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| author | Oleg Nesterov <oleg@redhat.com> | 2012-09-30 18:54:53 +0200 |
|---|---|---|
| committer | Oleg Nesterov <oleg@redhat.com> | 2012-10-07 21:19:41 +0200 |
| commit | 076a365b3da99b68c5d58e394714d0611f1fa002 (patch) | |
| tree | b58ae7da7bfa80200bb9982f344b93cf3f22a7fd /kernel | |
| parent | a5f658b71bc622b731961ea3addcf146ed3c599f (diff) | |
| download | linux-076a365b3da99b68c5d58e394714d0611f1fa002.tar.gz linux-076a365b3da99b68c5d58e394714d0611f1fa002.tar.xz | |
uprobes: Do not delete uprobe if uprobe_unregister() fails
delete_uprobe() must not be called if register_for_each_vma(false)
fails to remove all breakpoints, __uprobe_unregister() is correct.
The problem is that register_for_each_vma(false) always returns 0
and thus this logic does not work.
1. Change verify_opcode() to return 0 rather than -EINVAL when
unregister detects the !is_swbp insn, we can treat this case
as success and currently unregister paths ignore the error
code anyway.
2. Change remove_breakpoint() to propagate the error code from
write_opcode().
3. Change register_for_each_vma(is_register => false) to remove
as much breakpoints as possible but return non-zero if
remove_breakpoint() fails at least once.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/uprobes.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 588a5575d64c..a1b466d17c17 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -203,7 +203,7 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t return 0; } else { if (!is_swbp) /* unregister: was it changed by us? */ - return -EINVAL; + return 0; } return 1; @@ -616,15 +616,15 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, return ret; } -static void +static int remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr) { /* can happen if uprobe_register() fails */ if (!test_bit(MMF_HAS_UPROBES, &mm->flags)) - return; + return 0; set_bit(MMF_RECALC_UPROBES, &mm->flags); - set_orig_insn(&uprobe->arch, mm, vaddr); + return set_orig_insn(&uprobe->arch, mm, vaddr); } /* @@ -740,7 +740,7 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) struct mm_struct *mm = info->mm; struct vm_area_struct *vma; - if (err) + if (err && is_register) goto free; down_write(&mm->mmap_sem); @@ -756,7 +756,7 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) if (is_register) err = install_breakpoint(uprobe, mm, vma, info->vaddr); else - remove_breakpoint(uprobe, mm, info->vaddr); + err |= remove_breakpoint(uprobe, mm, info->vaddr); unlock: up_write(&mm->mmap_sem); |