Re: [PATCH] irqchip/jcore-aic: Fix lost IPIs on SMP

[John Paul Adrian Glaubitz]

Hi Karl,

On Mon, 2026-09-28 at 08:07 +0200, Karl Mehltretter wrote:
> On Mon, Sep 28, 2026 at 07:57:27AM +0100, John Paul Adrian Glaubitz wrote:
> > Can you tell me what toolchain you used to build the kernel for J2?
> > 
> > Last time I tried to use the one provided by Rob Landley, the build
> > failed due to an internal compiler error so I couldn't actually build
> > a kernel to test it on my J2 Turtleboard.
> > 
> 
> Hi Adrian,
> 
> musl.cc's sh2eb-linux-muslfdpic toolchain (GCC 11.2.1, binutils 2.37):
> 
>   https://musl.cc/sh2eb-linux-muslfdpic-cross.tgz
> 
> Your ICE is probably the one in kernel/nstree.c. Since listns() went in
> (v6.19), every GCC I tried ICEs there with j2_defconfig. The 64-bit
> put_user() asm prints %T (address + 4) of an "m" operand, and GCC can
> pick an indexed address that cannot be offset. The asm needs "o".
> GCC should still error out instead of crashing, so I filed a GCC bug
> too:
> 
>   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127639
> 
> Fix below, formal patch follows. With it, j2_defconfig with SMP=y
> builds fine with the musl.cc toolchain.
> 
> Would be great if you could test on your Turtleboard!
> 
> Karl
> 
> -- >8 --
> diff --git a/arch/sh/include/asm/uaccess_32.h b/arch/sh/include/asm/uaccess_32.h
> index 5d7ddc092afd7..879d262489219 100644
> --- a/arch/sh/include/asm/uaccess_32.h
> +++ b/arch/sh/include/asm/uaccess_32.h
> @@ -92,7 +92,7 @@ __asm__ __volatile__( \
>  	".long	1b + 2, 3b\n\t" \
>  	".previous" \
>  	:"=&r" (err), "=&r" (x) \
> -	:"m" (__m(addr)), "i" (-EFAULT), "0" (err)); })
> +	: "o" (__m(addr)), "i" (-EFAULT), "0" (err)); })
>  #else
>  #define __get_user_u64(x, addr, err) \
>  ({ \
> @@ -116,7 +116,7 @@ __asm__ __volatile__( \
>  	".long	1b + 2, 3b\n\t" \
>  	".previous" \
>  	:"=&r" (err), "=&r" (x) \
> -	:"m" (__m(addr)), "i" (-EFAULT), "0" (err)); })
> +	: "o" (__m(addr)), "i" (-EFAULT), "0" (err)); })
>  #endif
>  
>  #define __put_user_size(x,ptr,size,retval)		\
> @@ -196,7 +196,7 @@ __asm__ __volatile__( \
>  	".long	1b, 3b\n\t" \
>  	".previous" \
>  	: "=r" (retval) \
> -	: "r" (val), "m" (__m(addr)), "i" (-EFAULT), "0" (retval) \
> +	: "r" (val), "o" (__m(addr)), "i" (-EFAULT), "0" (retval) \
>          : "memory"); })
>  #else
>  #define __put_user_u64(val,addr,retval) \
> @@ -218,7 +218,7 @@ __asm__ __volatile__( \
>  	".long	1b, 3b\n\t" \
>  	".previous" \
>  	: "=r" (retval) \
> -	: "r" (val), "m" (__m(addr)), "i" (-EFAULT), "0" (retval) \
> +	: "r" (val), "o" (__m(addr)), "i" (-EFAULT), "0" (retval) \
>          : "memory"); })
>  #endif
>  

That patch indeed fixes the build issue and the ICE and I can finally
build a kernel image using Toybox for my J2 board again. Let me see
if the kernel also boots.

Unless your patch is identical to Florian's, you can post yours later.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer
`. `'   Physicist
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