From: Jisheng Zhang <Jisheng.Zhang@synaptics.com> To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@redhat.com>, "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>, Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>, "David S. Miller" <davem@davemloft.net>, Masami Hiramatsu <mhiramat@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Jonathan Corbet <corbet@lwn.net> Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Subject: Re: [PATCH v7 1/3] kprobes/ftrace: Use ftrace_location() when [dis]arming probes Date: Wed, 25 Dec 2019 09:46:35 +0000 [thread overview] Message-ID: <20191225173219.4f9db436@xhacker.debian> (raw) In-Reply-To: <20191225172752.70be1dc1@xhacker.debian> On Wed, 25 Dec 2019 09:42:07 +0000 Jisheng Zhang wrote: > oops, I missed "From: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>" I will take care this point when posting new version. > Ftrace location could include more than a single instruction in case > of some architectures (powerpc64, for now). In this case, kprobe is > permitted on any of those instructions, and uses ftrace infrastructure > for functioning. > > However, [dis]arm_kprobe_ftrace() uses the kprobe address when setting > up ftrace filter IP. This won't work if the address points to any > instruction apart from the one that has a branch to _mcount(). To > resolve this, have [dis]arm_kprobe_ftrace() use ftrace_function() to > identify the filter IP. > > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> > Acked-by: Masami Hiramatsu <mhiramat@kernel.org> > --- > kernel/kprobes.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 53534aa258a6..5c630b424e3a 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -986,9 +986,10 @@ static int prepare_kprobe(struct kprobe *p) > static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, > int *cnt) > { > + unsigned long ftrace_ip = ftrace_location((unsigned long)p->addr); > int ret = 0; > > - ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0); > + ret = ftrace_set_filter_ip(ops, ftrace_ip, 0, 0); > if (ret) { > pr_debug("Failed to arm kprobe-ftrace at %pS (%d)\n", > p->addr, ret); > @@ -1011,7 +1012,7 @@ static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, > * At this point, sinec ops is not registered, we should be sefe from > * registering empty filter. > */ > - ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0); > + ftrace_set_filter_ip(ops, ftrace_ip, 1, 0); > return ret; > } > > @@ -1028,6 +1029,7 @@ static int arm_kprobe_ftrace(struct kprobe *p) > static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, > int *cnt) > { > + unsigned long ftrace_ip = ftrace_location((unsigned long)p->addr); > int ret = 0; > > if (*cnt == 1) { > @@ -1038,7 +1040,7 @@ static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, > > (*cnt)--; > > - ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0); > + ret = ftrace_set_filter_ip(ops, ftrace_ip, 1, 0); > WARN_ONCE(ret < 0, "Failed to disarm kprobe-ftrace at %pS (%d)\n", > p->addr, ret); > return ret; > -- > 2.24.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.infradead.org_mailman_listinfo_linux-2Darm-2Dkernel&d=DwICAg&c=7dfBJ8cXbWjhc0BhImu8wQ&r=wlaKTGoVCDxOzHc2QUzpzGEf9oY3eidXlAe3OF1omvo&m=BG5GowWc97yveg-i3gFbh3N7PDT3S3FwcxnpOSRpvIs&s=plWeJUToTNi5CWx998a_VbVx3eFc-MNhUNv4fLpmyiU&e=
WARNING: multiple messages have this Message-ID (diff)
From: Jisheng Zhang <Jisheng.Zhang@synaptics.com> To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@redhat.com>, "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>, Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>, "David S. Miller" <davem@davemloft.net>, Masami Hiramatsu <mhiramat@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Jonathan Corbet <corbet@lwn.net> Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Subject: Re: [PATCH v7 1/3] kprobes/ftrace: Use ftrace_location() when [dis]arming probes Date: Wed, 25 Dec 2019 09:46:35 +0000 [thread overview] Message-ID: <20191225173219.4f9db436@xhacker.debian> (raw) In-Reply-To: <20191225172752.70be1dc1@xhacker.debian> On Wed, 25 Dec 