- 17 11月, 2016 1 次提交
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由 Martin KaFai Lau 提交于
gcc-6.2.1 gives the following warning: kernel/bpf/bpf_lru_list.c: In function ‘__bpf_lru_list_rotate_inactive.isra.3’: kernel/bpf/bpf_lru_list.c:201:28: warning: ‘next’ may be used uninitialized in this function [-Wmaybe-uninitialized] The "next" is currently initialized in the while() loop which must have >=1 iterations. This patch initializes next to get rid of the compiler warning. Fixes: 3a08c2fd ("bpf: LRU List") Reported-by: NDavid Miller <davem@davemloft.net> Signed-off-by: NMartin KaFai Lau <kafai@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 16 11月, 2016 5 次提交
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由 Martin KaFai Lau 提交于
Provide a LRU version of the existing BPF_MAP_TYPE_PERCPU_HASH Signed-off-by: NMartin KaFai Lau <kafai@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Martin KaFai Lau 提交于
Provide a LRU version of the existing BPF_MAP_TYPE_HASH. Signed-off-by: NMartin KaFai Lau <kafai@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Martin KaFai Lau 提交于
Refactor the codes that populate the value of a htab_elem in a BPF_MAP_TYPE_PERCPU_HASH typed bpf_map. Signed-off-by: NMartin KaFai Lau <kafai@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Martin KaFai Lau 提交于
Instead of having a common LRU list, this patch allows a percpu LRU list which can be selected by specifying a map attribute. The map attribute will be added in the later patch. While the common use case for LRU is #reads >> #updates, percpu LRU list allows bpf prog to absorb unusual #updates under pathological case (e.g. external traffic facing machine which could be under attack). Each percpu LRU is isolated from each other. The LRU nodes (including free nodes) cannot be moved across different LRU Lists. Here are the update performance comparison between common LRU list and percpu LRU list (the test code is at the last patch): [root@kerneltest003.31.prn1 ~]# for i in 1 4 8; do echo -n "$i cpus: "; \ ./map_perf_test 16 $i | awk '{r += $3}END{print r " updates"}'; done 1 cpus: 2934082 updates 4 cpus: 7391434 updates 8 cpus: 6500576 updates [root@kerneltest003.31.prn1 ~]# for i in 1 4 8; do echo -n "$i cpus: "; \ ./map_perf_test 32 $i | awk '{r += $3}END{printr " updates"}'; done 1 cpus: 2896553 updates 4 cpus: 9766395 updates 8 cpus: 17460553 updates Signed-off-by: NMartin KaFai Lau <kafai@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Martin KaFai Lau 提交于
Introduce bpf_lru_list which will provide LRU capability to the bpf_htab in the later patch. * General Thoughts: 1. Target use case. Read is more often than update. (i.e. bpf_lookup_elem() is more often than bpf_update_elem()). If bpf_prog does a bpf_lookup_elem() first and then an in-place update, it still counts as a read operation to the LRU list concern. 2. It may be useful to think of it as a LRU cache 3. Optimize the read case 3.1 No lock in read case 3.2 The LRU maintenance is only done during bpf_update_elem() 4. If there is a percpu LRU list, it will lose the system-wise LRU property. A completely isolated percpu LRU list has the best performance but the memory utilization is not ideal considering the work load may be imbalance. 5. Hence, this patch starts the LRU implementation with a global LRU list with batched operations before accessing the global LRU list. As a LRU cache, #read >> #update/#insert operations, it will work well. 6. There is a local list (for each cpu) which is named 'struct bpf_lru_locallist'. This local list is not used to sort the LRU property. Instead, the local list is to batch enough operations before acquiring the lock of the global LRU list. More details on this later. 7. In the later patch, it allows a percpu LRU list by specifying a map-attribute for scalability reason and for use cases that need to prepare for the worst (and pathological) case like DoS attack. The percpu LRU list is completely isolated from each other and the LRU nodes (including free nodes) cannot be moved across the list. The following description is for the global LRU list but mostly applicable to the percpu LRU list also. * Global LRU List: 1. It has three sub-lists: active-list, inactive-list and free-list. 2. The two list idea, active and inactive, is borrowed from the page cache. 3. All nodes are pre-allocated and all sit at the free-list (of the global LRU list) at the beginning. The pre-allocation reasoning is similar to the existing BPF_MAP_TYPE_HASH. However, opting-out prealloc (BPF_F_NO_PREALLOC) is not supported in the LRU map. * Active/Inactive List (of the global LRU list): 1. The active list, as its name says it, maintains the active set of the nodes. We can think of it as the working set or more frequently accessed nodes. The access frequency is approximated by a ref-bit. The ref-bit is set during the bpf_lookup_elem(). 