Re: [PATCH v9 2/7] kexec: define functions to map and unmap segments

[kernel test robot <lkp@intel.com>]

BCC: lkp@intel.com
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References: <20250304190351.96975-3-chenste@linux.microsoft.com>
TO: steven chen <chenste@linux.microsoft.com>
TO: zohar@linux.ibm.com
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TO: bauermann@kolabnow.com
TO: linux-integrity@vger.kernel.org
TO: kexec@lists.infradead.org
TO: linux-security-module@vger.kernel.org
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Hi steven,

kernel test robot noticed the following build warnings:

[auto build test WARNING on zohar-integrity/next-integrity]
[also build test WARNING on linus/master v6.14-rc5 next-20250305]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/steven-chen/ima-copy-only-complete-measurement-records-across-kexec/20250305-031719
base:   https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git next-integrity
patch link:    https://lore.kernel.org/r/20250304190351.96975-3-chenste%40linux.microsoft.com
patch subject: [PATCH v9 2/7] kexec: define functions to map and unmap segments
:::::: branch date: 35 hours ago
:::::: commit date: 35 hours ago
config: x86_64-randconfig-161-20250306 (https://download.01.org/0day-ci/archive/20250306/202503061449.gbVGafZc-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0

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@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202503061449.gbVGafZc-lkp@intel.com/

smatch warnings:
kernel/kexec_core.c:896 kimage_map_segment() error: uninitialized symbol 'dest_page_addr'.

vim +/dest_page_addr +896 kernel/kexec_core.c

2965faa5e03d1e Dave Young  2015-09-09  869  
bf06eab7ae0f04 steven chen 2025-03-04  870  void *kimage_map_segment(struct kimage *image,
bf06eab7ae0f04 steven chen 2025-03-04  871  			 unsigned long addr, unsigned long size)
bf06eab7ae0f04 steven chen 2025-03-04  872  {
bf06eab7ae0f04 steven chen 2025-03-04  873  	unsigned long eaddr = addr + size;
bf06eab7ae0f04 steven chen 2025-03-04  874  	unsigned long src_page_addr, dest_page_addr;
bf06eab7ae0f04 steven chen 2025-03-04  875  	unsigned int npages;
bf06eab7ae0f04 steven chen 2025-03-04  876  	struct page **src_pages;
bf06eab7ae0f04 steven chen 2025-03-04  877  	int i;
bf06eab7ae0f04 steven chen 2025-03-04  878  	kimage_entry_t *ptr, entry;
bf06eab7ae0f04 steven chen 2025-03-04  879  	void *vaddr = NULL;
bf06eab7ae0f04 steven chen 2025-03-04  880  
bf06eab7ae0f04 steven chen 2025-03-04  881  	/*
bf06eab7ae0f04 steven chen 2025-03-04  882  	 * Collect the source pages and map them in a contiguous VA range.
bf06eab7ae0f04 steven chen 2025-03-04  883  	 */
bf06eab7ae0f04 steven chen 2025-03-04  884  	npages = PFN_UP(eaddr) - PFN_DOWN(addr);
bf06eab7ae0f04 steven chen 2025-03-04  885  	src_pages = kmalloc_array(npages, sizeof(*src_pages), GFP_KERNEL);
bf06eab7ae0f04 steven chen 2025-03-04  886  	if (!src_pages) {
bf06eab7ae0f04 steven chen 2025-03-04  887  		pr_err("Could not allocate ima pages array.\n");
bf06eab7ae0f04 steven chen 2025-03-04  888  		return NULL;
bf06eab7ae0f04 steven chen 2025-03-04  889  	}
bf06eab7ae0f04 steven chen 2025-03-04  890  
bf06eab7ae0f04 steven chen 2025-03-04  891  	i = 0;
bf06eab7ae0f04 steven chen 2025-03-04  892  	for_each_kimage_entry(image, ptr, entry) {
bf06eab7ae0f04 steven chen 2025-03-04  893  		if (entry & IND_DESTINATION) {
bf06eab7ae0f04 steven chen 2025-03-04  894  			dest_page_addr = entry & PAGE_MASK;
bf06eab7ae0f04 steven chen 2025-03-04  895  		} else if (entry & IND_SOURCE) {
bf06eab7ae0f04 steven chen 2025-03-04 @896  			if (dest_page_addr >= addr && dest_page_addr < eaddr) {
bf06eab7ae0f04 steven chen 2025-03-04  897  				src_page_addr = entry & PAGE_MASK;
bf06eab7ae0f04 steven chen 2025-03-04  898  				src_pages[i++] =
bf06eab7ae0f04 steven chen 2025-03-04  899  					virt_to_page(__va(src_page_addr));
bf06eab7ae0f04 steven chen 2025-03-04  900  				if (i == npages)
bf06eab7ae0f04 steven chen 2025-03-04  901  					break;
bf06eab7ae0f04 steven chen 2025-03-04  902  				dest_page_addr += PAGE_SIZE;
bf06eab7ae0f04 steven chen 2025-03-04  903  			}
bf06eab7ae0f04 steven chen 2025-03-04  904  		}
bf06eab7ae0f04 steven chen 2025-03-04  905  	}
bf06eab7ae0f04 steven chen 2025-03-04  906  
bf06eab7ae0f04 steven chen 2025-03-04  907  	/* Sanity check. */
bf06eab7ae0f04 steven chen 2025-03-04  908  	WARN_ON(i < npages);
bf06eab7ae0f04 steven chen 2025-03-04  909  
bf06eab7ae0f04 steven chen 2025-03-04  910  	vaddr = vmap(src_pages, npages, VM_MAP, PAGE_KERNEL);
bf06eab7ae0f04 steven chen 2025-03-04  911  	kfree(src_pages);
bf06eab7ae0f04 steven chen 2025-03-04  912  
bf06eab7ae0f04 steven chen 2025-03-04  913  	if (!vaddr)
bf06eab7ae0f04 steven chen 2025-03-04  914  		pr_err("Could not map ima buffer.\n");
bf06eab7ae0f04 steven chen 2025-03-04  915  
bf06eab7ae0f04 steven chen 2025-03-04  916  	return vaddr;
bf06eab7ae0f04 steven chen 2025-03-04  917  }
bf06eab7ae0f04 steven chen 2025-03-04  918  

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