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* kernel/signal.c: use __ARCH_HAS_SA_RESTORER instead of SA_RESTORERAndrew Morton2013-03-131-1/+1
| | | | | | | | | | | | | | | | __ARCH_HAS_SA_RESTORER is the preferred conditional for use in 3.9 and later kernels, per Kees. Cc: Emese Revfy <re.emese@gmail.com> Cc: Emese Revfy <re.emese@gmail.com> Cc: PaX Team <pageexec@freemail.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Julien Tinnes <jln@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* signal: always clear sa_restorer on execveKees Cook2013-03-131-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the new signal handlers are set up, the location of sa_restorer is not cleared, leaking a parent process's address space location to children. This allows for a potential bypass of the parent's ASLR by examining the sa_restorer value returned when calling sigaction(). Based on what should be considered "secret" about addresses, it only matters across the exec not the fork (since the VMAs haven't changed until the exec). But since exec sets SIG_DFL and keeps sa_restorer, this is where it should be fixed. Given the few uses of sa_restorer, a "set" function was not written since this would be the only use. Instead, we use __ARCH_HAS_SA_RESTORER, as already done in other places. Example of the leak before applying this patch: $ cat /proc/$$/maps ... 7fb9f3083000-7fb9f3238000 r-xp 00000000 fd:01 404469 .../libc-2.15.so ... $ ./leak ... 7f278bc74000-7f278be29000 r-xp 00000000 fd:01 404469 .../libc-2.15.so ... 1 0 (nil) 0x7fb9f30b94a0 2 4000000 (nil) 0x7f278bcaa4a0 3 4000000 (nil) 0x7f278bcaa4a0 4 0 (nil) 0x7fb9f30b94a0 ... [akpm@linux-foundation.org: use SA_RESTORER for backportability] Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Emese Revfy <re.emese@gmail.com> Cc: Emese Revfy <re.emese@gmail.com> Cc: PaX Team <pageexec@freemail.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Julien Tinnes <jln@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* signals: fix new kernel-doc warningsRandy Dunlap2013-03-131-1/+1
| | | | | | | | | | | Fix new kernel-doc warnings in kernel/signal.c: Warning(kernel/signal.c:2689): No description found for parameter 'uset' Warning(kernel/signal.c:2689): Excess function parameter 'set' description in 'sys_rt_sigpending' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-03-031-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull sigprocmask compat fix from Al Viro: "generic compat_sys_rt_sigprocmask() had a very dumb braino; I'd spent quite a while staring at the offending commit before finally managing to spot the idiocy ;-/" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: fix compat_sys_rt_sigprocmask()
| * fix compat_sys_rt_sigprocmask()Al Viro2013-03-031-1/+1
| | | | | | | | | | | | | | Converting bitmask to 32bit granularity is fine, but we'd better _do_ something with the result. Such as "copy it to userland"... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | kernel/signal.c: fix suboptimal printk usageValdis Kletnieks2013-02-281-4/+4
| | | | | | | | | | | | | | | | | | | | | | Several printk's were missing KERN_INFO and KERN_CONT flags. In addition, a printk that was outside a #if/#endif should have been inside, which would result in stray blank line on non-x86 boxes. Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | signal: allow to send any siginfo to itselfAndrey Vagin2013-02-281-2/+4
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The idea is simple. We need to get the siginfo for each signal on checkpointing dump, and then return it back on restore. The first problem is that the kernel doesn't report complete siginfos to userspace. In a signal handler the kernel strips SI_CODE from siginfo. When a siginfo is received from signalfd, it has a different format with fixed sizes of fields. The interface of signalfd was extended. If a signalfd is created with the flag SFD_RAW, it returns siginfo in a raw format. rt_sigqueueinfo looks suitable for restoring signals, but it can't send siginfo with a positive si_code, because these codes are reserved for the kernel. In the real world each person has right to do anything with himself, so I think a process should able to send any siginfo to itself. This patch: The kernel prevents sending of siginfo with positive si_code, because these codes are reserved for kernel. I think we can allow a task to send such a siginfo to itself. This operation should not be dangerous. This functionality is required for restoring signals in checkpoint/restart. Signed-off-by: Andrey Vagin <avagin@openvz.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-02-241-39/+293
