[klibc] [klibc:master] zalloc: Fix infinite recursion with Clang 14

[klibc-bot for Ben Hutchings]

Commit-ID:  eec04ea422f69d09288da8475c82e030c0300a60
Gitweb:     http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=eec04ea422f69d09288da8475c82e030c0300a60
Author:     Ben Hutchings <ben at decadent.org.uk>
AuthorDate: Sun, 2 Oct 2022 00:23:26 +0200
Committer:  Ben Hutchings <ben at decadent.org.uk>
CommitDate: Sun, 2 Oct 2022 00:27:43 +0200

[klibc] zalloc: Fix infinite recursion with Clang 14

zalloc() calls malloc() followed by memset(), which Clang 14 optimises
to a call to calloc().  But our calloc() calls zalloc(), so this
results in recursion until the stack is exhausted.  Use the option
-fno-builtin-malloc to inhibit this optimisation for zalloc.c.

Signed-off-by: Ben Hutchings <ben at decadent.org.uk>

---
 usr/klibc/Kbuild | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/usr/klibc/Kbuild b/usr/klibc/Kbuild
index 973b0c81..eb13a70e 100644
--- a/usr/klibc/Kbuild
+++ b/usr/klibc/Kbuild
@@ -89,6 +89,10 @@ endif
 KLIBCCFLAGS_sprintf.o += $(call cc-option,-Wno-format-truncation, )
 KLIBCCFLAGS_vsprintf.o += $(call cc-option,-Wno-format-truncation, )
 
+# Clang 14 optimises zalloc() to recursively call calloc(), without
+# this option
+KLIBCCFLAGS_zalloc.o += $(call cc-option,-fno-builtin-malloc, )
+
 # sigsuspend.c includes <klibc/havesyscall.h> generated by syscalls/
 # build, so require that to build first
 $(obj)/sigsuspend.o: $(obj)/syscalls/klib.list