* [PATCH] riscv: kprobes/ftrace: Add recursion protection to the ftrace callback
@ 2021-03-29 18:14 ` Jisheng Zhang
0 siblings, 0 replies; 6+ messages in thread
From: Jisheng Zhang @ 2021-03-29 18:14 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Masami Hiramatsu,
Steven Rostedt (VMware),
Guo Ren
Cc: linux-riscv, linux-kernel
From: Jisheng Zhang <jszhang@kernel.org>
Currently, the riscv's kprobes(powerred by ftrace) handler is
preemptible. Futher check indicates we miss something similar as the
commit c536aa1c5b17 ("kprobes/ftrace: Add recursion protection to the
ftrace callback"), so do similar modifications as the commit does.
Fixes: 829adda597fe ("riscv: Add KPROBES_ON_FTRACE supported")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
arch/riscv/kernel/probes/ftrace.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/probes/ftrace.c b/arch/riscv/kernel/probes/ftrace.c
index 17ca5e923bb0..aab85a82f419 100644
--- a/arch/riscv/kernel/probes/ftrace.c
+++ b/arch/riscv/kernel/probes/ftrace.c
@@ -9,10 +9,16 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
struct kprobe *p;
struct pt_regs *regs;
struct kprobe_ctlblk *kcb;
+ int bit;
+ bit = ftrace_test_recursion_trylock(ip, parent_ip);
+ if (bit < 0)
+ return;
+
+ preempt_disable_notrace();
p = get_kprobe((kprobe_opcode_t *)ip);
if (unlikely(!p) || kprobe_disabled(p))
- return;
+ goto out;
regs = ftrace_get_regs(fregs);
kcb = get_kprobe_ctlblk();
@@ -45,6 +51,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
*/
__this_cpu_write(current_kprobe, NULL);
}
+out:
+ preempt_enable_notrace();
+ ftrace_test_recursion_unlock(bit);
}
NOKPROBE_SYMBOL(kprobe_ftrace_handler);
--
2.31.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH] riscv: kprobes/ftrace: Add recursion protection to the ftrace callback
@ 2021-03-29 18:14 ` Jisheng Zhang
0 siblings, 0 replies; 6+ messages in thread
From: Jisheng Zhang @ 2021-03-29 18:14 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou, Masami Hiramatsu,
Steven Rostedt (VMware),
Guo Ren
Cc: linux-riscv, linux-kernel
From: Jisheng Zhang <jszhang@kernel.org>
Currently, the riscv's kprobes(powerred by ftrace) handler is
preemptible. Futher check indicates we miss something similar as the
commit c536aa1c5b17 ("kprobes/ftrace: Add recursion protection to the
ftrace callback"), so do similar modifications as the commit does.
Fixes: 829adda597fe ("riscv: Add KPROBES_ON_FTRACE supported")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
arch/riscv/kernel/probes/ftrace.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/probes/ftrace.c b/arch/riscv/kernel/probes/ftrace.c
index 17ca5e923bb0..aab85a82f419 100644
--- a/arch/riscv/kernel/probes/ftrace.c
+++ b/arch/riscv/kernel/probes/ftrace.c
@@ -9,10 +9,16 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
struct kprobe *p;
struct pt_regs *regs;
struct kprobe_ctlblk *kcb;
+ int bit;
+ bit = ftrace_test_recursion_trylock(ip, parent_ip);
+ if (bit < 0)
+ return;
+
+ preempt_disable_notrace();
p = get_kprobe((kprobe_opcode_t *)ip);
if (unlikely(!p) || kprobe_disabled(p))
- return;
+ goto out;
regs = ftrace_get_regs(fregs);
kcb = get_kprobe_ctlblk();
@@ -45,6 +51,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
*/
__this_cpu_write(current_kprobe, NULL);
}
+out:
+ preempt_enable_notrace();
+ ftrace_test_recursion_unlock(bit);
}
NOKPROBE_SYMBOL(kprobe_ftrace_handler);
--
2.31.0
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linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] riscv: kprobes/ftrace: Add recursion protection to the ftrace callback
2021-03-29 18:14 ` Jisheng Zhang
@ 2021-03-30 19:39 ` Steven Rostedt
-1 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2021-03-30 19:39 UTC (permalink / raw)
To: Jisheng Zhang
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, Masami Hiramatsu,
Guo Ren, linux-riscv, linux-kernel
On Tue, 30 Mar 2021 02:14:40 +0800
Jisheng Zhang <jszhang3@mail.ustc.edu.cn> wrote:
> From: Jisheng Zhang <jszhang@kernel.org>
>
> Currently, the riscv's kprobes(powerred by ftrace) handler is
> preemptible. Futher check indicates we miss something similar as the
> commit c536aa1c5b17 ("kprobes/ftrace: Add recursion protection to the
> ftrace callback"), so do similar modifications as the commit does.
>
> Fixes: 829adda597fe ("riscv: Add KPROBES_ON_FTRACE supported")
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Looks fine to me.
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] riscv: kprobes/ftrace: Add recursion protection to the ftrace callback
@ 2021-03-30 19:39 ` Steven Rostedt
0 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2021-03-30 19:39 UTC (permalink / raw)
To: Jisheng Zhang
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, Masami Hiramatsu,
Guo Ren, linux-riscv, linux-kernel
On Tue, 30 Mar 2021 02:14:40 +0800
Jisheng Zhang <jszhang3@mail.ustc.edu.cn> wrote:
> From: Jisheng Zhang <jszhang@kernel.org>
>
> Currently, the riscv's kprobes(powerred by ftrace) handler is
> preemptible. Futher check indicates we miss something similar as the
> commit c536aa1c5b17 ("kprobes/ftrace: Add recursion protection to the
> ftrace callback"), so do similar modifications as the commit does.
