KernelNewbies:

Roel Kluin

Email: <roel.kluin@gmail.com> ...


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This is my old page, see updated personal page for more recent scripts and snippets.

all code is (c) Roel kluin, 2007 GNU GPL V.2.

Examples

These may require the script 'vars' below sourced, and should be called in a git tree. I simply paste them into my console (bash).

Match Unlikely(x) ?= y

git-grep -n "\(un\)\?likely$s([^()]*\(([^()]*)[^()]*\)*)$s.="

These can be replaced with strchr:

E="\([^\"\\\\]\|\\\\[\\\\tnr\?'\"0bafv]\|\\\\[0-7]\{1,3\}\|\\\\[a-f0-9]\{1,2\}\|\\\\[A-F0-9]\{1,2\}\)"
git-grep -n "strstr$s($s$W$s,$s\"$E\"$s)"

Show module initializing functions, not using __init or similarly exit:

git-grep -n "\(void\|int\)${s}[[:alnum:]_]*module_[ei][xn]it(void)" | grep -v "__[ie][xn]it"

Matches if(function) BUG():

q="${s}if$s(\($ccode$Q\)\?$L$s($ccode)$s$ccode$s)"
git-grep -n -B1 "^\($q\)\?${s}BUG($s)$s;$cendl" | grep "$q$cendl" |
grep -v "\(sizeof\|unlikely\|likely\)($ccode)" | less

A sed script to audit ioremap/iounmap balancing (can be adapted for others):

git-grep -l '[^[:alnum:]]ioremap' | while read -r g; do
echo "--------------------------[ $g ]--------------------------"
sed -n "/[^[:alnum:]]ioremap.*(\(.*\))/,/^[}{]$/{
s/\(.*return.*\)/\1\t\t-------return/
tp
s/\(.*goto.*\)/\1\t\t------goto/
tp
s/\(.*iounmap.*\)/\1\t\t<----/
tp
s/\(.*ioremap.*\)/\1\t\t---->/
Tp
=
:p
p
}" $g
done | less

Make sure no-one is freeing skbs with kfree instead of kfree_skb:

for f in $(git-grep -l "struct${s}sk_buff"); do
sed -n "s/^.*struct${S}sk_buff${s}\*${s}\(${V}\)$Q.*$/\1/p" $f | sort | uniq | while read -r n; do
sed -n "/struct${s}sk_buff${s}\*${s}${n}/,/^[{}].*$/{ /kfree(${s}${n}${s})/= }" $f | while read -r q; do
echo -e "kfreeing sk_buff $n at line $q in $f\n$q";
sed -n "/struct${s}sk_buff${s}\*${s}${n}/,/^[{}].*$/p" $f;
done
done
done 2>&1 | less

matches a comparison as the last argument of a function. This may be correct but it is sometimes a misplaced check (and should be placed after the parenthesis instead). Use getcalls and/or getfunc to determine whether a boolean as the last argument is correct:

h="\(([^()]*)\)\+"; 
git-grep -n -A9 ",[^);,]*="  | 
sed -n "s/^\([^\.]*\.[chsS]-[0-9]*-\|\([^\.]*\.[chsS]:[0-9]*:\)$s\)\(.*\)$/\2\3/p" |
tr "\n" "@" |
grep -o "@[^@]*$W$s(\(\([^,()]*\|$h\)*,\)\+\([^,()]*\|$h\)*[^\"]=${s}[^\",()]*)${s}[)&|]" |
tr "@\t" " " | tr -s " " | less

Find values used as a boolean instead of the more common bitwise usage:

f1="\($W${s}[&|]\|[0-9]\+${s}[&|]\|)${s}[&|]\)" # adds 2
h="\(([^()]*\(([^()]*\(([^()]*)[^()]*\)*[^()]*)[^()]*\)*)\)\?"
git-grep "\($f1$s$V$s$h$s\(&&\|||\|)\|?\)\|\(&&\|||\|(\)$s$V$s$h${s}[&|]$s\([0-9]*\($W\|[^0]\)[0-9]*\)\)" | 
sed -n "s/^.*\($f1$s\($V\)$s\(([^()]*)\)\?$s\(&&\|||\|)\)\|\(&&\|||\|(\)$s\($V\)$s\(([^()]*)\)\?${s}[&|]$s\([0-9]*\($W\|[^0]\)[0-9]*\)\).*$/\4\8/p" |
while read -r n; do
echo "$n"; 
done | 
sort | uniq -c | sort -rn | while read -r n a; do
b=$(git-grep -n "\(\(\(if\|while\)$s(\|&&\|||\|\!\)$s$a$s\(&&\|||\|\|)?\|(\)\|\(&&\|||\|(\)$s$a$s\(&&\|||\|(\|?\)\)" |
grep -v "Kconfig")
[ -z "$b" ] && continue;
c=`echo "$b" | wc -l`
let d=$(($n/$c))
echo "----[ a=\"$a\" # used $n times as bitwise, $c times as boolean, div $d ]----"
[ $c -gt 20 ] && continue; [ $d -lt 5 ] && continue;
echo "$b"
done | less

