn/__copy_insn to accept "struct file*" instead
of vma.
copy_insn() is called only once and mm/vma/vaddr are random, it
shouldn't depend on them.
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/20120615154342.GA9598@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/uprobes.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 2671d9ad49be..08ef566da763 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -591,10 +591,9 @@ static bool consumer_del(struct uprobe *uprobe, struct uprobe_consumer *uc) } static int -__copy_insn(struct address_space *mapping, struct vm_area_struct *vma, char *insn, +__copy_insn(struct address_space *mapping, struct file *filp, char *insn, unsigned long nbytes, unsigned long offset) { - struct file *filp = vma->vm_file; struct page *page; void *vaddr; unsigned long off1; @@ -625,15 +624,13 @@ __copy_insn(struct address_space *mapping, struct vm_area_struct *vma, char *ins return 0; } -static int -copy_insn(struct uprobe *uprobe, struct vm_area_struct *vma, unsigned long addr) +static int copy_insn(struct uprobe *uprobe, struct file *filp) { struct address_space *mapping; unsigned long nbytes; int bytes; - addr &= ~PAGE_MASK; - nbytes = PAGE_SIZE - addr; + nbytes = PAGE_SIZE - (uprobe->offset & ~PAGE_MASK); mapping = uprobe->inode->i_mapping; /* Instruction at end of binary; copy only available bytes */ @@ -644,13 +641,13 @@ copy_insn(struct uprobe *uprobe, struct vm_area_struct *vma, unsigned long addr) /* Instruction at the page-boundary; copy bytes in second page */ if (nbytes < bytes) { - if (__copy_insn(mapping, vma, uprobe->arch.insn + nbytes, + if (__copy_insn(mapping, filp, uprobe->arch.insn + nbytes, bytes - nbytes, uprobe->offset + nbytes)) return -ENOMEM; bytes = nbytes; } - return __copy_insn(mapping, vma, uprobe->arch.insn, bytes, uprobe->offset); + return __copy_insn(mapping, filp, uprobe->arch.insn, bytes, uprobe->offset); } /* @@ -696,7 +693,7 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, addr = (unsigned long)vaddr; if (!(uprobe->flags & UPROBE_COPY_INSN)) { - ret = copy_insn(uprobe, vma, addr); + ret = copy_insn(uprobe, vma->vm_file); if (ret) return ret; |