On 11/03/2022 02:38, Guo Ren wrote:
Hi Arnd,
On Mon, Feb 28, 2022 at 12:30 AM <guoren@xxxxxxxxxx> wrote:
From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
---
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].
would an if (IS_ENABLED(CONFIG_COMPAT)) { } around the lot be better
than an #ifdef here?
}
void flush_thread(void)
--
2.25.1
--
Ben Dooks http://www.codethink.co.uk/
Senior Engineer Codethink - Providing Genius
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