Messages in this thread Patch in this message | | | Date | Tue, 19 Nov 2013 17:25:45 +0100 | From | Oleg Nesterov <> | Subject | [PATCH] uprobes: Document xol_area and arch_uprobe->insn/ixol |
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On 11/11, Ingo Molnar wrote: > > * Oleg Nesterov <oleg@redhat.com> wrote: > > > On 11/11, Ingo Molnar wrote: > > > > > > You guys are changing code that reads like gobbledygook to people > > > reading it for the first time. > > > > Not that I am trying to defense uprobes, but this is equally true for > > any piece of kernel code, at least to me ;) > > I'm really not suggesting to do overly much - only for some minimal blurb > like the scheduler has in most places:
OK. Let me try to make a first step to improve this a little bit...
How about the patch below? Srikar?
Subject: [PATCH] uprobes: Document xol_area and arch_uprobe->insn/ixol
Document xol_area and arch_uprobe.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> --- kernel/events/uprobes.c | 15 +++++++++++++++ 1 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 51a7f53..b886a5e 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -73,6 +73,17 @@ struct uprobe { struct inode *inode; /* Also hold a ref to inode */ loff_t offset; unsigned long flags; + + /* + * The generic code assumes that it has two members of unknown type + * owned by the arch-specific code: + * + * insn - copy_insn() saves the original instruction here for + * arch_uprobe_analyze_insn(). + * + * ixol - potentially modified instruction to execute out of + * line, copied to xol_area by xol_get_insn_slot(). + */ struct arch_uprobe arch; }; @@ -86,6 +97,10 @@ struct return_instance { }; /* + * Execute out of line area: anonymous executable mapping installed + * by the probed task to execute the copy of the original instruction + * mangled by set_swbp(). + * * On a breakpoint hit, thread contests for a slot. It frees the * slot after singlestep. Currently a fixed number of slots are * allocated. -- 1.5.5.1
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