tools/syscalls/lttng-get-syscall-inout.sh

   1 #!/bin/bash
   2 # SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   3
   4 # example usage:
   5 # lttng-get-syscall-inout.sh table-syscall-inout.txt select 1
   6
   7 ARCH_NAME=$1
   8 SYSCALL_NAME=$2
   9 NB_ARGS=$3
  10 ARG_NR=$4
  11 TMPFILE=$(mktemp)
  12 GENERIC_INOUT_DESCRIPTION_FILE="$(dirname "$0")/table-syscall-inout.txt"
  13
  14 # Delete temp file on exit
  15 trap 'rm -f "$TMPFILE"' EXIT
  16
  17 if [ "${GENERIC_INOUT_DESCRIPTION_FILE}" = "" ]; then
  18         echo "Error: Please specify input file name as first argument" >&2
  19         exit 1
  20 fi
  21
  22 if [ "${SYSCALL_NAME}" = "" ]; then
  23         echo "Error: Please specify system call name as second argument" >&2
  24         exit 1
  25 fi
  26
  27 if [[ "${ARG_NR}" = "" || ${ARG_NR} == 0 ]]; then
  28         echo "Error: Please specify argument number larger than 0 as third argument" >&2
  29         exit 1
  30 fi
  31
  32 # Search for the in/out description of a syscall. This function attempts to find
  33 # a matching description in the per-architecture description override file (if it exists)
  34 # and falls back to the generic description file otherwise.
  35 #
  36 # Returns 0 if a description was found and written to the output file, 1 otherwise.
  37 function write_inout_description ()
  38 {
  39         local arch_name=$1
  40         local syscall_name=$2
  41         local nb_args=$3
  42         local output_file=$4
  43         local description_files=("$(dirname "$0")/table-syscall-inout-${arch_name}-override.txt" "$GENERIC_INOUT_DESCRIPTION_FILE")
  44         local match_count
  45
  46         for file in "${description_files[@]}"; do
  47                 if [ ! -f "$file" ]; then
  48                         continue
  49                 fi
  50
  51                 # Look for the syscall's in/out description
  52                 grep "^syscall ${syscall_name} " "${file}" > "${output_file}" || true
  53
  54                 # Error out if we got more than one syscall
  55                 match_count=$(wc -l < "${output_file}")
  56                 if [ "${match_count}" -gt 1 ]; then
  57                         # Fatal error; invalid description file
  58                         echo "Error: more than one system call match for ${SYSCALL_NAME}" >&2
  59                         exit 1
  60                 elif [ "${match_count}" -eq 1 ]; then
  61                         if ! grep -q "^syscall ${syscall_name} nbargs ${nb_args}" "${output_file}"; then
  62                                 echo "Error: number of arguments doesn't match for ${SYSCALL_NAME}" >&2
  63                                 exit 1
  64                         fi
  65                         # Description found
  66                         return 0
  67                 fi
  68         done
  69
  70         return 1
  71 }
  72
  73 # Abort on error and undefined variable
  74 set -eu
  75
  76
  77 # Default to sc_inout for unknown syscalls
  78 if ! write_inout_description "$ARCH_NAME" "$SYSCALL_NAME" "$NB_ARGS" "$TMPFILE"; then
  79         echo "Warning: no match for syscall '${SYSCALL_NAME}', set to 'inout'" >&2
  80         # no match, default to inout
  81         echo "sc_inout"
  82         exit 0
  83 fi
  84
  85 # Get the number of argument
  86 SC_ARGS=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) .*/\2/g' "${TMPFILE}")
  87
  88 if [ "${ARG_NR}" -gt "${SC_ARGS}" ]; then
  89         echo "Error: argument number (${ARG_NR}) for ${SYSCALL_NAME} is larger than number of syscall arguments (${SC_ARGS})" >&2
  90         exit 1
  91 fi
  92
  93 if [ "${ARG_NR}" == 1 ]; then
  94         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: (\([^,)]*\).*/\3/g' "${TMPFILE}")
  95 fi
  96
  97 if [ "${ARG_NR}" == 2 ]; then
  98         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
  99 fi
 100
 101 if [ "${ARG_NR}" == 3 ]; then
 102         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 103 fi
 104
 105 if [ "${ARG_NR}" == 4 ]; then
 106         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 107 fi
 108
 109 if [ "${ARG_NR}" == 5 ]; then
 110         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 111 fi
 112
 113 if [ "${ARG_NR}" == 6 ]; then
 114         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 115 fi
 116
 117
 118 if [ "${SC_ARG_TYPE}" = "r" ]; then
 119         echo "sc_in"
 120 fi
 121 if [ "${SC_ARG_TYPE}" = "w" ]; then
 122         echo "sc_out"
 123 fi
 124 if [ "${SC_ARG_TYPE}" = "rw" ]; then
 125         echo "sc_inout"
 126 fi
 127
 128 # EOF