kbuild: stop docproc segfaulting when SRCTREE isn't set.

Prevent docproc from segfaulting when SRCTREE isn't set.

Signed-off-by: Rob Landley <rob@landley.net>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

1 files changed, 9 insertions, 2 deletions

diff --git a/scripts/basic/docproc.c b/scripts/basic/docproc.c
index e5c6ac7bde9b..0e4bd5459df4 100644
--- a/scripts/basic/docproc.c
+++ b/scripts/basic/docproc.c
@@ -66,12 +66,15 @@ FILELINE * entity_system;
 #define FUNCTION      "-function"
 #define NOFUNCTION    "-nofunction"
 
+char *srctree;
+
 void usage (void)
 {
         fprintf(stderr, "Usage: docproc {doc|depend} file\n");
         fprintf(stderr, "Input is read from file.tmpl. Output is sent to stdout\n");
         fprintf(stderr, "doc: frontend when generating kernel documentation\n");
         fprintf(stderr, "depend: generate list of files referenced within file\n");
+        fprintf(stderr, "Environment variable SRCTREE: absolute path to kernel source tree.\n");
 }
 
 /*
@@ -90,7 +93,7 @@ void exec_kernel_doc(char **svec)
                         exit(1);
                 case  0:
                         memset(real_filename, 0, sizeof(real_filename));
-                        strncat(real_filename, getenv("SRCTREE"), PATH_MAX);
+                        strncat(real_filename, srctree, PATH_MAX);
                         strncat(real_filename, KERNELDOCPATH KERNELDOC,
                                         PATH_MAX - strlen(real_filename));
                         execvp(real_filename, svec);
@@ -171,7 +174,7 @@ void find_export_symbols(char * filename)
         if (filename_exist(filename) == NULL) {
                 char real_filename[PATH_MAX + 1];
                 memset(real_filename, 0, sizeof(real_filename));
-                strncat(real_filename, getenv("SRCTREE"), PATH_MAX);
+                strncat(real_filename, srctree, PATH_MAX);
                 strncat(real_filename, filename,
                                 PATH_MAX - strlen(real_filename));
                 sym = add_new_file(filename);
@@ -338,6 +341,10 @@ void parse_file(FILE *infile)
 int main(int argc, char *argv[])
 {
         FILE * infile;
+
+        srctree = getenv("SRCTREE");
+        if (!srctree)
+                srctree = getcwd(NULL, 0);
         if (argc != 3) {
                 usage();
                 exit(1);