[Qemu-devel] [PATCH v2] tcg: Remove stack protection from helper functions

[Jan Kiszka <jan.kiszka@siemens.com>]

This increases the overhead of frequently executed helpers. We need to
move rule past QEMU_CFLAGS assignment to ensure that the required simple
assignment picks up all bits. The signal workaround is moved just for
the sake of consistency.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

Changes in v2:
 - unbreak qemu-user build

Maybe some real make guru has a nicer solution for removing the switch.

 Makefile.target |   17 +++++++++--------
 1 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/Makefile.target b/Makefile.target
index 88d2f1f..b545161 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -89,14 +89,6 @@ translate-all.o: translate-all.c cpu.h
 
 tcg/tcg.o: cpu.h
 
-# HELPER_CFLAGS is used for all the code compiled with static register
-# variables
-op_helper.o user-exec.o: QEMU_CFLAGS += $(HELPER_CFLAGS)
-
-# Note: this is a workaround. The real fix is to avoid compiling
-# cpu_signal_handler() in user-exec.c.
-signal.o: QEMU_CFLAGS += $(HELPER_CFLAGS)
-
 #########################################################
 # Linux user emulator target
 
@@ -387,6 +379,15 @@ obj-y += $(addprefix ../, $(trace-obj-y))
 
 endif # CONFIG_SOFTMMU
 
+# HELPER_CFLAGS is used for all the code compiled with static register
+# variables
+# NOTE: Must be after the last QEMU_CFLAGS assignment
+op_helper.o user-exec.o: QEMU_CFLAGS := $(subst -fstack-protector-all,,$(QEMU_CFLAGS)) $(HELPER_CFLAGS)
+
+# Note: this is a workaround. The real fix is to avoid compiling
+# cpu_signal_handler() in user-exec.c.
+signal.o: QEMU_CFLAGS += $(HELPER_CFLAGS)
+
 ifndef CONFIG_LINUX_USER
 ifndef CONFIG_BSD_USER
 # libcacard needs qemu-thread support, and besides is only needed by devices
-- 
1.7.3.4