linux-ext4 - Re: [PATCH RFC PKS/PMEM 51/58] kernel: Utilize new kmap

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 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]

Date:   Fri, 09 Oct 2020 22:43:15 -0500
From:   ebiederm@...ssion.com (Eric W. Biederman)
To:     ira.weiny@...el.com
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>, x86@...nel.org,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Fenghua Yu <fenghua.yu@...el.com>, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-nvdimm@...ts.01.org,
        linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
        linux-kselftest@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        kvm@...r.kernel.org, netdev@...r.kernel.org, bpf@...r.kernel.org,
        kexec@...ts.infradead.org, linux-bcache@...r.kernel.org,
        linux-mtd@...ts.infradead.org, devel@...verdev.osuosl.org,
        linux-efi@...r.kernel.org, linux-mmc@...r.kernel.org,
        linux-scsi@...r.kernel.org, target-devel@...r.kernel.org,
        linux-nfs@...r.kernel.org, ceph-devel@...r.kernel.org,
        linux-ext4@...r.kernel.org, linux-aio@...ck.org,
        io-uring@...r.kernel.org, linux-erofs@...ts.ozlabs.org,
        linux-um@...ts.infradead.org, linux-ntfs-dev@...ts.sourceforge.net,
        reiserfs-devel@...r.kernel.org,
        linux-f2fs-devel@...ts.sourceforge.net,
        linux-nilfs@...r.kernel.org, cluster-devel@...hat.com,
        ecryptfs@...r.kernel.org, linux-cifs@...r.kernel.org,
        linux-btrfs@...r.kernel.org, linux-afs@...ts.infradead.org,
        linux-rdma@...r.kernel.org, amd-gfx@...ts.freedesktop.org,
        dri-devel@...ts.freedesktop.org, intel-gfx@...ts.freedesktop.org,
        drbd-dev@...ts.linbit.com, linux-block@...r.kernel.org,
        xen-devel@...ts.xenproject.org, linux-cachefs@...hat.com,
        samba-technical@...ts.samba.org, intel-wired-lan@...ts.osuosl.org
Subject: Re: [PATCH RFC PKS/PMEM 51/58] kernel: Utilize new kmap_thread()

ira.weiny@...el.com writes:

> From: Ira Weiny <ira.weiny@...el.com>
>
> This kmap() call is localized to a single thread.  To avoid the over
> head of global PKRS updates use the new kmap_thread() call.

Acked-by: "Eric W. Biederman" <ebiederm@...ssion.com>

>
> Cc: Eric Biederman <ebiederm@...ssion.com>
> Signed-off-by: Ira Weiny <ira.weiny@...el.com>
> ---
>  kernel/kexec_core.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
> index c19c0dad1ebe..272a9920c0d6 100644
> --- a/kernel/kexec_core.c
> +++ b/kernel/kexec_core.c
> @@ -815,7 +815,7 @@ static int kimage_load_normal_segment(struct kimage *image,
>  		if (result < 0)
>  			goto out;
>  
> -		ptr = kmap(page);
> +		ptr = kmap_thread(page);
>  		/* Start with a clear page */
>  		clear_page(ptr);
>  		ptr += maddr & ~PAGE_MASK;
> @@ -828,7 +828,7 @@ static int kimage_load_normal_segment(struct kimage *image,
>  			memcpy(ptr, kbuf, uchunk);
>  		else
>  			result = copy_from_user(ptr, buf, uchunk);
> -		kunmap(page);
> +		kunmap_thread(page);
>  		if (result) {
>  			result = -EFAULT;
>  			goto out;
> @@ -879,7 +879,7 @@ static int kimage_load_crash_segment(struct kimage *image,
>  			goto out;
>  		}
>  		arch_kexec_post_alloc_pages(page_address(page), 1, 0);
> -		ptr = kmap(page);
> +		ptr = kmap_thread(page);
>  		ptr += maddr & ~PAGE_MASK;
>  		mchunk = min_t(size_t, mbytes,
>  				PAGE_SIZE - (maddr & ~PAGE_MASK));
> @@ -895,7 +895,7 @@ static int kimage_load_crash_segment(struct kimage *image,
>  		else
>  			result = copy_from_user(ptr, buf, uchunk);
>  		kexec_flush_icache_page(page);
> -		kunmap(page);
> +		kunmap_thread(page);
>  		arch_kexec_pre_free_pages(page_address(page), 1);
>  		if (result) {
>  			result = -EFAULT;