Re: [PATCH 2/6] x86: Opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit

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 <redacted>
Signed-off-by: Thiago Macieira <redacted>
---
 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