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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 <josh@joshtriplett.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thiago Macieira <thiago.macieira@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Josh Triplett 2015-06-30 15:00:00 -07:00 committed by Linus Torvalds
parent 2026302909
commit c1bd55f922
3 changed files with 8 additions and 7 deletions
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1
arch/x86/Kconfig
View File

@ -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

6
arch/x86/kernel/process_32.c
View File

@ -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);

8
arch/x86/kernel/process_64.c
View File

@ -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;
}