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

   1 #!/bin/bash
   2 # SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   3 # SPDX-FileCopyrightText: 2014-2024 EfficiOS Inc.
   4
   5 # example usage:
   6 # lttng-get-syscall-inout.sh arm-64 select 5 1
   7
   8 ARCH_NAME=$1
   9 SYSCALL_NAME=$2
  10 NB_ARGS=$3
  11 ARG_NR=$4
  12 TMPFILE=$(mktemp)
  13 GENERIC_INOUT_DESCRIPTION_FILE="$(dirname "$0")/table-syscall-inout.txt"
  14
  15 # Delete temp file on exit
  16 trap 'rm -f "$TMPFILE"' EXIT
  17
  18 if [ "${ARCH_NAME}" = "" ]; then
  19         echo "Error: Please specify the arch name as first argument" >&2
  20         exit 1
  21 fi
  22
  23 if [ "${SYSCALL_NAME}" = "" ]; then
  24         echo "Error: Please specify the system call name as second argument" >&2
  25         exit 1
  26 fi
  27
  28 if [[ "${NB_ARGS}" = "" ]]; then
  29         echo "Error: Please specify a number of arguments as third argument" >&2
  30         exit 1
  31 fi
  32
  33 if [[ "${ARG_NR}" = "" || ${ARG_NR} == 0 ]]; then
  34         echo "Error: Please specify an argument number larger than 0 as fourth argument" >&2
  35         exit 1
  36 fi
  37
  38 # Search for the in/out description of a syscall. This function attempts to find
  39 # a matching description in the per-architecture description override file (if it exists)
  40 # and falls back to the generic description file otherwise.
  41 #
  42 # Returns 0 if a description was found and written to the output file, 1 otherwise.
  43 function write_inout_description ()
  44 {
  45         local arch_name=$1
  46         local syscall_name=$2
  47         local nb_args=$3
  48         local output_file=$4
  49         local description_files=("$(dirname "$0")/table-syscall-inout-${arch_name}-override.txt" "$GENERIC_INOUT_DESCRIPTION_FILE")
  50         local match_count
  51
  52         for file in "${description_files[@]}"; do
  53                 if [ ! -f "$file" ]; then
  54                         continue
  55                 fi
  56
  57                 # Look for the syscall's in/out description
  58                 grep "^syscall ${syscall_name} " "${file}" > "${output_file}" || true
  59
  60                 # Error out if we got more than one syscall
  61                 match_count=$(wc -l < "${output_file}")
  62                 if [ "${match_count}" -gt 1 ]; then
  63                         # Fatal error; invalid description file
  64                         echo "Error: more than one system call match for ${SYSCALL_NAME}" >&2
  65                         exit 1
  66                 elif [ "${match_count}" -eq 1 ]; then
  67                         if ! grep -q "^syscall ${syscall_name} nbargs ${nb_args}" "${output_file}"; then
  68                                 echo "Error: number of arguments doesn't match for ${SYSCALL_NAME}" >&2
  69                                 exit 1
  70                         fi
  71                         # Description found
  72                         return 0
  73                 fi
  74         done
  75
  76         return 1
  77 }
  78
  79 # Abort on error and undefined variable
  80 set -eu
  81
  82
  83 # Default to sc_inout for unknown syscalls
  84 if ! write_inout_description "$ARCH_NAME" "$SYSCALL_NAME" "$NB_ARGS" "$TMPFILE"; then
  85         echo "Warning: no match for syscall '${SYSCALL_NAME}', set to 'inout'" >&2
  86         # no match, default to inout
  87         echo "sc_inout"
  88         exit 0
  89 fi
  90
  91 # Get the number of argument
  92 SC_ARGS=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) .*/\2/g' "${TMPFILE}")
  93
  94 if [ "${ARG_NR}" -gt "${SC_ARGS}" ]; then
  95         echo "Error: argument number (${ARG_NR}) for ${SYSCALL_NAME} is larger than number of syscall arguments (${SC_ARGS})" >&2
  96         exit 1
  97 fi
  98
  99 if [ "${ARG_NR}" == 1 ]; then
 100         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: (\([^,)]*\).*/\3/g' "${TMPFILE}")
 101 fi
 102
 103 if [ "${ARG_NR}" == 2 ]; then
 104         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 105 fi
 106
 107 if [ "${ARG_NR}" == 3 ]; then
 108         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 109 fi
 110
 111 if [ "${ARG_NR}" == 4 ]; then
 112         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 113 fi
 114
 115 if [ "${ARG_NR}" == 5 ]; then
 116         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 117 fi
 118
 119 if [ "${ARG_NR}" == 6 ]; then
 120         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 121 fi
 122
 123
 124 if [ "${SC_ARG_TYPE}" = "r" ]; then
 125         echo "sc_in"
 126 fi
 127 if [ "${SC_ARG_TYPE}" = "w" ]; then
 128         echo "sc_out"
 129 fi
 130 if [ "${SC_ARG_TYPE}" = "rw" ]; then
 131         echo "sc_inout"
 132 fi
 133
 134 # EOF