Re: [PATCH] iommu: Convert unreachable() to BUG()

[Jason Gunthorpe]

On Wed, Mar 26, 2025 at 10:28:46PM -0700, Josh Poimboeuf wrote:
> Bare unreachable() should be avoided as it generates undefined behavior,
> e.g. falling through to the next function.  Use BUG() instead so the
> error is defined.
> 
> Fixes the following warnings:
> 
>   drivers/iommu/dma-iommu.o: warning: objtool: iommu_dma_sw_msi+0x92: can't find jump dest instruction at .text+0x54d5
>   vmlinux.o: warning: objtool: iommu_dma_get_msi_page() falls through to next function __iommu_dma_unmap()
> 
> Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Closes: https://lore.kernel.org/314f8809-cd59-479b-97d7-49356bf1c8d1@xxxxxxxxxxxxx
> Reported-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
> Closes: https://lore.kernel.org/5dd1f35e-8ece-43b7-ad6d-86d02d2718f6@paulmck-laptop
> Fixes: 6aa63a4ec947 ("iommu: Sort out domain user data")
> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> ---
>  drivers/iommu/dma-iommu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

The offending patch is in the iommufd tree, so applied thanks for the
quick response

Jason