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Diffstat (limited to 'man2/setfsgid.2')
| -rw-r--r-- | man2/setfsgid.2 | 109 |
1 files changed, 0 insertions, 109 deletions
diff --git a/man2/setfsgid.2 b/man2/setfsgid.2 deleted file mode 100644 index bd17d6999..000000000 --- a/man2/setfsgid.2 +++ /dev/null @@ -1,109 +0,0 @@ -.\" Copyright (C) 1995, Thomas K. Dyas <tdyas@eden.rutgers.edu> -.\" and Copyright (C) 2019, Michael Kerrisk <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.\" Created 1995-08-06 Thomas K. Dyas <tdyas@eden.rutgers.edu> -.\" Modified 2000-07-01 aeb -.\" Modified 2002-07-23 aeb -.\" Modified, 27 May 2004, Michael Kerrisk <mtk.manpages@gmail.com> -.\" Added notes on capability requirements -.\" -.TH setfsgid 2 (date) "Linux man-pages (unreleased)" -.SH NAME -setfsgid \- set group identity used for filesystem checks -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <sys/fsuid.h> -.PP -.BI "[[deprecated]] int setfsgid(gid_t " fsgid ); -.fi -.SH DESCRIPTION -On Linux, a process has both a filesystem group ID and an effective group ID. -The (Linux-specific) filesystem group ID is used -for permissions checking when accessing filesystem objects, -while the effective group ID is used for some other kinds -of permissions checks (see -.BR credentials (7)). -.PP -Normally, the value of the process's filesystem group ID -is the same as the value of its effective group ID. -This is so, because whenever a process's effective group ID is changed, -the kernel also changes the filesystem group ID to be the same as -the new value of the effective group ID. -A process can cause the value of its filesystem group ID to diverge -from its effective group ID by using -.BR setfsgid () -to change its filesystem group ID to the value given in -.IR fsgid . -.PP -.BR setfsgid () -will succeed only if the caller is the superuser or if -.I fsgid -matches either the caller's real group ID, effective group ID, -saved set-group-ID, or current the filesystem user ID. -.SH RETURN VALUE -On both success and failure, -this call returns the previous filesystem group ID of the caller. -.SH STANDARDS -Linux. -.SH HISTORY -Linux 1.2. -.\" Linux 1.1.44 -.\" and in libc since libc 4.7.6. -.SS C library/kernel differences -In glibc 2.15 and earlier, -when the wrapper for this system call determines that the argument can't be -passed to the kernel without integer truncation (because the kernel -is old and does not support 32-bit group IDs), -it will return \-1 and set \fIerrno\fP to -.B EINVAL -without attempting -the system call. -.SH NOTES -The filesystem group ID concept and the -.BR setfsgid () -system call were invented for historical reasons that are -no longer applicable on modern Linux kernels. -See -.BR setfsuid (2) -for a discussion of why the use of both -.BR setfsuid (2) -and -.BR setfsgid () -is nowadays unneeded. -.PP -The original Linux -.BR setfsgid () -system call supported only 16-bit group IDs. -Subsequently, Linux 2.4 added -.BR setfsgid32 () -supporting 32-bit IDs. -The glibc -.BR setfsgid () -wrapper function transparently deals with the variation across kernel versions. -.SH BUGS -No error indications of any kind are returned to the caller, -and the fact that both successful and unsuccessful calls return -the same value makes it impossible to directly determine -whether the call succeeded or failed. -Instead, the caller must resort to looking at the return value -from a further call such as -.I setfsgid(\-1) -(which will always fail), in order to determine if a preceding call to -.BR setfsgid () -changed the filesystem group ID. -At the very -least, -.B EPERM -should be returned when the call fails (because the caller lacks the -.B CAP_SETGID -capability). -.SH SEE ALSO -.BR kill (2), -.BR setfsuid (2), -.BR capabilities (7), -.BR credentials (7) |