lkml.org 
[lkml]   [2022]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH V7 13/20] riscv: compat: process: Add UXL_32 support in start_thread
Hi Arnd,

On Mon, Feb 28, 2022 at 12:30 AM <guoren@kernel.org> wrote:
>
> From: Guo Ren <guoren@linux.alibaba.com>
>
> 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>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>
> ---
> arch/riscv/kernel/process.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
> index 03ac3aa611f5..54787ca9806a 100644
> --- a/arch/riscv/kernel/process.c
> +++ b/arch/riscv/kernel/process.c
> @@ -97,6 +97,11 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
> }
> regs->epc = pc;
> regs->sp = sp;
> +
FIxup:

+ #ifdef CONFIG_COMPAT
> + if (is_compat_task())
> + regs->status = (regs->status & ~SR_UXL) | SR_UXL_32;
> + else
> + regs->status = (regs->status & ~SR_UXL) | SR_UXL_64;
+ #endif

We still need "#ifdef CONFIG_COMPAT" here, because for rv32 we can't
set SR_UXL at all. SR_UXL is BIT[32, 33].

> }
>
> void flush_thread(void)
> --
> 2.25.1
>


--
Best Regards
Guo Ren

ML: https://lore.kernel.org/linux-csky/

\
 
 \ /
  Last update: 2022-03-11 03:39    [W:0.199 / U:0.540 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site