user/sven/linux.git/init/version.c, branch v3.2.97

userns: add a user_namespace as creator/owner of uts_namespace

2011-03-24T02:46:59Z

The expected course of development for user namespaces targeted capabilities is laid out at https://wiki.ubuntu.com/UserNamespace. Goals: - Make it safe for an unprivileged user to unshare namespaces. They will be privileged with respect to the new namespace, but this should only include resources which the unprivileged user already owns. - Provide separate limits and accounting for userids in different namespaces. Status: Currently (as of 2.6.38) you can clone with the CLONE_NEWUSER flag to get a new user namespace if you have the CAP_SYS_ADMIN, CAP_SETUID, and CAP_SETGID capabilities. What this gets you is a whole new set of userids, meaning that user 500 will have a different 'struct user' in your namespace than in other namespaces. So any accounting information stored in struct user will be unique to your namespace. However, throughout the kernel there are checks which - simply check for a capability. Since root in a child namespace has all capabilities, this means that a child namespace is not constrained. - simply compare uid1 == uid2. Since these are the integer uids, uid 500 in namespace 1 will be said to be equal to uid 500 in namespace 2. As a result, the lxc implementation at lxc.sf.net does not use user namespaces. This is actually helpful because it leaves us free to develop user namespaces in such a way that, for some time, user namespaces may be unuseful. Bugs aside, this patchset is supposed to not at all affect systems which are not actively using user namespaces, and only restrict what tasks in child user namespace can do. They begin to limit privilege to a user namespace, so that root in a container cannot kill or ptrace tasks in the parent user namespace, and can only get world access rights to files. Since all files currently belong to the initila user namespace, that means that child user namespaces can only get world access rights to *all* files. While this temporarily makes user namespaces bad for system containers, it starts to get useful for some sandboxing. I've run the 'runltplite.sh' with and without this patchset and found no difference. This patch: copy_process() handles CLONE_NEWUSER before the rest of the namespaces. So in the case of clone(CLONE_NEWUSER|CLONE_NEWUTS) the new uts namespace will have the new user namespace as its owner. That is what we want, since we want root in that new userns to be able to have privilege over it. Changelog: Feb 15: don't set uts_ns->user_ns if we didn't create a new uts_ns. Feb 23: Move extern init_user_ns declaration from init/version.c to utsname.h. Signed-off-by: Serge E. Hallyn Acked-by: "Eric W. Biederman" Acked-by: Daniel Lezcano Acked-by: David Howells Cc: James Morris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kbuild: move utsrelease.h to include/generated

2009-12-12T12:08:15Z

Fix up all users of utsrelease.h Signed-off-by: Sam Ravnborg Signed-off-by: Michal Marek

kbuild: move compile.h to include/generated

2009-12-12T12:08:14Z

Signed-off-by: Sam Ravnborg Signed-off-by: Michal Marek

init/version.c: define version_string only if CONFIG_KALLSYMS is not defined

2008-07-25T17:53:29Z

int Version_* is only used with ksymoops, which is only needed (according to README and Documentation/Changes) if CONFIG_KALLSYMS is NOT defined. Therefore this patch defines version_string only if CONFIG_KALLSYMS is not defined. Signed-off-by: Daniel Guilak Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

init/version.c: silence sparse warning by declaring the version string

2008-07-25T17:53:28Z

Signed-off-by: Daniel Guilak Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] remove many unneeded #includes of sched.h

2007-02-14T16:09:54Z

After Al Viro (finally) succeeded in removing the sched.h #include in module.h recently, it makes sense again to remove other superfluous sched.h includes. There are quite a lot of files which include it but don't actually need anything defined in there. Presumably these includes were once needed for macros that used to live in sched.h, but moved to other header files in the course of cleaning it up. To ease the pain, this time I did not fiddle with any header files and only removed #includes from .c-files, which tend to cause less trouble. Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha, arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig, allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all configs in arch/arm/configs on arm. I also checked that no new warnings were introduced by the patch (actually, some warnings are removed that were emitted by unnecessarily included header files). Signed-off-by: Tim Schmielau Acked-by: Russell King Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Don't put "linux_banner" in the .init section

2007-01-12T02:18:04Z

It might save a few bytes after bootup, but it causes the string to be linked in at the end of the final vmlinux image, which defeats the whole point of doing all this, namely allowing some broken user-space binaries to search for the kernel version string in the kernel binary. So just remove the __init specifier. Cc: Olaf Hering Cc: Jean Delvare Cc: Roman Zippel Cc: Andrey Borzenkov Cc: Andrew Morton Acked-by: Andy Whitcroft Signed-off-by: Linus Torvalds

[PATCH] fix linux banner format string

2007-01-10T17:33:59Z

Revert previous attempts at messing with the linux banner string and simply use a separate format string for proc. Signed-off-by: Roman Zippel Acked-by: Olaf Hering Acked-by: Jean Delvare Cc: Andrey Borzenkov Cc: Andrew Morton Cc: Andy Whitcroft Cc: Herbert Poetzl Signed-off-by: Linus Torvalds

Make SLES9 "get_kernel_version" work on the kernel binary again

2006-12-11T19:34:11Z

As reported by Andy Whitcroft, at least the SLES9 initrd build process depends on getting the kernel version from the kernel binary. It does that by simply trawling the binary and looking for the signature of the "linux_banner" string (the string "Linux version " to be exact. Which is really broken in itself, but whatever..) That got broken when the string was changed to allow /proc/version to change the UTS release information dynamically, and "get_kernel_version" thus returned "%s" (see commit a2ee8649ba6d71416712e798276bf7c40b64e6e5: "[PATCH] Fix linux banner utsname information"). This just restores "linux_banner" as a static string, which should fix the version finding. And /proc/version simply uses a different string. To avoid wasting even that miniscule amount of memory, the early boot string should really be marked __initdata, but that just causes the same bug in SLES9 to re-appear, since it will then find other occurrences of "Linux version " first. Cc: Andy Whitcroft Acked-by: Herbert Poetzl Cc: Andi Kleen Cc: Andrew Morton Cc: Steve Fox Acked-by: Olaf Hering Signed-off-by: Linus Torvalds

[PATCH] Fix linux banner utsname information

2006-12-08T16:28:37Z

utsname information is shown in the linux banner, which also is used for /proc/version (which can have different utsname values inside a uts namespaces). this patch makes the varying data arguments and changes the string to a format string, using those arguments. Signed-off-by: Herbert Poetzl Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds