From mboxrd@z Thu Jan 1 00:00:00 1970 From: onestero@redhat.com (Oleg Nesterov) Date: Tue, 22 Oct 2013 07:25:51 -0400 (EDT) Subject: [PATCH v2 02/13] uprobes: allow ignoring of probe hits In-Reply-To: <5265F4EB.2060803@linaro.org> References: <1381871068-27660-1-git-send-email-dave.long@linaro.org> <1381871068-27660-3-git-send-email-dave.long@linaro.org> <20131019170214.GA8324@redhat.com> <5265F4EB.2060803@linaro.org> Message-ID: <1641249240.11471136.1382441151287.JavaMail.root@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Sorry for top-posting/formatting, Do you mean arch_uprobe_skip_sstep() ? Yes, this __weak is wrong, already fixed in my tree. See http://marc.info/?l=linux-mips&m=138132052022388&w=2 ----- Original Message ----- From: "David Long" To: "Oleg Nesterov" Cc: linux-arm-kernel at lists.infradead.org, "Rabin Vincent" , "Jon Medhurst (Tixy)" , "Srikar Dronamraju" , "Ingo Molnar" , linux-kernel at vger.kernel.org Sent: Tuesday, 22 October, 2013 5:45:47 AM Subject: Re: [PATCH v2 02/13] uprobes: allow ignoring of probe hits On 10/19/13 13:02, Oleg Nesterov wrote: > On 10/15, David Long wrote: >> >> @@ -1732,9 +1732,6 @@ static void handle_swbp(struct pt_regs *regs) >> return; >> } >> >> - /* change it in advance for ->handler() and restart */ >> - instruction_pointer_set(regs, bp_vaddr); >> - > > Well, this looks obviously wrong. This SET_IP() has the comment ;) > > Note also that with this breaks __skip_sstep() on x86. > > Oleg. > Yes, and there's a missing weak stub function in there too. It was a surprise to me that declaring an external as weak means that it quietly ignores the fact there is no definition for it at link time, and makes it zero. I think there may be some similar land mines elsewhere in the kernel, unrelated to these changes or uprobes in general. I have an updated version to go out with the v3 patches. It is working with v3.12-rc6 on x86 and ARM, to the extent I'm able to test it. -dl