fixes #8 - add checking for libstackusage arch compatibility

Author: d99kris

README.md

@@ -123,6 +123,18 @@ stack with a dummy data pattern. It also registers a callback routine to be
 called upon thread termination. In the callback routine the amount of remaining
 dummy pattern in the stack is checked, in order to determine the stack usage.
 
+Interception is only possible when stackusage is built for the same
+architecture as the program being analyzed. Stackusage tries to determine if
+there is a mismatch, if encountered it will output a warning like this:
+
+    warning: libstackusage.so architecture (ELF 64-bit) does not appear
+    to match <PROG> architecture (ELF 32-bit), analysis may fail.
+
+To solve this, simply compile stackusage for the appropriate architecture, for
+example by adding `-m32` to CMAKE_C_FLAGS in CMakeLists.txt, example:
+
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99 -g -m32 \
+
 License
 =======
 Stackusage is distributed under the BSD 3-Clause license. See LICENSE file.

src/stackusage

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# Copyright (C) 2015-2020 Kristofer Berggren
+# Copyright (C) 2015-2021 Kristofer Berggren
 # All rights reserved.
 #
 # stackusage is distributed under the BSD 3-Clause license, see LICENSE for details.
@@ -43,15 +43,33 @@ showusage()
 
 showversion()
 {
-  echo "stackusage v1.14"
+  echo "stackusage v1.15"
   echo ""
-  echo "Copyright (C) 2015-2020 Kristofer Berggren"
+  echo "Copyright (C) 2015-2021 Kristofer Berggren"
   echo ""
   echo "stackusage is distributed under the BSD 3-Clause license."
   echo ""
   echo "Written by Kristofer Berggren"
 }
 
+check_arch_compat()
+{
+  LIBPATH="${1}"
+  PRGPATH="$(which ${2})"
+  if [[ "${PRGPATH}" != "" ]]; then
+    PRGARCH=$(file -b ${PRGPATH} | awk '{print $1 " " $2}')
+    LIBARCH=$(file -b ${LIBPATH} | awk '{print $1 " " $2}')
+    PRGBITS=$(file -b ${PRGPATH} | awk '{print $2}' | awk -F'-' '{print $1}')
+    LIBBITS=$(file -b ${LIBPATH} | awk '{print $2}' | awk -F'-' '{print $1}')
+    if [[ "${PRGBITS}" =~ ^(32|64)$ ]] && [[ "${LIBBITS}" =~ ^(32|64)$ ]] && \
+       [[ "${PRGARCH}" != "${LIBARCH}" ]]; then
+      echo "warning: $(basename ${LIBPATH}) architecture (${LIBARCH}) does not appear"
+      echo "to match ${PRGPATH} architecture (${PRGARCH}), analysis may fail."
+      echo "see https://github.com/d99kris/stackusage#technical-details"
+    fi
+  fi
+}
+
 if [ "${1}" == "--help" ] ; then
   showusage
   exit 0
@@ -155,6 +173,9 @@ while [ "${LIBPATHS[CNT]}" != "" ]; do
   LIBPATH="${LIBPATHS[CNT]}"
   if [ -e "${LIBPATH}" ]; then
 
+    # Check if libstackusage is compatible with program to analyze
+    check_arch_compat "${LIBPATH}" "${1}"
+
     # Run program
     if [ "${DEBUG}" == "0" ]; then
       SU_FILE="${TMPLOG}${OUTFILE}"         \

src/stackusage.1

@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH STACKUSAGE "1" "August 2021" "stackusage v1.14" "User Commands"
+.TH STACKUSAGE "1" "December 2021" "stackusage v1.15" "User Commands"
 .SH NAME
 stackusage \- measure stack usage in applications
 .SH SYNOPSIS
@@ -57,6 +57,6 @@ Written by Kristofer Berggren
 .SH "REPORTING BUGS"
 Report bugs at https://github.com/d99kris/stackusage
 .SH COPYRIGHT
-Copyright \(co 2015\-2020 Kristofer Berggren
+Copyright \(co 2015\-2021 Kristofer Berggren
 .PP
 stackusage is distributed under the BSD 3\-Clause license.