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authorJosh Triplett <josh@joshtriplett.org>2015-07-01 01:00:00 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-07-01 05:45:01 +0300
commitc1bd55f922a2df6038060ed48a82d146d301ca12 (patch)
treed8665f69bbae52c8f10206550b483433b2348d2b /arch/x86
parent2026302909b5dc1b3834a89654315abd8b4e040c (diff)
downloadlinux-c1bd55f922a2df6038060ed48a82d146d301ca12.tar.xz
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>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/kernel/process_32.c6
-rw-r--r--arch/x86/kernel/process_64.c8
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;
}