arm: Implement copy_thread_tls

commit 167ee0b82429cb5df272808c7a21370b7c961ab2 upstream.

This is required for clone3 which passes the TLS value through a
struct rather than a register.

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: <stable@vger.kernel.org> # 5.3.x
Link: https://lore.kernel.org/r/20200102172413.654385-4-amanieu@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8a50efb559f35a2c75f6fa379f34e4580e6c5a8d..39002d769d956bb66d692e9698fa533f4176c1c3 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -73,6 +73,7 @@ config ARM
        select HAVE_ARM_SMCCC if CPU_V7
        select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
        select HAVE_CONTEXT_TRACKING
+       select HAVE_COPY_THREAD_TLS
        select HAVE_C_RECORDMCOUNT
        select HAVE_DEBUG_KMEMLEAK
        select HAVE_DMA_CONTIGUOUS if MMU

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 9485acc520a413451f0b925276c81c8d23a00d3f..e7fac125ea0d50c44307bf0e324c0edef67f48dc 100644 (file)
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -224,8 +224,8 @@ void release_thread(struct task_struct *dead_task)
 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 
 int
-copy_thread(unsigned long clone_flags, unsigned long stack_start,
-           unsigned long stk_sz, struct task_struct *p)
+copy_thread_tls(unsigned long clone_flags, unsigned long stack_start,
+           unsigned long stk_sz, struct task_struct *p, unsigned long tls)
 {
        struct thread_info *thread = task_thread_info(p);
        struct pt_regs *childregs = task_pt_regs(p);
@@ -259,7 +259,7 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start,
        clear_ptrace_hw_breakpoint(p);
 
        if (clone_flags & CLONE_SETTLS)
-               thread->tp_value[0] = childregs->ARM_r3;
+               thread->tp_value[0] = tls;
        thread->tp_value[1] = get_tpuser();
 
        thread_notify(THREAD_NOTIFY_COPY, thread);