2. The inactive list, as its name also says it, maintains a less active set of nodes. They are the candidates to be removed from the bpf_htab when we are running out of free nodes. 3. The ordering of these two lists is acting as a rough clock. The tail of the inactive list is the older nodes and should be released first if the bpf_htab needs free element. * Rotating the Active/Inactive List (of the global LRU list): 1. It is the basic operation to maintain the LRU property of the global list. 2. The active list is only rotated when the inactive list is running low. This idea is similar to the current page cache. Inactive running low is currently defined as "# of inactive < # of active". 3. The active list rotation always starts from the tail. It moves node without ref-bit set to the head of the inactive list. It moves node with ref-bit set back to the head of the active list and then clears its ref-bit. 4. The inactive rotation is pretty simply. It walks the inactive list and moves the nodes back to the head of active list if its ref-bit is set. The ref-bit is cleared after moving to the active list. If the node does not have ref-bit set, it just leave it as it is because it is already in the inactive list. * Shrinking the Inactive List (of the global LRU list): 1. Shrinking is the operation to get free nodes when the bpf_htab is full. 2. It usually only shrinks the inactive list to get free nodes. 3. During shrinking, it will walk the inactive list from the tail, delete the nodes without ref-bit set from bpf_htab. 4. If no free node found after step (3), it will forcefully get one node from the tail of inactive or active list. Forcefully is in the sense that it ignores the ref-bit. * Local List: 1. Each CPU has a 'struct bpf_lru_locallist'. The purpose is to batch enough operations before acquiring the lock of the global LRU. 2. A local list has two sub-lists, free-list and pending-list. 3. During bpf_update_elem(), it will try to get from the free-list of (the current CPU local list). 4. If the local free-list is empty, it will acquire from the global LRU list. The global LRU list can either satisfy it by its global free-list or by shrinking the global inactive list. Since we have acquired the global LRU list lock, it will try to get at most LOCAL_FREE_TARGET elements to the local free list. 5. When a new element is added to the bpf_htab, it will first sit at the pending-list (of the local list) first. The pending-list will be flushed to the global LRU list when it needs to acquire free nodes from the global list next time. * Lock Consideration: The LRU list has a lock (lru_lock). Each bucket of htab has a lock (buck_lock). If both locks need to be acquired together, the lock order is always lru_lock -> buck_lock and this only happens in the bpf_lru_list.c logic. In hashtab.c, both locks are not acquired together (i.e. one lock is always released first before acquiring another lock). Signed-off-by: NMartin KaFai Lau <kafai@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 15 11月, 2016 2 次提交
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由 Mickaël Salaün 提交于
Replace the custom u64_to_ptr() function with the u64_to_user_ptr() macro. Signed-off-by: NMickaël Salaün <mic@digikod.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Linus Torvalds 提交于
This reverts commit bfd8d3f2. It turns out that this flushes things much too aggressiverly, and causes lines to break up when the system logger races with new continuation lines being printed. There's a pending patch to make printk() flushing much more straightforward, but it's too invasive for 4.9, so in the meantime let's just not make the system message logging flush continuation lines. They'll be flushed by the final newline anyway. Suggested-by: NPetr Mladek <pmladek@suse.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 13 11月, 2016 1 次提交
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由 Daniel Borkmann 提交于
Commit 67f8b1dc ("net/mlx4_en: Refactor the XDP forwarding rings scheme") added a bug in that the prog's reference count is not dropped in the error path when mlx4_en_try_alloc_resources() is failing from mlx4_xdp_set(). We previously took bpf_prog_add(prog, priv->rx_ring_num - 1), that we need to release again. Earlier in the call path, dev_change_xdp_fd() itself holds a reference to the prog as well (hence the '- 1' in the bpf_prog_add()), so a simple atomic_sub() is safe to use here. When an error is propagated, then bpf_prog_put() is called eventually from dev_change_xdp_fd() Fixes: 67f8b1dc ("net/mlx4_en: Refactor the XDP forwarding rings scheme") Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 12 11月, 2016 1 次提交
