All of lore.kernel.org
 help / color / mirror / Atom feed
From: David Laight <david.laight.linux@gmail.com>
To: Zong Li <zong.li@sifive.com>
Cc: pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu,
	alex@ghiti.fr, debug@rivosinc.com,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] riscv: cif: reduce shadow stack size limit from 4GB to 2GB
Date: Mon, 18 May 2026 11:28:42 +0100	[thread overview]
Message-ID: <20260518112842.07f0f2af@pumpkin> (raw)
In-Reply-To: <20260518105725.7afe7a4c@pumpkin>

On Mon, 18 May 2026 10:57:25 +0100
David Laight <david.laight.linux@gmail.com> wrote:

..
> Actually would it be possible to initially just allocate one page?
> If you get an overflow fault on the shadow stack I think you can
> safely reallocate it at an entirely different user virtual address.
> That would remove all the problems over committing a lot of swap.
> Most threads will never do the 512 nested calls needed to blow the stack.

Forget that - probably breaks setjmp().

-- David

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

WARNING: multiple messages have this Message-ID (diff)
From: David Laight <david.laight.linux@gmail.com>
To: Zong Li <zong.li@sifive.com>
Cc: pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu,
	alex@ghiti.fr, debug@rivosinc.com,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] riscv: cif: reduce shadow stack size limit from 4GB to 2GB
Date: Mon, 18 May 2026 11:28:42 +0100	[thread overview]
Message-ID: <20260518112842.07f0f2af@pumpkin> (raw)
In-Reply-To: <20260518105725.7afe7a4c@pumpkin>

On Mon, 18 May 2026 10:57:25 +0100
David Laight <david.laight.linux@gmail.com> wrote:

..
> Actually would it be possible to initially just allocate one page?
> If you get an overflow fault on the shadow stack I think you can
> safely reallocate it at an entirely different user virtual address.
> That would remove all the problems over committing a lot of swap.
> Most threads will never do the 512 nested calls needed to blow the stack.

Forget that - probably breaks setjmp().

-- David

  reply	other threads:[~2026-05-18 10:29 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-14  7:50 [PATCH v3] riscv: cif: reduce shadow stack size limit from 4GB to 2GB Zong Li
2026-05-14  7:50 ` Zong Li
2026-05-14  8:56 ` David Laight
2026-05-14  8:56   ` David Laight
2026-05-15  3:42   ` Zong Li
2026-05-15  3:42     ` Zong Li
2026-05-15  9:24     ` David Laight
2026-05-15  9:24       ` David Laight
2026-05-15 14:29       ` Zong Li
2026-05-15 14:29         ` Zong Li
2026-05-15 19:16         ` David Laight
2026-05-15 19:16           ` David Laight
2026-05-18  3:54           ` Zong Li
2026-05-18  3:54             ` Zong Li
2026-05-18  9:57             ` David Laight
2026-05-18  9:57               ` David Laight
2026-05-18 10:28               ` David Laight [this message]
2026-05-18 10:28                 ` David Laight
2026-05-19  7:04               ` Zong Li
2026-05-19  7:04                 ` Zong Li
  -- strict thread matches above, loose matches on Subject: below --
2026-05-19  7:13 Zong Li
2026-05-19  7:13 ` Zong Li

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260518112842.07f0f2af@pumpkin \
    --to=david.laight.linux@gmail.com \
    --cc=alex@ghiti.fr \
    --cc=aou@eecs.berkeley.edu \
    --cc=debug@rivosinc.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=palmer@dabbelt.com \
    --cc=pjw@kernel.org \
    --cc=zong.li@sifive.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.