[PATCH 1/2] tools/nolibc: fix verrx() and errx() message formatting

[Danish Khateeb]

verrx() passes its va_list to warnx() instead of vwarnx(). warnx() is
variadic, so it takes the va_list as its first and only argument, and
the conversions in the format string print the va_list itself and then
whatever is left in the following argument slots. On x86_64, for
instance,

	errx(1, "int args: %d %d %d", 1, 2, 3);

prints something like "int args: -1699009032 1 2", where the first
number comes from the address of the va_list and changes from run to
run, and

	errx(1, "%d %s", 1234, "foo");

crashes with SIGSEGV, as "%s" takes a leftover argument slot for the
string. errx() goes through verrx(), so every message with arguments
printed by either of them is wrong.

Call vwarnx(), as verr() calls vwarn().

Fixes: 9da0f529c089 ("tools/nolibc: add err.h")
Assisted-by: LLM
Signed-off-by: Danish Khateeb <danishkhateeb03@xxxxxxxxx>
---
 tools/include/nolibc/err.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/include/nolibc/err.h b/tools/include/nolibc/err.h
index e22ae87a7289..61978d537ed8 100644
--- a/tools/include/nolibc/err.h
+++ b/tools/include/nolibc/err.h
@@ -60,7 +60,7 @@ void verr(int eval, const char *fmt, va_list args)
 static __attribute__((noreturn, unused))
 void verrx(int eval, const char *fmt, va_list args)
 {
-	warnx(fmt, args);
+	vwarnx(fmt, args);
 	exit(eval);
 }
 
-- 
2.55.0