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由 Hans de Goede 提交于
This reverts commit 05fd007e ("console: don't prefer first registered if DT specifies stdout-path"). The reverted commit changes existing behavior on which many ARM boards rely. Many ARM small-board-computers, like e.g. the Raspberry Pi have both a video output and a serial console. Depending on whether the user is using the device as a more regular computer; or as a headless device we need to have the console on either one or the other. Many users rely on the kernel behavior of the console being present on both outputs, before the reverted commit the console setup with no console= kernel arguments on an ARM board which sets stdout-path in dt would look like this: [root@localhost ~]# cat /proc/consoles ttyS0 -W- (EC p a) 4:64 tty0 -WU (E p ) 4:1 Where as after the reverted commit, it looks like this: [root@localhost ~]# cat /proc/consoles ttyS0 -W- (EC p a) 4:64 This commit reverts commit 05fd007e ("console: don't prefer first registered if DT specifies stdout-path") restoring the original behavior. Fixes: 05fd007e ("console: don't prefer first registered if DT specifies stdout-path") Link: http://lkml.kernel.org/r/20161104121135.4780-2-hdegoede@redhat.comSigned-off-by: NHans de Goede <hdegoede@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 10 11月, 2016 1 次提交
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由 Tobias Klauser 提交于
Remove the unused but set variables min_set and max_set in adjust_reg_min_max_vals to fix the following warning when building with 'W=1': kernel/bpf/verifier.c:1483:7: warning: variable ‘min_set’ set but not used [-Wunused-but-set-variable] There is no warning about max_set being unused, but since it is only used in the assignment of min_set it can be removed as well. They were introduced in commit 48461135 ("bpf: allow access into map value arrays") but seem to have never been used. Cc: Josef Bacik <jbacik@fb.com> Signed-off-by: NTobias Klauser <tklauser@distanz.ch> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 08 11月, 2016 3 次提交
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由 Thomas Gleixner 提交于
The type flags in the irq descriptor are there for historical reasons and only updated via irq_modify_status() or irq_set_type(). Both functions also update the type flags in irqdata. __setup_irq() is the only left over user of the type flags in the irq descriptor. If __setup_irq() is called with empty irq type flags, then the type flags are retrieved from irqdata. If an interrupt is shared, then the type flags are compared with the type flags stored in the irq descriptor. On x86 the ioapic does not have a irq_set_type() callback because the type is defined in the BIOS tables and cannot be changed. The type is stored in irqdata at setup time without updating the type data in the irq descriptor. As a result the comparison described above fails. There is no point in updating the irq descriptor flags because the only relevant storage is irqdata. Use the type flags from irqdata for both retrieval and comparison in __setup_irq() instead. Aside of that the print out in case of non matching type flags has the old and new type flags arguments flipped. Fix that as well. For correctness sake the flags stored in the irq descriptor should be removed, but this is beyond the scope of this bugfix and will be done in a later patch. Fixes: 4b357dae ("genirq: Look-up trigger type if not specified by caller") Reported-and-tested-by: NMika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Jon Hunter <jonathanh@nvidia.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1611072020360.3501@nanosSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Daniel Borkmann 提交于
In map_create(), we first find and create the map, then once that suceeded, we charge it to the user's RLIMIT_MEMLOCK, and then fetch a new anon fd through anon_inode_getfd(). The problem is, once the latter fails f.e. due to RLIMIT_NOFILE limit, then we only destruct the map via map->ops->map_free(), but without uncharging the previously locked memory first. That means that the user_struct allocation is leaked as well as the accounted RLIMIT_MEMLOCK memory not released. Make the label names in the fix consistent with bpf_prog_load(). Fixes: aaac3ba9 ("bpf: charge user for creation of BPF maps and programs") Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Daniel Borkmann 提交于