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull signal handling cleanups from Al Viro: "This is the first pile; another one will come a bit later and will contain SYSCALL_DEFINE-related patches. - a bunch of signal-related syscalls (both native and compat) unified. - a bunch of compat syscalls switched to COMPAT_SYSCALL_DEFINE (fixing several potential problems with missing argument validation, while we are at it) - a lot of now-pointless wrappers killed - a couple of architectures (cris and hexagon) forgot to save altstack settings into sigframe, even though they used the (uninitialized) values in sigreturn; fixed. - microblaze fixes for delivery of multiple signals arriving at once - saner set of helpers for signal delivery introduced, several architectures switched to using those." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (143 commits) x86: convert to ksignal sparc: convert to ksignal arm: switch to struct ksignal * passing alpha: pass k_sigaction and siginfo_t using ksignal pointer burying unused conditionals make do_sigaltstack() static arm64: switch to generic old sigaction() (compat-only) arm64: switch to generic compat rt_sigaction() arm64: switch compat to generic old sigsuspend arm64: switch to generic compat rt_sigqueueinfo() arm64: switch to generic compat rt_sigpending() arm64: switch to generic compat rt_sigprocmask() arm64: switch to generic sigaltstack sparc: switch to generic old sigsuspend sparc: COMPAT_SYSCALL_DEFINE does all sign-extension as well as SYSCALL_DEFINE sparc: kill sign-extending wrappers for native syscalls kill sparc32_open() sparc: switch to use of generic old sigaction sparc: switch sys_compat_rt_sigaction() to COMPAT_SYSCALL_DEFINE mips: switch to generic sys_fork() and sys_clone() ...
| * burying unused conditionalsAl Viro2013-02-141-12/+0
| | | | | | | | | | | | | | | | | | __ARCH_WANT_SYS_RT_SIGACTION, __ARCH_WANT_SYS_RT_SIGSUSPEND, __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND, __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL - not used anymore CONFIG_GENERIC_{SIGALTSTACK,COMPAT_RT_SIG{ACTION,QUEUEINFO,PENDING,PROCMASK}} - can be assumed always set.
| * make do_sigaltstack() staticAl Viro2013-02-141-1/+1
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * switch mips to generic rt_sigsuspend(), make it unconditionalAl Viro2013-02-041-2/+0
| | | | | | | | | | | | | | | | mips was the last architecture not using the generic variant. Both native and compat variants switched to generic, which is made unconditional now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * new helper: signal_setup_done()Al Viro2013-02-031-0/+9
| | | | | | | | | | | | | | usual "call force_sigsegv or signal_delivered" logics. Takes ksignal instead of separate siginfo/k_sigaction. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * generic sys_sigaction() and compat_sys_sigaction()Al Viro2013-02-031-0/+78
| | | | | | | | | | | | conditional on OLD_SIGACTION/COMPAT_OLD_SIGACTION Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * generic sys_compat_rt_sigaction()Al Viro2013-02-031-0/+49
| | | | | | | | | | | | | | Again, protected by a temporary config symbol (GENERIC_COMPAT_RT_SIGACTION); will be gone by the end of series. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * switch rt_tgsigqueueinfo to COMPAT_SYSCALL_DEFINEAl Viro2013-02-031-1/+16
| | | | | | | | | | | | C ABI violations on sparc, ppc and mips Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * old sigsuspend variants in kernel/signal.cAl Viro2013-02-031-0/+17
| | | | | | | | | | | | | | conditional on OLD_SIGSUSPEND/OLD_SIGSUSPEND3, depending on which variety of that fossil is needed. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * generic compat_sys_rt_sigqueueinfo()Al Viro2013-02-031-13/+32
| | | | | | | | | | | | | | conditional on GENERIC_COMPAT_RT_SIGQUEUEINFO; by the end of that series it will become the same thing as COMPAT and conditional will die out. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * generic compat_sys_rt_sigpending()Al Viro2013-02-031-17/+35
| | | | | | | | | | | | | | conditional on GENERIC_COMPAT_RT_SIGPENDING; by the end of that series it will become the same thing as COMPAT and conditional will die out. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * generic compat_sys_rt_sigprocmask()Al Viro2013-02-031-0/+41
| | | | | | | | | | | | | | conditional on GENERIC_COMPAT_RT_SIGPROCMASK; by the end of that series it will become the same thing as COMPAT and conditional will die out. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * consolidate rt_sigsuspend()Al Viro2013-02-031-1/+23
| | | | | | | | | | | | | | | | | | * pull compat version alongside with the native one * make little-endian compat variant just call the native * don't bother with separate conditional for compat (both native and compat are going to become unconditional very soon). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * sanitize rt_sigaction() situation a bitAl Viro2013-02-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | Switch from __ARCH_WANT_SYS_RT_SIGACTION to opposite (!CONFIG_ODD_RT_SIGACTION); the only two architectures that need it are alpha and sparc. The reason for use of CONFIG_... instead of __ARCH_... is that it's needed only kernel-side and doing it that way avoids a mess with include order on many architectures. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge tag 'full-dynticks-cputime-for-mingo' of ↵Ingo Molnar2013-02-051-4/+8
