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GCC warns about an unused result in trs_xinterface.c. The relevant line
is this.
setuid(getuid());
The web has scary things to say about the above.
https://c-skills.blogspot.com/2008/01/evilness-of-setuidgetuid.html
However, the fix seems easy. Here's why.
1. The code prior to the above call invokes trs_sound_init(), whose
entire body sits in an #ifdef SB_SOUND guard, and if SB_SOUND is
defined, plays around with I/O ports using ioperm(), inb(), and
outb();
2. Poking I/O ports is particular to x86 hardware;
3. Doing so requires root privileges;
4. xtrs is trying to _drop_ root privileges after doing this;
5. This functionality is predicated on having
SoundBlaster-compatible hardware installed;
6. The code preceding the trs_sound_init() call attempts to infer
some SoundBlaster card parameters from an X resource;
7. The corresponding command-line option for setting up a
SoundBlaster card is -sb, about which trs_cassette.c has to say:
"OSS_SOUND seems to work much better than SB_SOUND now, so
SB_SOUND is off by default and -sb has been removed from the
man page";
8. Nothing in the source code ever actually #defines SB_SOUND; you
would have to do it from Make, which Debian never has done.
Therefore, guard all this "Sb" resource reading stuff with #ifdef
SB_SOUND. Now it won't be compiled in to be complained about. Perhaps
all this SoundBlaster stuff should be "#if 0"ed or even deleted, but
I'll leave that up to upstream.
-- Branden Robinson, 2017-03-24T03:15:32-0400
--- a/trs_xinterface.c
+++ b/trs_xinterface.c
@@ -293,7 +293,7 @@
image.height = image.height * scale_y / 2;
image.bytes_per_line *= scale_x;
-#if __linux
+#if __linux && SB_SOUND
(void) sprintf(option, "%s%s", program_name, ".sb");
if (XrmGetResource(x_db, option, "Xtrs.Sb", &type, &value)) {
char *next; int ioport, vol;
@@ -305,7 +305,7 @@
}
}
setuid(getuid());
-#endif /* linux */
+#endif /* linux && SB_SOUND */
(void) sprintf(option, "%s%s", program_name, ".emtsafe");
if (XrmGetResource(x_db, option, "Xtrs.Emtsafe", &type, &value)) {
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