From: Oleg Nesterov <oleg@redhat.com>
To: Jeff Xu <jeffxu@chromium.org>
Cc: Kees Cook <keescook@chromium.org>,
srikar@linux.vnet.ibm.com, Ryan Roberts <ryan.roberts@arm.com>,
"adrian.hunter@intel.com" <adrian.hunter@intel.com>,
"glider@google.com" <glider@google.com>,
Matthew Wilcox <willy@infradead.org>,
zokeefe@google.com, hughd@google.com, luto@amacapital.net,
"jmarchan@redhat.com" <jmarchan@redhat.com>,
"rientjes@google.com" <rientjes@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>
Subject: Re: question on [uprobes] special vma
Date: Fri, 2 Aug 2024 11:00:40 +0200 [thread overview]
Message-ID: <20240802090040.GB12343@redhat.com> (raw)
In-Reply-To: <CABi2SkU9BRUnqf70-nksuMCQ+yyiWjo3fM4XkRkL-NrCZxYAyg@mail.gmail.com>
Hi Jeff,
On 08/01, Jeff Xu wrote:
>
> __create_xol_area() calls _install_special_mapping() to create a vma
> named [uprobes].
>
> I'm trying to find out the lifetime of this uprobes vma, e.g. when it
> is created, will it ever be unmapped/remapped/changed during the
> lifetime of the process.
>
> If the uprobes vma remains the same during the lifetime of the
> process,
Yes,
> I can call mseal on it so user space can't change it, i.e.
> blocking munmap/mremap/mprotect/mmap, etc.
I didn't even know about mm/mseal.c...
at first glance do_mseal() just adds VM_SEALED for can_modify_vma().
So it seems that xol_add_vma() can just pass the additional VM_SEALED
flag to _install_special_mapping(), no?
But why it depends on CONFIG_64_BIT?
Oleg.
next prev parent reply other threads:[~2024-08-02 9:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-01 23:38 Jeff Xu
2024-08-02 9:00 ` Oleg Nesterov [this message]
2024-08-02 14:59 ` Jeff Xu
2024-08-02 22:21 ` Oleg Nesterov
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