- 23 Mar, 2016 1 commit
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Linus Torvalds authored
Merge third patch-bomb from Andrew Morton: - more ocfs2 changes - a few hotfixes - Andy's compat cleanups - misc fixes to fatfs, ptrace, coredump, cpumask, creds, eventfd, panic, ipmi, kgdb, profile, kfifo, ubsan, etc. - many rapidio updates: fixes, new drivers. - kcov: kernel code coverage feature. Like gcov, but not "prohibitively expensive". - extable code consolidation for various archs * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (81 commits) ia64/extable: use generic search and sort routines x86/extable: use generic search and sort routines s390/extable: use generic search and sort routines alpha/extable: use generic search and sort routines kernel/...: convert pr_warning to pr_warn drivers: dma-coherent: use memset_io for DMA_MEMORY_IO mappings drivers: dma-coherent: use MEMREMAP_WC for DMA_MEMORY_MAP memremap: add MEMREMAP_WC flag memremap: don't modify flags kernel/signal.c: add compile-time check for __ARCH_SI_PREAMBLE_SIZE mm/mprotect.c: don't imply PROT_EXEC on non-exec fs ipc/sem: make semctl setting sempid consistent ubsan: fix tree-wide -Wmaybe-uninitialized false positives kfifo: fix sparse complaints scripts/gdb: account for changes in module data structure scripts/gdb: add cmdline reader command scripts/gdb: add version command kernel: add kcov code coverage profile: hide unused functions when !CONFIG_PROC_FS hpwdt: use nmi_panic() when kernel panics in NMI handler ...
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- 22 Mar, 2016 39 commits
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git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds authored
Pull more KVM updates from Paolo Bonzini: "Second round of KVM changes for 4.6: - build fixes for PPC KVM - miscellaneous bugfixes for ARM KVM - cleanup of memory barrier and removal of redundant barriers - x86 fixes: page tracking oops, support for old buggy KVM nested on 4.5 - support for protection keys in guests - lockdep fix - another conversion to simple wait queues and raw spinlocks, backported from PREEMPT_RT" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (27 commits) KVM: page_track: fix access to NULL slot KVM: PPC: do not compile in vfio.o unconditionally kvm, rt: change async pagefault code locking for PREEMPT_RT KVM/PPC: update the comment of memory barrier in the kvmppc_prepare_to_enter() KVM/x86: update the comment of memory barrier in the vcpu_enter_guest() KVM: Replace smp_mb() with smp_load_acquire() in the kvm_flush_remote_tlbs() KVM/x86: Call smp_wmb() before increasing tlbs_dirty KVM: Replace smp_mb() with smp_mb_after_atomic() in the kvm_make_all_cpus_request() KVM/x86: Replace smp_mb() with smp_store_mb/release() in the walk_shadow_page_lockless_begin/end() KVM: Remove redundant smp_mb() in the kvm_mmu_commit_zap_page() KVM, pkeys: expose CPUID/CR4 to guest KVM, pkeys: add pkeys support for permission_fault KVM, pkeys: introduce pkru_mask to cache conditions KVM, pkeys: save/restore PKRU when guest/host switches x86: pkey: introduce write_pkru() for KVM KVM, pkeys: add pkeys support for xsave state KVM, pkeys: disable pkeys for guests in non-paging mode KVM: x86: remove magic number with enum cpuid_leafs KVM: MMU: return page fault error code from permission_fault KVM: fix spin_lock_init order on x86 ... -
git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdmaLinus Torvalds authored
Pull more rdma updates from Doug Ledford: "Round two of 4.6 merge window patches. This is a monster pull request. I held off on the hfi1 driver updates (the hfi1 driver is intimately tied to the qib driver and the new rdmavt software library that was created to help both of them) in my first pull request. The hfi1/qib/rdmavt update is probably 90% of this pull request. The hfi1 driver is being left in staging so that it can be fixed up in regards to the API that Al and yourself didn't like. Intel has agreed to do the work, but in the meantime, this clears out 300+ patches in the backlog queue and brings my tree and their tree closer to sync. This also includes about 10 patches to the core and a few to mlx5 to create an infrastructure for configuring SRIOV ports on IB devices. That series includes one patch to the net core that we sent to netdev@ and Dave Miller with each of the three revisions to the series. We didn't get any response to the patch, so we took that as implicit approval. Finally, this series includes Intel's new iWARP driver for their x722 cards. It's not nearly the beast as the hfi1 driver. It also has a linux-next merge issue, but that has been resolved and it now passes just fine. Summary: - A few minor core fixups needed for the next patch series - The IB SRIOV series. This has bounced around for several versions. Of note is the fact that the first patch in this series effects the net core. It was directed to netdev and DaveM for each iteration of the series (three versions total). Dave did not object, but did not respond either. I've taken this as permission to move forward with the series. - The new Intel X722 iWARP driver - A huge set of updates to the Intel hfi1 driver. Of particular interest here is that we have left the driver in staging since it still has an API that people object to. Intel is working on a fix, but getting these patches in now helps keep me sane as the upstream and Intel's trees were over 300 patches apart" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (362 commits) IB/ipoib: Allow mcast packets from other VFs IB/mlx5: Implement callbacks for manipulating VFs net/mlx5_core: Implement modify HCA vport command net/mlx5_core: Add VF param when querying vport counter IB/ipoib: Add ndo operations for configuring VFs IB/core: Add interfaces to control VF attributes IB/core: Support accessing SA in virtualized environment IB/core: Add subnet prefix to port info IB/mlx5: Fix decision on using MAD_IFC net/core: Add support for configuring VF GUIDs IB/{core, ulp} Support above 32 possible device capability flags IB/core: Replace setting the zero values in ib_uverbs_ex_query_device net/mlx5_core: Introduce offload arithmetic hardware capabilities net/mlx5_core: Refactor device capability function net/mlx5_core: Fix caching ATOMIC endian mode capability ib_srpt: fix a WARN_ON() message i40iw: Replace the obsolete crypto hash interface with shash IB/hfi1: Add SDMA cache eviction algorithm IB/hfi1: Switch to using the pin query function IB/hfi1: Specify mm when releasing pages ... -
Ard Biesheuvel authored
Replace the arch specific versions of search_extable() and sort_extable() with calls to the generic ones, which now support relative exception tables as well. Signed-off-by:
Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by:
Tony Luck <tony.luck@intel.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Ard Biesheuvel authored
Replace the arch specific versions of search_extable() and sort_extable() with calls to the generic ones, which now support relative exception tables as well. Signed-off-by:
H. Peter Anvin <hpa@linux.intel.com> Signed-off-by:
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Ard Biesheuvel authored
Replace the arch specific versions of search_extable() and sort_extable() with calls to the generic ones, which now support relative exception tables as well. Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:
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Ard Biesheuvel authored
Replace the arch specific versions of search_extable() and sort_extable() with calls to the generic ones, which now support relative exception tables as well. Signed-off-by:
Richard Henderson <rth@twiddle.net> Signed-off-by:
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Joe Perches authored
Use the more common logging method with the eventual goal of removing pr_warning altogether. Miscellanea: - Realign arguments - Coalesce formats - Add missing space between a few coalesced formats Signed-off-by:
Joe Perches <joe@perches.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [kernel/power/suspend.c] Signed-off-by:
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Brian Starkey authored
Use memset_io() for DMA_MEMORY_IO mappings which are mapped as I/O memory, and regular memset() for DMA_MEMORY_MAP mappings. This fixes the below alignment fault on arm64 for DMA_MEMORY_IO mappings, where memset() uses the DC ZVA instruction which is invalid on device memory. Unhandled fault: alignment fault (0x96000061) at 0xffffff8000380000 Internal error: : 96000061 [#1] PREEMPT SMP Modules linked in: hdlcd(+) clk_scpi CPU: 4 PID: 1355 Comm: systemd-udevd Not tainted 4.4.0-rc1+ #5 Hardware name: ARM Juno development board (r0) (DT) task: ffffffc9763eee00 ti: ffffffc9758c4000 task.ti: ffffffc9758c4000 PC is at __efistub_memset+0x1ac/0x200 LR is at dma_alloc_from_coherent+0xb0/0x120 pc : [<ffffffc00030ff2c>] lr : [<ffffffc00042a918>] pstate: 400001c5 sp : ffffffc9758c79a0 x29: ffffffc9758c79a0 x28: ffffffc000635cd0 x27: 0000000000000124 x26: ffffffc000119ef4 x25: 0000000000010000 x24: 0000000000000140 x23: ffffffc07e9ac3a8 x22: ffffffc9758c7a58 x21: ffffffc9758c7a68 x20: 0000000000000004 x19: ffffffc07e9ac380 x18: 0000000000000001 x17: 0000007fae1bbba8 x16: ffffffc0001b2d1c x15: ffffffffffffffff x14: 0ffffffffffffffe x13: 0000000000000010 x12: ffffff800837ffff x11: ffffff800837ffff x10: 0000000040000000 x9 : 0000000000000000 x8 : ffffff8000380000 x7 : 0000000000000000 x6 : 000000000000003f x5 : 0000000000000040 x4 : 0000000000000000 x3 : 0000000000000004 x2 : 000000000000ffc0 x1 : 0000000000000000 x0 : ffffff8000380000 Signed-off-by:
Brian Starkey <brian.starkey@arm.com> Reviewed-by:
Catalin Marinas <catalin.marinas@arm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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Brian Starkey authored
When the DMA_MEMORY_MAP flag is used, memory which can be accessed directly should be returned, so use memremap(..., MEMREMAP_WC) to provide a writecombine mapping. Signed-off-by:
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Brian Starkey authored
Add a flag to memremap() for writecombine mappings. Mappings satisfied by this flag will not be cached, however writes may be delayed or combined into more efficient bursts. This is most suitable for buffers written sequentially by the CPU for use by other DMA devices. Signed-off-by:
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Brian Starkey authored
These patches implement a MEMREMAP_WC flag for memremap(), which can be used to obtain writecombine mappings. This is then used for setting up dma_coherent_mem regions which use the DMA_MEMORY_MAP flag. The motivation is to fix an alignment fault on arm64, and the suggestion to implement MEMREMAP_WC for this case was made at [1]. That particular issue is handled in patch 4, which makes sure that the appropriate memset function is used when zeroing allocations mapped as IO memory. This patch (of 4): Don't modify the flags input argument to memremap(). MEMREMAP_WB is already a special case so we can check for it directly instead of clearing flag bits in each mapper. Signed-off-by:
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Helge Deller authored
The value of __ARCH_SI_PREAMBLE_SIZE defines the size (including padding) of the part of the struct siginfo that is before the union, and it is then used to calculate the needed padding (SI_PAD_SIZE) to make the size of struct siginfo equal to 128 (SI_MAX_SIZE) bytes. Depending on the target architecture and word width it equals to either 3 or 4 times sizeof int. Since the very beginning we had __ARCH_SI_PREAMBLE_SIZE wrong on the parisc architecture for the 64bit kernel build. It's even more frustrating, because it can easily be checked at compile time if the value was defined correctly. This patch adds such a check for the correctness of __ARCH_SI_PREAMBLE_SIZE in the hope that it will prevent existing and future architectures from running into the same problem. I refrained from replacing __ARCH_SI_PREAMBLE_SIZE by offsetof() in copy_siginfo() in include/asm-generic/siginfo.h, because a) it doesn't make any difference and b) it's used in the Documentation/kmemcheck.txt example. I ran this patch through the 0-DAY kernel test infrastructure and only the parisc architecture triggered as expected. That means that this patch should be OK for all major architectures. Signed-off-by:
Helge Deller <deller@gmx.de> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by:
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Piotr Kwapulinski authored
The mprotect(PROT_READ) fails when called by the READ_IMPLIES_EXEC binary on a memory mapped file located on non-exec fs. The mprotect does not check whether fs is _executable_ or not. The PROT_EXEC flag is set automatically even if a memory mapped file is located on non-exec fs. Fix it by checking whether a memory mapped file is located on a non-exec fs. If so the PROT_EXEC is not implied by the PROT_READ. The implementation uses the VM_MAYEXEC flag set properly in mmap. Now it is consistent with mmap. I did the isolated tests (PT_GNU_STACK X/NX, multiple VMAs, X/NX fs). I also patched the official 3.19.0-47-generic Ubuntu 14.04 kernel and it seems to work. Signed-off-by:
Piotr Kwapulinski <kwapulinski.piotr@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by:
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Davidlohr Bueso authored
As indicated by bug#112271, Linux sets the sempid value upon semctl, and not only for semop calls. However, within semctl we only do this for SETVAL, leaving SETALL without updating the field, and therefore rather inconsistent behavior when compared to other Unices. There is really no documentation regarding this and therefore users should not make assumptions. With this patch, along with updating semctl.2 manpages, this scenario should become less ambiguous As such, set sempid on SETALL cmd. Also update some in-code documentation, specifying where the sempid is set. Passes ltp and custom testcase where a child (fork) does SETALL to the set. Signed-off-by:
Davidlohr Bueso <dbueso@suse.de> Reported-by:
Philip Semanchuk <linux_kernel.20.ick@spamgourmet.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Herton R. Krzesinski <herton@redhat.com> Signed-off-by:
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Andrey Ryabinin authored
-fsanitize=* options makes GCC less smart than usual and increase number of 'maybe-uninitialized' false-positives. So this patch does two things: * Add -Wno-maybe-uninitialized to CFLAGS_UBSAN which will disable all such warnings for instrumented files. * Remove CONFIG_UBSAN_SANITIZE_ALL from all[yes|mod]config builds. So the all[yes|mod]config build goes without -fsanitize=* and still with -Wmaybe-uninitialized. Signed-off-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Reported-by:
Fengguang Wu <fengguang.wu@intel.com> Signed-off-by:
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Stefani Seibold authored
This patch fix complaints by the sparse tool when using kfifo_put() with non scalar types like structures (i.e. drivers/iio/industrialio-event.c). Casting a pointer to the value and read this pointer instead of directly casting the value will fix this. The generated code is equal. Signed-off-by:
Stefani Seibold <stefani@seibold.net> Signed-off-by:
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Jan Kiszka authored