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/core Pull full-dynticks (user-space execution is undisturbed and receives no timer IRQs) preparation changes that convert the cputime accounting code to be full-dynticks ready, from Frederic Weisbecker: "This implements the cputime accounting on full dynticks CPUs. Typical cputime stats infrastructure relies on the timer tick and its periodic polling on the CPU to account the amount of time spent by the CPUs and the tasks per high level domains such as userspace, kernelspace, guest, ... Now we are preparing to implement full dynticks capability on Linux for Real Time and HPC users who want full CPU isolation. This feature requires a cputime accounting that doesn't depend on the timer tick. To implement it, this new cputime infrastructure plugs into kernel/user/guest boundaries to take snapshots of cputime and flush these to the stats when needed. This performs pretty much like CONFIG_VIRT_CPU_ACCOUNTING except that context location and cputime snaphots are synchronized between write and read side such that the latter can safely retrieve the pending tickless cputime of a task and add it to its latest cputime snapshot to return the correct result to the user." Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | cputime: Use accessors to read task cputime statsFrederic Weisbecker2013-01-271-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is in preparation for the full dynticks feature. While remotely reading the cputime of a task running in a full dynticks CPU, we'll need to do some extra-computation. This way we can account the time it spent tickless in userspace since its last cputime snapshot. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
* | | ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILLOleg Nesterov2013-01-221-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | putreg() assumes that the tracee is not running and pt_regs_access() can safely play with its stack. However a killed tracee can return from ptrace_stop() to the low-level asm code and do RESTORE_REST, this means that debugger can actually read/modify the kernel stack until the tracee does SAVE_REST again. set_task_blockstep() can race with SIGKILL too and in some sense this race is even worse, the very fact the tracee can be woken up breaks the logic. As Linus suggested we can clear TASK_WAKEKILL around the arch_ptrace() call, this ensures that nobody can ever wakeup the tracee while the debugger looks at it. Not only this fixes the mentioned problems, we can do some cleanups/simplifications in arch_ptrace() paths. Probably ptrace_unfreeze_traced() needs more callers, for example it makes sense to make the tracee killable for oom-killer before access_process_vm(). While at it, add the comment into may_ptrace_stop() to explain why ptrace_stop() still can't rely on SIGKILL and signal_pending_state(). Reported-by: Salman Qazi <sqazi@google.com> Reported-by: Suleiman Souhlal <suleiman@google.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | ptrace: introduce signal_wake_up_state() and ptrace_signal_wake_up()Oleg Nesterov2013-01-221-10/+4
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cleanup and preparation for the next change. signal_wake_up(resume => true) is overused. None of ptrace/jctl callers actually want to wakeup a TASK_WAKEKILL task, but they can't specify the necessary mask. Turn signal_wake_up() into signal_wake_up_state(state), reintroduce signal_wake_up() as a trivial helper, and add ptrace_signal_wake_up() which adds __TASK_TRACED. This way ptrace_signal_wake_up() can work "inside" ptrace_request() even if the tracee doesn't have the TASK_WAKEKILL bit set. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-linus' of ↵Linus Torvalds2013-01-201-2/+3
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull misc syscall fixes from Al Viro: - compat syscall fixes (discussed back in December) - a couple of "make life easier for sigaltstack stuff by reducing inter-tree dependencies" - fix up compiler/asmlinkage calling convention disagreement of sys_clone() - misc * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: sys_clone() needs asmlinkage_protect make sure that /linuxrc has std{in,out,err} x32: fix sigtimedwait x32: fix waitid() switch compat_sys_wait4() and compat_sys_waitid() to COMPAT_SYSCALL_DEFINE switch compat_sys_sigaltstack() to COMPAT_SYSCALL_DEFINE CONFIG_GENERIC_SIGALTSTACK build breakage with asm-generic/syscalls.h Ensure that kernel_init_freeable() is not inlined into non __init code
