pm24.git/include/linux/mm_types.h, branch v4.12

x86/mm: Introduce mmap_compat_base() for 32-bit mmap()

2017-03-13T13:59:22Z

mmap() uses a base address, from which it starts to look for a free space for allocation. The base address is stored in mm->mmap_base, which is calculated during exec(). The address depends on task's size, set rlimit for stack, ASLR randomization. The base depends on the task size and the number of random bits which are different for 64-bit and 32bit applications. Due to the fact, that the base address is fixed, its mmap() from a compat (32bit) syscall issued by a 64bit task will return a address which is based on the 64bit base address and does not fit into the 32bit address space (4GB). The returned pointer is truncated to 32bit, which results in an invalid address. To solve store a seperate compat address base plus a compat legacy address base in mm_struct. These bases are calculated at exec() time and can be used later to address the 32bit compat mmap() issued by 64 bit applications. As a consequence of this change 32-bit applications issuing a 64-bit syscall (after doing a long jump) will get a 64-bit mapping now. Before this change 32-bit applications always got a 32bit mapping. [ tglx: Massaged changelog and added a comment ] Signed-off-by: Dmitry Safonov Cc: 0x7f454c46@gmail.com Cc: linux-mm@kvack.org Cc: Andy Lutomirski Cc: Cyrill Gorcunov Cc: Borislav Petkov Cc: "Kirill A. Shutemov" Link: http://lkml.kernel.org/r/20170306141721.9188-4-dsafonov@virtuozzo.com Signed-off-by: Thomas Gleixner

mm/headers, sched/headers: Move task related MM types from to

2017-03-03T00:43:48Z

Separate all the MM types that are embedded directly in 'struct task_struct' into the header. The goal is to include this header in , not the full header, to reduce the size, complexity and coupling of . (This patch does not change yet.) Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

sched/headers: Move the 'init_mm' declaration from to

2017-03-03T00:43:39Z

Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

mm/headers, sched/headers: Prepare to split out of

2017-03-02T07:42:37Z

We are going to separate all the MM types that are embedded directly in 'struct task_struct' into the new header. Create a new that only contains some includes from mm_types.h itself. This should be trivially correct and easy to bisect to. (This patch does not materially move the types yet.) Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

mm/vmacache, sched/headers: Introduce 'struct vmacache' and move it from to

2017-03-02T07:42:25Z

The header includes various vmacache related defines, which are arguably misplaced. Move them to mm_types.h and minimize the sched.h impact by putting all task vmacache state into a new 'struct vmacache' structure. No change in functionality. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

mm: clarify mm_struct.mm_{users,count} documentation

2017-02-28T02:43:48Z

Clarify documentation relating to mm_users and mm_count, and switch to kernel-doc syntax. Link: http://lkml.kernel.org/r/20161218123229.22952-4-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum Acked-by: Michal Hocko Acked-by: Peter Zijlstra (Intel) Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-12-18T19:12:53Z

Pull x86 fixes and cleanups from Thomas Gleixner: "This set of updates contains: - Robustification for the logical package managment. Cures the AMD and virtualization issues. - Put the correct start_cpu() return address on the stack of the idle task. - Fixups for the fallout of the nodeid <-> cpuid persistent mapping modifciations - Move the x86/MPX specific mm_struct member to the arch specific mm_context where it belongs - Cleanups for C89 struct initializers and useless function arguments" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/floppy: Use designated initializers x86/mpx: Move bd_addr to mm_context_t x86/mm: Drop unused argument 'removed' from sync_global_pgds() ACPI/NUMA: Do not map pxm to node when NUMA is turned off x86/acpi: Use proper macro for invalid node x86/smpboot: Prevent false positive out of bounds cpumask access warning x86/boot/64: Push correct start_cpu() return address x86/boot/64: Use 'push' instead of 'call' in start_cpu() x86/smpboot: Make logical package management more robust

x86/mpx: Move bd_addr to mm_context_t

2016-12-17T11:29:56Z

Currently bd_addr lives in mm_struct, which is otherwise architecture independent. Architecture-specific data is supposed to live within mm_context_t (itself contained in mm_struct). Other x86-specific context like the pkey accounting data lives in mm_context_t, and there's no readon the MPX data can't also live there. So as to keep the arch-specific data togather, and to set a good example for others, this patch moves bd_addr into x86's mm_context_t. Signed-off-by: Mark Rutland Acked-by: Dave Hansen Cc: Andrew Morton Link: http://lkml.kernel.org/r/1481892055-24596-1-git-send-email-mark.rutland@arm.com Signed-off-by: Thomas Gleixner