Commit a6ed3ea6 ("bpf: restore behavior of bpf_map_update_elem") added an extra per-cpu reserve to the hash table map to restore old behaviour from pre prealloc times. When non-prealloc is in use for a map, then problem is that once a hash table extra element has been linked into the hash-table, and the hash table is destroyed due to refcount dropping to zero, then htab_map_free() -> delete_all_elements() will walk the whole hash table and drop all elements via htab_elem_free(). The problem is that the element from the extra reserve is first fed to the wrong backend allocator and eventually freed twice. Fixes: a6ed3ea6 ("bpf: restore behavior of bpf_map_update_elem") Reported-by: NDmitry Vyukov <dvyukov@google.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 04 11月, 2016 1 次提交
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由 WANG Cong 提交于
cgroupstats_cmd_get_policy is [CGROUPSTATS_CMD_ATTR_MAX+1], taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1], but their family.maxattr is TASKSTATS_CMD_ATTR_MAX. CGROUPSTATS_CMD_ATTR_MAX is less than TASKSTATS_CMD_ATTR_MAX, so we could end up accessing out-of-bound. Change cgroupstats_cmd_get_policy to TASKSTATS_CMD_ATTR_MAX+1, this is safe because the rest are initialized to 0's. Reported-by: NAndrey Konovalov <andreyknvl@google.com> Tested-by: NAndrey Konovalov <andreyknvl@google.com> Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 03 11月, 2016 2 次提交
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由 Linus Torvalds 提交于
In sched_show_task() we print out a useless hex number, not even a symbol, and there's a big question mark whether this even makes sense anyway, I suspect we should just remove it all. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org> Acked-by: NAndy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: brgerst@gmail.com Cc: jann@thejh.net Cc: keescook@chromium.org Cc: linux-api@vger.kernel.org Cc: tycho.andersen@canonical.com Link: http://lkml.kernel.org/r/CA+55aFzphURPFzAvU4z6Moy7ZmimcwPuUdYU8bj9z0J+S8X1rw@mail.gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Tetsuo Handa 提交于
When CONFIG_THREAD_INFO_IN_TASK=y, it is possible that an exited thread remains in the task list after its stack pointer was already set to NULL. Therefore, thread_saved_pc() and stack_not_used() in sched_show_task() will trigger NULL pointer dereference if an attempt to dump such thread's traces (e.g. SysRq-t, khungtaskd) is made. Since show_stack() in sched_show_task() calls try_get_task_stack() and sched_show_task() is called from interrupt context, calling try_get_task_stack() from sched_show_task() will be safe as well. Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: NAndy Lutomirski <luto@kernel.org> Acked-by: NLinus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: brgerst@gmail.com Cc: jann@thejh.net Cc: keescook@chromium.org Cc: linux-api@vger.kernel.org Cc: tycho.andersen@canonical.com Link: http://lkml.kernel.org/r/201611021950.FEJ34368.HFFJOOMLtQOVSF@I-love.SAKURA.ne.jpSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 02 11月, 2016 1 次提交
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由 Johan Hovold 提交于
Make sure to drop the reference taken by class_find_device() after opening the RTC device. Fixes: 77437fd4 (pm: boot time suspend selftest) Signed-off-by: NJohan Hovold <johan@kernel.org> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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- 01 11月, 2016 2 次提交
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由 Andy Lutomirski 提交于
If something goes wrong with task stack refcounting and a stack refcount hits zero too early, warn and leak it rather than potentially freeing it early (and silently). Signed-off-by: NAndy 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/f29119c783a9680a4b4656e751b6123917ace94b.1477926663.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Daniel Borkmann 提交于
While commit bb35a6ef ("bpf, inode: allow for rename and link ops") added support for hard links that can be used for prog and map nodes, this work adds simple symlink support, which can be used f.e. for directories also when unpriviledged and works with cmdline tooling that understands S_IFLNK anyway. Since the switch in e27f4a94 ("bpf: Use mount_nodev not mount_ns to mount the bpf filesystem"), there can be various mount instances with mount_nodev() and thus hierarchy can be flattened to facilitate object sharing. Thus, we can keep bpf tooling also working by repointing paths. Most of the functionality can be used from vfs library operations. The symlink is stored in the inode itself, that is in i_link, which is sufficient in our case as opposed to storing it in the page cache. While at it, I noticed that bpf_mkdir() and bpf_mkobj() don't update the directories mtime and ctime, so add a common helper for it called bpf_dentry_finalize() that takes care of it for all cases now. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 30 10月, 2016 1 次提交
