From: Oleg Nesterov <oleg@redhat.com>
To: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
bpf@vger.kernel.org, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
"Borislav Petkov (AMD)" <bp@alien8.de>,
x86@kernel.org
Subject: Re: [PATCH RFC bpf-next 1/3] uprobe: Add uretprobe syscall to speed up return probe
Date: Mon, 18 Mar 2024 15:22:12 +0100 [thread overview]
Message-ID: <20240318142211.GA7616@redhat.com> (raw)
In-Reply-To: <20240318093139.293497-2-jolsa@kernel.org>
On 03/18, Jiri Olsa wrote:
>
> +SYSCALL_DEFINE0(uretprobe)
> +{
> + struct pt_regs *regs = task_pt_regs(current);
> + unsigned long sregs[3], err;
> +
> + /*
> + * We set rax and syscall itself changes rcx and r11, so the syscall
> + * trampoline saves their original values on stack. We need to read
> + * them and set original register values and fix the rsp pointer back.
> + */
> + err = copy_from_user((void *) &sregs, (void *) regs->sp, sizeof(sregs));
^^^^^^^^^^^^^^^^^
IIUC, it should be (void __user *)regs->sp to shut up the sparse checks.
The 1st "(void *)" typecast is not needed.
Correctness-wise looks good to me, FWIW
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
next prev parent reply other threads:[~2024-03-18 14:23 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-18 9:31 [PATCH RFC bpf-next 0/3] uprobe: uretprobe speed up Jiri Olsa
2024-03-18 9:31 ` [PATCH RFC bpf-next 1/3] uprobe: Add uretprobe syscall to speed up return probe Jiri Olsa
2024-03-18 14:22 ` Oleg Nesterov [this message]
2024-03-19 1:11 ` Andrii Nakryiko
2024-03-19 6:32 ` Oleg Nesterov
2024-03-19 16:20 ` Andrii Nakryiko
2024-03-19 10:54 ` Jiri Olsa
2024-03-18 9:31 ` [PATCH RFC bpf-next 2/3] selftests/bpf: Add uretprobe syscall test Jiri Olsa
2024-03-19 1:16 ` Andrii Nakryiko
2024-03-19 11:09 ` Jiri Olsa
2024-03-18 9:31 ` [PATCH RFC bpf-next 3/3] selftests/bpf: Mark uprobe trigger functions with nocf_check attribute Jiri Olsa
2024-03-19 1:22 ` Andrii Nakryiko
2024-03-19 11:11 ` Jiri Olsa
2024-03-22 13:40 ` Jiri Olsa
2024-03-19 10:25 ` [PATCH RFC bpf-next 4/3] uprobe: ensure sys_uretprobe uses sysret Oleg Nesterov
2024-03-19 11:08 ` Jiri Olsa
2024-03-19 16:25 ` Andrii Nakryiko
2024-03-19 16:38 ` Oleg Nesterov
2024-03-19 19:35 ` Jiri Olsa
2024-03-19 19:31 ` Jiri Olsa
2024-03-19 20:13 ` Andrii Nakryiko
2024-03-20 11:04 ` Jiri Olsa
2024-03-20 14:37 ` Oleg Nesterov
2024-03-20 15:28 ` Oleg Nesterov
2024-03-20 17:44 ` Andrii Nakryiko
2024-03-20 19:08 ` Jiri Olsa
2024-03-21 10:10 ` Oleg Nesterov
2024-03-21 9:59 ` Jiri Olsa
2024-03-21 10:17 ` Oleg Nesterov
2024-03-21 10:52 ` Jiri Olsa
2024-03-21 12:14 ` Oleg Nesterov
2024-03-21 20:29 ` Jiri Olsa
2024-03-22 8:48 ` Oleg Nesterov
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