From 27342d1783449fe837ac42e9b382b2868af3256f Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Fri, 8 Sep 2017 16:19:21 +0000 Subject: Add fcntl sealing interfaces from Linux 3.17 to bits/fcntl-linux.h. While reviewing Linux 4.13 for glibc header changes needed, I noticed that bits/fcntl-linux.h was missing F_ADD_SEALS etc. from Linux 3.17. I didn't find any discussion indicating this omission is deliberate. Now, these interfaces can only be used with file descriptors created with memfd_create, and we don't have a memfd_create wrapper in glibc (a patch was submitted in October 2014, albeit without documentation / tests, and discussions continued over the next few months, but without consensus on whether to add the interface - and we still lack any general consensus on syscall wrappers), but I don't think that's a reason to exclude the constants from bits/fcntl-linux.h (especially as the header does not look compatible with simultaneously including linux/fcntl.h). (Some of those 2014/2015 discussions raised concerns about difficulty using the memfd_create / sealing interface, but those seem to me more like a question of whether it should be part of the OS-independent GNU API - in my view, even fairly specialized syscalls ought to have wrappers added to glibc if not obsolescent, but there may be cases where we only want to include them in the Linux-specific API and anything in the OS-independent GNU API should be different - rather than being relevant to whether constants for use with fcntl should appear in headers.) * sysdeps/unix/sysv/linux/bits/fcntl-linux.h [__USE_GNU] (F_ADD_SEALS): New macro. [__USE_GNU] (F_GET_SEALS): Likewise. [__USE_GNU] (F_SEAL_SEAL): Likewise. [__USE_GNU] (F_SEAL_SHRINK): Likewise. [__USE_GNU] (F_SEAL_GROW): Likewise. [__USE_GNU] (F_SEAL_WRITE): Likewise. --- sysdeps/unix/sysv/linux/bits/fcntl-linux.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'sysdeps/unix') diff --git a/sysdeps/unix/sysv/linux/bits/fcntl-linux.h b/sysdeps/unix/sysv/linux/bits/fcntl-linux.h index 0cd0a5d731..fc65fc2e4a 100644 --- a/sysdeps/unix/sysv/linux/bits/fcntl-linux.h +++ b/sysdeps/unix/sysv/linux/bits/fcntl-linux.h @@ -202,6 +202,8 @@ # define F_NOTIFY 1026 /* Request notifications on a directory. */ # define F_SETPIPE_SZ 1031 /* Set pipe page size array. */ # define F_GETPIPE_SZ 1032 /* Set pipe page size array. */ +# define F_ADD_SEALS 1033 /* Add seals to file. */ +# define F_GET_SEALS 1034 /* Get seals for file. */ #endif #ifdef __USE_XOPEN2K8 # define F_DUPFD_CLOEXEC 1030 /* Duplicate file descriptor with @@ -271,6 +273,14 @@ struct f_owner_ex }; #endif +#ifdef __USE_GNU +/* Types of seals. */ +# define F_SEAL_SEAL 0x0001 /* Prevent further seals from being set. */ +# define F_SEAL_SHRINK 0x0002 /* Prevent file from shrinking. */ +# define F_SEAL_GROW 0x0004 /* Prevent file from growing. */ +# define F_SEAL_WRITE 0x0008 /* Prevent writes. */ +#endif + /* Define some more compatibility macros to be backward compatible with BSD systems which did not managed to hide these kernel macros. */ #ifdef __USE_MISC -- cgit 1.4.1