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由 Thomas Graf 提交于
The verifier currently prints raw function ids when printing CALL instructions or when complaining: 5: (85) call 23 unknown func 23 print a meaningful function name instead: 5: (85) call bpf_redirect#23 unknown func bpf_redirect#23 Moves the function documentation to a single comment and renames all helpers names in the list to conform to the bpf_ prefix notation so they can be greped in the kernel source. Signed-off-by: NThomas Graf <tgraf@suug.ch> Acked-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 28 10月, 2016 7 次提交
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由 Jiri Olsa 提交于
The trinity syscall fuzzer triggered following WARN() on powerpc: WARNING: CPU: 9 PID: 2998 at arch/powerpc/kernel/hw_breakpoint.c:278 ... NIP [c00000000093aedc] .hw_breakpoint_handler+0x28c/0x2b0 LR [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0 Call Trace: [c0000002f7933580] [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0 (unreliable) [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0 [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0 [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0 [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100 [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48 Followed by a lockdep warning: =============================== [ INFO: suspicious RCU usage. ] 4.8.0-rc5+ #7 Tainted: G W ------------------------------- ./include/linux/rcupdate.h:556 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by ls/2998: #0: (rcu_read_lock){......}, at: [<c0000000000f6a00>] .__atomic_notifier_call_chain+0x0/0x1c0 #1: (rcu_read_lock){......}, at: [<c00000000093ac50>] .hw_breakpoint_handler+0x0/0x2b0 stack backtrace: CPU: 9 PID: 2998 Comm: ls Tainted: G W 4.8.0-rc5+ #7 Call Trace: [c0000002f7933150] [c00000000094b1f8] .dump_stack+0xe0/0x14c (unreliable) [c0000002f79331e0] [c00000000013c468] .lockdep_rcu_suspicious+0x138/0x180 [c0000002f7933270] [c0000000001005d8] .___might_sleep+0x278/0x2e0 [c0000002f7933300] [c000000000935584] .mutex_lock_nested+0x64/0x5a0 [c0000002f7933410] [c00000000023084c] .perf_event_ctx_lock_nested+0x16c/0x380 [c0000002f7933500] [c000000000230a80] .perf_event_disable+0x20/0x60 [c0000002f7933580] [c00000000093aeec] .hw_breakpoint_handler+0x29c/0x2b0 [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0 [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0 [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0 [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100 [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48 While it looks like the first WARN() is probably valid, the other one is triggered by disabling event via perf_event_disable() from atomic context. The event is disabled here in case we were not able to emulate the instruction that hit the breakpoint. By disabling the event we unschedule the event and make sure it's not scheduled back. But we can't call perf_event_disable() from atomic context, instead we need to use the event's pending_disable irq_work method to disable it. Reported-by: NJan Stancek <jstancek@redhat.com> Signed-off-by: NJiri Olsa <jolsa@kernel.org> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161026094824.GA21397@kravaSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Jiri Olsa 提交于
perf/core: Protect PMU device removal with a 'pmu_bus_running' check, to fix CONFIG_DEBUG_TEST_DRIVER_REMOVE=y kernel panic CAI Qian reported a crash in the PMU uncore device removal code, enabled by the CONFIG_DEBUG_TEST_DRIVER_REMOVE=y option: https://marc.info/?l=linux-kernel&m=147688837328451 The reason for the crash is that perf_pmu_unregister() tries to remove a PMU device which is not added at this point. We add PMU devices only after pmu_bus is registered, which happens in the perf_event_sysfs_init() call and sets the 'pmu_bus_running' flag. The fix is to get the 'pmu_bus_running' flag state at the point the PMU is taken out of the PMU list and remove the device later only if it's set. Reported-by: NCAI Qian <caiqian@redhat.com> Tested-by: NCAI Qian <caiqian@redhat.com> Signed-off-by: NJiri Olsa <jolsa@kernel.org> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Herring <robh@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161020111011.GA13361@kravaSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andrey Konovalov 提交于
