From c1bd55f922a2df6038060ed48a82d146d301ca12 Mon Sep 17 00:00:00 2001 From: Josh Triplett Date: Tue, 30 Jun 2015 15:00:00 -0700 Subject: [PATCH] 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. Patch co-authored by Josh Triplett and Thiago Macieira. Signed-off-by: Josh Triplett Acked-by: Andy Lutomirski Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Thiago Macieira Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/Kconfig | 1 + arch/x86/kernel/process_32.c | 6 +++--- arch/x86/kernel/process_64.c | 8 ++++---- 3 files changed, 8 insertions(+), 7 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 47365c7b9f47..55bced17dc95 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -88,6 +88,7 @@ config X86 select HAVE_CMPXCHG_DOUBLE select HAVE_CMPXCHG_LOCAL select HAVE_CONTEXT_TRACKING if X86_64 + select HAVE_COPY_THREAD_TLS select HAVE_C_RECORDMCOUNT select HAVE_DEBUG_KMEMLEAK select HAVE_DEBUG_STACKOVERFLOW diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index c09c99ccf3e3..f73c962fe636 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -128,8 +128,8 @@ void release_thread(struct task_struct *dead_task) release_vm86_irqs(dead_task); } -int copy_thread(unsigned long clone_flags, unsigned long sp, - unsigned long arg, struct task_struct *p) +int copy_thread_tls(unsigned long clone_flags, unsigned long sp, + unsigned long arg, struct task_struct *p, unsigned long tls) { struct pt_regs *childregs = task_pt_regs(p); struct task_struct *tsk; @@ -184,7 +184,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, */ if (clone_flags & CLONE_SETTLS) err = do_set_thread_area(p, -1, - (struct user_desc __user *)childregs->si, 0); + (struct user_desc __user *)tls, 0); if (err && p->thread.io_bitmap_ptr) { kfree(p->thread.io_bitmap_ptr); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 843f92e4c711..71d7849a07f7 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -150,8 +150,8 @@ static inline u32 read_32bit_tls(struct task_struct *t, int tls) return get_desc_base(&t->thread.tls_array[tls]); } -int copy_thread(unsigned long clone_flags, unsigned long sp, - unsigned long arg, struct task_struct *p) +int copy_thread_tls(unsigned long clone_flags, unsigned long sp, + unsigned long arg, struct task_struct *p, unsigned long tls) { int err; struct pt_regs *childregs; @@ -207,10 +207,10 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, #ifdef CONFIG_IA32_EMULATION if (is_ia32_task()) err = do_set_thread_area(p, -1, - (struct user_desc __user *)childregs->si, 0); + (struct user_desc __user *)tls, 0); else #endif - err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8); + err = do_arch_prctl(p, ARCH_SET_FS, tls); if (err) goto out; }