Hi Will, thank you for reporting this.
On 20/09/2019 15:27, Will Deacon wrote: > Hi Vincenzo, > > I've been running into a few issues with the COMPAT vDSO. Please could > you have a look? > I will be at Linux Recipes next week. I will look at this with priority when I come back. > If I do the following: > > $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig > [...] > $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig > [set CONFIG_CROSS_COMPILE_COMPAT_VDSO="arm-linux-gnueabihf-"] > $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- > > Then I see the following warning: > > arch/arm64/Makefile:62: CROSS_COMPILE_COMPAT not defined or empty, the compat > vDSO will not be built > > even though the compat vDSO *has* been built: > > $ file arch/arm64/kernel/vdso32/vdso.so > arch/arm64/kernel/vdso32/vdso.so: ELF 32-bit LSB pie executable, ARM, EABI5 > version 1 (SYSV), dynamically linked, > BuildID[sha1]=c67f6c786f2d2d6f86c71f708595594aa25247f6, stripped > > However, I also get some warnings because arm64 headers are being included > in the compat vDSO build: > > In file included from ./arch/arm64/include/asm/thread_info.h:17:0, > from ./include/linux/thread_info.h:38, > from ./arch/arm64/include/asm/preempt.h:5, > from ./include/linux/preempt.h:78, > from ./include/linux/spinlock.h:51, > from ./include/linux/seqlock.h:36, > from ./include/linux/time.h:6, > from > /usr/local/google/home/willdeacon/work/linux/lib/vdso/gettimeofday.c:7, > from <command-line>:0: > ./arch/arm64/include/asm/memory.h: In function ‘__tag_set’: > ./arch/arm64/include/asm/memory.h:233:15: warning: cast from pointer to > integer of different size [-Wpointer-to-int-cast] > u64 __addr = (u64)addr & ~__tag_shifted(0xff); > ^ > In file included from ./arch/arm64/include/asm/pgtable-hwdef.h:8:0, > from ./arch/arm64/include/asm/processor.h:34, > from ./arch/arm64/include/asm/elf.h:118, > from ./include/linux/elf.h:5, > from ./include/linux/elfnote.h:62, > from arch/arm64/kernel/vdso32/note.c:11: > ./arch/arm64/include/asm/memory.h: In function ‘__tag_set’: > ./arch/arm64/include/asm/memory.h:233:15: warning: cast from pointer to > integer of different size [-Wpointer-to-int-cast] > u64 __addr = (u64)addr & ~__tag_shifted(0xff); > ^ > Worse, if your compat binutils isn't up-to-date, you'll actually run into > a build failure: > > /tmp/ccFCrjUg.s:80: Error: invalid barrier type -- `dmb ishld' > /tmp/ccFCrjUg.s:124: Error: invalid barrier type -- `dmb ishld' > > There also appears to be a problem getting the toolchain prefix from Kconfig. > If, for example, I do: > > $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig > [...] > $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig > [set CONFIG_CROSS_COMPILE_COMPAT_VDSO="vincenzo"] > $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- > arch/arm64/Makefile:64: *** vincenzogcc not found, check > CROSS_COMPILE_COMPAT. Stop. > $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig > [set CONFIG_CROSS_COMPILE_COMPAT_VDSO="arm-linux-gnueabihf-"] > $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- > arch/arm64/Makefile:64: *** vincenzogcc not found, check > CROSS_COMPILE_COMPAT. Stop. > $ grep CONFIG_CROSS_COMPILE_COMPAT_VDSO .config > CONFIG_CROSS_COMPILE_COMPAT_VDSO="arm-linux-gnueabihf-" > > which is irritating, because it seems to force a 'mrproper' if you don't > get the prefix right first time. > > Cheers, > > Will > -- Regards, Vincenzo
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Description: application/pgp-keys