in_interrupt() returns a nonzero value when we are either in an interrupt or have bh disabled via local_bh_disable(). Since we are interested in only ignoring coverage from actual interrupts, do a proper check instead of just calling in_interrupt(). As a result of this change, kcov will start to collect coverage from within local_bh_disable()/local_bh_enable() sections. Link: http://lkml.kernel.org/r/1476115803-20712-1-git-send-email-andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com> Acked-by: NDmitry Vyukov <dvyukov@google.com> Cc: Nicolai Stange <nicstange@gmail.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Kees Cook <keescook@chromium.org> Cc: James Morse <james.morse@arm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Johannes Berg 提交于
Now genl_register_family() is the only thing (other than the users themselves, perhaps, but I didn't find any doing that) writing to the family struct. In all families that I found, genl_register_family() is only called from __init functions (some indirectly, in which case I've add __init annotations to clarifly things), so all can actually be marked __ro_after_init. This protects the data structure from accidental corruption. Signed-off-by: NJohannes Berg <johannes.berg@intel.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Johannes Berg 提交于
Instead of providing macros/inline functions to initialize the families, make all users initialize them statically and get rid of the macros. This reduces the kernel code size by about 1.6k on x86-64 (with allyesconfig). Signed-off-by: NJohannes Berg <johannes.berg@intel.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Johannes Berg 提交于
Static family IDs have never really been used, the only use case was the workaround I introduced for those users that assumed their family ID was also their multicast group ID. Additionally, because static family IDs would never be reserved by the generic netlink code, using a relatively low ID would only work for built-in families that can be registered immediately after generic netlink is started, which is basically only the control family (apart from the workaround code, which I also had to add code for so it would reserve those IDs) Thus, anything other than GENL_ID_GENERATE is flawed and luckily not used except in the cases I mentioned. Move those workarounds into a few lines of code, and then get rid of GENL_ID_GENERATE entirely, making it more robust. Signed-off-by: NJohannes Berg <johannes.berg@intel.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Linus Torvalds 提交于
The per-zone waitqueues exist because of a scalability issue with the page waitqueues on some NUMA machines, but it turns out that they hurt normal loads, and now with the vmalloced stacks they also end up breaking gfs2 that uses a bit_wait on a stack object: wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE) where 'gh' can be a reference to the local variable 'mount_gh' on the stack of fill_super(). The reason the per-zone hash table breaks for this case is that there is no "zone" for virtual allocations, and trying to look up the physical page to get at it will fail (with a BUG_ON()). It turns out that I actually complained to the mm people about the per-zone hash table for another reason just a month ago: the zone lookup also hurts the regular use of "unlock_page()" a lot, because the zone lookup ends up forcing several unnecessary cache misses and generates horrible code. As part of that earlier discussion, we had a much better solution for the NUMA scalability issue - by just making the page lock have a separate contention bit, the waitqueue doesn't even have to be looked at for the normal case. Peter Zijlstra already has a patch for that, but let's see if anybody even notices. In the meantime, let's fix the actual gfs2 breakage by simplifying the bitlock waitqueues and removing the per-zone issue. Reported-by: NAndreas Gruenbacher <agruenba@redhat.com> Tested-by: NBob Peterson <rpeterso@redhat.com> Acked-by: NMel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 27 10月, 2016 1 次提交
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由 Tobias Klauser 提交于
Since commit: 8663e24d ("sched/fair: Reorder cgroup creation code") ... the variable 'rq' in alloc_fair_sched_group() is set but no longer used. Remove it to fix the following GCC warning when building with 'W=1': kernel/sched/fair.c:8842:13: warning: variable ‘rq’ set but not used [-Wunused-but-set-variable] Signed-off-by: NTobias Klauser <tklauser@distanz.ch> 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/20161026113704.8981-1-tklauser@distanz.chSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 25 10月, 2016 4 次提交
