Hi Michal,
> On 19 Jun 2024, at 08:46, Michal Orzel <michal.or...@amd.com> wrote:
>
> Building Xen with CONFIG_STATIC_SHM=y results in a build failure:
>
> arch/arm/static-shmem.c: In function 'process_shm':
> arch/arm/static-shmem.c:327:41: error: 'gbase' may be used uninitialized
> [-Werror=maybe-uninitialized]
> 327 | if ( is_domain_direct_mapped(d) && (pbase != gbase) )
> arch/arm/static-shmem.c:305:17: note: 'gbase' was declared here
> 305 | paddr_t gbase, pbase, psize;
>
> This is because the commit cb1ddafdc573 adds a check referencing
> gbase/pbase variables which were not yet assigned a value. Fix it.
>
> Fixes: cb1ddafdc573 ("xen/arm/static-shmem: Static-shmem should be
> direct-mapped for direct-mapped domains")
> Signed-off-by: Michal Orzel <michal.or...@amd.com>
Reviewed-by: Bertrand Marquis <bertrand.marq...@arm.com>
Cheers
Bertrand
> ---
> Rationale for 4.19: this patch fixes a build failure reported by CI:
> https://gitlab.com/xen-project/xen/-/jobs/7131807878
> ---
> xen/arch/arm/static-shmem.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/xen/arch/arm/static-shmem.c b/xen/arch/arm/static-shmem.c
> index c434b96e6204..cd48d2896b7e 100644
> --- a/xen/arch/arm/static-shmem.c
> +++ b/xen/arch/arm/static-shmem.c
> @@ -324,12 +324,6 @@ int __init process_shm(struct domain *d, struct
> kernel_info *kinfo,
> printk("%pd: static shared memory bank not found: '%s'", d,
> shm_id);
> return -ENOENT;
> }
> - if ( is_domain_direct_mapped(d) && (pbase != gbase) )
> - {
> - printk("%pd: physical address 0x%"PRIpaddr" and guest address
> 0x%"PRIpaddr" are not direct-mapped.\n",
> - d, pbase, gbase);
> - return -EINVAL;
> - }
>
> pbase = boot_shm_bank->start;
> psize = boot_shm_bank->size;
> @@ -353,6 +347,13 @@ int __init process_shm(struct domain *d, struct
> kernel_info *kinfo,
> /* guest phys address is after host phys address */
> gbase = dt_read_paddr(cells + addr_cells, addr_cells);
>
> + if ( is_domain_direct_mapped(d) && (pbase != gbase) )
> + {
> + printk("%pd: physical address 0x%"PRIpaddr" and guest
> address 0x%"PRIpaddr" are not direct-mapped.\n",
> + d, pbase, gbase);
> + return -EINVAL;
> + }
> +
> for ( i = 0; i < PFN_DOWN(psize); i++ )
> if ( !mfn_valid(mfn_add(maddr_to_mfn(pbase), i)) )
> {
> --
> 2.25.1
>
