getunwind - copy the unwind data to caller's buffer
long getunwind(void *buf, size_t buf_size);
: There is no glibc wrapper for this system call; see NOTES.
Note: this function is obsolete.
The IA-64-specific getunwind
() system call copies the kernel's call frame
unwind data into the buffer pointed to by buf
and returns the size of
the unwind data; this data describes the gate page (kernel code that is mapped
into user space).
The size of the buffer buf
is specified in buf_size
. The data is
copied only if buf_size
is greater than or equal to the size of the
unwind data and buf
is not NULL; otherwise, no data is copied, and the
call succeeds, returning the size that would be needed to store the unwind
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:
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)
An entry whose start
value is zero indicates the end of the table. For
more information about the format, see the IA-64 Software Conventions and
On success, getunwind
() returns the size of the unwind data. On error, -1
is returned and errno
is set to indicate the error.
() fails with the error EFAULT
if the unwind info can't
be stored in the space specified by buf
This system call is available since Linux 2.4.
This system call is Linux-specific, and is available only on the IA-64
This system call has been deprecated. The modern way to obtain the kernel's
unwind data is via the vdso
Glibc does not provide a wrapper for this system call; in the unlikely event
that you want to call it, use syscall