riscv: Implement copy_thread_tls

BugLink: https://bugs.launchpad.net/bugs/1862227
commit 20bda4ed62f507ed72e30e817b43c65fdba60be7 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-riscv@lists.infradead.org
Cc: <stable@vger.kernel.org> # 5.3.x
Link: https://lore.kernel.org/r/20200102172413.654385-6-amanieu@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 59a4727ecd6c074672e82d8bb4ec7638912957f6..6520f36d859c297bdc848f294702b0adcf52e958 100644 (file)
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -54,6 +54,7 @@ config RISCV
        select EDAC_SUPPORT
        select ARCH_HAS_GIGANTIC_PAGE
        select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
+       select HAVE_COPY_THREAD_TLS
 
 config MMU
        def_bool y

diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index fb3a082362eb87554ff297f3e026d9663c5a8044..b90610fcc6b4cf73d04be6e13416c2518ecddae9 100644 (file)
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -97,8 +97,8 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
        return 0;
 }
 
-int copy_thread(unsigned long clone_flags, unsigned long usp,
-       unsigned long arg, struct task_struct *p)
+int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
+       unsigned long arg, struct task_struct *p, unsigned long tls)
 {
        struct pt_regs *childregs = task_pt_regs(p);
 
@@ -118,7 +118,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
                if (usp) /* User fork */
                        childregs->sp = usp;
                if (clone_flags & CLONE_SETTLS)
-                       childregs->tp = childregs->a5;
+                       childregs->tp = tls;
                childregs->a0 = 0; /* Return value of fork() */
                p->thread.ra = (unsigned long)ret_from_fork;
        }