Re: [Qemu-devel] [PATCH v2 01/15] target/arm/arm-semi: Capture errno in softmmu version of set_swi_errno()

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 9/16/19 4:15 PM, Peter Maydell wrote:
> The set_swi_errno() function is called to capture the errno
> from a host system call, so that we can return -1 from the
> semihosting function and later allow the guest to get a more
> specific error code with the SYS_ERRNO function. It comes in
> two versions, one for user-only and one for softmmu. We forgot
> to capture the errno in the softmmu version; fix the error.
> 
> (Semihosting calls directed to gdb are unaffected because
> they go through a different code path that captures the
> error return from the gdbstub call in arm_semi_cb() or
> arm_semi_flen_cb().)
> 

Fixes: 8e71621f784
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> NB that a later commit will put in some cleanup of TaskState
> that will let us reduce the duplication between the two
> implementations of this function.
> ---
>   target/arm/arm-semi.c | 9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c
> index 90423a35deb..03e60105c05 100644
> --- a/target/arm/arm-semi.c
> +++ b/target/arm/arm-semi.c
> @@ -114,8 +114,13 @@ static inline uint32_t set_swi_errno(TaskState *ts, uint32_t code)
>       return code;
>   }
>   #else
> +static target_ulong syscall_err;
> +
>   static inline uint32_t set_swi_errno(CPUARMState *env, uint32_t code)
>   {
> +    if (code == (uint32_t)-1) {
> +        syscall_err = errno;
> +    }
>       return code;
>   }
>   
> @@ -124,10 +129,6 @@ static inline uint32_t set_swi_errno(CPUARMState *env, uint32_t code)
>   
>   static target_ulong arm_semi_syscall_len;
>   
> -#if !defined(CONFIG_USER_ONLY)
> -static target_ulong syscall_err;
> -#endif
> -
>   static void arm_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
>   {
>       ARMCPU *cpu = ARM_CPU(cs);
>