There is no glibc wrapper for this system call; see NOTES.
.SH DESCRIPTION
.I Note: this function is obsolete.
-
+.PP
The
IA-64-specific
.BR getunwind ()
and returns the size of the unwind data;
this data describes the gate page (kernel code that
is mapped into user space).
-
+.PP
The size of the buffer
.I buf
is specified in
is not NULL;
otherwise, no data is copied, and the call succeeds,
returning the size that would be needed to store the unwind data.
-
+.PP
The first part of the unwind data contains an unwind table.
The rest contains the associated unwind information, in no particular order.
The unwind table contains entries of the following form:
-
+.PP
.nf
u64 start; (64-bit address of start of function)
u64 end; (64-bit address of end of function)
u64 info; (BUF-relative offset to unwind info)
.fi
-
+.PP
An entry whose
.I start
value is zero indicates the end of the table.
This system call has been deprecated.
The modern way to obtain the kernel's unwind data is via the
.BR vdso (7).
-
+.PP
Glibc does not provide a wrapper for this system call;
in the unlikely event that you want to call it, use
.BR syscall (2).