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2017-06-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller9-76/+46
The conflicts were two cases of overlapping changes in batman-adv and the qed driver. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-15Merge branches 'pm-cpufreq', 'pm-cpuidle' and 'pm-devfreq'Rafael J. Wysocki136-3847/+8988
* pm-cpufreq: cpufreq: conservative: Allow down_threshold to take values from 1 to 10 Revert "cpufreq: schedutil: Reduce frequencies slower" * pm-cpuidle: cpuidle: dt: Add missing 'of_node_put()' * pm-devfreq: PM / devfreq: exynos-ppmu: Staticize event list PM / devfreq: exynos-ppmu: Handle return value of clk_prepare_enable PM / devfreq: exynos-nocp: Handle return value of clk_prepare_enable
2017-06-14bpf: permits narrower load from bpf program context fieldsYonghong Song2-25/+67
Currently, verifier will reject a program if it contains an narrower load from the bpf context structure. For example, __u8 h = __sk_buff->hash, or __u16 p = __sk_buff->protocol __u32 sample_period = bpf_perf_event_data->sample_period which are narrower loads of 4-byte or 8-byte field. This patch solves the issue by: . Introduce a new parameter ctx_field_size to carry the field size of narrower load from prog type specific *__is_valid_access validator back to verifier. . The non-zero ctx_field_size for a memory access indicates (1). underlying prog type specific convert_ctx_accesses supporting non-whole-field access (2). the current insn is a narrower or whole field access. . In verifier, for such loads where load memory size is less than ctx_field_size, verifier transforms it to a full field load followed by proper masking. . Currently, __sk_buff and bpf_perf_event_data->sample_period are supporting narrowing loads. . Narrower stores are still not allowed as typical ctx stores are just normal stores. Because of this change, some tests in verifier will fail and these tests are removed. As a bonus, rename some out of bound __sk_buff->cb access to proper field name and remove two redundant "skb cb oob" tests. Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-12Revert "cpufreq: schedutil: Reduce frequencies slower"Rafael J. Wysocki1-3/+0
Revert commit 39b64aa1c007 (cpufreq: schedutil: Reduce frequencies slower) that introduced unintentional changes in behavior leading to adverse effects on some systems. Reported-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-10bpf: reset id on spilled regs in clear_all_pkt_pointersDaniel Borkmann1-2/+2
Right now, we don't reset the id of spilled registers in case of clear_all_pkt_pointers(). Given pkt_pointers are highly likely to contain an id, do so by reusing __mark_reg_unknown_value(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-10bpf: reset id on CONST_IMM transitionDaniel Borkmann1-0/+2
Whenever we set the register to the type CONST_IMM, we currently don't reset the id to 0. id member is not used in CONST_IMM case, so don't let it become stale, where pruning won't be able to match later on. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-10bpf: don't check spilled reg state for non-STACK_SPILLed type slotsDaniel Borkmann1-0/+2
spilled_regs[] state is only used for stack slots of type STACK_SPILL, never for STACK_MISC. Right now, in states_equal(), even if we have old and current stack state of type STACK_MISC, we compare spilled_regs[] for that particular offset. Just skip these like we do everywhere else. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-10bpf: avoid excessive stack usage for perf_sample_dataDaniel Borkmann1-4/+6
perf_sample_data consumes 386 bytes on stack, reduce excessive stack usage and move it to per cpu buffer. It's allowed due to preemption being disabled for tracing, xdp and tc programs, thus at all times only one program can run on a specific CPU and programs cannot run from interrupt. We similarly also handle bpf_pt_regs. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-10Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-2/+2
Pull CPU hotplug fix from Ingo Molnar: "An error handling corner case fix" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu/hotplug: Drop the device lock on error
2017-06-10Merge branch 'rcu-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds3-9/+8
Pull RCU fixes from Ingo Molnar: "Fix an SRCU bug affecting KVM IRQ injection" * 'rcu-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: srcu: Allow use of Classic SRCU from both process and interrupt context srcu: Allow use of Tiny/Tree SRCU from both process and interrupt context
2017-06-10Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+21
Pull perf fixes from Ingo Molnar: "This is mostly tooling fixes, plus an instruction pointer filtering fix. It's more fixes than usual - Arnaldo got back from a longer vacation and there was a backlog" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) perf symbols: Kill dso__build_id_is_kmod() perf symbols: Keep DSO->symtab_type after decompress perf tests: Decompress kernel module before objdump perf tools: Consolidate error path in __open_dso() perf tools: Decompress kernel module when reading DSO data perf annotate: Use dso__decompress_kmodule_path() perf tools: Introduce dso__decompress_kmodule_{fd,path} perf tools: Fix a memory leak in __open_dso() perf annotate: Fix symbolic link of build-id cache perf/core: Drop kernel samples even though :u is specified perf script python: Remove dups in documentation examples perf script python: Updated trace_unhandled() signature perf script python: Fix wrong code snippets in documentation perf script: Fix documentation errors perf script: Fix outdated comment for perf-trace-python perf probe: Fix examples section of documentation perf report: Ensure the perf DSO mapping matches what libdw sees perf report: Include partial stacks unwound with libdw perf annotate: Add missing powerpc triplet perf test: Disable breakpoint signal tests for powerpc ...
