kernel-doc: fix syscall wrapper processing

Fix kernel-doc processing of SYSCALL wrappers.

The SYSCALL wrapper patches played havoc with kernel-doc for
syscalls.  Syscalls that were scanned for DocBook processing
reported warnings like this one, for sys_tgkill:

Warning(kernel/signal.c:2285): No description found for parameter 'tgkill'
Warning(kernel/signal.c:2285): No description found for parameter 'pid_t'
Warning(kernel/signal.c:2285): No description found for parameter 'int'

because the macro parameters all "look like" function parameters,
although they are not:

/**
 *  sys_tgkill - send signal to one specific thread
 *  @tgid: the thread group ID of the thread
 *  @pid: the PID of the thread
 *  @sig: signal to be sent
 *
 *  This syscall also checks the @tgid and returns -ESRCH even if the PID
 *  exists but it's not belonging to the target process anymore. This
 *  method solves the problem of threads exiting and PIDs getting reused.
 */
SYSCALL_DEFINE3(tgkill, pid_t, tgid, pid_t, pid, int, sig)
{
...

This patch special-cases the handling SYSCALL_DEFINE* function
prototypes by expanding them to
	long sys_foobar(type1 arg1, type1 arg2, ...)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/scripts/kernel-doc b/scripts/kernel-doc
index 8bb83a1..0f11870 100755 (executable)
--- a/scripts/kernel-doc
+++ b/scripts/kernel-doc
@@ -1827,6 +1827,40 @@ sub reset_state {
     $state = 0;
 }
 
+sub syscall_munge() {
+       my $void = 0;
+
+       $prototype =~ s@[\r\n\t]+@ @gos; # strip newlines/CR's/tabs
+##     if ($prototype =~ m/SYSCALL_DEFINE0\s*\(\s*(a-zA-Z0-9_)*\s*\)/) {
+       if ($prototype =~ m/SYSCALL_DEFINE0/) {
+               $void = 1;
+##             $prototype = "long sys_$1(void)";
+       }
+
+       $prototype =~ s/SYSCALL_DEFINE.*\(/long sys_/; # fix return type & func name
+       if ($prototype =~ m/long (sys_.*?),/) {
+               $prototype =~ s/,/\(/;
+       } elsif ($void) {
+               $prototype =~ s/\)/\(void\)/;
+       }
+
+       # now delete all of the odd-number commas in $prototype
+       # so that arg types & arg names don't have a comma between them
+       my $count = 0;
+       my $len = length($prototype);
+       if ($void) {
+               $len = 0;       # skip the for-loop
+       }
+       for (my $ix = 0; $ix < $len; $ix++) {
+               if (substr($prototype, $ix, 1) eq ',') {
+                       $count++;
+                       if ($count % 2 == 1) {
+                               substr($prototype, $ix, 1) = ' ';
+                       }
+               }
+       }
+}
+
 sub process_state3_function($$) {
     my $x = shift;
     my $file = shift;
@@ -1839,11 +1873,15 @@ sub process_state3_function($$) {
     elsif ($x =~ /([^\{]*)/) {
        $prototype .= $1;
     }
+
     if (($x =~ /\{/) || ($x =~ /\#\s*define/) || ($x =~ /;/)) {
        $prototype =~ s@/\*.*?\*/@@gos; # strip comments.
        $prototype =~ s@[\r\n]+@ @gos; # strip newlines/cr's.
        $prototype =~ s@^\s+@@gos; # strip leading spaces
-       dump_function($prototype,$file);
+       if ($prototype =~ /SYSCALL_DEFINE/) {
+               syscall_munge();
+       }
+       dump_function($prototype, $file);
        reset_state();
     }
 }