From: Jisheng Zhang <Jisheng.Zhang@synaptics.com> To: Masami Hiramatsu <mhiramat@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de>, Catalin Marinas <catalin.marinas@arm.com>, Jonathan Corbet <corbet@lwn.net>, Will Deacon <will@kernel.org>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>, "x86@kernel.org" <x86@kernel.org>, "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>, Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>, "David S. Miller" <davem@davemloft.net>, "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org> Subject: Re: [PATCH v2 1/3] kprobes/x86: use instruction_pointer and instruction_pointer_set Date: Wed, 21 Aug 2019 02:09:10 +0000 [thread overview] Message-ID: <20190821095527.729b2b0d@xhacker.debian> (raw) In-Reply-To: <20190821105247.f0236d2c04b2c0c4d4e1847e@kernel.org> Hi, On Wed, 21 Aug 2019 10:52:47 +0900 Masami Hiramatsu wrote: > > > Hi Jisheng, > > On Tue, 20 Aug 2019 09:02:59 +0000 > Jisheng Zhang <Jisheng.Zhang@synaptics.com> wrote: > > > Hi Thomas, > > > > On Tue, 20 Aug 2019 10:53:58 +0200 (CEST) Thomas Gleixner wrote: > > > > > > > > > > > On Tue, 20 Aug 2019, Jisheng Zhang wrote: > > > > > > > This is to make the x86 kprobe_ftrace_handler() more common so that > > > > the code could be reused in future. > > > > > > While I agree with the change in general, I can't find anything which > > > reuses that code. So the change log is pretty useless and I have no idea > > > how this is related to the rest of the series. > > > > In v1, this code is moved from x86 to common kprobes.c [1] > > But I agree with Masami, consolidation could be done when arm64 kprobes > > on ftrace is stable. > > We'll revisit to consolidate the code after we got 3rd or 4th clones. > > > > > In v2, actually, the arm64 version's kprobe_ftrace_handler() is the same > > as x86's, the only difference is comment, e.g > > > > /* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */ > > > > while in arm64 > > > > /* Kprobe handler expects regs->pc = ip + 1 as breakpoint hit */ > > As Peter pointed, on arm64, is that really 1 or 4 bytes? > This part is heavily depends on the processor software-breakpoint > implementation. Per my understanding, the "+1" here means "+ one kprobe_opcode_t". > > > > > > > W/ above, any suggestion about the suitable change log? > > I think you just need to keep the first half of the description. > Since this patch itself is not related to the series, could you update > the description and resend it as a single cleanup patch out of the series? > Got it. Will do today. Thanks a lot
WARNING: multiple messages have this Message-ID (diff)
From: Jisheng Zhang <Jisheng.Zhang@synaptics.com> To: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net>, Catalin Marinas <catalin.marinas@arm.com>, "x86@kernel.org" <x86@kernel.org>, "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>, "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>, Thomas Gleixner <tglx@linutronix.de>, Will Deacon <will@kernel.org>, "David S. Miller" <davem@davemloft.net>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org> Subject: Re: [PATCH v2 1/3] kprobes/x86: use instruction_pointer and instruction_pointer_set Date: Wed, 21 Aug 2019 02:09:10 +0000 [thread overview] Message-ID: <20190821095527.729b2b0d@xhacker.debian> (raw) In-Reply-To: <20190821105247.f0236d2c04b2c0c4d4e1847e@kernel.org> Hi, On Wed, 21 Aug 2019 10:52:47 +0900 Masami Hiramatsu wrote: > > > Hi Jisheng, > > On Tue, 20 Aug 2019 09:02:59 +0000 > Jisheng Zhang <Jisheng.Zhang@synaptics.com> wrote: > > > Hi Thomas, > > > > On Tue, 20 Aug 2019 10:53:58 +0200 (CEST) Thomas Gleixner wrote: > > > > > > > > > > > On Tue, 20 Aug 2019, Jisheng Zhang wrote: > > > > > > > This is to make the x86 kprobe_ftrace_handler() more common so that > > > > the code could be reused in future. > > > > > > While I agree with the change in general, I can't find anything which > > > reuses that code. So the change log is pretty useless and I have no idea > > > how this is related to the rest of the series. > > > > In v1, this code is moved from x86 to common kprobes.c [1] > > But I agree with Masami, consolidation could be done when arm64 kprobes > > on ftrace is stable. > > We'll revisit to consolidate the code after we got 3rd or 4th clones. > > > > > In v2, actually, the arm64 version's kprobe_ftrace_handler() is the same > > as x86's, the only difference is comment, e.g > > > > /* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */ > > > > while in arm64 > > > > /* Kprobe handler expects regs->pc = ip + 1 as breakpoint hit */ > > As Peter pointed, on arm64, is that really 1 or 4 bytes? > This part is heavily depends on the processor software-breakpoint > implementation. Per my understanding, the "+1" here means "+ one kprobe_opcode_t". > > > > > > > W/ above, any suggestion about the suitable change log? > > I think you just need to keep the first half of the description. > Since this patch itself is not related to the series, could you update > the description and resend it as a single cleanup patch out of the series? > Got it. Will do today. Thanks a lot _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-08-21 2:09 UTC|newest] Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-08-20 3:50 [PATCH v2 0/3] arm64: KPROBES_ON_FTRACE Jisheng Zhang 2019-08-20 3:50 ` Jisheng Zhang 2019-08-20 3:52 ` [PATCH v2 1/3] kprobes/x86: use instruction_pointer and instruction_pointer_set Jisheng Zhang 2019-08-20 3:52 ` Jisheng Zhang 2019-08-20 8:53 ` Thomas Gleixner 2019-08-20 8:53 ` Thomas Gleixner 2019-08-20 9:02 ` Jisheng Zhang 2019-08-20 9:02 ` Jisheng Zhang 2019-08-20 9:20 ` Jisheng Zhang 2019-08-20 9:20 ` Jisheng Zhang 2019-08-20 13:21 ` Peter Zijlstra 2019-08-20 13:21 ` Peter Zijlstra 2019-08-21 2:02 ` Jisheng Zhang 2019-08-21 2:02 ` Jisheng Zhang 2019-08-21 1:52 ` Masami Hiramatsu 2019-08-21 1:52 ` Masami Hiramatsu 2019-08-21 2:09 ` Jisheng Zhang [this message] 2019-08-21 2:09 ` Jisheng Zhang 2019-08-23 14:51 ` Masami Hiramatsu 2019-08-23 14:51 ` Masami Hiramatsu 2019-08-20 3:53 ` [PATCH v2 2/3] kprobes: adjust kprobe addr for KPROBES_ON_FTRACE Jisheng Zhang 2019-08-20 3:53 ` Jisheng Zhang 2019-08-20 10:15 ` Naveen N. Rao 2019-08-20 10:15 ` Naveen N. Rao 2019-08-20 10:41 ` Jisheng Zhang 2019-08-20 10:41 ` Jisheng Zhang 2019-08-21 2:07 ` Masami Hiramatsu 2019-08-21 2:07 ` Masami Hiramatsu 2019-08-21 2:50 ` Jisheng Zhang 2019-08-21 2:50 ` Jisheng Zhang 2019-08-20 3:54 ` [PATCH v2 3/3] arm64: implement KPROBES_ON_FTRACE Jisheng Zhang 2019-08-20 3:54 ` Jisheng Zhang 2019-08-20 7:17 ` Jisheng Zhang 2019-08-20 7:17 ` Jisheng Zhang 2019-08-20 8:53 ` Thomas Gleixner 2019-08-20 8:53 ` Thomas Gleixner
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