linux-kernel - Re: [PATCH v2] riscv: misaligned: remove CONFIG_RISCV_M

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Message-ID: <20240424-sampling-autopilot-313efe9aa9aa@spud>
Date: Wed, 24 Apr 2024 11:21:39 +0100
From: Conor Dooley <conor@...nel.org>
To: Clément Léger <cleger@...osinc.com>
Cc: Paul Walmsley <paul.walmsley@...ive.com>,
	Palmer Dabbelt <palmer@...belt.com>,
	Albert Ou <aou@...s.berkeley.edu>, linux-riscv@...ts.infradead.org,
	linux-kernel@...r.kernel.org, Ben Dooks <ben.dooks@...ethink.co.uk>,
	David Laight <David.Laight@...lab.com>,
	Charlie Jenkins <charlie@...osinc.com>
Subject: Re: [PATCH v2] riscv: misaligned: remove CONFIG_RISCV_M_MODE
 specific code

On Tue, Feb 06, 2024 at 04:40:59PM +0100, Clément Léger wrote:
> While reworking code to fix sparse errors, it appears that the
> RISCV_M_MODE specific could actually be removed and use the one for
> normal mode. Even though RISCV_M_MODE can do direct user memory access,
> using the user uaccess helpers is also going to work. Since there is no
> need anymore for specific accessors (load_u8()/store_u8()), we can
> directly use memcpy()/copy_{to/from}_user() and get rid of the copy
> loop entirely. __read_insn() is also fixed to use an unsigned long
> instead of a pointer which was cast in __user address space. The
> insn_addr parameter is now cast from unsigned lnog to the correct
> address space directly.
> 
> Signed-off-by: Clément Léger <cleger@...osinc.com>

Removing some m-mode only code always feels like a win to me, given how
little testing and attention it usually gets.
Reviewed-by: Conor Dooley <conor.dooley@...rochip.com>

Cheers,
Conor.

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