2017-06-09Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into rcu/urgentIngo Molnar3-9/+8
Pull RCU fix from Paul E. McKenney: " This series enables srcu_read_lock() and srcu_read_unlock() to be used from interrupt handlers, which fixes a bug in KVM's use of SRCU in delivery of interrupts to guest OSes. " Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-08Merge tag 'pm-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds2-26/+5
Pull power management fixes from Rafael Wysocki: "These revert one problematic commit related to system sleep and fix one recent intel_pstate regression. Specifics: - Revert a recent commit that attempted to avoid spurious wakeups from suspend-to-idle via ACPI SCI, but introduced regressions on some systems (Rafael Wysocki). We will get back to the problem it tried to address in the next cycle. - Fix a possible division by 0 during intel_pstate initialization due to a missing check (Rafael Wysocki)" * tag 'pm-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle" cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min()
2017-06-09Merge branches 'intel_pstate' and 'pm-sleep'Rafael J. Wysocki2-26/+5
* intel_pstate: cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min() * pm-sleep: Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
2017-06-08Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printkLinus Torvalds1-36/+10
Pull printk fix from Petr Mladek: "This reverts a fix added into 4.12-rc1. It caused the kernel log to be printed on another console when two consoles of the same type were defined, e.g. console=ttyS0 console=ttyS1. This configuration was never supported by kernel itself, but it started to make sense with systemd. In other words, the commit broke userspace" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: Revert "printk: fix double printing with earlycon"
2017-06-08srcu: Allow use of Classic SRCU from both process and interrupt contextPaolo Bonzini1-3/+2
Linu Cherian reported a WARN in cleanup_srcu_struct() when shutting down a guest running iperf on a VFIO assigned device. This happens because irqfd_wakeup() calls srcu_read_lock(&kvm->irq_srcu) in interrupt context, while a worker thread does the same inside kvm_set_irq(). If the interrupt happens while the worker thread is executing __srcu_read_lock(), updates to the Classic SRCU ->lock_count[] field or the Tree SRCU ->srcu_lock_count[] field can be lost. The docs say you are not supposed to call srcu_read_lock() and srcu_read_unlock() from irq context, but KVM interrupt injection happens from (host) interrupt context and it would be nice if SRCU supported the use case. KVM is using SRCU here not really for the "sleepable" part, but rather due to its IPI-free fast detection of grace periods. It is therefore not desirable to switch back to RCU, which would effectively revert commit 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING", 2014-01-16). However, the docs are overly conservative. You can have an SRCU instance only has users in irq context, and you can mix process and irq context as long as process context users disable interrupts. In addition, __srcu_read_unlock() actually uses this_cpu_dec() on both Tree SRCU and Classic SRCU. For those two implementations, only srcu_read_lock() is unsafe. When Classic SRCU's __srcu_read_unlock() was changed to use this_cpu_dec(), in commit 5a41344a3d83 ("srcu: Simplify __srcu_read_unlock() via this_cpu_dec()", 2012-11-29), __srcu_read_lock() did two increments. Therefore it kept __this_cpu_inc(), with preempt_disable/enable in the caller. Tree SRCU however only does one increment, so on most architectures it is more efficient for __srcu_read_lock() to use this_cpu_inc(), and any performance differences appear to be down in the noise. Cc: stable@vger.kernel.org Fixes: 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING") Reported-by: Linu Cherian <linuc.decode@gmail.com> Suggested-by: Linu Cherian <linuc.decode@gmail.com> Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08srcu: Allow use of Tiny/Tree SRCU from both process and interrupt contextPaolo Bonzini2-6/+6
