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Diffstat (limited to 'man2/lookup_dcookie.2')
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diff --git a/man2/lookup_dcookie.2 b/man2/lookup_dcookie.2 new file mode 100644 index 000000000..9e0079a13 --- /dev/null +++ b/man2/lookup_dcookie.2 @@ -0,0 +1,89 @@ +.\" Hey Emacs! This file is -*- nroff -*- source. +.\" +.\" Copyright (C) 2003 John Levon <levon@movementarian.org> +.\" +.\" Permission is granted to make and distribute verbatim copies of this +.\" manual provided the copyright notice and this permission notice are +.\" preserved on all copies. +.\" +.\" Permission is granted to copy and distribute modified versions of this +.\" manual under the conditions for verbatim copying, provided that the +.\" entire resulting derived work is distributed under the terms of a +.\" permission notice identical to this one. +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date. The author(s) assume no +.\" responsibility for errors or omissions, or for damages resulting from +.\" the use of the information contained herein. The author(s) may not +.\" have taken the same level of care in the production of this manual, +.\" which is licensed free of charge, as they might when working +.\" professionally. +.\" +.\" Formatted or processed versions of this manual, if unaccompanied by +.\" the source, must acknowledge the copyright and authors of this work. +.\" +.\" Modified 2004-06-17 Michael Kerrisk <mtk16@ext.canterbury.ac.nz> +.\" +.TH LOOKUP_DCOOKIE 2 2004-06-17 "Linux 2.6.7" "Linux Programmer's Manual" +.SH NAME +lookup_dcookie \- return a directory entry's path +.SH SYNOPSIS +.sp +.BI "int lookup_dcookie(u64 " cookie ", char * " buffer ", size_t " len ); +.SH DESCRIPTION +Look up the full path of the directory entry specified by the value +.I cookie +. +The cookie is an opaque identifier uniquely identifying a particular directory +entry. The buffer given is filled in with the full path of the directory +entry. + +For +.B lookup_dcookie +to return successfully, +the kernel must still hold a cookie reference to the directory entry. + +.SH "NOTES" +.B lookup_dcookie +is a special-purpose system call, currently used only by the oprofile profiler. +It relies on a kernel driver to register cookies for directory entries. + +The path returned may be suffixed by the string " (deleted)" if the directory +entry has been removed. + +.SH "RETURN VALUE" +On success, +.B lookup_dcookie +returns the length of the path string copied into the buffer. +On error, \-1 is returned, and +.I errno +is set appropriately. +.SH ERRORS +.TP +.B EFAULT +The buffer was not valid. +.TP +.B EINVAL +The kernel has no registered cookie/directory entry mappings at the +time of lookup, or the cookie does not refer to a valid directory entry. +.TP +.B ENAMETOOLONG +The name could not fit in the buffer. +.TP +.B ENOMEM +The kernel could not allocate memory for the temporary buffer holding +the path. +.TP +.B EPERM +The process does not have the capability +.B CAP_SYS_ADMIN +required to look up cookie values. +.TP +.B ERANGE +The buffer was not large enough to hold the path of the directory entry. +.SH "CONFORMING TO" +.B lookup_dcookie +is Linux-specific. +.SH AVAILABILITY +Since Linux 2.5.43. +The ENAMETOOLONG error return was added in 2.5.70. |