From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C9A893B5830; Thu, 12 Mar 2026 11:23:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773314639; cv=none; b=C1vaFGLXFrblzMw0opLJvB4nsrBq8v7O7GOArIixsj6vnv077xDypmwH0uC3NIdWMxA9UHrweXiI5vkE4tEcrztXGdHXyhzDC2d8CeZ0g1mW3k8gzXefYR+pV1d3O2dMnVWYZEhnzDdmdZm54SnfgWXpJGxN8bfCw518BHP22pM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773314639; c=relaxed/simple; bh=QmUndoWKkvGu15ytPgiNk/W/zfIzuga6NPM0kq37X6g=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DVZMMu5F8Emq9RA6SJy2FW6YC6XhlmhstWdARHvlrbqpti9noN6QvdE60KsBPFGlkMhkGP0hTfJZI2EwV9vgfVVEUkfDeWI1urWdbnn0v+1fOxy2T0Lil7tc0BlDahqSwp94A8qdK66lI77CjwJ+8NmYdycfD/D6Y0lnHGa1H9k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gddxThvu; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gddxThvu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C32B8C4CEF7; Thu, 12 Mar 2026 11:23:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773314639; bh=QmUndoWKkvGu15ytPgiNk/W/zfIzuga6NPM0kq37X6g=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=gddxThvuN8nEkxb1oe2xYVqYBPcAGoZjE0JamctgWmvcBJC+2RXK4H1Oaf+f3JOwW fxwH+WLkxZbJY0MknBkur5pI7FCchUtXNdDKsThu5lMuoBANKs+UeoyfTMkJ1sO3+r 4hpyJwTo29UlAt3cBAFFMBFuxc1orHcop3iw89T3rJ87yz2VKPaAXnDxEi2c/fTd87 eJ/zbtp6tA8W/XODS6RYQsmWksPaTPRpOv5PRjQnkFFww5eYDtX/ErhgfeDObPX20h SEdGEgkqgOZOHOJQuURbLLXig62kg6JD5Fx4CH2RFeTqabIPhh1ARDfQqZ3yTDKMjS /FQjMq5HRAp3w== Message-ID: <0bc30137-3f1d-4a4a-8573-8f26866fcc26@kernel.org> Date: Thu, 12 Mar 2026 12:23:50 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 09/15] arch/powerpc: don't initialize kasan if it's disabled To: Sourabh Jain , Baoquan He , kasan-dev@googlegroups.com Cc: linux-mm@kvack.org, andreyknvl@gmail.com, ryabinin.a.a@gmail.com, glider@google.com, dvyukov@google.com, linux-kernel@vger.kernel.org, linux-um@lists.infradead.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, x86@kernel.org, chris@zankel.net, jcmvbkbc@gmail.com, linux-s390@vger.kernel.org, hca@linux.ibm.com References: <20260225081412.76502-1-bhe@redhat.com> <20260225081412.76502-10-bhe@redhat.com> <71921cca-b890-41c4-93e9-957d3f647ffa@linux.ibm.com> Content-Language: fr-FR From: "Christophe Leroy (CS GROUP)" In-Reply-To: <71921cca-b890-41c4-93e9-957d3f647ffa@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Le 12/03/2026 à 12:12, Sourabh Jain a écrit : > > > On 25/02/26 13:44, Baoquan He wrote: >> Here, kasan is disabled if specified 'kasan=off' in kernel cmdline. >> >> This includes 32bit, book3s/64 and book3e/64. >> >> Signed-off-by: Baoquan He >> Cc: linuxppc-dev@lists.ozlabs.org >> --- >>   arch/powerpc/mm/kasan/init_32.c        | 6 +++++- >>   arch/powerpc/mm/kasan/init_book3e_64.c | 4 ++++ >>   arch/powerpc/mm/kasan/init_book3s_64.c | 4 ++++ >>   3 files changed, 13 insertions(+), 1 deletion(-) >> >> diff --git a/arch/powerpc/mm/kasan/init_32.c b/arch/powerpc/mm/kasan/ >> init_32.c >> index 1d083597464f..0ea2a636c992 100644 >> --- a/arch/powerpc/mm/kasan/init_32.c >> +++ b/arch/powerpc/mm/kasan/init_32.c >> @@ -141,6 +141,10 @@ void __init kasan_init(void) >>       u64 i; >>       int ret; >> +    /* If KASAN is disabled via command line, don't initialize it. */ >> +    if (kasan_arg_disabled) >> +        return; >> + >>       for_each_mem_range(i, &base, &end) { >>           phys_addr_t top = min(end, total_lowmem); >> @@ -170,7 +174,7 @@ void __init kasan_init(void) >>   void __init kasan_late_init(void) >>   { >> -    if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) >> +    if (IS_ENABLED(CONFIG_KASAN_VMALLOC) && kasan_enabled()) >>           kasan_unmap_early_shadow_vmalloc(); >>   } >> diff --git a/arch/powerpc/mm/kasan/init_book3e_64.c b/arch/powerpc/mm/ >> kasan/init_book3e_64.c >> index 0d3a73d6d4b0..fbe4c9a7e460 100644 >> --- a/arch/powerpc/mm/kasan/init_book3e_64.c >> +++ b/arch/powerpc/mm/kasan/init_book3e_64.c >> @@ -111,6 +111,10 @@ void __init kasan_init(void) >>       u64 i; >>       pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), >> PAGE_KERNEL_RO); >> +    /* If KASAN is disabled via command line, don't initialize it. */ >> +    if (kasan_arg_disabled) >> +        return; >> + >>       for_each_mem_range(i, &start, &end) >>           kasan_init_phys_region(phys_to_virt(start), phys_to_virt(end)); >> diff --git a/arch/powerpc/mm/kasan/init_book3s_64.c b/arch/powerpc/mm/ >> kasan/init_book3s_64.c >> index dcafa641804c..f7906f9ef9be 100644 >> --- a/arch/powerpc/mm/kasan/init_book3s_64.c >> +++ b/arch/powerpc/mm/kasan/init_book3s_64.c >> @@ -54,6 +54,10 @@ void __init kasan_init(void) >>       u64 i; >>       pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), >> PAGE_KERNEL); >> +    /* If KASAN is disabled via command line, don't initialize it. */ >> +    if (kasan_arg_disabled) >> +        return; >> + >>       if (!early_radix_enabled()) { >>           pr_warn("KASAN not enabled as it requires radix!"); >>           return; > > Should we log in the kernel log buffer that KASAN is disabled? > > Right now, I don't see the kernel advertising the same. When KASAN is enabled it is advertised with: pr_info("KernelAddressSanitizer initialized (generic)\n"); Isn't the absence of that message enough to understand KASAN is not there ? > > $ dmesg | grep -i kasan > [    0.000000] Kernel command line: BOOT_IMAGE=(ieee1275//vdevice/v- > scsi@30000070/disk@8100000000000000,msdos2)/vmlinuz-7.0.0-rc3+ > crashkernel=2G kasan=off > > Tested this series on powerpc Pseries platform. > So feel free to add: > Tested-by: Sourabh Jain > > - Sourabh Jain >