Section (2) getunwind
getunwind — copy the unwind data to caller_zsingle_quotesz_s buffer
#include <syscall.h> #include <linux/unwind.h>
|There is no glibc wrapper for this system call; see NOTES.|
Note: this function is obsolete.
getunwind() system call copies the kernel_zsingle_quotesz_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
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 Runtime Architecture manual.
returns the size of the unwind data. On error, −1 is
errno is set to
indicate the error.
getunwind() fails with the
error EFAULT if the unwind
info can_zsingle_quotesz_t be stored in the space specified by
This system call has been deprecated. The modern way to obtain the kernel_zsingle_quotesz_s unwind data is via the vdso(7).
Glibc does not provide a wrapper for this system call; in the unlikely event that you want to call it, use syscall(2).
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