Commit 7523e4dc ("module: use a structure to encapsulate layout.") factored out the module_layout structure. Adjust the symbol loader and the lsmod command to this. Signed-off-by:
Jan Kiszka <jan.kiszka@siemens.com> Reviewed-by:
Kieran Bingham <kieran.bingham@linaro.org> Tested-by: Kieran Bingham <kieran.bingham@linaro.org> (qemu-{ARM,x86}) Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: <stable@vger.kernel.org> [4.4+] Signed-off-by:
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Kieran Bingham authored
lx-cmdline Report the Linux Commandline used in the current kernel [jan.kiszka@siemens.com: remove blank line from help output and fix pep8 warning] Signed-off-by:
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Kieran Bingham authored
lx-version Report the Linux Version of the current kernel. Add a command to identify the version specified by the banner in the debugged kernel. This lets the user identify the kernel of the running kernel, and will let later scripts compare the banner of the attached kernel against the banner in the vmlinux symbols files to verify that the files are correct. [jan.kiszka@siemens.com: remove blank line from help output and fix pep8 warning] Signed-off-by:
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Dmitry Vyukov authored
kcov provides code coverage collection for coverage-guided fuzzing (randomized testing). Coverage-guided fuzzing is a testing technique that uses coverage feedback to determine new interesting inputs to a system. A notable user-space example is AFL (http://lcamtuf.coredump.cx/afl/). However, this technique is not widely used for kernel testing due to missing compiler and kernel support. kcov does not aim to collect as much coverage as possible. It aims to collect more or less stable coverage that is function of syscall inputs. To achieve this goal it does not collect coverage in soft/hard interrupts and instrumentation of some inherently non-deterministic or non-interesting parts of kernel is disbled (e.g. scheduler, locking). Currently there is a single coverage collection mode (tracing), but the API anticipates additional collection modes. Initially I also implemented a second mode which exposes coverage in a fixed-size hash table of counters (what Quentin used in his original patch). I've dropped the second mode for simplicity. This patch adds the necessary support on kernel side. The complimentary compiler support was added in gcc revision 231296. We've used this support to build syzkaller system call fuzzer, which has found 90 kernel bugs in just 2 months: https://github.com/google/syzkaller/wiki/Found-Bugs We've also found 30+ bugs in our internal systems with syzkaller. Another (yet unexplored) direction where kcov coverage would greatly help is more traditional "blob mutation". For example, mounting a random blob as a filesystem, or receiving a random blob over wire. Why not gcov. Typical fuzzing loop looks as follows: (1) reset coverage, (2) execute a bit of code, (3) collect coverage, repeat. A typical coverage can be just a dozen of basic blocks (e.g. an invalid input). In such context gcov becomes prohibitively expensive as reset/collect coverage steps depend on total number of basic blocks/edges in program (in case of kernel it is about 2M). Cost of kcov depends only on number of executed basic blocks/edges. On top of that, kernel requires per-thread coverage because there are always background threads and unrelated processes that also produce coverage. With inlined gcov instrumentation per-thread coverage is not possible. kcov exposes kernel PCs and control flow to user-space which is insecure. But debugfs should not be mapped as user accessible. Based on a patch by Quentin Casasnovas. [akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode'] [akpm@linux-foundation.org: unbreak allmodconfig] [akpm@linux-foundation.org: follow x86 Makefile layout standards] Signed-off-by:
Dmitry Vyukov <dvyukov@google.com> Reviewed-by:
Kees Cook <keescook@chromium.org> Cc: syzkaller <syzkaller@googlegroups.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Tavis Ormandy <taviso@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Kees Cook <keescook@google.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: David Drysdale <drysdale@google.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by:
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Arnd Bergmann authored
A couple of functions and variables in the profile implementation are used only on SMP systems by the procfs code, but are unused if either procfs is disabled or in uniprocessor kernels. gcc prints a harmless warning about the unused symbols: kernel/profile.c:243:13: error: 'profile_flip_buffers' defined but not used [-Werror=unused-function] static void profile_flip_buffers(void) ^ kernel/profile.c:266:13: error: 'profile_discard_flip_buffers' defined but not used [-Werror=unused-function] static void profile_discard_flip_buffers(void) ^ kernel/profile.c:330:12: error: 'profile_cpu_callback' defined but not used [-Werror=unused-function] static int profile_cpu_callback(struct notifier_block *info, ^ This adds further #ifdef to the file, to annotate exactly in which cases they are used. I have done several thousand ARM randconfig kernels with this patch applied and no longer get any warnings in this file. Signed-off-by:Arnd Bergmann <arnd@arndb.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Robin Holt <robinmholt@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
