linux-kernel - Re: [PATCH V8 13/44] mm/pkeys: Add initial PKS Test code

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Date:   Wed, 9 Feb 2022 15:44:41 -0800
From:   Ira Weiny <ira.weiny@...el.com>
To:     "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
Cc:     "hpa@...or.com" <hpa@...or.com>,
        "Williams, Dan J" <dan.j.williams@...el.com>,
        "dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
        "Yu, Fenghua" <fenghua.yu@...el.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH V8 13/44] mm/pkeys: Add initial PKS Test code

On Mon, Jan 31, 2022 at 11:30:14AM -0800, Edgecombe, Rick P wrote:
> On Thu, 2022-01-27 at 09:54 -0800, ira.weiny@...el.com wrote:
> > +static void crash_it(void)
> > +{
> > +       struct pks_test_ctx *ctx;
> > +       void *ptr;
> > +
> > +       pr_warn("     ***** BEGIN: Unhandled fault test *****\n");
> > +
> > +       ctx = alloc_ctx(PKS_KEY_TEST);
> > +       if (IS_ERR(ctx)) {
> > +               pr_err("Failed to allocate context???\n");
> > +               return;
> > +       }
> > +
> > +       ptr = alloc_test_page(ctx->pkey);
> > +       if (!ptr) {
> > +               pr_err("Failed to vmalloc page???\n");
> > +               return;
> > +       }
> > +
> > +       /* This purposely faults */
> > +       memcpy(ptr, ctx->data, 8);
> > +
> > +       /* Should never get here if so the test failed */
> > +       last_test_pass = false;
> > +
> > +       vfree(ptr);
> > +       free_ctx(ctx);
> 
> So these only gets cleaned up if the test fails? Could you clean them
> up in pks_release_file() like the later test patch?

Not a bad idea.  Although if someone is running this they are most likely not
concerned with it.

> 
> > +}
> 
> snip
> 
> > +
> > +static void __exit pks_test_exit(void)
> > +{
> > +       debugfs_remove(pks_test_dentry);
> > +       pr_info("test exit\n");
> > +}
> 
> How does this get called?

Left over from when this was a module.  Thanks for catching.

Ira