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| -rw-r--r-- | man2/getunwind.2 | 87 |
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diff --git a/man2/getunwind.2 b/man2/getunwind.2 new file mode 100644 index 0000000..eaf7117 --- /dev/null +++ b/man2/getunwind.2 @@ -0,0 +1,87 @@ +.\" Copyright (C) 2006 Red Hat, Inc. All Rights Reserved. +.\" Written by Marcela Maslanova <mmaslano@redhat.com> +.\" and Copyright 2013, Michael Kerrisk <mtk.manpages@gmail.com> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.TH getunwind 2 2023-03-30 "Linux man-pages 6.05.01" +.SH NAME +getunwind \- copy the unwind data to caller's buffer +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <linux/unwind.h> +.BR "#include <sys/syscall.h>" " /* Definition of " SYS_* " constants */" +.B #include <unistd.h> +.PP +.BI "[[deprecated]] long syscall(SYS_getunwind, void " buf [. buf_size ], +.BI " size_t " buf_size ); +.fi +.SH DESCRIPTION +.I Note: this system call is obsolete. +.PP +The +IA-64-specific +.BR getunwind () +system call copies the kernel's call frame +unwind data into the buffer pointed to by +.I buf +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 +.IR buf_size . +The data is copied only if +.I buf_size +is greater than or equal to the size of the unwind data and +.I buf +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 +.in +4n +.EX +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) +.EE +.in +.PP +An entry whose +.I start +value is zero indicates the end of the table. +For more information about the format, see the +.I IA-64 Software Conventions and Runtime Architecture +manual. +.SH RETURN VALUE +On success, +.BR getunwind () +returns the size of the unwind data. +On error, \-1 is returned and +.I errno +is set to indicate the error. +.SH ERRORS +.BR getunwind () +fails with the error +.B EFAULT +if the unwind info can't be stored in the space specified by +.IR buf . +.SH STANDARDS +Linux on IA-64. +.SH HISTORY +Linux 2.4. +.PP +This system call has been deprecated. +The modern way to obtain the kernel's unwind data is via the +.BR vdso (7). +.SH SEE ALSO +.BR getauxval (3) |