On 10/1/19 2:21 PM, Will Deacon wrote: > On Thu, Sep 26, 2019 at 10:43:40PM +0100, Vincenzo Frascino wrote: >> As reported by Will Deacon the following compilation warning appears >> during the compilation of the vdso32: >> >> 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 .../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); >> ^ >> >> This happens because few 64 bit compilation headers are included during >> the generation of vdso32. >> >> Fix the issue redefining the __tag_set function. >> >> Note: This fix is meant to be temporary, a more comprehensive solution >> based on the refactoring of the generic headers will be provided with a >> future patch set. At that point it will be possible to revert this patch. >> >> Cc: Will Deacon <[email protected]> >> Cc: Catalin Marinas <[email protected]> >> Signed-off-by: Vincenzo Frascino <[email protected]> >> --- >> arch/arm64/include/asm/memory.h | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/arch/arm64/include/asm/memory.h >> b/arch/arm64/include/asm/memory.h >> index b61b50bf68b1..c61b2eb50a3b 100644 >> --- a/arch/arm64/include/asm/memory.h >> +++ b/arch/arm64/include/asm/memory.h >> @@ -228,11 +228,14 @@ static inline unsigned long kaslr_offset(void) >> #define __tag_get(addr) 0 >> #endif /* CONFIG_KASAN_SW_TAGS */ >> >> +#ifdef __aarch64__ >> +/* Do not attempt to compile this code with compat vdso */ >> static inline const void *__tag_set(const void *addr, u8 tag) >> { >> u64 __addr = (u64)addr & ~__tag_shifted(0xff); >> return (const void *)(__addr | __tag_shifted(tag)); >> } >> +#endif > > Sorry, but I'm not taking this. > > I know you're trying to fix the issues I reported as quickly as you can (and > thank you for that), but I'm sure that you agree this needs more thought to > develop a proper solution to what is a much bigger issue than can be solved > by sprinkling #ifdefs. I can live with the warning on the basis that a > proper fix is in the pipeline, but in the meantime it can serve as a > reminder that we're not done here. >
This was my original preference as well, if we silence the warnings we tend to forget about them. Since you reported the issue as urgent, I reacted with something that fixes it temporarily, but I have not objections if you want to wait for a more comprehensive solution. > Will > -- Regards, Vincenzo
