From the book "Linux Device Drivers".
Error recovery is sometimes best handled with the goto statement. We
normally hate
to use goto, but in our opinion, this is one situation where it is
useful. Careful use of
goto in error situations can eliminate a great deal of complicated,
highly-indented,
“structured” logic. Thus, in the kernel, goto is often used as shown
here to deal with
errors.
The following sample code (using fictitious registration and
unregistration func-
tions) behaves correctly if initialization fails at any point:
int __init my_init_function(void)
{
int err;
/* registration takes a pointer and a name */
err = register_this(ptr1, "skull");
if (err) goto fail_this;
err = register_that(ptr2, "skull");
if (err) goto fail_that;
err = register_those(ptr3, "skull");
if (err) goto fail_those;
return 0; /* success */
fail_those: unregister_that(ptr2, "skull");
fail_that: unregister_this(ptr1, "skull");
fail_this: return err; /* propagate the error */
}
This code attempts to register three (fictitious)facilities. The goto
statement is used
in case of failure to cause the unregistration of only the facilities
that had been suc-
cessfully registered before things went bad.
On 26/9/22 10:17, David Crayford wrote:
On 26/9/22 10:13, Steve Smith wrote:
lol... We definitely need a guide to refracturing code.
More seriously, a decent commentary on how to use goto "correctly"
would be
a nice thing to see.
Here you go, just in case you missed it the first time I posted
https://koblents.com/Ches/Links/Month-Mar-2013/20-Using-Goto-in-Linux-Kernel-Code/
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