2019 09:42:07 +0000 Jisheng Zhang wrote: > oops, I missed "From: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>" I will take care this point when posting new version. > Ftrace location could include more than a single instruction in case > of some architectures (powerpc64, for now). In this case, kprobe is > permitted on any of those instructions, and uses ftrace infrastructure > for functioning. > > However, [dis]arm_kprobe_ftrace() uses the kprobe address when setting > up ftrace filter IP. This won't work if the address points to any > instruction apart from the one that has a branch to _mcount(). To > resolve this, have [dis]arm_kprobe_ftrace() use ftrace_function() to > identify the filter IP. > > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> > Acked-by: Masami Hiramatsu <mhiramat@kernel.org> > --- > kernel/kprobes.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 53534aa258a6..5c630b424e3a 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -986,9 +986,10 @@ static int prepare_kprobe(struct kprobe *p) > static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, > int *cnt) > { > + unsigned long ftrace_ip = ftrace_location((unsigned long)p->addr); > int ret = 0; > > - ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 0, 0); > + ret = ftrace_set_filter_ip(ops, ftrace_ip, 0, 0); > if (ret) { > pr_debug("Failed to arm kprobe-ftrace at %pS (%d)\n", > p->addr, ret); > @@ -1011,7 +1012,7 @@ static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, > * At this point, sinec ops is not registered, we should be sefe from > * registering empty filter. > */ > - ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0); > + ftrace_set_filter_ip(ops, ftrace_ip, 1, 0); > return ret; > } > > @@ -1028,6 +1029,7 @@ static int arm_kprobe_ftrace(struct kprobe *p) > static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, > int *cnt) > { > + unsigned long ftrace_ip = ftrace_location((unsigned long)p->addr); > int ret = 0; > > if (*cnt == 1) { > @@ -1038,7 +1040,7 @@ static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops, > > (*cnt)--; > > - ret = ftrace_set_filter_ip(ops, (unsigned long)p->addr, 1, 0); > + ret = ftrace_set_filter_ip(ops, ftrace_ip, 1, 0); > WARN_ONCE(ret < 0, "Failed to disarm kprobe-ftrace at %pS (%d)\n", > p->addr, ret); > return ret; > -- > 2.24.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.infradead.org_mailman_listinfo_linux-2Darm-2Dkernel&d=DwICAg&c=7dfBJ8cXbWjhc0BhImu8wQ&r=wlaKTGoVCDxOzHc2QUzpzGEf9oY3eidXlAe3OF1omvo&m=BG5GowWc97yveg-i3gFbh3N7PDT3S3FwcxnpOSRpvIs&s=plWeJUToTNi5CWx998a_VbVx3eFc-MNhUNv4fLpmyiU&e= _______________________________________________ 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:[~2019-12-25 9:46 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-12-25 9:40 [PATCH v7 0/3] arm64: implement KPROBES_ON_FTRACE Jisheng Zhang 2019-12-25 9:40 ` Jisheng Zhang 2019-12-25 9:42 ` [PATCH v7 1/3] kprobes/ftrace: Use ftrace_location() when [dis]arming probes Jisheng Zhang 2019-12-25 9:42 ` Jisheng Zhang 2019-12-25 9:46 ` Jisheng Zhang [this message] 2019-12-25 9:46 ` Jisheng Zhang 2019-12-25 9:42 ` [PATCH v7 2/3] ftrace: introduce FTRACE_IP_EXTENSION Jisheng Zhang 2019-12-25 9:42 ` Jisheng Zhang 2019-12-26 2:45 ` Masami Hiramatsu 2019-12-26 2:45 ` Masami Hiramatsu 2020-01-08 0:05 ` Steven Rostedt 2020-01-08 0:05 ` Steven Rostedt 2019-12-25 9:44 ` [PATCH v7 3/3] arm64: implement KPROBES_ON_FTRACE Jisheng Zhang 2019-12-25 9:44 ` Jisheng Zhang 2019-12-26 2:57 ` Masami Hiramatsu 2019-12-26 2:57 ` Masami Hiramatsu 2019-12-26 3:18 ` Jisheng Zhang 2019-12-26 3:18 ` Jisheng Zhang 2019-12-26 4:25 ` Jisheng Zhang 2019-12-26 4:25 ` Jisheng Zhang 2019-12-26 9:26 ` Masami Hiramatsu 2019-12-26 9:26 ` Masami Hiramatsu 2020-07-21 13:24 ` Masami Hiramatsu 2020-07-21 13:24 ` Masami Hiramatsu 2020-07-24 7:06 ` Jisheng Zhang 2020-07-24 7:06 ` Jisheng Zhang 2020-07-24 16:54 ` Masami Hiramatsu 2020-07-24 16:54 ` Masami Hiramatsu 2020-02-28 15:31 ` Mark Rutland 2020-02-28 15:31 ` Mark Rutland
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