Linu Cherian reported a WARN in cleanup_srcu_struct() when shutting down a guest running iperf on a VFIO assigned device. This happens because irqfd_wakeup() calls srcu_read_lock(&kvm->irq_srcu) in interrupt context, while a worker thread does the same inside kvm_set_irq(). If the interrupt happens while the worker thread is executing __srcu_read_lock(), updates to the Classic SRCU ->lock_count[] field or the Tree SRCU ->srcu_lock_count[] field can be lost. The docs say you are not supposed to call srcu_read_lock() and srcu_read_unlock() from irq context, but KVM interrupt injection happens from (host) interrupt context and it would be nice if SRCU supported the use case. KVM is using SRCU here not really for the "sleepable" part, but rather due to its IPI-free fast detection of grace periods. It is therefore not desirable to switch back to RCU, which would effectively revert commit 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING", 2014-01-16). However, the docs are overly conservative. You can have an SRCU instance only has users in irq context, and you can mix process and irq context as long as process context users disable interrupts. In addition, __srcu_read_unlock() actually uses this_cpu_dec() on both Tree SRCU and Classic SRCU. For those two implementations, only srcu_read_lock() is unsafe. When Classic SRCU's __srcu_read_unlock() was changed to use this_cpu_dec(), in commit 5a41344a3d83 ("srcu: Simplify __srcu_read_unlock() via this_cpu_dec()", 2012-11-29), __srcu_read_lock() did two increments. Therefore it kept __this_cpu_inc(), with preempt_disable/enable in the caller. Tree SRCU however only does one increment, so on most architectures it is more efficient for __srcu_read_lock() to use this_cpu_inc(), and any performance differences appear to be down in the noise. Unlike Classic and Tree SRCU, Tiny SRCU does increments and decrements on a single variable. Therefore, as Peter Zijlstra pointed out, Tiny SRCU's implementation already supports mixed-context use of srcu_read_lock() and srcu_read_unlock(), at least as long as uses of srcu_read_lock() and srcu_read_unlock() in each handler are nested and paired properly. In other words, it is still illegal to (say) invoke srcu_read_lock() in an interrupt handler and to invoke the matching srcu_read_unlock() in a softirq handler. Therefore, the only change required for Tiny SRCU is to its comments. Fixes: 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING") Reported-by: Linu Cherian <linuc.decode@gmail.com> Suggested-by: Linu Cherian <linuc.decode@gmail.com> Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-08Revert "printk: fix double printing with earlycon"Petr Mladek1-36/+10
This reverts commit cf39bf58afdaabc0b86f141630fb3fd18190294e. The commit regression to users that define both console=ttyS1 and console=ttyS0 on the command line, see https://lkml.kernel.org/r/20170509082915.GA13236@bistromath.localdomain The kernel log messages always appeared only on one serial port. It is even documented in Documentation/admin-guide/serial-console.rst: "Note that you can only define one console per device type (serial, video)." The above mentioned commit changed the order in which the command line parameters are searched. As a result, the kernel log messages go to the last mentioned ttyS* instead of the first one. We long thought that using two console=ttyS* on the command line did not make sense. But then we realized that console= parameters were handled also by systemd, see http://0pointer.de/blog/projects/serial-console.html "By default systemd will instantiate one serial-getty@.service on the main kernel console, if it is not a virtual terminal." where "[4] If multiple kernel consoles are used simultaneously, the main console is the one listed first in /sys/class/tty/console/active, which is the last one listed on the kernel command line." This puts the original report into another light. The system is running in qemu. The first serial port is used to store the messages into a file. The second one is used to login to the system via a socket. It depends on systemd and the historic kernel behavior. By other words, systemd causes that it makes sense to define both console=ttyS1 console=ttyS0 on the command line. The kernel fix caused regression related to userspace (systemd) and