From: David Laight <david.laight.linux@gmail•com>
To: "Mukesh Kumar Chaurasiya (IBM)" <mkchauras@gmail•com>
Cc: maddy@linux•ibm.com, mpe@ellerman•id.au, npiggin@gmail•com,
chleroy@kernel•org, peterz@infradead•org, jpoimboe@kernel•org,
jbaron@akamai•com, aliceryhl@google•com, rostedt@goodmis•org,
ardb@kernel•org, sumit.semwal@linaro•org,
christian.koenig@amd•com, ojeda@kernel•org, boqun@kernel•org,
gary@garyguo•net, bjorn3_gh@protonmail•com, lossin@kernel•org,
a.hindborg@kernel•org, tmgross@umich•edu, dakr@kernel•org,
nathan@kernel•org, nick.desaulniers+lkml@gmail•com,
morbo@google•com, justinstitt@google•com, tamird@kernel•org,
arnd@arndb•de, nsc@kernel•org, simona.vetter@ffwll•ch,
linuxppc-dev@lists•ozlabs.org, linux-kernel@vger•kernel.org,
linux-media@vger•kernel.org, dri-devel@lists•freedesktop.org,
linaro-mm-sig@lists•linaro.org, rust-for-linux@vger•kernel.org,
llvm@lists•linux.dev, Link Mauve <linkmauve@linkmauve•fr>
Subject: Re: [PATCH V13 5/7] rust: Make __udivdi3() and __umoddi3() panic
Date: Fri, 24 Apr 2026 10:14:25 +0100 [thread overview]
Message-ID: <20260424101425.6bde0e17@pumpkin> (raw)
In-Reply-To: <20260424054742.45832-6-mkchauras@gmail.com>
On Fri, 24 Apr 2026 11:17:40 +0530
"Mukesh Kumar Chaurasiya (IBM)" <mkchauras@gmail•com> wrote:
> From: Link Mauve <linkmauve@linkmauve•fr>
>
> The core crate currently depends on these two functions for i64/u64/
> i128/u128/core::time::Duration formatting, but we shouldn’t use that in
> the kernel so let’s panic if they are ever called.
Ugg.
Surely you can make it a link-time failure?
Or change the underlying code to avoid the divide.
David
>
> This doesn’t yet fix drm_panic_qr.rs, which also uses __udivdi3 when
> CONFIG_CC_OPTIMIZE_FOR_SIZE=y, but at least makes the rest of the kernel
> build on PPC32.
>
> Signed-off-by: Link Mauve <linkmauve@linkmauve•fr>
> Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail•com>
> ---
> rust/Makefile | 4 ++++
> rust/compiler_builtins.rs | 6 ++++++
> 2 files changed, 10 insertions(+)
>
> diff --git a/rust/Makefile b/rust/Makefile
> index 2a5428a5503d..ee11fba7a03d 100644
> --- a/rust/Makefile
> +++ b/rust/Makefile
> @@ -616,6 +616,10 @@ ifneq ($(or $(CONFIG_ARM64),$(and $(CONFIG_RISCV),$(CONFIG_64BIT))),)
> __ashrti3 \
> __ashlti3 __lshrti3
> endif
> +ifdef CONFIG_PPC32
> + redirect-intrinsics += \
> + __udivdi3 __umoddi3
> +endif
>
> ifdef CONFIG_MODVERSIONS
> cmd_gendwarfksyms = $(if $(skip_gendwarfksyms),, \
> diff --git a/rust/compiler_builtins.rs b/rust/compiler_builtins.rs
> index dd16c1dc899c..fc6b54636dd5 100644
> --- a/rust/compiler_builtins.rs
> +++ b/rust/compiler_builtins.rs
> @@ -97,5 +97,11 @@ pub extern "C" fn $ident() {
> __aeabi_uldivmod,
> });
>
> +#[cfg(target_arch = "powerpc")]
> +define_panicking_intrinsics!("`u64` division/modulo should not be used", {
> + __udivdi3,
> + __umoddi3,
> +});
> +
> // NOTE: if you are adding a new intrinsic here, you should also add it to
> // `redirect-intrinsics` in `rust/Makefile`.