| * switch compat_sys_sigaltstack() to COMPAT_SYSCALL_DEFINEAl Viro2012-12-261-2/+3
| | | | | | | | | | | | | | Makes sigaltstack conversion easier to split into per-architecture parts. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | signals: set_current_blocked() can use __set_current_blocked()Oleg Nesterov2013-01-061-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Cleanup. And I think we need more cleanups, in particular __set_current_blocked() and sigprocmask() should die. Nobody should ever block SIGKILL or SIGSTOP. - Change set_current_blocked() to use __set_current_blocked() - Change sys_sigprocmask() to use set_current_blocked(), this way it should not worry about SIGKILL/SIGSTOP. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | signals: sys_ssetmask() uses uninitialized newmaskOleg Nesterov2013-01-061-0/+1
|/ | | | | | | | | | | | | | | Commit 77097ae503b1 ("most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set") removed the initialization of newmask by accident, causing ltp to complain like this: ssetmask01 1 TFAIL : sgetmask() failed: TEST_ERRNO=???(0): Success Restore the proper initialization. Reported-and-tested-by: CAI Qian <caiqian@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: stable@kernel.org # v3.5+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-12-211-0/+74
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull signal handling cleanups from Al Viro: "sigaltstack infrastructure + conversion for x86, alpha and um, COMPAT_SYSCALL_DEFINE infrastructure. Note that there are several conflicts between "unify SS_ONSTACK/SS_DISABLE definitions" and UAPI patches in mainline; resolution is trivial - just remove definitions of SS_ONSTACK and SS_DISABLED from arch/*/uapi/asm/signal.h; they are all identical and include/uapi/linux/signal.h contains the unified variant." Fixed up conflicts as per Al. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: alpha: switch to generic sigaltstack new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those generic compat_sys_sigaltstack() introduce generic sys_sigaltstack(), switch x86 and um to it new helper: compat_user_stack_pointer() new helper: restore_altstack() unify SS_ONSTACK/SS_DISABLE definitions new helper: current_user_stack_pointer() missing user_stack_pointer() instances Bury the conditionals from kernel_thread/kernel_execve series COMPAT_SYSCALL_DEFINE: infrastructure
| * new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to thoseAl Viro2012-12-201-0/+16
| | | | | | | | | | | | note that they are relying on access_ok() already checked by caller. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * generic compat_sys_sigaltstack()Al Viro2012-12-201-0/+45
| | | | | | | | | | | | Again, conditional on CONFIG_GENERIC_SIGALTSTACK Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * introduce generic sys_sigaltstack(), switch x86 and um to itAl Viro2012-12-201-0/+6
| | | | | | | | | | | | | | Conditional on CONFIG_GENERIC_SIGALTSTACK; architectures that do not select it are completely unaffected Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * new helper: restore_altstack()Al Viro2012-12-201-0/+7
| | | | | | | | | | | | to be used by rt_sigreturn instances Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-12-181-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace changes from Eric Biederman: "While small this set of changes is very significant with respect to containers in general and user namespaces in particular. The user space interface is now complete. This set of changes adds support for unprivileged users to create user namespaces and as a user namespace root to create other namespaces. The tyranny of supporting suid root preventing unprivileged users from using cool new kernel features is broken. This set of changes completes the work on setns, adding support for the pid, user, mount namespaces. This set of changes includes a bunch of basic pid namespace cleanups/simplifications. Of particular significance is the rework of the pid namespace cleanup so it no longer requires sending out tendrils into all kinds of unexpected cleanup paths for operation. At least one case of broken error handling is fixed by this cleanup. The files under /proc/<pid>/ns/ have been converted from regular files to magic symlinks which prevents incorrect caching by the VFS, ensuring the files always refer to the namespace the process is currently using and ensuring that the ptrace_mayaccess permission checks are always applied. The files under /proc/<pid>/ns/ have been given stable inode numbers so it is now possible to see if different processes share the same namespaces. Through the David Miller's net tree are changes to relax many of the permission checks in the networking stack to allowing the user namespace root to usefully use the networking stack. Similar changes for the mount namespace and the pid namespace are coming through my tree. Two small changes to add user namespace support were commited here adn in David Miller's -net tree so that I could complete the work on the /proc/<pid>/ns/ files in this tree. Work remains to make it safe to build user namespaces and 9p, afs, ceph, cifs, coda, gfs2, ncpfs, nfs, nfsd, ocfs2, and xfs so the Kconfig guard remains in place preventing that user namespaces from being built when any of those filesystems are enabled. Future design work remains to allow root users outside of the initial user namespace to mount more than just /proc and /sys." