linux/tools/include/uapi/asm-generic, branch v5.12

fs: add mount_setattr()

2021-01-24T13:42:45Z

This implements the missing mount_setattr() syscall. While the new mount api allows to change the properties of a superblock there is currently no way to change the properties of a mount or a mount tree using file descriptors which the new mount api is based on. In addition the old mount api has the restriction that mount options cannot be applied recursively. This hasn't changed since changing mount options on a per-mount basis was implemented in [1] and has been a frequent request not just for convenience but also for security reasons. The legacy mount syscall is unable to accommodate this behavior without introducing a whole new set of flags because MS_REC | MS_REMOUNT | MS_BIND | MS_RDONLY | MS_NOEXEC | [...] only apply the mount option to the topmost mount. Changing MS_REC to apply to the whole mount tree would mean introducing a significant uapi change and would likely cause significant regressions. The new mount_setattr() syscall allows to recursively clear and set mount options in one shot. Multiple calls to change mount options requesting the same changes are idempotent: int mount_setattr(int dfd, const char *path, unsigned flags, struct mount_attr *uattr, size_t usize); Flags to modify path resolution behavior are specified in the @flags argument. Currently, AT_EMPTY_PATH, AT_RECURSIVE, AT_SYMLINK_NOFOLLOW, and AT_NO_AUTOMOUNT are supported. If useful, additional lookup flags to restrict path resolution as introduced with openat2() might be supported in the future. The mount_setattr() syscall can be expected to grow over time and is designed with extensibility in mind. It follows the extensible syscall pattern we have used with other syscalls such as openat2(), clone3(), sched_{set,get}attr(), and others. The set of mount options is passed in the uapi struct mount_attr which currently has the following layout: struct mount_attr { __u64 attr_set; __u64 attr_clr; __u64 propagation; __u64 userns_fd; }; The @attr_set and @attr_clr members are used to clear and set mount options. This way a user can e.g. request that a set of flags is to be raised such as turning mounts readonly by raising MOUNT_ATTR_RDONLY in @attr_set while at the same time requesting that another set of flags is to be lowered such as removing noexec from a mount tree by specifying MOUNT_ATTR_NOEXEC in @attr_clr. Note, since the MOUNT_ATTR_ values are an enum starting from 0, not a bitmap, users wanting to transition to a different atime setting cannot simply specify the atime setting in @attr_set, but must also specify MOUNT_ATTR__ATIME in the @attr_clr field. So we ensure that MOUNT_ATTR__ATIME can't be partially set in @attr_clr and that @attr_set can't have any atime bits set if MOUNT_ATTR__ATIME isn't set in @attr_clr. The @propagation field lets callers specify the propagation type of a mount tree. Propagation is a single property that has four different settings and as such is not really a flag argument but an enum. Specifically, it would be unclear what setting and clearing propagation settings in combination would amount to. The legacy mount() syscall thus forbids the combination of multiple propagation settings too. The goal is to keep the semantics of mount propagation somewhat simple as they are overly complex as it is. The @userns_fd field lets user specify a user namespace whose idmapping becomes the idmapping of the mount. This is implemented and explained in detail in the next patch. [1]: commit 2e4b7fcd9260 ("[PATCH] r/o bind mounts: honor mount writer counts at remount") Link: https://lore.kernel.org/r/20210121131959.646623-35-christian.brauner@ubuntu.com Cc: David Howells Cc: Aleksa Sarai Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Cc: linux-api@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner

tools headers UAPI: Update epoll_pwait2 affected files

2020-12-24T12:24:19Z

To pick the changes from: b0a0c2615f6f199a ("epoll: wire up syscall epoll_pwait2") That addresses these perf build warning: Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/unistd.h' differs from latest version at 'include/uapi/asm-generic/unistd.h' diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h Warning: Kernel ABI header at 'tools/perf/arch/x86/entry/syscalls/syscall_64.tbl' differs from latest version at 'arch/x86/entry/syscalls/syscall_64.tbl' diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: Willem de Bruijn Signed-off-by: Arnaldo Carvalho de Melo

tools headers UAPI: Update asm-generic/unistd.h

2020-12-18T20:32:28Z

Just a comment change, trivial. Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

tools headers UAPI: Update process_madvise affected files

2020-11-03T11:29:30Z

To pick the changes from: ecb8ac8b1f146915 ("mm/madvise: introduce process_madvise() syscall: an external memory hinting API") That addresses these perf build warning: Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/unistd.h' differs from latest version at 'include/uapi/asm-generic/unistd.h' diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h Warning: Kernel ABI header at 'tools/perf/arch/x86/entry/syscalls/syscall_64.tbl' differs from latest version at 'arch/x86/entry/syscalls/syscall_64.tbl' diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Linus Torvalds Cc: Minchan Kim Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

Merge branch 'compat.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-10-12T23:44:57Z

Pull compat mount cleanups from Al Viro: "The last remnants of mount(2) compat buried by Christoph. Buried into NFS, that is. Generally I'm less enthusiastic about "let's use in_compat_syscall() deep in call chain" kind of approach than Christoph seems to be, but in this case it's warranted - that had been an NFS-specific wart, hopefully not to be repeated in any other filesystems (read: any new filesystem introducing non-text mount options will get NAKed even if it doesn't mess the layout up). IOW, not worth trying to grow an infrastructure that would avoid that use of in_compat_syscall()..." * 'compat.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: remove compat_sys_mount fs,nfs: lift compat nfs4 mount data handling into the nfs code nfs: simplify nfs4_parse_monolithic

mm: remove compat_process_vm_{readv,writev}

2020-10-03T04:02:15Z

Now that import_iovec handles compat iovecs, the native syscalls can be used for the compat case as well. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

fs: remove compat_sys_vmsplice

2020-10-03T04:02:15Z

Now that import_iovec handles compat iovecs, the native vmsplice syscall can be used for the compat case as well. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

fs: remove the compat readv/writev syscalls

2020-10-03T04:02:14Z

Now that import_iovec handles compat iovecs, the native readv and writev syscalls can be used for the compat case as well. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

fs: remove compat_sys_mount

2020-09-23T03:45:57Z

compat_sys_mount is identical to the regular sys_mount now, so remove it and use the native version everywhere. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

tools headers API: Update close_range affected files

2020-08-06T12:52:41Z

To pick the changes from: 55db9c0e8534 ("net: remove compat_sys_{get,set}sockopt") 9b4feb630e8e ("arch: wire-up close_range()") That automagically add the 'close_range' syscall to tools such as 'perf trace'. Before: # perf trace -e close_range event syntax error: 'close_range' \___ parser error Run 'perf list' for a list of valid events Usage: perf trace [] [] or: perf trace [] -- [] or: perf trace record [] [] or: perf trace record [] -- [] -e, --event event/syscall selector. use 'perf list' to list available events # After, system wide strace like tracing for this syscall: # perf trace -e close_range ^C# No calls, I need some test proggie :-) Cc: Adrian Hunter Cc: Christian Brauner Cc: Christoph Hellwig Cc: David S. Miller Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo