From: Oleg Nesterov <oleg@redhat.com>
To: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
peterz@infradead.org, antonb@thinktux.localdomain,
lkml <linux-kernel@vger.kernel.org>,
michael@ellerman.id.au, Jim Keniston <jkenisto@us.ibm.com>,
Paul Mackerras <paulus@samba.org>, Ingo Molnar <mingo@elte.hu>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2 1/2] uprobes: Pass probed vaddr to arch_uprobe_analyze_insn()
Date: Mon, 11 Jun 2012 18:12:15 +0200 [thread overview]
Message-ID: <20120611161215.GA12116@redhat.com> (raw)
In-Reply-To: <20120608093257.GG13409@in.ibm.com>
Ananth, Srikar,
I think the patch is correct and I am sorry for nit-picking,
this is really minor.
But,
On 06/08, Ananth N Mavinakayanahalli wrote:
>
> Changes in V2:
> Pass (unsigned long)addr
Well, IMHO, this is confusing.
First of all, why do we have this "addr" or even "vaddr"? It should
not exists. We pass it to copy_insn(), but for what?? copy_insn()
should simply use uprobe->offset, the virtual address for this
particular mapping does not matter at all. I am going to send
the cleanup.
Note also that we should move this !UPROBE_COPY_INSN from
install_breakpoint() to somewhere near alloc_uprobe(). This code
is called only once, it looks a bit strange to use the "random" mm
(the first mm vma_prio_tree_foreach() finds) and its mapping to
verify the insn. In fact this is simply not correct and should be
fixed, note that on x86 arch_uprobe_analyze_insn() checks
mm->context.ia32_compat.
IOW, Perhaps uprobe->offset makes more sense?
> --- linux-3.5-rc1.orig/kernel/events/uprobes.c
> +++ linux-3.5-rc1/kernel/events/uprobes.c
> @@ -697,7 +697,7 @@ install_breakpoint(struct uprobe *uprobe
> if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn))
> return -EEXIST;
>
> - ret = arch_uprobe_analyze_insn(&uprobe->arch, mm);
> + ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, addr);
Just fyi, this conflicts with
"[PATCH 1/3] uprobes: install_breakpoint() should fail if is_swbp_insn() == T"
I sent, but the conflict is trivial.
Oleg.
next prev parent reply other threads:[~2012-06-11 16:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-08 9:32 [PATCH v2 1/2] uprobes: Pass probed vaddr to arch_uprobe_analyze_insn() Ananth N Mavinakayanahalli
2012-06-08 9:34 ` [PATCH v2 2/2] [POWERPC] uprobes: powerpc port Ananth N Mavinakayanahalli
2012-06-11 16:12 ` Oleg Nesterov [this message]
2012-06-11 19:09 ` Q: a_ops->readpage() && struct file Oleg Nesterov
2012-06-13 9:58 ` Peter Zijlstra
2012-06-13 19:19 ` Oleg Nesterov
2012-06-12 16:54 ` [PATCH v2 1/2] uprobes: Pass probed vaddr to arch_uprobe_analyze_insn() Srikar Dronamraju
2012-06-12 17:43 ` Oleg Nesterov
2012-06-13 19:15 ` Oleg Nesterov
2012-06-14 11:45 ` Srikar Dronamraju
2012-06-14 18:19 ` Oleg Nesterov
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