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 ARG_NR=$3
  10 TMPFILE=$(mktemp)
  11 GENERIC_INOUT_DESCRIPTION_FILE="$(dirname "$0")/table-syscall-inout.txt"
  12
  13 # Delete temp file on exit
  14 trap 'rm -f "$TMPFILE"' EXIT
  15
  16 if [ "${GENERIC_INOUT_DESCRIPTION_FILE}" = "" ]; then
  17         echo "Error: Please specify input file name as first argument" >&2
  18         exit 1
  19 fi
  20
  21 if [ "${SYSCALL_NAME}" = "" ]; then
  22         echo "Error: Please specify system call name as second argument" >&2
  23         exit 1
  24 fi
  25
  26 if [[ "${ARG_NR}" = "" || ${ARG_NR} == 0 ]]; then
  27         echo "Error: Please specify argument number larger than 0 as third argument" >&2
  28         exit 1
  29 fi
  30
  31 # Search for the in/out description of a syscall. This function attempts to find
  32 # a matching description in the per-architecture description override file (if it exists)
  33 # and falls back to the generic description file otherwise.
  34 #
  35 # Returns 0 if a description was found and written to the output file, 1 otherwise.
  36 function write_inout_description ()
  37 {
  38         local arch_name=$1
  39         local syscall_name=$2
  40         local output_file=$3
  41         local description_files=("$(dirname "$0")/table-syscall-inout-${arch_name}-override.txt" "$GENERIC_INOUT_DESCRIPTION_FILE")
  42         local match_count
  43
  44         for file in "${description_files[@]}"; do
  45                 if [ ! -f "$file" ]; then
  46                         continue
  47                 fi
  48
  49                 # Look for the syscall's in/out description
  50                 grep "^syscall ${syscall_name} " "${file}" > "${output_file}" || true
  51
  52                 # Error out if we got more than one syscall
  53                 match_count=$(wc -l < "${output_file}")
  54                 if [ "${match_count}" -gt 1 ]; then
  55                         # Fatal error; invalid description file
  56                         echo "Error: more than one system call match for ${SYSCALL_NAME}" >&2
  57                         exit 1
  58                 elif [ "${match_count}" -eq 1 ]; then
  59                         # Description found
  60                         return 0
  61                 fi
  62         done
  63
  64         return 1
  65 }
  66
  67 # Abort on error and undefined variable
  68 set -eu
  69
  70
  71 # Default to sc_inout for unknown syscalls
  72 if ! write_inout_description "$ARCH_NAME" "$SYSCALL_NAME" "$TMPFILE"; then
  73         echo "Warning: no match for syscall '${SYSCALL_NAME}', set to 'inout'" >&2
  74         # no match, default to inout
  75         echo "sc_inout"
  76         exit 0
  77 fi
  78
  79 # Get the number of argument
  80 SC_ARGS=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) .*/\2/g' "${TMPFILE}")
  81
  82 if [ "${ARG_NR}" -gt "${SC_ARGS}" ]; then
  83         echo "Error: argument number (${ARG_NR}) for ${SYSCALL_NAME} is larger than number of syscall arguments (${SC_ARGS})" >&2
  84         exit 1
  85 fi
  86
  87 if [ "${ARG_NR}" == 1 ]; then
  88         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: (\([^,)]*\).*/\3/g' "${TMPFILE}")
  89 fi
  90
  91 if [ "${ARG_NR}" == 2 ]; then
  92         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
  93 fi
  94
  95 if [ "${ARG_NR}" == 3 ]; then
  96         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
  97 fi
  98
  99 if [ "${ARG_NR}" == 4 ]; then
 100         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 101 fi
 102
 103 if [ "${ARG_NR}" == 5 ]; then
 104         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 105 fi
 106
 107 if [ "${ARG_NR}" == 6 ]; then
 108         SC_ARG_TYPE=$(sed 's/^syscall \([^ ]*\) nbargs \([^ ]*\) rw: ([^,]*, [^,]*, [^,]*, [^,]*, [^,]*, \([^,)]*\).*/\3/g' "${TMPFILE}")
 109 fi
 110
 111
 112 if [ "${SC_ARG_TYPE}" = "r" ]; then
 113         echo "sc_in"
 114 fi
 115 if [ "${SC_ARG_TYPE}" = "w" ]; then
 116         echo "sc_out"
 117 fi
 118 if [ "${SC_ARG_TYPE}" = "rw" ]; then
 119         echo "sc_inout"
 120 fi
 121
 122 # EOF