[PATCH v15 00/10] arm64: Add kernel probes (kprobes) support

On 07/19/2016 02:27 PM, Catalin Marinas wrote:

On Fri, Jul 08, 2016 at 12:35:44PM -0400, David Long wrote:

quoted

From: "David A. Long" <redacted>

This patchset is heavily based on Sandeepa Prabhu's ARM v8 kprobes patches,
first seen in October 2013. This version attempts to address concerns
raised by reviewers and also fixes problems discovered during testing.

This patchset adds support for kernel probes(kprobes), jump probes(jprobes)
and return probes(kretprobes) support for ARM64.

Some more errors with this patchset applied and CONFIG_NET_TCPPROBE
enabled (it's fine with this option disabled though). I boot on a Juno
with NFS over UDP and then try to ssh into it (hence establish the first
TCP connection):

Unable to handle kernel NULL pointer dereference at virtual address 00000003
pgd = ffff000008ceb000
[00000003] *pgd=00000009fff6d003, *pud=00000009fff6c003, *pmd=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.7.0-rc4+ #9
Hardware name: ARM Juno development board (r0) (DT)
task: ffff800976901900 ti: ffff800976910000 task.ti: ffff800976910000
PC is at enqueue_task_fair+0x818/0x1188
LR is at enqueue_task_fair+0x8a4/0x1188
pc : [<ffff0000080e73d8>] lr : [<ffff0000080e7464>] pstate: 600001c5
sp : ffff80097fec3a80

[...]

I've reproduced the failure on hikey. I'm looking at it.

-dl