catch tests below 0 on unsigned

# define what to search for
left_operator="\([;,|^?:(]\|[\!+*/%&|~^-]=\|>>=\|<<=\|\[\|&&\|$an_$s&\)"
right_operator="\([;,&|^?:)]\|[\!+*/%&|~^<>-]=\|>>=\|<<=\|>[^>]\|<[^<]\|\]\)"
variable="$s\(\(++\|--\)$w\|$w\(++\|--\)\|$w\)$s"
comparison="\(\(>=\|<\)${s}0\|\([><\!=]=\|[<>]\)$s-$s$D\)$s"
query="$left_operator$variable$comparison$right_operator"

arr="\(\[[^\]]*\]$s\)*"
attr="__attribute__$s(([^;]*))"
# for each unsigned typedefs
for ut in "unsigned" "unsigned long" $(
git-grep "^${s}typedef${S}unsigned$S\($V$S\)*\($V$s$arr\|$attr$S$V$s$arr\|$V$s$arr$S$attr\)$s;$cendl" | 
sed -n "s/^[^.]*\.[hc]:${s}typedef${S}unsigned$S\($V$S\)*\(\($V\)$s$arr\|$attr$S\($V\)$s$arr\|\($V\)$s$arr$S$attr\)$s;$cendl/\3\5\7/p" |
sort | uniq); do

# create the spatch
  cat > ../spatches/negative_unsigned.cocci << EOF
@@
constant C;
$ut i;
@@
(
* i < 0
|
* i < -C
|
* i > -C
|
* i <= -C
|
* i >= -C
)
EOF

  # find
  for f in $(git-grep -l "\(^\|$Q\)$ut\($Q\|$\)" | grep "[^.]*\.[ch]" | xargs grep -l "$query"); do
    spatch -quiet -all_includes -I ./include -sp_file ../spatches/negative_unsigned $f;
  done
done > ../spatch.log

to display the results of the previous patch as 'vi file +line' commands:

sed -n "s/^\(.\)\(-- \([^[:space:]]*\)[[:space:]]\|@ -\([0-9]*\),\|\).*$/\1 \3\4/p" ../spatch.log|
while read a b; do
  if [ "$a" = "-" ]; then
    if [ -f "$b" ]; then
      f="$b"
    elif [ -z "$b" ]; then
      echo "vi $f +$i";
      i=$(($i+1));
    fi
  elif [ "$a" = "@" ]; then
    i=$b;
  else
    i=$(($i+1));
  fi
done

Scripts

I called it vars, it contains some functions for kernel hacking. usage: "source path/to/vars" N.B. do not source this in a shell that you plan to use to compile a kernel ($Q is used in Makefiles as well, which will give some problems)

# (c) Roel kluin, 2008 GNU GPL V.2

alias gg="git-grep -n"

# Usage: v /path/to/sourcefile.c[:- ]linenr or 
# (as pasted from git-grep -n)
v()
{
  f="$1"
  [ $# -eq 2 ] && l=$2
  if [ ! -f "$f" ]; then
    l=${f##*[:-]};
    f="${f%[:-]*}";
  fi
  [ -f "$f" -a $l -gt 0 ] && vi "$f" +"$l";
}

export int="[0-9]"
export hex="[a-f0-9]"
export hEx="[A-Fa-f0-9]"
export HEX="[A-F0-9]"
export upp="[A-Z]"
export up_="[A-Z_]"
export low="[a-z0-9]"
export lo_="[a-z0-9_]"
export alp="[A-Za-z]"
export al_="[A-Za-z_]"
export ALN="[A-Z0-9]"
export AN_="[A-Z0-9_]"
export aln="[A-Za-z0-9]"
export an_="[A-Za-z0-9_]"
# to match something like 1ul, floats or hexes as well:
export D="$int*\.\?$int\+x\?$hex*[uUlL]\{0,3\}[fF]\?"

