Re: [PATCH 1/2 v2] kprobe: Do not use uaccess functions to access kernel memory that can fault

On Fri, 15 Feb 2019 18:14:21 -0800 Andy Lutomirski luto@amacapital.net wrote:

...

In the uprobes case, we have:

static nokprobe_inline int probe_mem_read(void *dest, void *src, size_t size) { void __user *vaddr = (void __force __user *)src;

return copy_from_user(dest, vaddr, size) ? -EFAULT : 0; }

Because that is adding probes on userspace code.

Can the kprobe case call probe_kernel_read? Maybe it does already?

Yes, the probe_mem_read() is only used in the trace_probe_tmpl.h which for uprobes is the above "copy_from_user()" and for the kprobes case it is probe_kernel_read().

-- Steve