core/CMake_readelf.cmake

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# caller must set READELF_EXECUTABLE so it can be a cache variable
# caller must also set "lib" to point to target library

# PR 212290: ensure no text relocations (they violate selinux execmod policies)
# looking for dynamic section tag:
#   0x00000016 (TEXTREL)                    0x0
execute_process(COMMAND
  ${READELF_EXECUTABLE} -d ${lib}
  RESULT_VARIABLE readelf_result
  ERROR_VARIABLE readelf_error
  OUTPUT_VARIABLE string
  )
if (readelf_result OR readelf_error)
  message(FATAL_ERROR "*** ${READELF_EXECUTABLE} failed: ***\n${readelf_error}")
endif (readelf_result OR readelf_error)
string(REGEX MATCH
  "TEXTREL"
  has_textrel "${string}")
if (has_textrel)
  message(FATAL_ERROR "*** Error: ${lib} has text relocations")
endif (has_textrel)

# also check for execstack
# looking for stack properties:
#   GNU_STACK      0x000000 0x00000000 0x00000000 0x00000 0x00000 RWE 0x4
execute_process(COMMAND
  ${READELF_EXECUTABLE} -l ${lib}
  RESULT_VARIABLE readelf_result
  ERROR_VARIABLE readelf_error
  OUTPUT_VARIABLE string
  )
if (readelf_result OR readelf_error)
  message(FATAL_ERROR "*** ${READELF_EXECUTABLE} failed: ***\n${readelf_error}")
endif (readelf_result OR readelf_error)
string(REGEX MATCH
  "STACK.*RWE"
  has_execstack "${string}")
if (has_execstack)
  message(FATAL_ERROR "*** Error: ${lib} has executable stack")
endif (has_execstack)