[PATCH 5/7] riscv: Implement copy_thread_tls

From: Amanieu d'Antras
Date: Thu Jan 02 2020 - 12:24:39 EST


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

Signed-off-by: Amanieu d'Antras <amanieu@xxxxxxxxx>
Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx> # 5.3.x
---
arch/riscv/Kconfig | 1 +
arch/riscv/kernel/process.c | 6 +++---
2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index d8efbaa78d67..d6c3d44f96b5 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -64,6 +64,7 @@ config RISCV
select SPARSEMEM_STATIC if 32BIT
select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
select HAVE_ARCH_MMAP_RND_BITS if MMU
+ select HAVE_COPY_THREAD_TLS

config ARCH_MMAP_RND_BITS_MIN
default 18 if 64BIT
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index 95a3031e5c7c..817cf7b0974c 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -99,8 +99,8 @@ 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);

@@ -121,7 +121,7 @@ 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;
}
--
2.24.1