Commit-ID: a3d7bb47937b3a40b9f0c75655e97b3bb6407cbe Gitweb: http://git.kernel.org/tip/a3d7bb47937b3a40b9f0c75655e97b3bb6407cbe Author: Oleg Nesterov <oleg@xxxxxxxxxx> AuthorDate: Tue, 29 May 2012 21:27:59 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Wed, 6 Jun 2012 17:14:49 +0200 uprobes: Change read_opcode() to use FOLL_FORCE set_orig_insn()->read_opcode() should not fail if the probed task did mprotect() after uprobe_register(), change it to use FOLL_FORCE. Without FOLL_WRITE this doesn't have any "side" effect but allows to read the !VM_READ memory. There is another reason for this change, we are going to use is_swbp_at_addr() from handle_swbp() which can race with another thread doing mprotect(). Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Acked-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx> Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx> Cc: Anton Arapov <anton@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20120529192759.GB8057@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- kernel/events/uprobes.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index d0f5ec0..a0dbc87 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -312,7 +312,7 @@ static int read_opcode(struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_ void *vaddr_new; int ret; - ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &page, NULL); + ret = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL); if (ret <= 0) return ret; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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