Avoid false-positive mem_section validation with vmlinux

Resolves: bz2081323
Upstream: github.com/makedumpfile/makedumpfile.git
Conflicts: None

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>

Signed-off-by: Philipp Rudo <prudo@redhat.com>

kexec-tools-2.0.23-makedumpfile-Avoid_false_positive_mem_section_validation_with_vmlinux.patch

@@ -0,0 +1,76 @@
+ 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;

kexec-tools.spec

@@ -124,6 +124,7 @@ Patch604: ./kexec-tools-2.0.23-02-_PATCH_v2_2_3_use_pointer_arithmetics_for_dump
 Patch605: ./kexec-tools-2.0.23-03-_PATCH_v2_3_3_use_cycle_detection_when_parsing_the_prink_log_buf.patch
 Patch606: ./kexec-tools-2.0.23-04-_PATCH_print_error_when_reading_with_unsupported_compression.patch
 Patch607: ./kexec-tools-2.0.23-05-util_lib_elf_info_harden_parsing_of_printk_buffer.patch
+Patch608: ./kexec-tools-2.0.23-makedumpfile-Avoid_false_positive_mem_section_validation_with_vmlinux.patch
 
 %description
 kexec-tools provides /sbin/kexec binary that facilitates a new
@@ -151,6 +152,7 @@ tar -z -x -v -f %{SOURCE19}
 %patch605 -p1
 %patch606 -p1
 %patch607 -p1
+%patch608 -p1
 
 %ifarch ppc
 %define archdef ARCH=ppc