need to be reverted. In addition, it went out that the fix helped only partially. The messages still were duplicated when the boot console was removed early by late_initcall(printk_late_init). Then the entire log was replayed when the same console was registered as a normal one. Link: 20170606160339.GC7604@pathway.suse.cz Cc: Aleksey Makarov <aleksey.makarov@linaro.org> Cc: Sabrina Dubroca <sd@queasysnail.net> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Robin Murphy <robin.murphy@arm.com>, Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Nair, Jayachandran" <Jayachandran.Nair@cavium.com> Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reported-by: Sabrina Dubroca <sd@queasysnail.net> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2017-06-08perf/core: Drop kernel samples even though :u is specifiedJin Yao1-0/+21
When doing sampling, for example: perf record -e cycles:u ... On workloads that do a lot of kernel entry/exits we see kernel samples, even though :u is specified. This is due to skid existing. This might be a security issue because it can leak kernel addresses even though kernel sampling support is disabled. The patch drops the kernel samples if exclude_kernel is specified. For example, test on Haswell desktop: perf record -e cycles:u <mgen> perf report --stdio Before patch applied: 99.77% mgen mgen [.] buf_read 0.20% mgen mgen [.] rand_buf_init 0.01% mgen [kernel.vmlinux] [k] apic_timer_interrupt 0.00% mgen mgen [.] last_free_elem 0.00% mgen libc-2.23.so [.] __random_r 0.00% mgen libc-2.23.so [.] _int_malloc 0.00% mgen mgen [.] rand_array_init 0.00% mgen [kernel.vmlinux] [k] page_fault 0.00% mgen libc-2.23.so [.] __random 0.00% mgen libc-2.23.so [.] __strcasestr 0.00% mgen ld-2.23.so [.] strcmp 0.00% mgen ld-2.23.so [.] _dl_start 0.00% mgen libc-2.23.so [.] sched_setaffinity@@GLIBC_2.3.4 0.00% mgen ld-2.23.so [.] _start We can see kernel symbols apic_timer_interrupt and page_fault. After patch applied: 99.79% mgen mgen [.] buf_read 0.19% mgen mgen [.] rand_buf_init 0.00% mgen libc-2.23.so [.] __random_r 0.00% mgen mgen [.] rand_array_init 0.00% mgen mgen [.] last_free_elem 0.00% mgen libc-2.23.so [.] vfprintf 0.00% mgen libc-2.23.so [.] rand 0.00% mgen libc-2.23.so [.] __random 0.00% mgen libc-2.23.so [.] _int_malloc 0.00% mgen libc-2.23.so [.] _IO_doallocbuf 0.00% mgen ld-2.23.so [.] do_lookup_x 0.00% mgen ld-2.23.so [.] open_verify.constprop.7 0.00% mgen ld-2.23.so [.] _dl_important_hwcaps 0.00% mgen libc-2.23.so [.] sched_setaffinity@@GLIBC_2.3.4 0.00% mgen ld-2.23.so [.] _start There are only userspace symbols. Signed-off-by: Jin Yao <yao.jin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Cc: kan.liang@intel.com Cc: mark.rutland@arm.com Cc: will.deacon@arm.com Cc: yao.jin@intel.com Link: http://lkml.kernel.org/r/1495706947-3744-1-git-send-email-yao.jin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller8-23/+56
Just some simple overlapping changes in marvell PHY driver and the DSA core code. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-07Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"Rafael J. Wysocki2-26/+5
Revert commit eed4d47efe95 (ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle) as it turned out to be premature and triggered a number of different issues on various systems. That includes, but is not limited to, premature suspend-to-RAM aborts on Dell XPS 13 (9343) reported by Dominik. The issue the commit in question attempted to address is real and will need to be taken care of going forward, but evidently more work is needed for this purpose. Reported-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-06bpf: cgroup skb progs cannot access ld_abs/indDaniel Borkmann1-1/+0
Commit fb9a307d11d6 ("bpf: Allow CGROUP_SKB eBPF program to access sk_buff") enabled programs of BPF_PROG_TYPE_CGROUP_SKB type to use ld_abs/ind instructions. However, at this point, we cannot use them, since offsets relative to SKF_LL_OFF will end up pointing skb_mac_header(skb) out of bounds since in the egress path it is not yet set at that point in time, but only after __dev_queue_xmit() did a general reset on the mac header. bpf_internal_load_pointer_neg_helper() will then end up reading data from a wrong offset. BPF_PROG_TYPE_CGROUP_SKB programs can use bpf_skb_load_bytes() already to access packet data, which is also more flexible than the insns carried over from cBPF. Fixes: fb9a307d11d6 ("bpf: Allow CGROUP_SKB eBPF program to access sk_buff") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Chenbo Feng <fengc@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-06bpf: Add BPF_OBJ_GET_INFO_BY_FDMartin KaFai Lau1-17/+146
