linux-kernel - Re: [PATCH v3 1/3] kprobes: Add text_alloc() and text

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200716090253.GP10769@hirez.programming.kicks-ass.net>
Date:   Thu, 16 Jul 2020 11:02:53 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
Cc:     linux-kernel@...r.kernel.org, x86@...r.kernel.org,
        Andi Kleen <ak@...ux.intel.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@...nel.org>,
        "H. Peter Anvin" <hpa@...or.com>,
        "Naveen N. Rao" <naveen.n.rao@...ux.ibm.com>,
        Anil S Keshavamurthy <anil.s.keshavamurthy@...el.com>,
        "David S. Miller" <davem@...emloft.net>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Jessica Yu <jeyu@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        "Aneesh Kumar K.V" <aneesh.kumar@...ux.ibm.com>,
        Kees Cook <keescook@...omium.org>,
        Will Deacon <will@...nel.org>,
        Sami Tolvanen <samitolvanen@...gle.com>,
        Alexandre Ghiti <alex@...ti.fr>,
        Masahiro Yamada <masahiroy@...nel.org>,
        Peter Collingbourne <pcc@...gle.com>,
        Frederic Weisbecker <frederic@...nel.org>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        Arnd Bergmann <arnd@...db.de>, Stephen Boyd <sboyd@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        Miroslav Benes <mbenes@...e.cz>,
        Babu Moger <Babu.Moger@....com>,
        Omar Sandoval <osandov@...com>,
        Nayna Jain <nayna@...ux.ibm.com>,
        Marco Elver <elver@...gle.com>,
        Brian Gerst <brgerst@...il.com>, Jiri Kosina <jkosina@...e.cz>,
        Joe Lawrence <joe.lawrence@...hat.com>,
        Mike Rapoport <rppt@...ux.ibm.com>
Subject: Re: [PATCH v3 1/3] kprobes: Add text_alloc() and text_free()

On Wed, Jul 15, 2020 at 01:32:27AM +0300, Jarkko Sakkinen wrote:
> +void *text_alloc(unsigned long size)
> +{
> +	void *p;
> +
> +	if (PAGE_ALIGN(size) > MODULES_LEN)
> +		return NULL;
> +
> +	p = __vmalloc_node_range(size, MODULE_ALIGN,
> +				    MODULES_VADDR + get_module_load_offset(),
> +				    MODULES_END, GFP_KERNEL,
> +				    PAGE_KERNEL, 0, NUMA_NO_NODE,
> +				    __builtin_return_address(0));
> +	if (p && (kasan_module_alloc(p, size) < 0)) {
> +		vfree(p);
> +		return NULL;
> +	}
> +
> +	return p;
> +}
> +
> +void text_free(void *region)
> +{
> +	/*
> +	 * This memory may be RO, and freeing RO memory in an interrupt is not
> +	 * supported by vmalloc.
> +	 */
> +	WARN_ON(in_interrupt());

I think that wants to be:

	lockdep_assert_irqs_enabled();

in_interrupt() isn't sufficient, interrupts must also not be disabled
when issuesing TLB invalidations.

> +
> +	vfree(region);
> +}