unw_init_remote - Man Page

initialize cursor for remote unwinding

Synopsis

#include <libunwind.h>

int unw_init_remote(unw_cursor_t *c, unw_addr_space_t as, void *arg);

Description

The unw_init_remote() routine initializes the unwind cursor  pointed to by c for unwinding in the address space identified by  as. The as argument can either be set to  unw_local_addr_space (local address space) or to an arbitrary  address space created with unw_create_addr_space().

The arg opaque pointer tells the address space exactly what entity  should be unwound. For example, if unw_local_addr_space is  passed in as, then arg needs to be a pointer to a context  structure containing the machine-state of the initial stack frame.  However, other address spaces may instead expect a process ID, a  thread ID, or a pointer to an arbitrary structure which identifies the  stack frame chain to be unwound. In other words, the interpretation  of arg is entirely dependent on the address space in use;  libunwind never interprets the argument in any way on its own.

Note that unw_init_remote() can be used to initiate unwinding  in any process, including the local process in which the  unwinder itself is running. However, for local unwinding, it is  generally preferable to use unw_init_local() instead, because  it is easier to use and because it may perform better.

Return Value

On successful completion, unw_init_remote() returns 0.  Otherwise the negative value of one of the error-codes below is  returned.

Thread and Signal Safety

unw_init_remote() is thread safe. If the local address space  is passed in argument as, this routine is also safe to use from  a signal handler.

Errors

UNW_EINVAL

unw_init_remote() was called in a  version of libunwind which supports local unwinding only  (this normally happens when defining UNW_LOCAL_ONLY before  including <libunwind.h> and then calling  unw_init_remote()).

UNW_EUNSPEC

An unspecified error occurred.

UNW_EBADREG

A register needed by unw_init_remote() wasn't accessible.

See Also

libunwind(3libunwind), unw_create_addr_space(3libunwind), unw_init_local(3libunwind)

Author

David Mosberger-Tang
Email: dmosberger@gmail.com
WWW: http://www.nongnu.org/libunwind/.

Info

29 August 2023 Programming Library