On Wed, May 30, 2018 at 6:26 PM, Kees Cook <[email protected]> wrote: > On Wed, May 30, 2018 at 6:12 PM, Masahiro Yamada > <[email protected]> wrote: >> Hi. >> (+CC Kees) >> >> 2018-05-31 7:40 GMT+09:00 Stephen Rothwell <[email protected]>: >>> Hi Masahiro, >>> >>> After merging the kbuild tree, today's linux-next build (x86_64 >>> allmodconfig) produced these warnings: >>> >>> drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function >>> 'wlc_phy_workarounds_nphy_rev7': >>> drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c:16563:1: >>> warning: the frame size of 3136 bytes is larger than 2048 bytes >>> [-Wframe-larger-than=] >>> } >>> ^ >>> drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function >>> 'wlc_phy_workarounds_nphy_rev3': >>> drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c:16905:1: >>> warning: the frame size of 2872 bytes is larger than 2048 bytes >>> [-Wframe-larger-than=] >>> } >>> ^ >>> drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function >>> 'wlc_phy_cal_txiqlo_nphy': >>> drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c:26033:1: >>> warning: the frame size of 2432 bytes is larger than 2048 bytes >>> [-Wframe-larger-than=] >>> } >>> ^ >>> >>> I have no idea what caused these warnings to appear ... nothing in those >>> functions looks too bad. >> >> >> This has been triggered by the following commit: >> >> >> commit 0e461945f3504e09b8ecf947b6398adce1287a28 >> Author: Masahiro Yamada <[email protected]> >> Date: Mon May 28 18:22:07 2018 +0900 >> >> gcc-plugins: allow to enable GCC_PLUGINS for COMPILE_TEST >> >> >> >> CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL was previously disabled >> for COMPILE_TEST, which is now enabled. > > Weird -- I do build tests with plugins enabled pretty regularly. I > hadn't seen this before. I'll see if I can figure out what the > combination is...
Weirdly, I only see this after merging kbuild/for-next into next-20180530. (I don't get the warning if I just force the plugins on.) Regardless, I can confirm that CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL trips it. I'll investigate more tomorrow... -Kees -- Kees Cook Pixel Security
