[PATCH 5.12 094/161] wireguard: do not use -O3

From: Greg Kroah-Hartman
Date: Tue Jun 08 2021 - 15:23:51 EST


From: Jason A. Donenfeld <Jason@xxxxxxxxx>

commit cc5060ca0285efe2728bced399a1955a7ce808b2 upstream.

Apparently, various versions of gcc have O3-related miscompiles. Looking
at the difference between -O2 and -O3 for gcc 11 doesn't indicate
miscompiles, but the difference also doesn't seem so significant for
performance that it's worth risking.

Link: https://lore.kernel.org/lkml/CAHk-=wjuoGyxDhAF8SsrTkN0-YfCx7E6jUN3ikC_tn2AKWTTsA@xxxxxxxxxxxxxx/
Link: https://lore.kernel.org/lkml/CAHmME9otB5Wwxp7H8bR_i2uH2esEMvoBMC8uEXBMH9p0q1s6Bw@xxxxxxxxxxxxxx/
Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/wireguard/Makefile | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/net/wireguard/Makefile
+++ b/drivers/net/wireguard/Makefile
@@ -1,5 +1,4 @@
-ccflags-y := -O3
-ccflags-y += -D'pr_fmt(fmt)=KBUILD_MODNAME ": " fmt'
+ccflags-y := -D'pr_fmt(fmt)=KBUILD_MODNAME ": " fmt'
ccflags-$(CONFIG_WIREGUARD_DEBUG) += -DDEBUG
wireguard-y := main.o
wireguard-y += noise.o