mm: Add a user_ns owner to mm_struct and fix ptrace permission checks

2016-11-22T17:49:48Z

During exec dumpable is cleared if the file that is being executed is not readable by the user executing the file. A bug in ptrace_may_access allows reading the file if the executable happens to enter into a subordinate user namespace (aka clone(CLONE_NEWUSER), unshare(CLONE_NEWUSER), or setns(fd, CLONE_NEWUSER). This problem is fixed with only necessary userspace breakage by adding a user namespace owner to mm_struct, captured at the time of exec, so it is clear in which user namespace CAP_SYS_PTRACE must be present in to be able to safely give read permission to the executable. The function ptrace_may_access is modified to verify that the ptracer has CAP_SYS_ADMIN in task->mm->user_ns instead of task->cred->user_ns. This ensures that if the task changes it's cred into a subordinate user namespace it does not become ptraceable. The function ptrace_attach is modified to only set PT_PTRACE_CAP when CAP_SYS_PTRACE is held over task->mm->user_ns. The intent of PT_PTRACE_CAP is to be a flag to note that whatever permission changes the task might go through the tracer has sufficient permissions for it not to be an issue. task->cred->user_ns is always the same as or descendent of mm->user_ns. Which guarantees that having CAP_SYS_PTRACE over mm->user_ns is the worst case for the tasks credentials. To prevent regressions mm->dumpable and mm->user_ns are not considered when a task has no mm. As simply failing ptrace_may_attach causes regressions in privileged applications attempting to read things such as /proc//stat Cc: stable@vger.kernel.org Acked-by: Kees Cook Tested-by: Cyrill Gorcunov Fixes: 8409cca70561 ("userns: allow ptrace from non-init user namespaces") Signed-off-by: "Eric W. Biederman"

kernel, oom: fix potential pgd_lock deadlock from __mmdrop

2016-10-08T01:46:27Z

Lockdep complains that __mmdrop is not safe from the softirq context: ================================= [ INFO: inconsistent lock state ] 4.6.0-oomfortification2-00011-geeb3eadeab96-dirty #949 Tainted: G W --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes: (pgd_lock){+.?...}, at: pgd_free+0x19/0x6b {SOFTIRQ-ON-W} state was registered at: __lock_acquire+0xa06/0x196e lock_acquire+0x139/0x1e1 _raw_spin_lock+0x32/0x41 __change_page_attr_set_clr+0x2a5/0xacd change_page_attr_set_clr+0x16f/0x32c set_memory_nx+0x37/0x3a free_init_pages+0x9e/0xc7 alternative_instructions+0xa2/0xb3 check_bugs+0xe/0x2d start_kernel+0x3ce/0x3ea x86_64_start_reservations+0x2a/0x2c x86_64_start_kernel+0x17a/0x18d irq event stamp: 105916 hardirqs last enabled at (105916): free_hot_cold_page+0x37e/0x390 hardirqs last disabled at (105915): free_hot_cold_page+0x2c1/0x390 softirqs last enabled at (105878): _local_bh_enable+0x42/0x44 softirqs last disabled at (105879): irq_exit+0x6f/0xd1 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(pgd_lock); lock(pgd_lock); *** DEADLOCK *** 1 lock held by swapper/1/0: #0: (rcu_callback){......}, at: rcu_process_callbacks+0x390/0x800 stack backtrace: CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 4.6.0-oomfortification2-00011-geeb3eadeab96-dirty #949 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 Call Trace: print_usage_bug.part.25+0x259/0x268 mark_lock+0x381/0x567 __lock_acquire+0x993/0x196e lock_acquire+0x139/0x1e1 _raw_spin_lock+0x32/0x41 pgd_free+0x19/0x6b __mmdrop+0x25/0xb9 __put_task_struct+0x103/0x11e delayed_put_task_struct+0x157/0x15e rcu_process_callbacks+0x660/0x800 __do_softirq+0x1ec/0x4d5 irq_exit+0x6f/0xd1 smp_apic_timer_interrupt+0x42/0x4d apic_timer_interrupt+0x8e/0xa0 arch_cpu_idle+0xf/0x11 default_idle_call+0x32/0x34 cpu_startup_entry+0x20c/0x399 start_secondary+0xfe/0x101 More over commit a79e53d85683 ("x86/mm: Fix pgd_lock deadlock") was explicit about pgd_lock not to be called from the irq context. This means that __mmdrop called from free_signal_struct has to be postponed to a user context. We already have a similar mechanism for mmput_async so we can use it here as well. This is safe because mm_count is pinned by mm_users. This fixes bug introduced by "oom: keep mm of the killed task available" Link: http://lkml.kernel.org/r/1472119394-11342-5-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko Cc: Tetsuo Handa Cc: Oleg Nesterov Cc: David Rientjes Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds