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scripts/atomic/gen-atomic-instrumented.sh 4.26 KB
ace9bad4d   Mark Rutland   locking/atomics: ...
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  #!/bin/sh
  # SPDX-License-Identifier: GPL-2.0
  
  ATOMICDIR=$(dirname $0)
  
  . ${ATOMICDIR}/atomic-tbl.sh
  
  #gen_param_check(arg)
  gen_param_check()
  {
  	local arg="$1"; shift
  	local type="${arg%%:*}"
  	local name="$(gen_param_name "${arg}")"
  	local rw="write"
  
  	case "${type#c}" in
  	i) return;;
  	esac
  
  	# We don't write to constant parameters
  	[ ${type#c} != ${type} ] && rw="read"
  
  	printf "\tkasan_check_${rw}(${name}, sizeof(*${name}));
  "
  }
  
  #gen_param_check(arg...)
  gen_params_checks()
  {
  	while [ "$#" -gt 0 ]; do
  		gen_param_check "$1"
  		shift;
  	done
  }
  
  # gen_guard(meta, atomic, pfx, name, sfx, order)
  gen_guard()
  {
  	local meta="$1"; shift
  	local atomic="$1"; shift
  	local pfx="$1"; shift
  	local name="$1"; shift
  	local sfx="$1"; shift
  	local order="$1"; shift
  
  	local atomicname="arch_${atomic}_${pfx}${name}${sfx}${order}"
  
  	local template="$(find_fallback_template "${pfx}" "${name}" "${sfx}" "${order}")"
  
  	# We definitely need a preprocessor symbol for this atomic if it is an
  	# ordering variant, or if there's a generic fallback.
  	if [ ! -z "${order}" ] || [ ! -z "${template}" ]; then
  		printf "defined(${atomicname})"
  		return
  	fi
  
  	# If this is a base variant, but a relaxed variant *may* exist, then we
  	# only have a preprocessor symbol if the relaxed variant isn't defined
  	if meta_has_relaxed "${meta}"; then
  		printf "!defined(${atomicname}_relaxed) || defined(${atomicname})"
  	fi
  }
  
  #gen_proto_order_variant(meta, pfx, name, sfx, order, atomic, int, arg...)
  gen_proto_order_variant()
  {
  	local meta="$1"; shift
  	local pfx="$1"; shift
  	local name="$1"; shift
  	local sfx="$1"; shift
  	local order="$1"; shift
  	local atomic="$1"; shift
  	local int="$1"; shift
  
  	local atomicname="${atomic}_${pfx}${name}${sfx}${order}"
  
  	local guard="$(gen_guard "${meta}" "${atomic}" "${pfx}" "${name}" "${sfx}" "${order}")"
  
  	local ret="$(gen_ret_type "${meta}" "${int}")"
  	local params="$(gen_params "${int}" "${atomic}" "$@")"
  	local checks="$(gen_params_checks "$@")"
  	local args="$(gen_args "$@")"
  	local retstmt="$(gen_ret_stmt "${meta}")"
  
  	[ ! -z "${guard}" ] && printf "#if ${guard}
  "
  
  cat <<EOF
  static inline ${ret}
  ${atomicname}(${params})
  {
  ${checks}
  	${retstmt}arch_${atomicname}(${args});
  }
  #define ${atomicname} ${atomicname}
  EOF
  
  	[ ! -z "${guard}" ] && printf "#endif
  "
  
  	printf "
  "
  }
  
  gen_xchg()
  {
  	local xchg="$1"; shift
  	local mult="$1"; shift
  
  cat <<EOF
  #define ${xchg}(ptr, ...)						\\
  ({									\\
  	typeof(ptr) __ai_ptr = (ptr);					\\
  	kasan_check_write(__ai_ptr, ${mult}sizeof(*__ai_ptr));		\\
  	arch_${xchg}(__ai_ptr, __VA_ARGS__);				\\
  })
  EOF
  }
  
  gen_optional_xchg()
  {
  	local name="$1"; shift
  	local sfx="$1"; shift
  	local guard="defined(arch_${name}${sfx})"
  
  	[ -z "${sfx}" ] && guard="!defined(arch_${name}_relaxed) || defined(arch_${name})"
  
  	printf "#if ${guard}
  "
  	gen_xchg "${name}${sfx}" ""
  	printf "#endif
  
  "
  }
  
  cat << EOF
  // SPDX-License-Identifier: GPL-2.0
  
  // Generated by $0
  // DO NOT MODIFY THIS FILE DIRECTLY
  
  /*
   * This file provides wrappers with KASAN instrumentation for atomic operations.
   * To use this functionality an arch's atomic.h file needs to define all
   * atomic operations with arch_ prefix (e.g. arch_atomic_read()) and include
   * this file at the end. This file provides atomic_read() that forwards to
   * arch_atomic_read() for actual atomic operation.
   * Note: if an arch atomic operation is implemented by means of other atomic
   * operations (e.g. atomic_read()/atomic_cmpxchg() loop), then it needs to use
   * arch_ variants (i.e. arch_atomic_read()/arch_atomic_cmpxchg()) to avoid
   * double instrumentation.
   */
  #ifndef _ASM_GENERIC_ATOMIC_INSTRUMENTED_H
  #define _ASM_GENERIC_ATOMIC_INSTRUMENTED_H
  
  #include <linux/build_bug.h>
  #include <linux/kasan-checks.h>
  
  EOF
  
  grep '^[a-z]' "$1" | while read name meta args; do
  	gen_proto "${meta}" "${name}" "atomic" "int" ${args}
  done
  
  grep '^[a-z]' "$1" | while read name meta args; do
  	gen_proto "${meta}" "${name}" "atomic64" "s64" ${args}
  done
  
  for xchg in "xchg" "cmpxchg" "cmpxchg64"; do
  	for order in "" "_acquire" "_release" "_relaxed"; do
  		gen_optional_xchg "${xchg}" "${order}"
  	done
  done
  
  for xchg in "cmpxchg_local" "cmpxchg64_local" "sync_cmpxchg"; do
  	gen_xchg "${xchg}" ""
  	printf "
  "
  done
  
  gen_xchg "cmpxchg_double" "2 * "
  
  printf "
  
  "
  
  gen_xchg "cmpxchg_double_local" "2 * "
  
  cat <<EOF
  
  #endif /* _ASM_GENERIC_ATOMIC_INSTRUMENTED_H */
  EOF