1GETUNWIND(2)               Linux Programmer's Manual              GETUNWIND(2)
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NAME

6       getunwind - copy the unwind data to caller's buffer
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SYNOPSIS

9       #include <syscall.h>
10       #include <linux/unwind.h>
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12       long getunwind(void *buf, size_t buf_size);
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14       Note: There is no glibc wrapper for this system call; see NOTES.
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DESCRIPTION

17       Note: this function is obsolete.
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19       The  IA-64-specific  getunwind()  system  call copies the kernel's call
20       frame unwind data into the buffer pointed to by  buf  and  returns  the
21       size of the unwind data; this data describes the gate page (kernel code
22       that is mapped into user space).
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24       The size of the buffer buf is  specified  in  buf_size.   The  data  is
25       copied  only  if  buf_size  is greater than or equal to the size of the
26       unwind data and buf is not NULL; otherwise, no data is copied, and  the
27       call  succeeds,  returning  the  size that would be needed to store the
28       unwind data.
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30       The first part of the unwind data contains an unwind table.   The  rest
31       contains  the  associated  unwind  information, in no particular order.
32       The unwind table contains entries of the following form:
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34            u64 start;      (64-bit address of start of function)
35            u64 end;        (64-bit address of end of function)
36            u64 info;       (BUF-relative offset to unwind info)
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38       An entry whose start value is zero indicates the end of the table.  For
39       more  information  about the format, see the IA-64 Software Conventions
40       and Runtime Architecture manual.
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RETURN VALUE

43       On success, getunwind() returns the size of unwind table.  On error, -1
44       is returned and errno is set to indicate the error.
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ERRORS

47       getunwind()  fails  with  the  error EFAULT if the unwind info can't be
48       stored in the space specified by buf.
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VERSIONS

51       This system call is available since Linux 2.4.
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CONFORMING TO

54       This system call is Linux specific, and is available only on the  IA-64
55       architecture.
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NOTES

58       This  system  call  has  been deprecated.  The modern way to obtain the
59       kernel's unwind data is via the gate  DSO.   The  address  of  the  ELF
60       header  for  this  DSO is passed to user level via AT_SYSINFO_EHDR (see
61       getauxval(3)).
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63       Glibc does not provide a wrapper for this system call; in the  unlikely
64       event that you want to call it, use syscall(2).
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SEE ALSO

67       getauxval(3)
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COLOPHON

70       This  page  is  part of release 3.53 of the Linux man-pages project.  A
71       description of the project, and information about reporting  bugs,  can
72       be found at http://www.kernel.org/doc/man-pages/.
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76Linux                             2013-02-13                      GETUNWIND(2)
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