Re: Inline Macro issue

[Saket Sinha <saket.sinha89@xxxxxxxxx>]

BTW....I forgot to mention the problem got solved. Thanks to your suggestions.

Regards,

Saket Sinha

On Mon, Jul 15, 2013 at 9:38 PM, Saket Sinha <saket.sinha89@xxxxxxxxx> wrote:

Russel:

Thank you a curly bracket was missing. How could I not notice.

Valdis:

I shall take your suggestions.

Mandeep:

Thank you for that enlighting ideas

Regards,

Saket Sinha

On Mon, Jul 15, 2013 at 7:52 PM, <Valdis.Kletnieks@xxxxxx> wrote:

On Mon, 15 Jul 2013 17:39:15 +0530, Mandeep Sandhu said:

> #define push_root() \
>       recursive_mutex_lock(&context->id_lock);        \
>       context->uid = current->fsuid;                  \
>       context->gid = current->fsgid;                  \
>         do {                                            \
>             struct cred *new1 = prepare_creds();           \
>             //make changes to any member of this structure \
>             commit_creds(new1);                            \
>         } while(0);

Actually, this has 3 problems:

1) You have a call to mutex_loc() that doesn't get unlocked. This Is Bad.

2) If you're using the 'do { foo } while (0)' trick, you want to
put the *whole thing* inside the { } (Hint - you can put local variable
definitions inside the curlies as well).

3) Leave the ; off the 'while (0)' in the macro definition, because:

> int main()
> {
>    printf("in main\n");
>    pushme
>   return 0;
> }

Somebody will forget and put a ; after pushme - and in some contexts, the
additional ; will then cause issues.

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