# more strict and catches it (costs one backreference for (git-)grep)
export d="\($int\+[uUlLfF]\?\|$int\+[uU]\?[lL][lL]\?\|0x$hex\+\|0x$HEX\+\|$i\+[lL][lL][uU]\|$i*\.$i\+[fF]\?\)"

# capital: can be used to catch a definition or config option
export K="$UP_\+$AN_*";

# can be used for a variable/function name:
export V="$al_\+$an_*"

# works the same as above, but also for members and arrays: one backreference
# is more strict
export W="$V\(\[$s$V$s\]\|\[$s$D$s\]\|\.$V\|->$V\)*"
# catches it at once (less strict)
export w="\($V\|${V}\[$s$an_*${s}\]\|$V\.\|$V->\)\+"

# seperators:
export s="[[:space:]]*";
export S="[[:space:]]\+"

# useful to delimit a variable name:
export Q="[^[:alnum:]_]"

# match the end of the line, including comments: one backreference (but at eol)
export cendl="$s\(\/[*\/].*\)\?$"

# match something that is not comment, string or character: 2 backreferences
export ccode="\([^\/\"']*\|\/[^*\/]\|\/\*\([^*]*\|\**[^*\/]\)*\*\+\/\|'[^']*'\|\"[^\"]*\"\)*"

# resp function open and end (only works when indentation is correct.
export fo="^[\{]$cendl"
export fe="^[\}]$cendl"

# to match nested parentheses
export nps="[^()]*"
export nstdps="\(($nps\(($nps\(($nps\(($nps\(($nps)$nps\)*)$nps\)*)$nps\)*)$nps\)*)$nps\)*"

# works similar to git-grep -n "$query" | tr ":" " "
# except that :'s in the line are preserved
ggrep2fnl()
{
  git-grep -n "$1" | while read -r fnl; do
    f="$(echo "$fnl"| cut -d":" -f1)";
    e="$(echo "$f" | rev | cut --complement -c3- | rev)";
    [ "$e" != ".h" -a "$e" != ".c" ] && continue;
    echo "$f $(echo "$fnl"| cut -d":" -f2) $(echo "$fnl"| cut -d":" -f3-)";
  done
}

#print function declaration at file "$1", line "$2"
# also works for /path/to/filename.c:nr
getfuncat()
{
  [ $# -ne 1 ] && return 1;
  f="${1%[:-]*}"
  [ ! -f "$f" ] && return 2;
  l="${1##*[:-]}"

  Z="[@[:space:]]"
  func="\($V$Z\+\)*${V}[*@[:space:]]\+$V$s($nps$nstdps)"
  eol="$Z*\($Z\|\/\/[^@]*@\|\/\*\([^*]*\|\**[^\/*]\)*\*\+\/\)*@{"
  head -n$l "$f" | tr "\n" "@" |
  sed -n "s/.*@\($func\)$eol.*/\1@/p" |
  tail -n1 | 
  tr "@" "\n"
}

#print function declaration(s)
getfunc()
{
  q="^\(${V}[*&[:space:]]\+\)*$1$s(${ccode}[^;]$cendl";
  ggrep2fnl "$q" | while read -r f n l; do
    [ -z "`echo $l | grep "{$cendl"`" -a \
         -n "`sed -n "$n,/{$cendl/{/;/p}" "$f"`" ] &&
      continue
    echo "//---[ vi $f +$n ]---"
    [ -n "`echo $l | grep "^$s$1"`" ] && 
      let "n--"
    sed -n "$n,/$fe/p" "$f"
  done
}

getstruct()
{
  q="^$s\($V$S\)*struct\(${S}__$V\($s($nps$nstdps)\)\?\)*$S$1\(${S}__$V\($s($nps$nstdps)\)\?\)*${s}[{]\?$cendl";
  ggrep2fnl "$q" | while read -r f n l; do
    [ -z "`echo $l | grep "{$cendl"`" -a \
         -n "`sed -n "$n,/{$cendl/{/;/p}" "$f"`" ] &&
      continue
    echo "//---[ vi $f +$n ]---"
    [ -n "`echo $l | grep "^$s$1"`" ] && 
      let "n--"
    sed -n "$n,/$se/p" "$f"
  done
}

getdef()
{
  del="[[:space:](]"
  sed_print=":a; /\\\\\\\\$/{N;ba}; p}"

  while getopts dmho Options; do
    case $Options in
      h) echo "getdef [options] DEFINITION_NAME(s)

print definition(s) / macro(s)