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由 Thomas Gleixner 提交于
When a timer is enqueued we try to forward the timer base clock. This mechanism has two issues: 1) Forwarding a remote base unlocked The forwarding function is called from get_target_base() with the current timer base lock held. But if the new target base is a different base than the current base (can happen with NOHZ, sigh!) then the forwarding is done on an unlocked base. This can lead to corruption of base->clk. Solution is simple: Invoke the forwarding after the target base is locked. 2) Possible corruption due to jiffies advancing This is similar to the issue in get_net_timer_interrupt() which was fixed in the previous patch. jiffies can advance between check and assignement and therefore advancing base->clk beyond the next expiry value. So we need to read jiffies into a local variable once and do the checks and assignment with the local copy. Fixes: a683f390("timers: Forward the wheel clock whenever possible") Reported-by: NAshton Holmes <scoopta@gmail.com> Reported-by: NMichael Thayer <michael.thayer@oracle.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Michal Necasek <michal.necasek@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: knut.osmundsen@oracle.com Cc: stable@vger.kernel.org Cc: stern@rowland.harvard.edu Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161022110552.253640125@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Thomas Gleixner 提交于
Ashton and Michael reported, that kernel versions 4.8 and later suffer from USB timeouts which are caused by the timer wheel rework. This is caused by a bug in the base clock forwarding mechanism, which leads to timers expiring early. The scenario which leads to this is: run_timers() while (jiffies >= base->clk) { collect_expired_timers(); base->clk++; expire_timers(); } So base->clk = jiffies + 1. Now the cpu goes idle: idle() get_next_timer_interrupt() nextevt = __next_time_interrupt(); if (time_after(nextevt, base->clk)) base->clk = jiffies; jiffies has not advanced since run_timers(), so this assignment effectively decrements base->clk by one. base->clk is the index into the timer wheel arrays. So let's assume the following state after the base->clk increment in run_timers(): jiffies = 0 base->clk = 1 A timer gets enqueued with an expiry delta of 63 ticks (which is the case with the USB timeout and HZ=250) so the resulting bucket index is: base->clk + delta = 1 + 63 = 64 The timer goes into the first wheel level. The array size is 64 so it ends up in bucket 0, which is correct as it takes 63 ticks to advance base->clk to index into bucket 0 again. If the cpu goes idle before jiffies advance, then the bug in the forwarding mechanism sets base->clk back to 0, so the next invocation of run_timers() at the next tick will index into bucket 0 and therefore expire the timer 62 ticks too early. Instead of blindly setting base->clk to jiffies we must make the forwarding conditional on jiffies > base->clk, but we cannot use jiffies for this as we might run into the following issue: if (time_after(jiffies, base->clk) { if (time_after(nextevt, base->clk)) base->clk = jiffies; jiffies can increment between the check and the assigment far enough to advance beyond nextevt. So we need to use a stable value for checking. get_next_timer_interrupt() has the basej argument which is the jiffies value snapshot taken in the calling code. So we can just that. Thanks to Ashton for bisecting and providing trace data! Fixes: a683f390 ("timers: Forward the wheel clock whenever possible") Reported-by: NAshton Holmes <scoopta@gmail.com> Reported-by: NMichael Thayer <michael.thayer@oracle.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Michal Necasek <michal.necasek@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: knut.osmundsen@oracle.com Cc: stable@vger.kernel.org Cc: stern@rowland.harvard.edu Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161022110552.175308322@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Thomas Gleixner 提交于
Linus stumbled over the unlocked modification of the timer expiry value in mod_timer() which is an optimization for timers which stay in the same bucket - due to the bucket granularity - despite their expiry time getting updated. The optimization itself still makes sense even if we take the lock, because in case that the bucket stays the same, we avoid the pointless queue/enqueue dance. Make the check and the modification of timer->expires protected by the base lock and shuffle the remaining code around so we can keep the lock held when we actually have to requeue the timer to a different bucket. Fixes: f00c0afd ("timers: Implement optimization for same expiry time in mod_timer()") Reported-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610241711220.4983@nanos Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org>