A single BPF_OBJ_GET_INFO_BY_FD cmd is used to obtain the info for both bpf_prog and bpf_map. The kernel can figure out the fd is associated with a bpf_prog or bpf_map. The suggested struct bpf_prog_info and struct bpf_map_info are not meant to be a complete list and it is not the goal of this patch. New fields can be added in the future patch. The focus of this patch is to create the interface, BPF_OBJ_GET_INFO_BY_FD cmd for exposing the bpf_prog's and bpf_map's info. The obj's info, which will be extended (and get bigger) over time, is separated from the bpf_attr to avoid bloating the bpf_attr. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-06bpf: Add BPF_MAP_GET_FD_BY_IDMartin KaFai Lau1-10/+85
Add BPF_MAP_GET_FD_BY_ID command to allow user to get a fd from a bpf_map's ID. bpf_map_inc_not_zero() is added and is called with map_idr_lock held. __bpf_map_put() is also added which has the 'bool do_idr_lock' param to decide if the map_idr_lock should be acquired when freeing the map->id. In the error path of bpf_map_inc_not_zero(), it may have to call __bpf_map_put(map, false) which does not need to take the map_idr_lock when freeing the map->id. It is currently limited to CAP_SYS_ADMIN which we can consider to lift it in followup patches. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-06bpf: Add BPF_PROG_GET_FD_BY_IDMartin KaFai Lau1-10/+81
Add BPF_PROG_GET_FD_BY_ID command to allow user to get a fd from a bpf_prog's ID. bpf_prog_inc_not_zero() is added and is called with prog_idr_lock held. __bpf_prog_put() is also added which has the 'bool do_idr_lock' param to decide if the prog_idr_lock should be acquired when freeing the prog->id. In the error path of bpf_prog_inc_not_zero(), it may have to call __bpf_prog_put(map, false) which does not need to take the prog_idr_lock when freeing the prog->id. It is currently limited to CAP_SYS_ADMIN which we can consider to lift it in followup patches. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-06bpf: Add BPF_(PROG|MAP)_GET_NEXT_ID commandMartin KaFai Lau1-0/+38
This patch adds BPF_PROG_GET_NEXT_ID and BPF_MAP_GET_NEXT_ID to allow userspace to iterate all bpf_prog IDs and bpf_map IDs. The API is trying to be consistent with the existing BPF_MAP_GET_NEXT_KEY. It is currently limited to CAP_SYS_ADMIN which we can consider to lift it in followup patches. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-06bpf: Introduce bpf_map IDMartin KaFai Lau1-1/+33
This patch generates an unique ID for each created bpf_map. The approach is similar to the earlier patch for bpf_prog ID. It is worth to note that the bpf_map's ID and bpf_prog's ID are in two independent ID spaces and both have the same valid range: [1, INT_MAX). Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-06bpf: Introduce bpf_prog IDMartin KaFai Lau1-1/+39
This patch generates an unique ID for each BPF_PROG_LOAD-ed prog. It is worth to note that each BPF_PROG_LOAD-ed prog will have a different ID even they have the same bpf instructions. The ID is generated by the existing idr_alloc_cyclic(). The ID is ranged from [1, INT_MAX). It is allocated in cyclic manner, so an ID will get reused every 2 billion BPF_PROG_LOAD. The bpf_prog_alloc_id() is done after bpf_prog_select_runtime() because the jit process may have allocated a new prog. Hence, we need to ensure the value of pointer 'prog' will not be changed any more before storing the prog to the prog_idr. After bpf_prog_select_runtime(), the prog is read-only. Hence, the id is stored in 'struct bpf_prog_aux'. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05Merge branch 'for-4.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroupLinus Torvalds2-2/+7