next prev parent reply other threads:[~2026-04-24 9:14 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-24 5:47 [PATCH V13 0/7] Rust support for powerpc Mukesh Kumar Chaurasiya (IBM)
2026-04-24 5:47 ` [PATCH V13 1/7] rust: Fix "multiple candidates for rmeta dependency core" error Mukesh Kumar Chaurasiya (IBM)
2026-04-24 5:47 ` [PATCH V13 2/7] dma-resv: Fix undefined symbol when CONFIG_DMA_SHARED_BUFFER is disabled Mukesh Kumar Chaurasiya (IBM)
2026-04-24 7:56 ` Christian König
2026-04-24 8:06 ` Mukesh Kumar Chaurasiya
2026-04-24 8:25 ` Christian König
2026-04-24 8:34 ` Mukesh Kumar Chaurasiya
2026-04-24 8:44 ` Christian König
2026-04-24 5:47 ` [PATCH V13 3/7] powerpc/jump_label: adjust inline asm to be consistent Mukesh Kumar Chaurasiya (IBM)
2026-04-24 5:47 ` [PATCH V13 4/7] rust/powerpc: Set min rustc version for powerpc Mukesh Kumar Chaurasiya (IBM)
2026-04-24 5:47 ` [PATCH V13 5/7] rust: Make __udivdi3() and __umoddi3() panic Mukesh Kumar Chaurasiya (IBM)
2026-04-24 8:59 ` Arnd Bergmann
2026-04-24 9:14 ` David Laight [this message]
2026-04-24 9:43 ` Link Mauve
2026-04-24 10:20 ` Arnd Bergmann
2026-04-24 10:34 ` Miguel Ojeda
2026-04-24 10:26 ` Miguel Ojeda
2026-04-24 11:09 ` David Laight
2026-04-27 16:05 ` [Linaro-mm-sig] " Arnd Bergmann
2026-04-24 11:54 ` Segher Boessenkool
2026-04-24 11:57 ` Segher Boessenkool
2026-04-24 12:53 ` Segher Boessenkool
2026-04-24 12:43 ` Gary Guo
2026-04-26 7:52 ` Mukesh Kumar Chaurasiya
2026-04-26 14:20 ` Gary Guo
2026-04-26 22:04 ` David Laight
2026-04-27 13:04 ` Gary Guo
2026-04-24 5:47 ` [PATCH V13 6/7] rust: Add PowerPC support Mukesh Kumar Chaurasiya (IBM)
2026-04-24 5:47 ` [PATCH V13 7/7] powerpc: Enable Rust for ppc64le Mukesh Kumar Chaurasiya (IBM)
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=20260424101425.6bde0e17@pumpkin \
--to=david.laight.linux@gmail$(echo .)com \
--cc=a.hindborg@kernel$(echo .)org \
--cc=aliceryhl@google$(echo .)com \
--cc=ardb@kernel$(echo .)org \
--cc=arnd@arndb$(echo .)de \
--cc=bjorn3_gh@protonmail$(echo .)com \
--cc=boqun@kernel$(echo .)org \
--cc=chleroy@kernel$(echo .)org \
--cc=christian.koenig@amd$(echo .)com \
--cc=dakr@kernel$(echo .)org \
--cc=dri-devel@lists$(echo .)freedesktop.org \
--cc=gary@garyguo$(echo .)net \
--cc=jbaron@akamai$(echo .)com \
--cc=jpoimboe@kernel$(echo .)org \
--cc=justinstitt@google$(echo .)com \
--cc=linaro-mm-sig@lists$(echo .)linaro.org \
--cc=linkmauve@linkmauve$(echo .)fr \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linux-media@vger$(echo .)kernel.org \
--cc=linuxppc-dev@lists$(echo .)ozlabs.org \
--cc=llvm@lists$(echo .)linux.dev \
--cc=lossin@kernel$(echo .)org \
--cc=maddy@linux$(echo .)ibm.com \
--cc=mkchauras@gmail$(echo .)com \
--cc=morbo@google$(echo .)com \
--cc=mpe@ellerman$(echo .)id.au \
--cc=nathan@kernel$(echo .)org \
--cc=nick.desaulniers+lkml@gmail$(echo .)com \
--cc=npiggin@gmail$(echo .)com \
--cc=nsc@kernel$(echo .)org \
--cc=ojeda@kernel$(echo .)org \
--cc=peterz@infradead$(echo .)org \
--cc=rostedt@goodmis$(echo .)org \
--cc=rust-for-linux@vger$(echo .)kernel.org \
--cc=simona.vetter@ffwll$(echo .)ch \
--cc=sumit.semwal@linaro$(echo .)org \
--cc=tamird@kernel$(echo .)org \
--cc=tmgross@umich$(echo .)edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox