[PATCH] pru: Fix memory corruption on syscall return

[Dimitar Dimitrov]

On сряда, 3 юни 2020 г. 19:14:22 EEST Dimitar Dimitrov wrote:
> In the initial code I missed one level of pointer indirection. Instead
> of storing errno in impure_data, _impure_ptr was corrupted.
> 
> Only simulator is impacted. Real targets have no OS and no syscalls.
> 
> This resolves a bunch of stdio cases from the GCC testsuite:
>   FAIL->PASS: gcc.c-torture/execute/printf-2.c   -O0  execution test
> 
> Signed-off-by: Dimitar Dimitrov <dimitar@dinux.eu>
> ---
>  libgloss/pru/syscalls.S | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/libgloss/pru/syscalls.S b/libgloss/pru/syscalls.S
> index 8ed7601a4..3ad0d9215 100644
> --- a/libgloss/pru/syscalls.S
> +++ b/libgloss/pru/syscalls.S
> @@ -42,6 +42,7 @@ __SC_ret:
>  	/* Invert return code and store to errno (first int in _impure_ptr).  */
>  	rsb	r14, r14, 0
>  	ldi32	r1, _impure_ptr
> +	lbbo	r1, r1, 0, 4
>  	sbbo	r14, r1, 0, 4
>  	/* Return -1 (for both int32_t or int64_t).  */
>  	fill	r14, 8

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