Проект OpenNet: MAN i386_clr_watch (3) Библиотечные вызовы (FreeBSD и Linux)

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i386_clr_watch (3)

>> i386_clr_watch (3) ( FreeBSD man: Библиотечные вызовы )

BSD mandoc

NAME

i386_clr_watch

 
i386_set_watch

 - manage i386 debug register values

LIBRARY

Lb libc

SYNOPSIS

#include <machine/reg.h>
#include <machine/sysarch.h>
int i386_clr_watch (int watchnum struct dbreg *d);
int i386_set_watch (int watchnum unsigned int watchaddr int size int access struct dbreg *d);

DESCRIPTION

The i386_clr_watch ();
function will disable the indicated watch point within the specified debug register set.

The i386_set_watch ();
function will set up the specified debug registers as indicated by the arguments. The Fa watchnum argument specifies which watch register is used, 0, 1, 2, 3, or -1. If Fa watchnum is -1, a free watch register is found and used. If there are no free watch registers, an error code of -1 is returned. The Fa watchaddr argument specifies the watch address, Fa size specifies the size in bytes of the area to be watched (1, 2, or 4 bytes), and Fa access specifies the type of watch point:

DBREG_DR7_EXEC    An execution breakpoint.
DBREG_DR7_WRONLY  Break only when the watch area is written to.
DBREG_DR7_RDWR    Break when the watch area is read from or written
                  to.

Note that these functions do not actually set or clear breakpoints; they manipulate the indicated debug register set. You must use ptrace(2) to retrieve and install the debug register values for a process.

RETURN VALUES

On success, the i386_clr_watch ();
function returns 0. On error, -1 returned which indicates that Fa watchnum is invalid (not in the range of 0-3). If the specified watchnum was already disabled, no error is returned.

On success, the i386_set_watch ();
function returns the Fa watchnum argument, or the watchnum actually used in the case where the specified Fa watchnum was -1. On error, the i386_set_watch ();
function returns -1 indicating that the watchpoint could not established because either no more watchpoints are available, or Fa watchnum , Fa size , or Fa access is invalid.