commit 6d0d95ecc04a70f8448d562ff0fbbae237f5c929
 Author: Kazuhito Hagio <k-hagio-ab@nec.com>
 Date:   Thu Apr 21 08:58:29 2022 +0900
 
     [PATCH] Avoid false-positive mem_section validation with vmlinux
     
     Currently get_mem_section() validates if SYMBOL(mem_section) is the address
     of the mem_section array first.  But there was a report that the first
     validation wrongly returned TRUE with -x vmlinux and SPARSEMEM_EXTREME
     (4.15+) on s390x.  This leads to crash failing statup with the following
     seek error:
     
       crash: seek error: kernel virtual address: 67fffc2800  type: "memory section root table"
     
     Skip the first validation when satisfying the conditions.
     
     Reported-by: Dave Wysochanski <dwysocha@redhat.com>
     Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
     Reviewed-and-Tested-by: Philipp Rudo <prudo@redhat.com>
     Reviewed-by: Pingfan Liu <piliu@redhat.com>
 
 diff --git a/makedumpfile-1.7.0/makedumpfile.c b/makedumpfile-1.7.0/makedumpfile.c
 index a2f45c84cee3ba57ce3d3cf3f1905e6a03f4fd09..65d1c7c2f02c9ae8ead9de0f0217235fe72b3ca7 100644
 --- a/makedumpfile-1.7.0/makedumpfile.c
 +++ b/makedumpfile-1.7.0/makedumpfile.c
 @@ -3698,6 +3698,22 @@ validate_mem_section(unsigned long *mem_sec,
  	return ret;
  }
  
 +/*
 + * SYMBOL(mem_section) varies with the combination of memory model and
 + * its source:
 + *
 + * SPARSEMEM
 + *   vmcoreinfo: address of mem_section root array
 + *   -x vmlinux: address of mem_section root array
 + *
 + * SPARSEMEM_EXTREME v1
 + *   vmcoreinfo: address of mem_section root array
 + *   -x vmlinux: address of mem_section root array
 + *
 + * SPARSEMEM_EXTREME v2 (with 83e3c48729d9 and a0b1280368d1) 4.15+
 + *   vmcoreinfo: address of mem_section root array
 + *   -x vmlinux: address of pointer to mem_section root array
 + */
  static int
  get_mem_section(unsigned int mem_section_size, unsigned long *mem_maps,
  		unsigned int num_section)
 @@ -3710,12 +3726,27 @@ get_mem_section(unsigned int mem_section_size, unsigned long *mem_maps,
  		    strerror(errno));
  		return FALSE;
  	}
 +
 +	/*
 +	 * There was a report that the first validation wrongly returned TRUE
 +	 * with -x vmlinux and SPARSEMEM_EXTREME v2 on s390x, so skip it.
 +	 * Howerver, leave the fallback validation as it is for the -i option.
 +	 */
 +	if (is_sparsemem_extreme() && info->name_vmlinux) {
 +		unsigned long flag = 0;
 +		if (get_symbol_type_name("mem_section", DWARF_INFO_GET_SYMBOL_TYPE,
 +					NULL, &flag)
 +		    && !(flag & TYPE_ARRAY))
 +			goto skip_1st_validation;
 +	}
 +
  	ret = validate_mem_section(mem_sec, SYMBOL(mem_section),
  				   mem_section_size, mem_maps, num_section);
  
  	if (!ret && is_sparsemem_extreme()) {
  		unsigned long mem_section_ptr;
  
 +skip_1st_validation:
  		if (!readmem(VADDR, SYMBOL(mem_section), &mem_section_ptr,
  			     sizeof(mem_section_ptr)))
  			goto out;