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (38 commits) proc: Usable inode numbers for the namespace file descriptors. proc: Fix the namespace inode permission checks. proc: Generalize proc inode allocation userns: Allow unprivilged mounts of proc and sysfs userns: For /proc/self/{uid,gid}_map derive the lower userns from the struct file procfs: Print task uids and gids in the userns that opened the proc file userns: Implement unshare of the user namespace userns: Implent proc namespace operations userns: Kill task_user_ns userns: Make create_new_namespaces take a user_ns parameter userns: Allow unprivileged use of setns. userns: Allow unprivileged users to create new namespaces userns: Allow setting a userns mapping to your current uid. userns: Allow chown and setgid preservation userns: Allow unprivileged users to create user namespaces. userns: Ignore suid and sgid on binaries if the uid or gid can not be mapped userns: fix return value on mntns_install() failure vfs: Allow unprivileged manipulation of the mount namespace. vfs: Only support slave subtrees across different user namespaces vfs: Add a user namespace reference from struct mnt_namespace ...
| * | pidns: Use task_active_pid_ns where appropriateEric W. Biederman2012-11-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The expressions tsk->nsproxy->pid_ns and task_active_pid_ns aka ns_of_pid(task_pid(tsk)) should have the same number of cache line misses with the practical difference that ns_of_pid(task_pid(tsk)) is released later in a processes life. Furthermore by using task_active_pid_ns it becomes trivial to write an unshare implementation for the the pid namespace. So I have used task_active_pid_ns everywhere I can. In fork since the pid has not yet been attached to the process I use ns_of_pid, to achieve the same effect. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2012-12-121-8/+7
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull big execve/kernel_thread/fork unification series from Al Viro: "All architectures are converted to new model. Quite a bit of that stuff is actually shared with architecture trees; in such cases it's literally shared branch pulled by both, not a cherry-pick. A lot of ugliness and black magic is gone (-3KLoC total in this one): - kernel_thread()/kernel_execve()/sys_execve() redesign. We don't do syscalls from kernel anymore for either kernel_thread() or kernel_execve(): kernel_thread() is essentially clone(2) with callback run before we return to userland, the callbacks either never return or do successful do_execve() before returning. kernel_execve() is a wrapper for do_execve() - it doesn't need to do transition to user mode anymore. As a result kernel_thread() and kernel_execve() are arch-independent now - they live in kernel/fork.c and fs/exec.c resp. sys_execve() is also in fs/exec.c and it's completely architecture-independent. - daemonize() is gone, along with its parts in fs/*.c - struct pt_regs * is no longer passed to do_fork/copy_process/ copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump. - sys_fork()/sys_vfork()/sys_clone() unified; some architectures still need wrappers (ones with callee-saved registers not saved in pt_regs on syscall entry), but the main part of those suckers is in kernel/fork.c now." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits) do_coredump(): get rid of pt_regs argument print_fatal_signal(): get rid of pt_regs argument ptrace_signal(): get rid of unused arguments get rid of ptrace_signal_deliver() arguments new helper: signal_pt_regs() unify default ptrace_signal_deliver flagday: kill pt_regs argument of do_fork() death to idle_regs() don't pass regs to copy_process() flagday: don't pass regs to copy_thread() bfin: switch to generic vfork, get rid of pointless wrappers xtensa: switch to generic clone() openrisc: switch to use of generic fork and clone unicore32: switch to generic clone(2) score: switch to generic fork/vfork/clone c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone() take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h mn10300: switch to generic fork/vfork/clone h8300: switch to generic fork/vfork/clone tile: switch to generic clone() ... Conflicts: arch/microblaze/include/asm/Kbuild
| * | do_coredump(): get rid of pt_regs argumentAl Viro2012-11-291-1/+1
