linux-kernel - Re: [PATCH v22 10/28] riscv/mm: Implement map_shadow

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: <020e2f6e-9c1b-648e-3017-31eb8a89c493@kernel.org>
Date: Fri, 31 Oct 2025 13:48:10 -0600 (MDT)
From: Paul Walmsley <pjw@...nel.org>
To: Deepak Gupta <debug@...osinc.com>
cc: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, 
    Borislav Petkov <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>, 
    x86@...nel.org, "H. Peter Anvin" <hpa@...or.com>, 
    Andrew Morton <akpm@...ux-foundation.org>, 
    "Liam R. Howlett" <Liam.Howlett@...cle.com>, 
    Vlastimil Babka <vbabka@...e.cz>, 
    Lorenzo Stoakes <lorenzo.stoakes@...cle.com>, 
    Paul Walmsley <paul.walmsley@...ive.com>, 
    Palmer Dabbelt <palmer@...belt.com>, Albert Ou <aou@...s.berkeley.edu>, 
    Conor Dooley <conor@...nel.org>, Rob Herring <robh@...nel.org>, 
    Krzysztof Kozlowski <krzk+dt@...nel.org>, Arnd Bergmann <arnd@...db.de>, 
    Christian Brauner <brauner@...nel.org>, 
    Peter Zijlstra <peterz@...radead.org>, Oleg Nesterov <oleg@...hat.com>, 
    Eric Biederman <ebiederm@...ssion.com>, Kees Cook <kees@...nel.org>, 
    Jonathan Corbet <corbet@....net>, Shuah Khan <shuah@...nel.org>, 
    Jann Horn <jannh@...gle.com>, Conor Dooley <conor+dt@...nel.org>, 
    Miguel Ojeda <ojeda@...nel.org>, Alex Gaynor <alex.gaynor@...il.com>, 
    Boqun Feng <boqun.feng@...il.com>, Gary Guo <gary@...yguo.net>, 
    Björn Roy Baron <bjorn3_gh@...tonmail.com>, 
    Andreas Hindborg <a.hindborg@...nel.org>, 
    Alice Ryhl <aliceryhl@...gle.com>, Trevor Gross <tmgross@...ch.edu>, 
    Benno Lossin <lossin@...nel.org>, linux-kernel@...r.kernel.org, 
    linux-fsdevel@...r.kernel.org, linux-mm@...ck.org, 
    linux-riscv@...ts.infradead.org, devicetree@...r.kernel.org, 
    linux-arch@...r.kernel.org, linux-doc@...r.kernel.org, 
    linux-kselftest@...r.kernel.org, alistair.francis@....com, 
    richard.henderson@...aro.org, jim.shu@...ive.com, andybnac@...il.com, 
    kito.cheng@...ive.com, charlie@...osinc.com, atishp@...osinc.com, 
    evan@...osinc.com, cleger@...osinc.com, alexghiti@...osinc.com, 
    samitolvanen@...gle.com, broonie@...nel.org, rick.p.edgecombe@...el.com, 
    rust-for-linux@...r.kernel.org, Zong Li <zong.li@...ive.com>
Subject: Re: [PATCH v22 10/28] riscv/mm: Implement map_shadow_stack()
 syscall

On Thu, 23 Oct 2025, Deepak Gupta via B4 Relay wrote:

> From: Deepak Gupta <debug@...osinc.com>
> 
> As discussed extensively in the changelog for the addition of this
> syscall on x86 ("x86/shstk: Introduce map_shadow_stack syscall") the
> existing mmap() and madvise() syscalls do not map entirely well onto the
> security requirements for shadow stack memory since they lead to windows
> where memory is allocated but not yet protected or stacks which are not
> properly and safely initialised. Instead a new syscall map_shadow_stack()
> has been defined which allocates and initialises a shadow stack page.
> 
> This patch implements this syscall for riscv. riscv doesn't require token
> to be setup by kernel because user mode can do that by itself. However to
> provide compatibility and portability with other architectues, user mode
> can specify token set flag.
> 
> Reviewed-by: Zong Li <zong.li@...ive.com>
> Signed-off-by: Deepak Gupta <debug@...osinc.com>

This patch introduces a 'checkpatch.pl --strict' message:

CHECK: Lines should not end with a '('
#78: FILE: arch/riscv/kernel/usercfi.c:36:
+	asm goto(

I'll fix it up here in the event that v22 goes in, but please do the same 
on your side in case a new version is needed.


thanks,

- Paul