On Thu, Mar 12, 2015 at 6:40 PM, Josh Triplett <josh@xxxxxxxxxxxxxxxx> wrote: > For 32-bit userspace on a 64-bit kernel, this requires modifying > stub32_clone to actually swap the appropriate arguments to match > CONFIG_CLONE_BACKWARDS, rather than just leaving the C argument for tls > broken. > > Signed-off-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx> > Signed-off-by: Thiago Macieira <thiago.macieira@xxxxxxxxx> > --- > arch/x86/Kconfig | 1 + > arch/x86/ia32/ia32entry.S | 2 +- > arch/x86/kernel/process_32.c | 6 +++--- > arch/x86/kernel/process_64.c | 8 ++++---- > 4 files changed, 9 insertions(+), 8 deletions(-) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index b7d31ca..4960b0d 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -124,6 +124,7 @@ config X86 > select MODULES_USE_ELF_REL if X86_32 > select MODULES_USE_ELF_RELA if X86_64 > select CLONE_BACKWARDS if X86_32 > + select HAVE_COPY_THREAD_TLS > select ARCH_USE_BUILTIN_BSWAP > select ARCH_USE_QUEUE_RWLOCK > select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION > diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S > index 156ebca..0286735 100644 > --- a/arch/x86/ia32/ia32entry.S > +++ b/arch/x86/ia32/ia32entry.S > @@ -487,7 +487,7 @@ GLOBAL(\label) > ALIGN > GLOBAL(stub32_clone) > leaq sys_clone(%rip),%rax > - mov %r8, %rcx > + xchg %r8, %rcx > jmp ia32_ptregs_common Do I understand correct that whatever function this is a stub for just takes its arguments in the wrong order? If so, can we just fix it instead of using xchg here? In general, I much prefer C code to new asm where it makes sense to make this tradeoff. Other than that, this is a huge improvement. You'll have minor conflicts against -tip, though. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
