Subject: Re: [PATCH V11 1/4] rust: Fix "multiple candidates for rmeta dependency core" error

From: Link Mauve <[email-masked]>
Date: Wed, 22 Apr 2026 10:01:55 +0200

On Wed, Apr 22, 2026 at 01:23:41PM +0530, Mukesh Kumar Chaurasiya wrote:
> On Tue, Apr 21, 2026 at 08:16:06PM +0200, Miguel Ojeda wrote:
> > On Tue, Apr 21, 2026 at 7:47 PM Mukesh Kumar Chaurasiya
> > <[email-masked]> wrote:
> > >
> > > There are some other build errors apart from this on 1.85. So few months
> > > back in the meeting with LLVM team we concluded that for sometime
> > > powerpc will be ahead of other archs at 1.95 till others catch up.
> > 
> > In that case you may want to modify `scripts/min-tool-version.sh` in
> > this series too.
> > 
> > I hope that helps!
> > 
> Yeah this helps, Thanks :) 
> 
> Will post out a new series soon.

Great thanks!

For your new series you might want to incorporate the attached patch,
which makes the core crate build on PowerPC.

> Regards,
> Mukesh
> > Cheers,
> > Miguel

-- 
Link Mauve
>From 120e1283d1e49d73df483496ffc669328511657c Mon Sep 17 00:00:00 2001
From: Link Mauve <[email-masked]>
Date: Fri, 10 Apr 2026 13:51:24 +0200
Subject: [PATCH] rust: Make __udivdi3() and __umoddi3() panic
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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.

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 <[email-masked]>
---
 rust/Makefile             | 4 ++++
 rust/compiler_builtins.rs | 6 ++++++
 2 files changed, 10 insertions(+)

diff --git a/rust/Makefile b/rust/Makefile
index 99537c2c55ee..568f241a21a7 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -626,6 +626,10 @@ 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`.
-- 
2.54.0