Pull cgroup fixes from Tejun Heo: "Two cgroup fixes. One to address RCU delay of cpuset removal affecting userland visible behaviors. The other fixes a race condition between controller disable and cgroup removal" * 'for-4.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: consider dying css as offline cgroup: Prevent kill_css() from being called more than once
2017-06-04perf, bpf: Add BPF support to all perf_event typesAlexei Starovoitov3-54/+43
Allow BPF_PROG_TYPE_PERF_EVENT program types to attach to all perf_event types, including HW_CACHE, RAW, and dynamic pmu events. Only tracepoint/kprobe events are treated differently which require BPF_PROG_TYPE_TRACEPOINT/BPF_PROG_TYPE_KPROBE program types accordingly. Also add support for reading all event counters using bpf_perf_event_read() helper. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-03cpu/hotplug: Drop the device lock on errorSebastian Andrzej Siewior1-2/+2
If a custom CPU target is specified and that one is not available _or_ can't be interrupted then the code returns to userland without dropping a lock as notices by lockdep: |echo 133 > /sys/devices/system/cpu/cpu7/hotplug/target | ================================================ | [ BUG: lock held when returning to user space! ] | ------------------------------------------------ | bash/503 is leaving the kernel with locks still held! | 1 lock held by bash/503: | #0: (device_hotplug_lock){+.+...}, at: [<ffffffff815b5650>] lock_device_hotplug_sysfs+0x10/0x40 So release the lock then. Fixes: 757c989b9994 ("cpu/hotplug: Make target state writeable") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20170602142714.3ogo25f2wbq6fjpj@linutronix.de
2017-06-02bpf: Remove the capability check for cgroup skb eBPF programChenbo Feng1-1/+3
Currently loading a cgroup skb eBPF program require a CAP_SYS_ADMIN capability while attaching the program to a cgroup only requires the user have CAP_NET_ADMIN privilege. We can escape the capability check when load the program just like socket filter program to make the capability requirement consistent. Change since v1: Change the code style in order to be compliant with checkpatch.pl preference Signed-off-by: Chenbo Feng <fengc@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-02bpf: Allow CGROUP_SKB eBPF program to access sk_buffChenbo Feng1-0/+1
This allows cgroup eBPF program to classify packet based on their protocol or other detail information. Currently program need CAP_NET_ADMIN privilege to attach a cgroup eBPF program, and A process with CAP_NET_ADMIN can already see all packets on the system, for example, by creating an iptables rules that causes the packet to be passed to userspace via NFLOG. Signed-off-by: Chenbo Feng <fengc@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-02Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatchingLinus Torvalds1-0/+1
Pull livepatching fix from Jiri Kosina: "Kconfig dependency fix for livepatching infrastructure from Miroslav Benes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: Make livepatch dependent on !TRIM_UNUSED_KSYMS
2017-05-31bpf: use different interpreter depending on required stack sizeAlexei Starovoitov1-9/+31
16 __bpf_prog_run() interpreters for various stack sizes add .text but not a lot comparing to run-time stack savings text data bss dec hex filename 26350 10328 624 37302 91b6 kernel/bpf/core.o.before_split 25777 10328 624 36729 8f79 kernel/bpf/core.o.after_split 26970 10328 624 37922 9422 kernel/bpf/core.o.now Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-31bpf: reconcile bpf_tail_call and stack_depthAlexei Starovoitov1-0/+1
The next set of patches will take advantage of stack_depth tracking, so make sure that the program that does bpf_tail_call() has stack depth large enough for the callee. We could have tracked the stack depth of the prog_array owner program and only allow insertion of the programs with stack depth less than the owner, but it will break existing applications. Some of them have trivial root bpf program that only does multiple bpf_tail_calls and at init time the prog array is empty. In the future we may add a flag to do such tracking optionally, but for now play simple and safe. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-31bpf: teach verifier to track stack depthAlexei Starovoitov1-1/+9
