| Message ID | 20190710130452.44111-1-vincenzo.frascino@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: vdso: Fix ABI regression in compat vdso | expand |
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 <john.stultz@linaro.org> > Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> > --- > 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
On 10/07/2019 14:25, Will Deacon wrote: > 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 <john.stultz@linaro.org> >> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> >> --- >> 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 ? > Yes, I realized it after I pushed the patch that CONFIG_GENERIC_COMPAT_VDSO can be removed. Posting v2 shortly. > John -- can you give this a whirl, please? > > Cheers, > > Will >
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) #define COMPAT_ARCH_DLINFO \ do { \ /* \
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. Reported-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> --- arch/arm64/include/asm/elf.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)