- 16 Sep, 2016 3 commits
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Oleg Nesterov authored
get_task_struct(tsk) no longer pins tsk->stack so all users of to_live_kthread() should do try_get_task_stack/put_task_stack to protect "struct kthread" which lives on kthread's stack. TODO: Kill to_live_kthread(), perhaps we can even kill "struct kthread" too, and rework kthread_stop(), it can use task_work_add() to sync with the exiting kernel thread. Message-Id: <20160629180357.GA7178@redhat.com> Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Signed-off-by:
Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jann Horn <jann@thejh.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/cb9b16bbc19d4aea4507ab0552e4644c1211d130.1474003868.git.luto@kernel.orgSigned-off-by:
Ingo Molnar <mingo@kernel.org>
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Andy Lutomirski authored
There are a few places in the kernel that access stack memory belonging to a different task. Before we can start freeing task stacks before the task_struct is freed, we need a way for those code paths to pin the stack. Signed-off-by:
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Andy Lutomirski authored
When I rebased my thread_info changes onto Brian's switch_to() changes, I carefully checked that I fixed up all the code correctly, but I missed a comment :( Signed-off-by:
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- 15 Sep, 2016 11 commits
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Joerg Roedel authored
The semaphore used by the AMD IOMMU to signal command completion lived on the stack until now, which was safe as the driver busy-waited on the semaphore with IRQs disabled, so the stack can't go away under the driver. But the recently introduced vmap-based stacks break this as the physical address of the semaphore can't be determinded easily anymore. The driver used the __pa() macro, but that only works in the direct-mapping. The result were Completion-Wait timeout errors seen by the IOMMU driver, breaking system boot. Since putting the semaphore on the stack is bad design anyway, move the semaphore into 'struct amd_iommu'. It is protected by the per-iommu lock and now in the direct mapping again. This fixes the Completion-Wait timeout errors and makes AMD IOMMU systems boot again with vmap-based stacks enabled. Reported-by:
Borislav Petkov <bp@alien8.de> Signed-off-by:
Joerg Roedel <jroedel@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Andy Lutomirski authored
Now that most of the thread_info users have been cleaned up, this is straightforward. Most of this code was written by Linus. Originally-from: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Andy Lutomirski authored
If an arch opts in by setting CONFIG_THREAD_INFO_IN_TASK_STRUCT, then thread_info is defined as a single 'u32 flags' and is the first entry of task_struct. thread_info::task is removed (it serves no purpose if thread_info is embedded in task_struct), and thread_info::cpu gets its own slot in task_struct. This is heavily based on a patch written by Linus. Originally-from: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Linus Torvalds authored
thread_info may move in the future, so use the accessors. [ Andy Lutomirski wrote this changelog message and changed "task_thread_info(child)->cpu" to "task_cpu(child)". ] Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Linus Torvalds authored
It was a nice optimization while it lasted, but thread_info is moving and this optimization will no longer work. Quoting Linus: Oh Gods, Andy. That pt_regs_to_thread_info() thing made me want to do unspeakable acts on a poor innocent wax figure that looked _exactly_ like you. [ Changelog written by Andy. ] Signed-off-by: -
Andy Lutomirski authored
Because sched.h and thread_info.h are a tangled mess, I turned in_compat_syscall() into a macro. If we had current_thread_struct() or similar and we could use it from thread_info.h, then this would be a bit cleaner. Signed-off-by:
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Ingo Molnar authored
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Josh Poimboeuf authored
in_exception_stack() has some recursion checking which makes sure the stack trace code never traverses a given exception stack more than once. This prevents an infinite loop if corruption somehow causes a stack's "next stack" pointer to point to itself (directly or indirectly). The recursion checking can be useful for other stacks in addition to the exception stack, so extend it to work for all stacks. Signed-off-by:
Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/95de5db4cfe111754845a5cef04e20630d01423f.1473905218.git.jpoimboe@redhat.comSigned-off-by:
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Josh Poimboeuf authored
When an interrupt happens in entry code while running on a software IRQ stack, and the IRQ stack was empty, regs->sp will contain the stack end address (e.g., irq_stack_ptr). If the regs are passed to dump_trace(), get_stack_info() will report STACK_TYPE_UNKNOWN, causing dump_trace() to return prematurely without trying to go to the next stack. Update the bounds checking for software interrupt stacks so that the ending address is now considered part of the stack. This means that it's now possible for the 'walk_stack' callbacks -- print_context_stack() and print_context_stack_bp() -- to be called with an empty stack. But that's fine; they're already prepared to deal with that due to their on_stack() checks. Signed-off-by:
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Josh Poimboeuf authored
valid_stack_ptr() is buggy: it assumes that all stacks are of size THREAD_SIZE, which is not true for exception stacks. So the walk_stack() callbacks will need to know the location of the beginning of the stack as well as the end. Another issue is that in general the various features of a stack (type, size, next stack pointer, description string) are scattered around in various places throughout the stack dump code. Encapsulate all that information in a single place with a new stack_info struct and a get_stack_info() interface. Signed-off-by:
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Josh Poimboeuf authored
in_exception_stack() does some bad, bad things just so the unwinder can print different values for different areas of the debug exception stack. There's no need to clarify where exactly on the stack it is. Just print "#DB" and be done with it. Signed-off-by:
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- 14 Sep, 2016 5 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pciLinus Torvalds authored
Pull PCI fixes from Bjorn Helgaas: "Here are two changes for v4.8. The first fixes a "[Firmware Bug]: reg 0x10: invalid BAR (can't size)" warning on Haswell, and the second fixes a problem in some new runtime suspend functionality we merged for v4.8. Summary: Enumeration: Mark Haswell Power Control Unit as having non-compliant BARs (Bjorn Helgaas) Power management: Fix bridge_d3 update on device removal (Lukas Wunner)" * tag 'pci-v4.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: PCI: Fix bridge_d3 update on device removal PCI: Mark Haswell Power Control Unit as having non-compliant BARs -
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds authored
Pull uaccess fixes from Al Viro: "Fixes for broken uaccess primitives - mostly lack of proper zeroing in copy_from_user()/get_user()/__get_user(), but for several architectures there's more (broken clear_user() on frv and strncpy_from_user() on hexagon)" * 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) avr32: fix copy_from_user() microblaze: fix __get_user() microblaze: fix copy_from_user() m32r: fix __get_user() blackfin: fix copy_from_user() sparc32: fix copy_from_user() sh: fix copy_from_user() sh64: failing __get_user() should zero score: fix copy_from_user() and friends score: fix __get_user/get_user s390: get_user() should zero on failure ppc32: fix copy_from_user() parisc: fix copy_from_user() openrisc: fix copy_from_user() nios2: fix __get_user() nios2: copy_from_user() should zero the tail of destination mn10300: copy_from_user() should zero on access_ok() failure... mn10300: failing __get_user() and get_user() should zero mips: copy_from_user() must zero the destination on access_ok() failure ARC: uaccess: get_user to zero out dest in cause of fault ...