>
> Fixes: 829adda597fe ("riscv: Add KPROBES_ON_FTRACE supported")
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Looks fine to me.
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] riscv: kprobes/ftrace: Add recursion protection to the ftrace callback
2021-03-29 18:14 ` Jisheng Zhang
@ 2021-04-12 1:09 ` Palmer Dabbelt
-1 siblings, 0 replies; 6+ messages in thread
From: Palmer Dabbelt @ 2021-04-12 1:09 UTC (permalink / raw)
To: jszhang3
Cc: Paul Walmsley, aou, mhiramat, rostedt, guoren, linux-riscv, linux-kernel
On Mon, 29 Mar 2021 11:14:40 PDT (-0700), jszhang3@mail.ustc.edu.cn wrote:
> From: Jisheng Zhang <jszhang@kernel.org>
>
> Currently, the riscv's kprobes(powerred by ftrace) handler is
> preemptible. Futher check indicates we miss something similar as the
> commit c536aa1c5b17 ("kprobes/ftrace: Add recursion protection to the
> ftrace callback"), so do similar modifications as the commit does.
>
> Fixes: 829adda597fe ("riscv: Add KPROBES_ON_FTRACE supported")
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
> ---
> arch/riscv/kernel/probes/ftrace.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/probes/ftrace.c b/arch/riscv/kernel/probes/ftrace.c
> index 17ca5e923bb0..aab85a82f419 100644
> --- a/arch/riscv/kernel/probes/ftrace.c
> +++ b/arch/riscv/kernel/probes/ftrace.c
> @@ -9,10 +9,16 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> struct kprobe *p;
> struct pt_regs *regs;
> struct kprobe_ctlblk *kcb;
> + int bit;
>
> + bit = ftrace_test_recursion_trylock(ip, parent_ip);
> + if (bit < 0)
> + return;
> +
> + preempt_disable_notrace();
> p = get_kprobe((kprobe_opcode_t *)ip);
> if (unlikely(!p) || kprobe_disabled(p))
> - return;
> + goto out;
>
> regs = ftrace_get_regs(fregs);
> kcb = get_kprobe_ctlblk();
> @@ -45,6 +51,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> */
> __this_cpu_write(current_kprobe, NULL);
> }
> +out:
> + preempt_enable_notrace();
> + ftrace_test_recursion_unlock(bit);
> }
> NOKPROBE_SYMBOL(kprobe_ftrace_handler);
Thanks, this is on fixes.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] riscv: kprobes/ftrace: Add recursion protection to the ftrace callback
@ 2021-04-12 1:09 ` Palmer Dabbelt
0 siblings, 0 replies; 6+ messages in thread
From: Palmer Dabbelt @ 2021-04-12 1:09 UTC (permalink / raw)
To: jszhang3
Cc: Paul Walmsley, aou, mhiramat, rostedt, guoren, linux-riscv, linux-kernel
On Mon, 29 Mar 2021 11:14:40 PDT (-0700), jszhang3@mail.ustc.edu.cn wrote:
> From: Jisheng Zhang <jszhang@kernel.org>
>
> Currently, the riscv's kprobes(powerred by ftrace) handler is
> preemptible. Futher check indicates we miss something similar as the
> commit c536aa1c5b17 ("kprobes/ftrace: Add recursion protection to the
> ftrace callback"), so do similar modifications as the commit does.
>
> Fixes: 829adda597fe ("riscv: Add KPROBES_ON_FTRACE supported")
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
> ---
> arch/riscv/kernel/probes/ftrace.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/probes/ftrace.c b/arch/riscv/kernel/probes/ftrace.c
> index 17ca5e923bb0..aab85a82f419 100644
> --- a/arch/riscv/kernel/probes/ftrace.c
> +++ b/arch/riscv/kernel/probes/ftrace.c
> @@ -9,10 +9,16 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> struct kprobe *p;
> struct pt_regs *regs;
> struct kprobe_ctlblk *kcb;
> + int bit;
>
> + bit = ftrace_test_recursion_trylock(ip, parent_ip);
> + if (bit < 0)
> + return;
> +
> + preempt_disable_notrace();
> p = get_kprobe((kprobe_opcode_t *)ip);
> if (unlikely(!p) || kprobe_disabled(p))
> - return;
> + goto out;
>
> regs = ftrace_get_regs(fregs);
> kcb = get_kprobe_ctlblk();
> @@ -45,6 +51,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> */
> __this_cpu_write(current_kprobe, NULL);
> }
> +out:
> + preempt_enable_notrace();
> + ftrace_test_recursion_unlock(bit);
> }
> NOKPROBE_SYMBOL(kprobe_ftrace_handler);
Thanks, this is on fixes.
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-04-12 1:09 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2021-03-29 18:14 [PATCH] riscv: kprobes/ftrace: Add recursion protection to the ftrace callback Jisheng Zhang
2021-03-29 18:14 ` Jisheng Zhang
2021-03-30 19:39 ` Steven Rostedt
2021-03-30 19:39 ` Steven Rostedt
2021-04-12 1:09 ` Palmer Dabbelt
2021-04-12 1:09 ` Palmer Dabbelt
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