linux/kernel/sys.c, branch v3.5

c/r: prctl: less paranoid prctl_set_mm_exe_file()

2012-07-11T23:04:43Z

"no other files mapped" requirement from my previous patch (c/r: prctl: update prctl_set_mm_exe_file() after mm->num_exe_file_vmas removal) is too paranoid, it forbids operation even if there mapped one shared-anon vma. Let's check that current mm->exe_file already unmapped, in this case exe_file symlink already outdated and its changing is reasonable. Plus, this patch fixes exit code in case operation success. Signed-off-by: Konstantin Khlebnikov Reported-by: Cyrill Gorcunov Tested-by: Cyrill Gorcunov Cc: Oleg Nesterov Cc: Matt Helsley Cc: Kees Cook Cc: KOSAKI Motohiro Cc: Tejun Heo Cc: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

c/r: prctl: Move PR_GET_TID_ADDRESS to a proper place

2012-06-20T21:39:36Z

During merging of PR_GET_TID_ADDRESS patch the code has been misplaced (it happened to appear under PR_MCE_KILL) in result noone can use this option. Fix it by moving code snippet to a proper place. Signed-off-by: Cyrill Gorcunov Acked-by: Kees Cook Cc: Oleg Nesterov Cc: Pavel Emelyanov Cc: Andrey Vagin Cc: Serge Hallyn Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

c/r: prctl: drop VMA flags test on PR_SET_MM_ stack data assignment

2012-06-07T21:43:55Z

In commit b76437579d13 ("procfs: mark thread stack correctly in proc//maps") the stack allocated via clone() is marked in /proc//maps as [stack:%d] thus it might be out of the former mm->start_stack/end_stack values (and even has some custom VMA flags set). So to be able to restore mm->start_stack/end_stack drop vma flags test, but still require the underlying VMA to exist. As always note this feature is under CONFIG_CHECKPOINT_RESTORE and requires CAP_SYS_RESOURCE to be granted. Signed-off-by: Cyrill Gorcunov Cc: Oleg Nesterov Acked-by: Kees Cook Cc: Pavel Emelyanov Cc: Serge Hallyn Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

c/r: prctl: add ability to get clear_tid_address

2012-06-07T21:43:55Z

Zero is written at clear_tid_address when the process exits. This functionality is used by pthread_join(). We already have sys_set_tid_address() to change this address for the current task but there is no way to obtain it from user space. Without the ability to find this address and dump it we can't restore pthread'ed apps which call pthread_join() once they have been restored. This patch introduces the PR_GET_TID_ADDRESS prctl option which allows the current process to obtain own clear_tid_address. This feature is available iif CONFIG_CHECKPOINT_RESTORE is set. [akpm@linux-foundation.org: fix prctl numbering] Signed-off-by: Andrew Vagin Signed-off-by: Cyrill Gorcunov Cc: Pedro Alves Cc: Oleg Nesterov Cc: Pavel Emelyanov Cc: Tejun Heo Acked-by: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

c/r: prctl: add minimal address test to PR_SET_MM

2012-06-07T21:43:55Z

Make sure the address being set is greater than mmap_min_addr (as suggested by Kees Cook). Signed-off-by: Cyrill Gorcunov Acked-by: Kees Cook Cc: Serge Hallyn Cc: Tejun Heo Cc: Pavel Emelyanov Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

c/r: prctl: update prctl_set_mm_exe_file() after mm->num_exe_file_vmas removal

2012-06-07T21:43:55Z

A fix for commit b32dfe377102 ("c/r: prctl: add ability to set new mm_struct::exe_file"). After removing mm->num_exe_file_vmas kernel keeps mm->exe_file until final mmput(), it never becomes NULL while task is alive. We can check for other mapped files in mm instead of checking mm->num_exe_file_vmas, and mark mm with flag MMF_EXE_FILE_CHANGED in order to forbid second changing of mm->exe_file. Signed-off-by: Konstantin Khlebnikov Reviewed-by: Cyrill Gorcunov Cc: Oleg Nesterov Cc: Matt Helsley Cc: Kees Cook Cc: KOSAKI Motohiro Cc: Tejun Heo Cc: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

c/r: prctl: add ability to set new mm_struct::exe_file

2012-06-01T00:49:32Z

When we do restore we would like to have a way to setup a former mm_struct::exe_file so that /proc/pid/exe would point to the original executable file a process had at checkpoint time. For this the PR_SET_MM_EXE_FILE code is introduced. This option takes a file descriptor which will be set as a source for new /proc/$pid/exe symlink. Note it allows to change /proc/$pid/exe if there are no VM_EXECUTABLE vmas present for current process, simply because this feature is a special to C/R and mm::num_exe_file_vmas become meaningless after that. To minimize the amount of transition the /proc/pid/exe symlink might have, this feature is implemented in one-shot manner. Thus once changed the symlink can't be changed again. This should help sysadmins to monitor the symlinks over all process running in a system. In particular one could make a snapshot of processes and ring alarm if there unexpected changes of /proc/pid/exe's in a system. Note -- this feature is available iif CONFIG_CHECKPOINT_RESTORE is set and the caller must have CAP_SYS_RESOURCE capability granted, otherwise the request to change symlink will be rejected. Signed-off-by: Cyrill Gorcunov Reviewed-by: Oleg Nesterov Cc: KOSAKI Motohiro Cc: Pavel Emelyanov Cc: Kees Cook Cc: Tejun Heo Cc: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

c/r: prctl: extend PR_SET_MM to set up more mm_struct entries

2012-06-01T00:49:32Z

During checkpoint we dump whole process memory to a file and the dump includes process stack memory. But among stack data itself, the stack carries additional parameters such as command line arguments, environment data and auxiliary vector. So when we do restore procedure and once we've restored stack data itself we need to setup mm_struct::arg_start/end, env_start/end, so restored process would be able to find command line arguments and environment data it had at checkpoint time. The same applies to auxiliary vector. For this reason additional PR_SET_MM_(ARG_START | ARG_END | ENV_START | ENV_END | AUXV) codes are introduced. Signed-off-by: Cyrill Gorcunov Acked-by: Kees Cook Cc: Tejun Heo Cc: Andrew Vagin Cc: Serge Hallyn Cc: Pavel Emelyanov Cc: Vasiliy Kulikov Cc: KAMEZAWA Hiroyuki Cc: Michael Kerrisk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kmod: convert two call sites to call_usermodehelper_fns()

2012-06-01T00:49:28Z

Both kernel/sys.c && security/keys/request_key.c where inlining the exact same code as call_usermodehelper_fns(); So simply convert these sites to directly use call_usermodehelper_fns(). Signed-off-by: Boaz Harrosh Cc: Oleg Nesterov Cc: Tetsuo Handa Cc: Ingo Molnar Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sethostname/setdomainname: notify userspace when there is a change in uts_kern_table

2012-06-01T00:49:26Z

sethostname() and setdomainname() notify userspace on failure (without modifying uts_kern_table). Change things so that we only notify userspace on success, when uts_kern_table was actually modified. Signed-off-by: Sasikantha babu Cc: Paul Gortmaker Cc: Greg Kroah-Hartman Cc: WANG Cong Reviewed-by: Cyrill Gorcunov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds