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 arm-64 select 5 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 [ "${ARCH_NAME}" = "" ]; then
  18         echo "Error: Please specify the arch name as first argument" >&2
  19         exit 1
  20 fi
  21
  22 if [ "${SYSCALL_NAME}" = "" ]; then
  23         echo "Error: Please specify the system call name as second argument" >&2
  24         exit 1
  25 fi
  26
  27 if [[ "${NB_ARGS}" = "" ]]; then
  28         echo "Error: Please specify a number of arguments as third argument" >&2
  29         exit 1
  30 fi
  31
  32 if [[ "${ARG_NR}" = "" || ${ARG_NR} == 0 ]]; then
  33         echo "Error: Please specify an argument number larger than 0 as fourth argument" >&2
  34         exit 1
  35 fi
  36
  37 # Search for the in/out description of a syscall. This function attempts to find
  38 # a matching description in the per-architecture description override file (if it exists)
  39 # and falls back to the generic description file otherwise.
  40 #
  41 # Returns 0 if a description was found and written to the output file, 1 otherwise.
  42 function write_inout_description ()
  43 {
  44         local arch_name=$1
  45         local syscall_name=$2
  46         local nb_args=$3
  47         local output_file=$4
  48         local description_files=("$(dirname "$0")/table-syscall-inout-${arch_name}-override.txt" "$GENERIC_INOUT_DESCRIPTION_FILE")
  49         local match_count
  50
  51         for file in "${description_files[@]}"; do
  52                 if [ ! -f "$file" ]; then
  53                         continue
  54                 fi
  55
  56                 # Look for the syscall's in/out description
  57                 grep "^syscall ${syscall_name} " "${file}" > "${output_file}" || true
  58
  59                 # Error out if we got more than one syscall
  60                 match_count=$(wc -l < "${output_file}")
  61                 if [ "${match_count}" -gt 1 ]; then
  62                         # Fatal error; invalid description file
  63                         echo "Error: more than one system call match for ${SYSCALL_NAME}" >&2
  64                         exit 1
  65                 elif [ "${match_count}" -eq 1 ]; then
  66                         if ! grep -q "^syscall ${syscall_name} nbargs ${nb_args}" "${output_file}"; then
  67                                 echo "Error: number of arguments doesn't match for ${SYSCALL_NAME}" >&2
  68                                 exit 1
  69                         fi
  70                         # Description found
  71                         return 0
  72                 fi
  73         done
  74
  75         return 1
  76 }
  77
  78 # Abort on error and undefined variable
  79 set -eu
  80
  81
  82 # Default to sc_inout for unknown syscalls
  83 if ! write_inout_description "$ARCH_NAME" "$SYSCALL_NAME" "$NB_ARGS" "$TMPFILE"; then
  84         echo "Warning: no match for syscall '${SYSCALL_NAME}', set to 'inout'" >&2
  85         # no match, default to inout
  86         echo "sc_inout"
  87         exit 0
  88 fi
  89
  90 # Get the number of argument
  91 SC_ARGS=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) .*/\2/g' "${TMPFILE}")
  92
  93 if [ "${ARG_NR}" -gt "${SC_ARGS}" ]; then
  94         echo "Error: argument number (${ARG_NR}) for ${SYSCALL_NAME} is larger than number of syscall arguments (${SC_ARGS})" >&2
  95         exit 1
  96 fi
  97
  98 if [ "${ARG_NR}" == 1 ]; then
  99         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: (\([^,)]*\).*/\3/g' "${TMPFILE}")
 100 fi
 101
 102 if [ "${ARG_NR}" == 2 ]; then
 103         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 104 fi
 105
 106 if [ "${ARG_NR}" == 3 ]; then
 107         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 108 fi
 109
 110 if [ "${ARG_NR}" == 4 ]; then
 111         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 112 fi
 113
 114 if [ "${ARG_NR}" == 5 ]; then
 115         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 116 fi
 117
 118 if [ "${ARG_NR}" == 6 ]; then
 119         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 120 fi
 121
 122
 123 if [ "${SC_ARG_TYPE}" = "r" ]; then
 124         echo "sc_in"
 125 fi
 126 if [ "${SC_ARG_TYPE}" = "w" ]; then
 127         echo "sc_out"
 128 fi
 129 if [ "${SC_ARG_TYPE}" = "rw" ]; then
 130         echo "sc_inout"
 131 fi
 132
 133 # EOF