KFunc `bpf_throw`

Throw a BPF exception from the program

Definition

Throw a BPF exception from the program, immediately terminating its execution and unwinding the stack. The supplied cookie parameter will be the return value of the program when an exception is thrown, and the default exception callback is used. Otherwise, if an exception callback is set using the __exception_cb(callback) declaration tag on the main program, the cookie parameter will be the callback's only input argument.

Thus, in case of default exception callback, cookie is subjected to constraints on the program's return value (as with R0 on exit). Otherwise, the return value of the marked exception callback will be subjected to the same checks.

Note

throwing an exception with lingering resources (locks, references, etc.) will lead to a verification error.

Note

callbacks cannot call this helper.

Return

Never.

Throws

An exception with the specified cookie value.

void bpf_throw(u64 cookie)

Usage

Docs could be improved

This part of the docs is incomplete, contributions are very welcome

Program types

The following program types can make use of this kfunc:

Example