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Hidehiro Kawai authored
Commit 1717f209 ("panic, x86: Fix re-entrance problem due to panic on NMI") introduced nmi_panic() which prevents concurrent and recursive execution of panic(). It also saves registers for the crash dump on x86 by later commit 58c5661f ("panic, x86: Allow CPUs to save registers even if looping in NMI context"). hpwdt driver can call panic() from NMI handler, so replace it with nmi_panic(). Also, do some cleanups. Signed-off-by:
Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Acked-by:
Guenter Roeck <linux@roeck-us.net> Cc: Thomas Mingarelli <thomas.mingarelli@hpe.com> Cc: Wim Van Sebroeck <wim@iguana.be> Signed-off-by:
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Hidehiro Kawai authored
Commit 1717f209 ("panic, x86: Fix re-entrance problem due to panic on NMI") introduced nmi_panic() which prevents concurrent and recursive execution of panic(). It also saves registers for the crash dump on x86 by later commit 58c5661f ("panic, x86: Allow CPUs to save registers even if looping in NMI context"). ipmi_watchdog driver can call panic() from NMI handler, so replace it with nmi_panic(). Signed-off-by:
Corey Minyard <cminyard@mvista.com> Acked-by:
Michal Hocko <mhocko@suse.com> Signed-off-by:
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Hidehiro Kawai authored
Commit 1717f209 ("panic, x86: Fix re-entrance problem due to panic on NMI") and commit 58c5661f ("panic, x86: Allow CPUs to save registers even if looping in NMI context") introduced nmi_panic() which prevents concurrent/recursive execution of panic(). It also saves registers for the crash dump on x86. However, there are some cases where NMI handlers still use panic(). This patch set partially replaces them with nmi_panic() in those cases. Even this patchset is applied, some NMI or similar handlers (e.g. MCE handler) continue to use panic(). This is because I can't test them well and actual problems won't happen. For example, the possibility that normal panic and panic on MCE happen simultaneously is very low. This patch (of 3): Convert nmi_panic() to a proper function and export it instead of exporting internal implementation details to modules, for obvious reasons. Signed-off-by:
Borislav Petkov <bp@suse.de> Acked-by:
Michal Nazarewicz <mina86@mina86.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Javi Merino <javi.merino@arm.com> Cc: Gobinda Charan Maji <gobinda.cemk07@gmail.com> Cc: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
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Paolo Bonzini authored
Since commit e22553e2 ("eventfd: don't take the spinlock in eventfd_poll", 2015-02-17), eventfd is reading ctx->count outside ctx->wqh.lock. However, things aren't as simple as the read barrier in eventfd_poll would suggest. In fact, the read barrier, besides lacking a comment, is not paired in any obvious manner with another read barrier, and it is pointless because it is sitting between a write (deep in poll_wait) and the read of ctx->count. The read barrier is acting just as a compiler barrier, for which we can use READ_ONCE instead. This is what the code change in this patch does. The documentation change is just as important, however. The question, posed by Andrea Arcangeli, is then why the thing is safe on architectures where spin_unlock does not imply a store-load memory barrier. The answer is that it's safe because writes of ctx->count use the same lock as poll_wait, and hence an acquire barrier implicit in poll_wait provides the necessary synchronization between eventfd_poll and callers of wake_up_locked_poll. This is sort of mentioned in the commit message with respect to eventfd_ctx_read ("eventfd_read is similar, it will do a single decrement with the lock held") but it applies to all other callers too. It's tricky enough that it should be documented in the code. Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com> Reviewed-by:
Andrea Arcangeli <aarcange@redhat.com> Cc: Chris Mason <clm@fb.com> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by:
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Arnd Bergmann authored
The current_user_ns() macro currently returns &init_user_ns when user namespaces are disabled, and that causes several warnings when building with gcc-6.0 in code that compares the result of the macro to &init_user_ns itself: fs/xfs/xfs_ioctl.c: In function 'xfs_ioctl_setattr_check_projid': fs/xfs/xfs_ioctl.c:1249:22: error: self-comparison always evaluates to true [-Werror=tautological-compare] if (current_user_ns() == &init_user_ns) This is a legitimate warning in principle, but here it isn't really helpful, so I'm reprasing the definition in a way that shuts up the warning. Apparently gcc only warns when comparing identical literals, but it can figure out that the result of an inline function can be identical to a constant expression in order to optimize a condition yet not warn about the fact that the condition is known at compile time. This is exactly what we want here, and it looks reasonable because we generally prefer inline functions over macros anyway. Signed-off-by:Serge Hallyn <serge.hallyn@canonical.com> Cc: David Howells <dhowells@redhat.com> Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by:
