[v2] linux-user: target <-> host errno conversion code refactor

[PATCH v2 7/8] linux-user/syscall: Introduce errno_exists()

Posted by Philippe Mathieu-Daudé 4 years, 7 months ago

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 linux-user/syscall.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 4842a1987b7..56682b06cbd 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -509,6 +509,11 @@ static inline int next_free_host_timer(void)
 
 #define ERRNO_TABLE_SIZE 1200
 
+static inline bool errno_exists(int err)
+{
+    return err >= 0 && err < ERRNO_TABLE_SIZE;
+}
+
 /* target_to_host_errno_table[] is initialized from
  * host_to_target_errno_table[] in syscall_init(). */
 static uint16_t target_to_host_errno_table[ERRNO_TABLE_SIZE] = {
@@ -672,7 +677,7 @@ const char *target_strerror(int err)
         return "Successful exit from sigreturn";
     }
 
-    if ((err >= ERRNO_TABLE_SIZE) || (err < 0)) {
+    if (!errno_exists(err)) {
         return NULL;
     }
     return strerror(target_to_host_errno(err));
-- 
2.31.1

Re: [PATCH v2 7/8] linux-user/syscall: Introduce errno_exists()

Posted by Richard Henderson 4 years, 7 months ago

On 7/8/21 7:11 AM, Philippe Mathieu-Daudé wrote:
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>   linux-user/syscall.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 4842a1987b7..56682b06cbd 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -509,6 +509,11 @@ static inline int next_free_host_timer(void)
>   
>   #define ERRNO_TABLE_SIZE 1200
>   
> +static inline bool errno_exists(int err)
> +{
> +    return err >= 0 && err < ERRNO_TABLE_SIZE;
> +}
> +
>   /* target_to_host_errno_table[] is initialized from
>    * host_to_target_errno_table[] in syscall_init(). */
>   static uint16_t target_to_host_errno_table[ERRNO_TABLE_SIZE] = {
> @@ -672,7 +677,7 @@ const char *target_strerror(int err)
>           return "Successful exit from sigreturn";
>       }
>   
> -    if ((err >= ERRNO_TABLE_SIZE) || (err < 0)) {
> +    if (!errno_exists(err)) {
>           return NULL;
>       }
>       return strerror(target_to_host_errno(err));

After patch 8, you can simply remove this test entirely, as well as the otherwise unused 
and totally arbitrary ERRNO_TABLE_SIZE.


r~

Re: [PATCH v2 7/8] linux-user/syscall: Introduce errno_exists()

Posted by Laurent Vivier 4 years, 7 months ago

Le 08/07/2021 à 16:11, Philippe Mathieu-Daudé a écrit :
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  linux-user/syscall.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 4842a1987b7..56682b06cbd 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -509,6 +509,11 @@ static inline int next_free_host_timer(void)
>  
>  #define ERRNO_TABLE_SIZE 1200
>  
> +static inline bool errno_exists(int err)
> +{
> +    return err >= 0 && err < ERRNO_TABLE_SIZE;
> +}
> +
>  /* target_to_host_errno_table[] is initialized from
>   * host_to_target_errno_table[] in syscall_init(). */
>  static uint16_t target_to_host_errno_table[ERRNO_TABLE_SIZE] = {
> @@ -672,7 +677,7 @@ const char *target_strerror(int err)
>          return "Successful exit from sigreturn";
>      }
>  
> -    if ((err >= ERRNO_TABLE_SIZE) || (err < 0)) {
> +    if (!errno_exists(err)) {
>          return NULL;
>      }
>      return strerror(target_to_host_errno(err));
> 

Reviewed-by: Laurent Vivier <laurent@vivier.eu>