linux-kernel - Re: arch/powerpc/kexec/core.c:217:20: sparse: sparse: incorrect type in assignment (different base types)

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Message-ID: <42679785-1831-4657-8ab8-c2fc1070a785@linux.ibm.com>
Date: Wed, 24 Dec 2025 22:30:00 +0530
From: Sourabh Jain <sourabhjain@...ux.ibm.com>
To: kernel test robot <lkp@...el.com>, Ben Collins <bcollins@...nel.org>
Cc: oe-kbuild-all@...ts.linux.dev, linux-kernel@...r.kernel.org,
        Madhavan Srinivasan <maddy@...ux.ibm.com>,
        linuxppc-dev <linuxppc-dev@...ts.ozlabs.org>,
        shivang upadhyay <shivangu@...ux.ibm.com>,
        "Ritesh Harjani (IBM)" <ritesh.list@...il.com>,
        Christophe Leroy <christophe.leroy@...roup.eu>,
        Hari Bathini <hbathini@...ux.ibm.com>
Subject: Re: arch/powerpc/kexec/core.c:217:20: sparse: sparse: incorrect type
 in assignment (different base types)



On 23/12/25 18:27, Sourabh Jain wrote:
> +Cc: PowerPC mailing list.
>
> and added some comments below.
>
> On 22/12/25 12:14, kernel test robot wrote:
>> tree: 
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 
>> master
>> head:   9448598b22c50c8a5bb77a9103e2d49f134c9578
>> commit: 38c64dfe0af12778953846df5f259e913275cfe5 kexec: Include 
>> kernel-end even without crashkernel
>> date:   6 weeks ago
>> config: powerpc-randconfig-r111-20251222 
>> (https://download.01.org/0day-ci/archive/20251222/202512221405.VHPKPjnp-lkp@intel.com/config)
>> compiler: clang version 22.0.0git 
>> (https://github.com/llvm/llvm-project 
>> 42b3483ac4987cae1bdb632398e8a3ce2dea6633)
>> reproduce (this is a W=1 build): 
>> (https://download.01.org/0day-ci/archive/20251222/202512221405.VHPKPjnp-lkp@intel.com/reproduce)
>>
>> If you fix the issue in a separate patch/commit (i.e. not just a new 
>> version of
>> the same patch/commit), kindly add following tags
>> | Reported-by: kernel test robot <lkp@...el.com>
>> | Closes: 
>> https://lore.kernel.org/oe-kbuild-all/202512221405.VHPKPjnp-lkp@intel.com/
>>
>> sparse warnings: (new ones prefixed by >>)
>>>> arch/powerpc/kexec/core.c:217:20: sparse: sparse: incorrect type in 
>>>> assignment (different base types) @@     expected unsigned int 
>>>> static [addressable] [toplevel] [usertype] kernel_end @@     got 
>>>> restricted __be32 [usertype] @@
>>     arch/powerpc/kexec/core.c:217:20: sparse:     expected unsigned 
>> int static [addressable] [toplevel] [usertype] kernel_end
>>     arch/powerpc/kexec/core.c:217:20: sparse:     got restricted 
>> __be32 [usertype]
>
> If CONFIG_CRASH_DUMP is enabled (which is not done in config shared by 
> kernel test robot) sparse warn
> about other assignments in the same file. And these warnings are not 
> limited to 32-bit.
>
> ../arch/powerpc/kexec/core.c:181:29: sparse: warning: incorrect type 
> in assignment (different base types)
> ../arch/powerpc/kexec/core.c:181:29: sparse:    expected unsigned int 
> static [addressable] [toplevel] [usertype] crashk_base
> ../arch/powerpc/kexec/core.c:181:29: sparse:    got restricted __be32 
> [usertype]
> ../arch/powerpc/kexec/core.c:183:29: sparse: warning: incorrect type 
> in assignment (different base types)
> ../arch/powerpc/kexec/core.c:183:29: sparse:    expected unsigned int 
> static [addressable] [toplevel] [usertype] crashk_size
> ../arch/powerpc/kexec/core.c:183:29: sparse:    got restricted __be32 
> [usertype]
> ../arch/powerpc/kexec/core.c:191:19: sparse: warning: incorrect type 
> in assignment (different base types)
> ../arch/powerpc/kexec/core.c:191:19: sparse:    expected unsigned long 
> long static [addressable] [toplevel] mem_limit
> ../arch/powerpc/kexec/core.c:191:19: sparse:    got restricted __be32 
> [usertype]
> ../arch/powerpc/kexec/core.c:217:20: sparse: warning: incorrect type 
> in assignment (different base types)
> ../arch/powerpc/kexec/core.c:217:20: sparse:    expected unsigned int 
> static [addressable] [toplevel] [usertype] kernel_end
> ../arch/powerpc/kexec/core.c:217:20: sparse:    got restricted __be32 
> [usertype]
>   CHECK   ../arch/powerpc/kexec/core_32.c
>
> To resolve these warnings:
>
> Should we use __force tpyecast and silence the warnings?
> for example:
> kernel_end = (__force phys_addr_t) cpu_to_be_ulong(__pa(_end));
>
> Or
>
> Use proper data types __be<32|64> and duplicated the definition and 
> assignment? seems like bit too much.

Found a better way to define variables as __be<32|64> without duplication,
so I have posted a fix:
https://lore.kernel.org/all/20251224151257.28672-1-sourabhjain@linux.ibm.com/

- Sourabh Jain


>
> Or
>
> Do we have better way to handle these warnings? If yes, please share.
>
> - Sourabh Jain
>
>>
>> vim +217 arch/powerpc/kexec/core.c
>>
>> 6f29c3298b1821 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-17  203
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  204  static int __init kexec_setup(void)
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  205  {
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  206      struct device_node *node;
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  207
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  208      node = of_find_node_by_path("/chosen");
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  209      if (!node)
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  210          return -ENOENT;
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  211
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  212      /* remove any stale properties so ours can be 
>> found */
>> 38c64dfe0af127 arch/powerpc/kexec/core.c           Ben Collins     
>> 2025-04-21  213      of_remove_property(node, of_find_property(node, 
>> kernel_end_prop.name,
>> 38c64dfe0af127 arch/powerpc/kexec/core.c           Ben Collins     
>> 2025-04-21  214                            NULL));
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  215
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  216      /* information needed by userspace when using 
>> default_machine_kexec */
>> ea961a828fe725 arch/powerpc/kernel/machine_kexec.c Anton Blanchard 
>> 2014-01-22 @217      kernel_end = cpu_to_be_ulong(__pa(_end));
>> 79d1c712958f94 arch/powerpc/kernel/machine_kexec.c Nathan Fontenot 
>> 2012-10-02  218      of_add_property(node, &kernel_end_prop);
>> 2e8e4f5b80e101 arch/powerpc/kernel/machine_kexec.c Dale Farnsworth 
>> 2008-12-16  219
>>
>> :::::: The code at line 217 was first introduced by commit
>> :::::: ea961a828fe7250e954f086d74d9323c3d44c3e4 powerpc: Fix endian 
>> issues in kexec and crash dump code
>>
>> :::::: TO: Anton Blanchard <anton@...ba.org>
>> :::::: CC: Benjamin Herrenschmidt <benh@...nel.crashing.org>
>>
>
>