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Alexandre Bounine authored
Add mport character device driver to provide user space interface to basic RapidIO subsystem operations. See included Documentation/rapidio/mport_cdev.txt for more details. [akpm@linux-foundation.org: fix printk warning on i386] [dan.carpenter@oracle.com: mport_cdev: fix some error codes] Signed-off-by:
Alexandre Bounine <alexandre.bounine@idt.com> Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Tested-by:
Barry Wood <barry.wood@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com> Cc: Barry Wood <barry.wood@idt.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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Alexandre Bounine authored
Add DMA channel re-initialization after an error to avoid termination of all pending transfer requests. Signed-off-by:
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Alexandre Bounine authored
Fix synchronization issues found during testing using multiple DMA transfer requests to the same channel: - lost MSI-X interrupt notifications - non-synchronized attempts to start DMA channel HW resulting in error message from the driver - cookie tracking/update race conditions resulting in incorrect DMA transfer status report Signed-off-by:
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Alexandre Bounine authored
Switch to returning error-valued pointer instead of simple NULL pointer. This allows to properly identify situation when request queue is full and therefore gives to upper layer an option to retry operation later. Signed-off-by:
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Alexandre Bounine authored
Replace "all-or-nothing" debug output with controlled debug output using functional block masks. This allows run time control of debug messages through 'dbg_level' module parameter. Signed-off-by:
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Alexandre Bounine authored
Add device-specific callback functions to support outbound windows mapping and release. Signed-off-by:
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Alexandre Bounine authored
Add RapidIO controller (mport) outbound window configuration operations. This patch is a part of the original patch submitted by Li Yang: https://lists.ozlabs.org/pipermail/linuxppc-dev/2009-April/071210.html For some reason the original part was not applied to mainline code tree. The inbound window mapping part has been applied later during tsi721 mport driver submission. Now goes the second part with corresponding HW support. Signed-off-by:
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Alexandre Bounine authored
- Add spinlock protection into outbound message queuing routine. - Change outbound message interrupt handler to avoid deadlock when calling registered callback routine. - Allow infinite retries for outbound messages to avoid retry threshold error signaling in systems with nodes that have slow message receive queue processing. Signed-off-by:
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Alexandre Bounine authored
Add new Port Write handler registration interfaces that attach PW handlers to local mport device objects. This is different from old interface that attaches PW callback to individual RapidIO device. The new interfaces are intended for use for common event handling (e.g. hot-plug notifications) while the old interface is available for individual device drivers. This patch is based on patch proposed by Andre van Herk but preserves existing per-device interface and adds lock protection for list handling. Signed-off-by:
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Alexandre Bounine authored
Make rio_pw_enable() routine available to other RapidIO drivers. Signed-off-by:
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Alexandre Bounine authored
Make function rio_local_set_device_id() common for all components of RapidIO subsystem. Signed-off-by:
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Alexandre Bounine authored
Add lock protection around doorbell list handling to prevent list corruption on SMP platforms. Signed-off-by:
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Alexandre Bounine authored
Add handling of a local mport device removal. RIONET driver registers itself as class interface that supports only removal notification, 'add_device' callback is not provided because RIONET network device can be initialized only after enumeration is completed and the existing method (using remote peer addition) satisfies this condition. Signed-off-by:
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