ctf: allow dwarf2ctf to run as root but produce no output

This leads to no CTF file writes (and thus no writes) at all,
which is as safe as we can get as root: this is treated by the
makefiles as an empty CTF file.  The resulting module will
appear to DTrace to have no types.

The warning is still emitted (rephrased slightly).

Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Reviewed-by: Dhaval Giani <dhaval.giani@oracle.com>
Orabug: 27205676

diff --git a/scripts/dwarf2ctf/dwarf2ctf.c b/scripts/dwarf2ctf/dwarf2ctf.c
index 516812dbb944b5df5a7d85af2725f6191cae2df9..e33d519962f77cb1e29925745d74bf9e1f27661d 100644 (file)
--- a/scripts/dwarf2ctf/dwarf2ctf.c
+++ b/scripts/dwarf2ctf/dwarf2ctf.c
@@ -808,13 +808,18 @@ int main(int argc, char *argv[])
 {
        char *output;
 
-       trace = getenv("DWARF2CTF_TRACE");
-
        if (getuid() == 0 || geteuid() == 0) {
-               fprintf(stderr, "dwarf2ctf: run as a regular user, not root.\n");
-               exit(1);
+               fprintf(stderr, "dwarf2ctf: root run: doing nothing.\n");
+               fprintf(stderr, "CTF type information will not be produced.\n");
+               fprintf(stderr, "Please run as a non-root user.\n");
+               /*
+                * Refuse to produce any output.
+                */
+               exit(0);
        }
 
+       trace = getenv("DWARF2CTF_TRACE");
+
        if ((argc != 4 && argc != 7) ||
            (argc == 4 && strcmp(argv[2], "-e") != 0)) {
                fprintf(stderr, "Syntax: dwarf2ctf output-file srcdir "