teach verifier to track bpf program stack depth Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-31bpf: split bpf core interpreterAlexei Starovoitov1-7/+14
split __bpf_prog_run() interpreter into stack allocation and execution parts. The code section shrinks which helps interpreter performance in some cases. text data bss dec hex filename 26350 10328 624 37302 91b6 kernel/bpf/core.o.before 25777 10328 624 36729 8f79 kernel/bpf/core.o.after Very short programs got slower (due to extra function call): Before: test_bpf: #89 ALU64_ADD_K: 1 + 2 = 3 jited:0 7 PASS test_bpf: #90 ALU64_ADD_K: 3 + 0 = 3 jited:0 8 PASS test_bpf: #91 ALU64_ADD_K: 1 + 2147483646 = 2147483647 jited:0 7 PASS test_bpf: #92 ALU64_ADD_K: 4294967294 + 2 = 4294967296 jited:0 11 PASS test_bpf: #93 ALU64_ADD_K: 2147483646 + -2147483647 = -1 jited:0 7 PASS After: test_bpf: #89 ALU64_ADD_K: 1 + 2 = 3 jited:0 11 PASS test_bpf: #90 ALU64_ADD_K: 3 + 0 = 3 jited:0 11 PASS test_bpf: #91 ALU64_ADD_K: 1 + 2147483646 = 2147483647 jited:0 11 PASS test_bpf: #92 ALU64_ADD_K: 4294967294 + 2 = 4294967296 jited:0 14 PASS test_bpf: #93 ALU64_ADD_K: 2147483646 + -2147483647 = -1 jited:0 10 PASS Longer programs got faster: Before: test_bpf: #266 BPF_MAXINSNS: Ctx heavy transformations jited:0 20286 20513 PASS test_bpf: #267 BPF_MAXINSNS: Call heavy transformations jited:0 31853 31768 PASS test_bpf: #268 BPF_MAXINSNS: Jump heavy test jited:0 9815 PASS test_bpf: #269 BPF_MAXINSNS: Very long jump backwards jited:0 6 PASS test_bpf: #270 BPF_MAXINSNS: Edge hopping nuthouse jited:0 13959 PASS test_bpf: #271 BPF_MAXINSNS: Jump, gap, jump, ... jited:0 210 PASS test_bpf: #272 BPF_MAXINSNS: ld_abs+get_processor_id jited:0 21724 PASS test_bpf: #273 BPF_MAXINSNS: ld_abs+vlan_push/pop jited:0 19118 PASS After: test_bpf: #266 BPF_MAXINSNS: Ctx heavy transformations jited:0 19008 18827 PASS test_bpf: #267 BPF_MAXINSNS: Call heavy transformations jited:0 29238 28450 PASS test_bpf: #268 BPF_MAXINSNS: Jump heavy test jited:0 9485 PASS test_bpf: #269 BPF_MAXINSNS: Very long jump backwards jited:0 12 PASS test_bpf: #270 BPF_MAXINSNS: Edge hopping nuthouse jited:0 13257 PASS test_bpf: #271 BPF_MAXINSNS: Jump, gap, jump, ... jited:0 213 PASS test_bpf: #272 BPF_MAXINSNS: ld_abs+get_processor_id jited:0 19389 PASS test_bpf: #273 BPF_MAXINSNS: ld_abs+vlan_push/pop jited:0 19583 PASS For real world production programs the difference is noise. This patch is first step towards reducing interpreter stack consumption. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-31bpf: free up BPF_JMP | BPF_CALL | BPF_X opcodeAlexei Starovoitov2-2/+2
free up BPF_JMP | BPF_CALL | BPF_X opcode to be used by actual indirect call by register and use kernel internal opcode to mark call instruction into bpf_tail_call() helper. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-27Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-8/+16
Pull timer fixlet from Thomas Gleixner: "Silence dmesg spam by making the posix cpu timer printks depend on print_fatal_signals" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: posix-timers: Make signal printks conditional
2017-05-27Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-6/+18
Pull locking fix from Thomas Gleixner: "A fix for a state leak which was introduced in the recent rework of futex/rtmutex interaction" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex,rt_mutex: Fix rt_mutex_cleanup_proxy_lock()
2017-05-27Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-5/+12
Pull kthread fix from Thomas Gleixner: "A single fix which prevents a use after free when kthread fork fails" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kthread: Fix use-after-free if kthread fork fails
2017-05-27Merge tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-traceLinus Torvalds2-2/+2
