On Wed, Jul 10, 2019 at 02:04:52PM +0100, Vincenzo Frascino wrote: > Prior to the introduction of Unified vDSO support and compat layer for > vDSO on arm64, AT_SYSINFO_EHDR was not defined for compat tasks. > In the current implementation, AT_SYSINFO_EHDR is defined even if the > compat vdso layer is not built and this causes a regression in the > expected behavior of the ABI. > > Restore the ABI behavior making sure that AT_SYSINFO_EHDR for compat > tasks is defined only when CONFIG_GENERIC_COMPAT_VDSO and > CONFIG_COMPAT_VDSO are enabled.
I think you could do a better job in the changelog of explaining what's actually going on here. The problem seems to be that you're advertising the presence of a non-existent vDSO to userspace. > Reported-by: John Stultz <[email protected]> > Signed-off-by: Vincenzo Frascino <[email protected]> > --- > arch/arm64/include/asm/elf.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h > index 3c7037c6ba9b..b7992bb9d414 100644 > --- a/arch/arm64/include/asm/elf.h > +++ b/arch/arm64/include/asm/elf.h > @@ -202,7 +202,7 @@ typedef compat_elf_greg_t > compat_elf_gregset_t[COMPAT_ELF_NGREG]; > ({ \ > set_thread_flag(TIF_32BIT); \ > }) > -#ifdef CONFIG_GENERIC_COMPAT_VDSO > +#if defined(CONFIG_COMPAT_VDSO) && defined(CONFIG_GENERIC_COMPAT_VDSO) Can't this just be #ifdef CONFIG_COMPAT_VDSO ? John -- can you give this a whirl, please? Cheers, Will
