sigsegv_install_handler - stall a global SIGSEGV handler
#include <sigsegv.h> int sigsegv_install_handler (sigsegv_handler_t handler); void sigsegv_deinstall_handler (void);
Library Functions Manual sigsegv_install_handler(3)
NAME
sigsegv_install_handler, sigsegv_deinstall_handler - Install and dein-
stall a global SIGSEGV handler
SYNOPSIS
#include <sigsegv.h>
int sigsegv_install_handler (sigsegv_handler_t handler);
void sigsegv_deinstall_handler (void);
DESCRIPTION
Pageable virtual memory is usually done in the operating system's ker-
nel. This library helps in implementing the others.
Installing a page fault handler is usually more efficient than doing
access checks in software at every access, because it's effectively the
hardware (the MMU) which checks whether a page is present or not.
Note that if you use system calls (like read()) to write into write-
protected pages, the system will react by returning -1 and setting
errno to EFAULT, instead of signalling SIGSEGV and restarting the sys-
tem call. In this case, the program has to do what the SIGSEGV handler
would do, and then restart the read() operation.
Sigsegv_install_handler installs a global SIGSEGV handler. This should
be called once only, and it ignores any previously installed SIGSEGV
handler.
Sigsegv_deinstall_handler deinstalls the global SIGSEGV handler. This
goes back to the state where no SIGSEGV handler is installed.
OPERANDS
typedef int (*sigsegv_handler_t) (void* fault_address,
int serious);
Sigsegv_handler_t is the type of a global SIGSEGV handler. The fault
address is passed as an argument. The access type (read access or write
access) is not passed; your handler has to know itself how to distin-
guish these two cases. If the second argument is 0, it means that it
could also be a stack overflow, or 1, meaning the handler should seri-
ously try to fix the fault. The return value should be nonzero if the
handler has done its job and no other handler should be called, or 0 if
the handler declines responsibility for the given address.
The handler is run at a moment when nothing about the global state of
the program is known. Therefore it cannot use facilities that manipu-
late global variables or locks. In particular, it cannot use malloc();
use mmap() instead. It cannot use fopen(); use open() instead. Etc. All
global variables that are accessed by the handler should be marked
'volatile'.
EXIT STATUS
If success, sigsegv_install_handler returns 0, or -1 if the system
doesn't support catching SIGSEGV.
COPYRIGHT
Copyright 1998-1999, 2002-2012, 2016-2021 Bruno Haible
<bruno@clisp.org>
Copyright 2002-2005, 2009 Paolo Bonzini <bonzini@gnu.org>
Copyright 2008-2010 Eric Blake <ebb9@byu.net>
Copyright 2002-2021 Free Software Foundation, Inc.
GNU libsigsegv library and manual pages are licensed under GNU GPL ver-
sion 2 or later <https://gnu.org/licenses/gpl-2.0.html>. This is free
software: you are free to change and redistribute it. There is NO WAR-
RANTY, to the extent permitted by law.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+--------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+--------------------+
|Availability | library/libsigsegv |
+---------------+--------------------+
|Stability | Uncommitted |
+---------------+--------------------+
SEE ALSO
attributes(7), sigsegv(3), standards(7)
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from https://ftp.gnu.org/gnu/libsigsegv/lib-
sigsegv-2.13.tar.gz.
Further information about this software can be found on the open source
community website at https://www.gnu.org/software/libsigsegv.
Solaris 11.4 17 June 2021
sigsegv_install_handler(3)