2015-12-03 20:05 GMT+03:00 Johannes Berg <johannes@xxxxxxxxxxxxxxxx>: > On Thu, 2015-12-03 at 18:50 +0300, Andrey Ryabinin wrote: >> With upcoming CONFIG_UBSAN the following BUILD_BUG_ON in >> net/mac80211/debugfs.c starts to trigger: >> BUILD_BUG_ON(hw_flag_names[NUM_IEEE80211_HW_FLAGS] != (void >> *)0x1); >> >> It seems, that compiler instrumentation causes some code >> deoptimizations. >> Because of that GCC is not being able to resolve condition in >> BUILD_BUG_ON() >> at compile time. >> >> We could make size of hw_flag_names array unspecified and replace the >> condition in BUILD_BUG_ON() with following: >> ARRAY_SIZE(hw_flag_names) != NUM_IEEE80211_HW_FLAGS >> >> That will have the same effect as before (adding new flag without >> updating >> array will trigger build failure) except it doesn't fail with >> CONFIG_UBSAN. >> As a bonus this patch slightly decreases size of hw_flag_names array. >> > Seems fine, would you want to take it through some other tree together > with UBSAN, or do you expect that to still take long enough to allow > this to trickle through our trees? > I expect that Andrew will take it with UBSAN for 4.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
