sys/linux: use nested flag definitions where sensible

All flags that are subset of other flags were identified with the
following Bash script [1]. Only a small set of flags identified by the
script were rewritten to use nested flag definitions, after manually
checking if it makes sense (based on syzkaller context and man pages).

For example, msgget_flags was rewritten as follows:

    -msgget_flags = IPC_CREAT, IPC_EXCL, S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IWGRP, S_IXGRP, S_IROTH, S_IWOTH, S_IXOTH
    +msgget_flags = IPC_CREAT, IPC_EXCL, open_mode

According to the msgget(2) man page:

    Upon creation, the least significant bits of the argument msgflg
    define the permissions of the message queue.  These permission bits
    have the same format and semantics as the permissions specified for
    the mode argument of open(2).

So it is correct to use open_mode directly in the definition of the
flags for msgget(2).

1 -

    #!/bin/bash

    regexp_flags="^(\w+)\s*=\s+([a-zA-Z\"][^=]*)$"

    is_subset() {
      local -n subset=$1
      local -n superset=$2
      for element in "${subset[@]}"; do
        if [[ ! " ${superset[@]} " =~ " $element " ]]; then
          return 1
        fi
      done
      return 0
    }

    declare -A parsed_lines

    while IFS= read -r line; do
      if [[ ! "$line" =~ $regexp_flags ]]; then
        continue
      fi
      list_name="${BASH_REMATCH[1]}"
      values="${BASH_REMATCH[2]}"
      IFS=',' read -r -a values_array <<< "$(echo "$values" | sed 's/ //g' | tr ',' '\n' | sort | tr '\n' ',')"

      # Skip flags with too few value.
      if [ "${#values_array[@]}" -lt 3 ]; then
        continue
      fi
      # Skip the syz0, syz1, etc. lists.
      if [ "${values_array[0]}" = "\"syz0\"" ]; then
        continue
      fi
      parsed_lines["${list_name}"]="${values_array[@]}"
    done

    for list_name in "${!parsed_lines[@]}"; do
      values_array=(${parsed_lines["$list_name"]})
      for other_list_name in "${!parsed_lines[@]}"; do
        other_values_array=(${parsed_lines["$other_list_name"]})
        if [ "$list_name" = "$other_list_name" ]; then
          continue
        fi

        if is_subset values_array other_values_array; then
          if [ "${#values_array[@]}" -eq "${#other_values_array[@]}" ]; then
            echo "$list_name EQUALS $other_list_name"
          else
            echo "$list_name is a SUBET of $other_list_name"
          fi
        fi
      done
    done

Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/sys/linux/ipc.txt b/sys/linux/ipc.txt
index 12b6dbbce..12fe7e582 100644
--- a/sys/linux/ipc.txt
+++ b/sys/linux/ipc.txt
@@ -70,14 +70,14 @@ shmctl$SHM_LOCK(shmid ipc_shm, cmd const[SHM_LOCK])
 shmctl$SHM_UNLOCK(shmid ipc_shm, cmd const[SHM_UNLOCK])
 shmdt(addr shmaddr)
 
-msgget_flags = IPC_CREAT, IPC_EXCL, S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IWGRP, S_IXGRP, S_IROTH, S_IWOTH, S_IXOTH
+msgget_flags = IPC_CREAT, IPC_EXCL, open_mode
 msgbuf_type = 0, 1, 2, 3
 msgsnd_flags = IPC_NOWAIT
 msgrcv_flags = IPC_NOWAIT, MSG_EXCEPT, MSG_NOERROR
-semget_flags = IPC_CREAT, IPC_EXCL, S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IWGRP, S_IXGRP, S_IROTH, S_IWOTH, S_IXOTH
+semget_flags = IPC_CREAT, IPC_EXCL, open_mode
 semop_flags = IPC_NOWAIT, SEM_UNDO
 sem_sem_id = 0, 1, 2, 3, 4
-shmget_flags = IPC_CREAT, IPC_EXCL, SHM_HUGETLB, SHM_HUGE_2MB, SHM_HUGE_1GB, SHM_NORESERVE, S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IWGRP, S_IXGRP, S_IROTH, S_IWOTH, S_IXOTH
+shmget_flags = IPC_CREAT, IPC_EXCL, SHM_HUGETLB, SHM_HUGE_2MB, SHM_HUGE_1GB, SHM_NORESERVE, open_mode
 shmat_flags = SHM_RND, SHM_RDONLY, SHM_REMAP
 
 ipc_perm {