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git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds authored
Pull xen regression fix from David Vrabel: "Fix SMP boot in arm guests" * tag 'for-linus-4.8b-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: arm/xen: fix SMP guests boot
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Josh Poimboeuf authored
show_stack_log_lvl() and dump_trace() are already preemption safe: - If they're running in irq or exception context, preemption is already disabled and the percpu stack pointers can be trusted. - If they're running with preemption enabled, they must be running on the task stack anyway, so it doesn't matter if they're comparing the stack pointer against a percpu stack pointer from this CPU or another one: either way it won't match. Signed-off-by:
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Vitaly Kuznetsov authored
Commit 88e957d6 ("xen: introduce xen_vcpu_id mapping") broke SMP ARM guests on Xen. When FIFO-based event channels are in use (this is the default), evtchn_fifo_alloc_control_block() is called on CPU_UP_PREPARE event and this happens before we set up xen_vcpu_id mapping in xen_starting_cpu. Temporary fix the issue by setting direct Linux CPU id <-> Xen vCPU id mapping for all possible CPUs at boot. We don't currently support kexec/kdump on Xen/ARM so these ids always match. In future, we have several ways to solve the issue, e.g.: - Eliminate all hypercalls from CPU_UP_PREPARE, do them from the starting CPU. This can probably be done for both x86 and ARM and, if done, will allow us to get Xen's idea of vCPU id from CPUID/MPIDR on the starting CPU directly, no messing with ACPI/device tree required. - Save vCPU id information from ACPI/device tree on ARM and use it to initialize xen_vcpu_id mapping. This is the same trick we currently do on x86. Reported-by:
Julien Grall <julien.grall@arm.com> Tested-by:
Wei Chen <Wei.Chen@arm.com> Signed-off-by:
Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by:
Stefano Stabellini <sstabellini@kernel.org> Signed-off-by:
David Vrabel <david.vrabel@citrix.com>
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- 13 Sep, 2016 21 commits
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Al Viro authored
really ugly, but apparently avr32 compilers turns access_ok() into something so bad that they want it in assembler. Left that way, zeroing added in inline wrapper. Cc: stable@vger.kernel.org Signed-off-by:Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
Cc: stable@vger.kernel.org Acked-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
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Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
It could be done in exception-handling bits in __get_user_b() et.al., but the surgery involved would take more knowledge of sh64 details than I have or _want_ to have. Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
* should zero on any failure * __get_user() should use __copy_from_user(), not copy_from_user() Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
should clear on access_ok() failures. Also remove the useless range truncation logics. Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
... that should zero on faults. Also remove the <censored> helpful logics wrt range truncation copied from ppc32. Where it had ever been needed only in case of copy_from_user() *and* had not been merged into the mainline until a month after the need had disappeared. A decade before openrisc went into mainline, I might add... Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
a) should not leave crap on fault b) should _not_ require access_ok() in any cases. Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by: -
Vineet Gupta authored
Al reported potential issue with ARC get_user() as it wasn't clearing out destination pointer in case of fault due to bad address etc. Verified using following | { | u32 bogus1 = 0xdeadbeef; | u64 bogus2 = 0xdead; | int rc1, rc2; | | pr_info("Orig values %x %llx\n", bogus1, bogus2); | rc1 = get_user(bogus1, (u32 __user *)0x40000000); | rc2 = get_user(bogus2, (u64 __user *)0x50000000); | pr_info("access %d %d, new values %x %llx\n", | rc1, rc2, bogus1, bogus2); | } | [ARCLinux]# insmod /mnt/kernel-module/qtn.ko | Orig values deadbeef dead | access -14 -14, new values 0 0 Reported-by:Vineet Gupta <vgupta@synopsys.com> Signed-off-by:
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Al Viro authored
Cc: stable@vger.kernel.org Acked-by:
James Hogan <james.hogan@imgtec.com> Signed-off-by:
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