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | print_fatal_signal(): get rid of pt_regs argumentAl Viro2012-11-291-2/+3
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | ptrace_signal(): get rid of unused argumentsAl Viro2012-11-291-4/+2
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | get rid of ptrace_signal_deliver() argumentsAl Viro2012-11-291-1/+1
| |/ | | | | | | | | | | | | the first one is equal to signal_pt_regs(), the second is never used (and always NULL, while we are at it). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* / freezer: change ptrace_stop/do_signal_stop to use freezable_schedule()Oleg Nesterov2012-10-261-14/+6
|/ | | | | | | | | | | | | | | | | | | | | | | | try_to_freeze_tasks() and cgroup_freezer rely on scheduler locks to ensure that a task doing STOPPED/TRACED -> RUNNING transition can't escape freezing. This mostly works, but ptrace_stop() does not necessarily call schedule(), it can change task->state back to RUNNING and check freezing() without any lock/barrier in between. We could add the necessary barrier, but this patch changes ptrace_stop() and do_signal_stop() to use freezable_schedule(). This fixes the race, freezer_count() and freezer_should_skip() carefully avoid the race. And this simplifies the code, try_to_freeze_tasks/update_if_frozen no longer need to use task_is_stopped_or_traced() checks with the non trivial assumptions. We can rely on the mechanism which was specially designed to mark the sleeping task as "frozen enough". v2: As Tejun pointed out, we can also change get_signal_to_deliver() and move try_to_freeze() up before 'relock' label. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* coredump: pass siginfo_t* to do_coredump() and below, not merely signrDenys Vlasenko2012-10-051-1/+1
| | | | | | | | | | | | | | | | | | | This is a preparatory patch for the introduction of NT_SIGINFO elf note. With this patch we pass "siginfo_t *siginfo" instead of "int signr" to do_coredump() and put it into coredump_params. It will be used by the next patch. Most changes are simple s/signr/siginfo->si_signo/. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: "Jonathan M. Foote" <jmfoote@cert.org> Cc: Roland McGrath <roland@hack.frob.com> Cc: Pedro Alves <palves@redhat.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump: update coredump-related headersAlex Kelly2012-10-051-0/+1
| | | | | | | | | | | | | Create a new header file, fs/coredump.h, which contains functions only used by the new coredump.c. It also moves do_coredump to the include/linux/coredump.h header file, for consistency. Signed-off-by: Alex Kelly <alex.page.kelly@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* task_work: Simplify the usage in ptrace_notify() and get_signal_to_deliver()Oleg Nesterov2012-09-131-14/+4
| | | | | | | | | | | | | | | | | | | | | | | ptrace_notify() and get_signal_to_deliver() do unnecessary things before task_work_run(): 1. smp_mb__after_clear_bit() is not needed, test_and_clear_bit() implies mb(). 2. And we do not need the barrier at all, in this case we only care about the "synchronous" works added by the task itself. 3. No need to clear TIF_NOTIFY_RESUME, and we should not assume task_works is the only user of this flag. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20120826191217.GA4238@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* signal: make sure we don't get stopped with pending task_workAl Viro2012-07-221-0/+15
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helper: signal_delivered()Al Viro2012-06-011-9/+13
| | | | | | | | | | | | | | Does block_sigmask() + tracehook_signal_handler(); called when sigframe has been successfully built. All architectures converted to it; block_sigmask() itself is gone now (merged into this one). I'm still not too happy with the signature, but that's a separate story (IMO we need a structure that would contain signal number + siginfo + k_sigaction, so that get_signal_to_deliver() would fill one, signal_delivered(), handle_signal() and probably setup...frame() - take one). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from setAl Viro2012-06-011-6/+12
| | | | | | | | Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(), added set_current_blocked() that will exclude unblockable signals, switched open-coded instances to it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pull clearing RESTORE_SIGMASK into block_sigmask()Al Viro2012-06-011-0/+6
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* HAVE_RESTORE_SIGMASK is defined on all architectures nowAl Viro2012-06-011-2/+0
| | | | | | | | | Everyone either defines it in arch thread_info.h or has TIF_RESTORE_SIGMASK and picks default set_restore_sigmask() in linux/thread_info.h. Kill the ifdefs, slap #error in linux/thread_info.h to catch breakage when new ones get merged. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>