# git rev-parse -q --verify 8d17c0c83c07bad137e2df3a45e9cd4e80d85418^{commit} 8d17c0c83c07bad137e2df3a45e9cd4e80d85418 already have revision, skipping fetch # git checkout -q -f -B kisskb 8d17c0c83c07bad137e2df3a45e9cd4e80d85418 # git clean -qxdf # < git log -1 # commit 8d17c0c83c07bad137e2df3a45e9cd4e80d85418 # Author: Ard Biesheuvel # Date: Wed Oct 28 09:04:33 2020 +0100 # # powerpc: Avoid broken GCC __attribute__((optimize)) # # Commit 7053f80d9696 ("powerpc/64: Prevent stack protection in early # boot") introduced a couple of uses of __attribute__((optimize)) with # function scope, to disable the stack protector in some early boot # code. # # Unfortunately, and this is documented in the GCC man pages [0], # overriding function attributes for optimization is broken, and is only # supported for debug scenarios, not for production: the problem appears # to be that setting GCC -f flags using this method will cause it to # forget about some or all other optimization settings that have been # applied. # # So the only safe way to disable the stack protector is to disable it # for the entire source file. # # [0] https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html # # Fixes: 7053f80d9696 ("powerpc/64: Prevent stack protection in early boot") # Signed-off-by: Ard Biesheuvel # [mpe: Drop one remaining use of __nostackprotector, reported by snowpatch] # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20201028080433.26799-1-ardb@kernel.org # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 8d17c0c83c07bad137e2df3a45e9cd4e80d85418 # < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_mpc885_ads_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- mpc885_ads_defconfig # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_mpc885_ads_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- INFO: Uncompressed kernel (size 0x40a3f0) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x500000) Image Name: Linux-5.10.0-rc1-g8d17c0c83c07 Created: Fri Oct 30 02:31:52 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2029776 Bytes = 1982.20 KiB = 1.94 MiB Load Address: 00500000 Entry Point: 00500204 Completed OK # rm -rf /kisskb/build/powerpc-next_mpc885_ads_defconfig_powerpc-gcc5 # Build took: 0:00:28.138658