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由 Thomas Gleixner 提交于
Linus noticed that lock_timer_base() lacks a READ_ONCE() for accessing the timer flags. As a consequence the compiler is allowed to reload the flags between the initial check for TIMER_MIGRATION and the following timer base computation and the spin lock of the base. While this has not been observed (yet), we need to make sure that it never happens. Fixes: 0eeda71b ("timer: Replace timer base by a cpu index") Reported-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610241711220.4983@nanos Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org>
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- 24 10月, 2016 1 次提交
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由 Jon Hunter 提交于
Commit 4bcc595c (printk: reinstate KERN_CONT for printing continuation lines) exposed a missing KERN_CONT from one of the messages shown on entering suspend. With v4.9-rc1, the 'done.' shown after syncing the filesystems no longer appears as a continuation but a new message with its own timestamp. [ 9.259566] PM: Syncing filesystems ... [ 9.264119] done. Fix this by adding the KERN_CONT log level for the 'done.' part of the message seen after syncing filesystems. While we are at it, convert these suspend printks to pr_info and pr_cont, respectively. Signed-off-by: NJon Hunter <jonathanh@nvidia.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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- 23 10月, 2016 2 次提交
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由 Daniel Borkmann 提交于
Use case is mainly for soreuseport to select sockets for the local numa node, but since generic, lets also add this for other networking and tracing program types. Suggested-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Florian Fainelli 提交于
This reverts commit 97dcaa0f. Based on the review discussion with Eric, we will come up with a different fix for the bcm_sf2 driver which does not make it rely on the kexec_in_progress value. Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 22 10月, 2016 1 次提交
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由 Sagi Grimberg 提交于
This library was moved to the generic area and was renamed to irq-poll. Hence, update proc/softirqs output accordingly. Signed-off-by: NSagi Grimberg <sagi@grimberg.me> Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de> Reviewed-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 21 10月, 2016 2 次提交
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由 Sudip Mukherjee 提交于
The TPS65217 driver grew interrupt support which uses irq_set_parent(). While it's not yet clear why this is used in the first place, building the driver as a module fails with: ERROR: ".irq_set_parent" [drivers/mfd/tps65217.ko] undefined! The correctness of the driver change is still investigated, but for now it's less trouble to export irq_set_parent() than dealing with the build wreckage. [ tglx: Rewrote changelog and made the export GPL ] Fixes: 6556bdac ("mfd: tps65217: Add support for IRQs") Signed-off-by: NSudip Mukherjee <sudip.mukherjee@codethink.co.uk> Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Cc: Marcin Niestroj <m.niestroj@grinn-global.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Lee Jones <lee.jones@linaro.org> Link: http://lkml.kernel.org/r/1475775403-27207-1-git-send-email-sudipm.mukherjee@gmail.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Florian Fainelli 提交于
The bcm_sf2 driver uses kexec_in_progress to know whether it can power down an integrated PHY during shutdown, and can be built as a module. Other modules may be using this in the future, so export it. Fixes: 2399d614 ("net: dsa: bcm_sf2: Prevent GPHY shutdown for kexec'd kernels") Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 20 10月, 2016 1 次提交
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由 Linus Torvalds 提交于
We have a fairly common pattern where you print several things as continuations on one single line in a loop, and then at the end you do printk(KERN_CONT "\n"); to flush the buffered output. But if the output was flushed by something else (concurrent printk activity, or just system logging), we don't want that final flushing to just print an empty line. So just suppress empty continuation lines when they couldn't be merged into the line they are a continuation of. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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