[PATCH V8 13/20] riscv: compat: process: Add UXL_32 support in start_thread

guoren
2022-03-16T07:05:04Z

If the current task is in COMPAT mode, set SR_UXL_32 in status for
returning userspace. We need CONFIG _COMPAT to prevent compiling
errors with rv32 defconfig.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
---
arch/riscv/kernel/process.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index 03ac3aa611f5..8c7665481a9f 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -97,6 +97,15 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
}
regs->epc = pc;
regs->sp = sp;
+
+#ifdef CONFIG_64BIT
+ regs->status &= ~SR_UXL;
+
+ if (is_compat_task())
+ regs->status |= SR_UXL_32;
+ else
+ regs->status |= SR_UXL_64;
+#endif
}

void flush_thread(void)
--
2.25.1