options
-d              print only definitions
-m              print only macros
-o              print as a single line (squeezes spaces)"
        return ;;
      d)
        del="[[:space:]]" ;;
      m)
        del="(" ;;
      o)
        sed_print=":a; /\\\\\\\\$/{N;ba}; s/\(\/\(\/.*\|\*\([^*]*\|\**[^\/]\)*\*\/$s\)\?\(\\\\\\\\\n\|$\)\|$S\)\+/ /g; s/^$S//g; p}" ;;
    esac
  done
while [ $OPTIND -gt 1 ]; do
  shift;
  OPTIND=$(($OPTIND-1));
done
  def="^$s#${s}define$S$1$del"
  for f in $(git-grep -l -I "$def"); do
    sed -n "/$def/,/[^\\\\]$/{/$def/=; $sed_print" "$f" |
    sed "/^[0-9]*$/s/^\([0-9]*\)$/\/\/---[ vi ${f//\//\\/} +\1 ]---/"
  done
}

# rparse [source.c]: prints contents with comments removed and extended lines joined.
rparse()
{
sed "
:a
s:\($S$S\|$s\n$s\): :
ta
/^$ccode\?\/\*/{
/^$ccode\?\/\*\([^*]*\|\**[^\/*]\)*\**$/N
s:^$ccode\?\/\*\([^*]*\|\**[^\/*]\)*\*\+\/$ccode\?:\1 \4:
ba
}
/^$ccode\?\/\//s:^$ccode\?\/\/.*$:\1:
s: $::
s:^ ::
/\\\\$s$/{
N
s:$s\\\\$s\n$s: :
ba
}
/^\([^#].*[^;{}]\)\?$/{
N
ba
}
" "$1"
}

# echoes "function name" at file "$1" line "$2"
det_func()
{
  q="^\(${V}[*&[:space:]]\+\)*\($V\)$s(${ccode}[^;]$cendl"
  head "$1" -n"$2" | tac | sed -n "/$q/{s/$q/\2/p;q}"
}

getcalls()
{
 git-grep -n "\(^\|^$ccode$Q\)$1$s(\($ccode\()$s;\|[^)]\|)$ccode)$ccode\)\)\?$cendl"
}

# get filename in git-diff with match $1 (matches from start of line)
# in after (default, $2 == "+") or before ($2 == "-") changes were made
gdfwm()
{
dil="+";
[ $# -eq 2 ] && dil="$2";
echo "$dil"
git-diff | grep "^\($dil\{3\}\|$dil$1$\)" | grep -B1 "^${dil}[^$dil]" | 
sed -n "s/^$dil\{3\} [^\/]*\/\([^\n]*\)$/\1/p"; 
}

# get filename and line in git-diff with match $1 (matches from start to end of line)
gdflwm()
{
git-diff |
sed -n "s/^\(.\)\(++ [^\/]*\/\(.*\)\|@ -[0-9]*,[0-9]* +\([0-9]*\),.*\|\($1\)\|.*\)$/\1 \3\4\5/p" |
while read a b; do
  if [ "$a" = "+" ]; then
    if [ -f "$b" ]; then
      f="$b"
    elif [ -n "$b" ]; then
      echo "$f $i";
      i=$(($i+1));
    fi
  elif [ "$a" = "@" ]; then
    i=$b;
  elif [ "$a" != "-" ]; then
    i=$(($i+1))
  fi
done
}

To translate a module name (as listed in modprobe -l or modinfo -n module) into a kernel .config option:

mod="${1%.ko}";
dir="${1%/*}";
sed -e :a -e '/\\$/N; s/\\\n//; ta' "${dir#*/kernel/}/Makefile" | \
sed -n "s/^obj-\$(CONFIG_\([A-Z0-9_]*\))\W*+=\W*"${mod##*/}"\.o$/\1/p";

Based on Linus' script to get the email address of a maintainer, I wrote this script to get the address of a list rather than a maintainers address for mailing.

git log --since="1 year ago"  "$@" | sed -n "s/^    .[-a-z]*by: \(.*\) <.*$/\1/p" |
sort | uniq | sort -n -r | while read -r name; do
        sed -n "/^P:[ \t]*.*$name/,/^$/{
                s/^L:[ \t]*\(.*\)$/\1/p
        }" ./MAINTAINERS
done | sort | uniq -c | sort -n -r | while read -r nr list; do
        tot=`grep -c "^L:\W*.*$list.*" ./MAINTAINERS`
        echo "`expr $nr / \( $tot + 1 \)` $nr $tot $list"
done | sort -r | cut -d " " -f2- | while read -r nr tot list; do
        echo -e "$nr/$tot Acks were commited by maintainers of list $list"
done

KernelNewbies: RoelKluin (last edited 2017-12-30 01:30:32 by localhost)