[PATCH v2 2/7] x86: Opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit
From: Josh Triplett <hidden>
Date: 2015-03-15 07:59:37
Also in:
linux-fsdevel, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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> Acked-by: Andy Lutomirski <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 ALIGN
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 603c4f9..ead28ff 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c@@ -129,8 +129,8 @@ 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;
@@ -185,7 +185,7 @@ 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 67fcc43..c69cabc 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c@@ -151,8 +151,8 @@ 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;
@@ -209,10 +209,10 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, #ifdef CONFIG_IA32_EMULATION if (test_thread_flag(TIF_IA32)) 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; }
--
2.1.4