GETUNWIND(2) Linux System Calls GETUNWIND(2)NAMEgetunwind - copy the unwind data to caller's buffer
SYNOPSIS
#include <syscall.h>
#include <linux/unwind.h>
long getunwind (void *buf, size_t buf_size);
DESCRIPTION
The sys_getunwind function returns size of unwind table, which
describes gate page (kernel code that is mapped into user space).
The unwind data is copied to the buffer buf, which has size 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. The system call returns
the size of the unwind data in both cases.
The first part of the unwind data contains an unwind table. The rest
contains the associated unwind info in random order. The unwind table
contains a table looking like:
u64 start; (64-bit address of start of function)
u64 end; (64-bit address of start of function)
u64 info; (BUF-relative offset to unwind info)
An entry with a START address of zero is the end of table. For more
information about the format you can see the IA-64 Software Conventions
and Runtime Architecture.
RETURN VALUE
The sys_getunwind function returns size of unwind table.
ERRORS
The sys_getunwind function fails with EFAULT if the unwind info can't
be stored in the space specified by the buf argument.
AVAILABILITY
This system call is available only on the IA-64 architecture.
APPLICATION USAGE
This system call has been deprecated. It's highly recommended to get at
the kernel's unwind info by the gate DSO. The address of the ELF header
for this DSO is passed to user level via AT_SYSINFO_EHDR.
The system call is not available to application programs as a function;
it can be called using the syscall(2) function.
SEE ALSOsyscall(2),
Linux 29 August 2006 GETUNWIND(2)
