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_tn2AKW... Link: https://lore.kernel.org/lkml/CAHmME9otB5Wwxp7H8bR_i2uH2esEMvoBMC8uEXBMH9p0q1... Reported-by: Linus Torvalds torvalds@linux-foundation.org Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com --- drivers/net/wireguard/Makefile | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/net/wireguard/Makefile b/drivers/net/wireguard/Makefile index fc52b2cb500b..dbe1f8514efc 100644 --- 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