Pull ftrace fixes from Steven Rostedt: "There's been a few memory issues found with ftrace. One was simply a memory leak where not all was being freed that should have been in releasing a file pointer on set_graph_function. Then Thomas found that the ftrace trampolines were marked for read/write as well as execute. To shrink the possible attack surface, he added calls to set them to ro. Which also uncovered some other issues with freeing module allocated memory that had its permissions changed. Kprobes had a similar issue which is fixed and a selftest was added to trigger that issue again" * tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: x86/ftrace: Make sure that ftrace trampolines are not RWX x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range() selftests/ftrace: Add a testcase for many kprobe events kprobes/x86: Fix to set RWX bits correctly before releasing trampoline ftrace: Fix memory leak in ftrace_graph_release()
2017-05-26kprobes/x86: Fix to set RWX bits correctly before releasing trampolineMasami Hiramatsu1-1/+1
Fix kprobes to set(recover) RWX bits correctly on trampoline buffer before releasing it. Releasing readonly page to module_memfree() crash the kernel. Without this fix, if kprobes user register a bunch of kprobes in function body (since kprobes on function entry usually use ftrace) and unregister it, kernel hits a BUG and crash. Link: http://lkml.kernel.org/r/149570868652.3518.14120169373590420503.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Fixes: d0381c81c2f7 ("kprobes/x86: Set kprobes pages read-only") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-26ftrace: Fix memory leak in ftrace_graph_release()Luis Henriques1-1/+1
ftrace_hash is being kfree'ed in ftrace_graph_release(), however the ->buckets field is not. This results in a memory leak that is easily captured by kmemleak: unreferenced object 0xffff880038afe000 (size 8192): comm "trace-cmd", pid 238, jiffies 4294916898 (age 9.736s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff815f561e>] kmemleak_alloc+0x4e/0xb0 [<ffffffff8113964d>] __kmalloc+0x12d/0x1a0 [<ffffffff810bf6d1>] alloc_ftrace_hash+0x51/0x80 [<ffffffff810c0523>] __ftrace_graph_open.isra.39.constprop.46+0xa3/0x100 [<ffffffff810c05e8>] ftrace_graph_open+0x68/0xa0 [<ffffffff8114003d>] do_dentry_open.isra.1+0x1bd/0x2d0 [<ffffffff81140df7>] vfs_open+0x47/0x60 [<ffffffff81150f95>] path_openat+0x2a5/0x1020 [<ffffffff81152d6a>] do_filp_open+0x8a/0xf0 [<ffffffff811411df>] do_sys_open+0x12f/0x200 [<ffffffff811412ce>] SyS_open+0x1e/0x20 [<ffffffff815fa6e0>] entry_SYSCALL_64_fastpath+0x13/0x94 [<ffffffffffffffff>] 0xffffffffffffffff Link: http://lkml.kernel.org/r/20170525152038.7661-1-lhenriques@suse.com Cc: stable@vger.kernel.org Fixes: b9b0c831bed2 ("ftrace: Convert graph filter to use hash tables") Signed-off-by: Luis Henriques <lhenriques@suse.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-05-27livepatch: Make livepatch dependent on !TRIM_UNUSED_KSYMSMiroslav Benes1-0/+1
If TRIM_UNUSED_KSYMS is enabled, all unneeded exported symbols are made unexported. Two-pass build of the kernel is done to find out which symbols are needed based on a configuration. This effectively complicates things for out-of-tree modules. Livepatch exports functions to (un)register and enable/disable a live patch. The only in-tree module which uses these functions is a sample in samples/livepatch/. If the sample is disabled, the functions are trimmed and out-of-tree live patches cannot be built. Note that live patches are intended to be built out-of-tree. Suggested-by: Michal Marek <mmarek@suse.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Jessica Yu <jeyu@redhat.com> Signed-off-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-05-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds4-30/+29
Pull networking fixes from David Miller: 1) Fix state pruning in bpf verifier wrt. alignment, from Daniel Borkmann. 2) Handle non-linear SKBs properly in SCTP ICMP parsing, from Davide Caratti. 3) Fix bit field definitions for rss_hash_type of descriptors in mlx5 driver, from Jesper Brouer. 4) Defer slave->link updates until bonding is ready to do a full commit to the new settings, from Nithin Sujir. 5) Properly reference count ipv4 FIB metrics to avoid use after free situations, from Eric Dumazet and several others including Cong Wang and Julian Anastasov. 6) Fix races in llc_ui_bind(), from Lin Zhang. 7) Fix regression of ESP UDP encapsulation for TCP packets, from Steffen Klassert. 8) Fix mdio-octeon driver Kconfig deps, from Randy Dunlap. 9) Fix regression in setting DSCP on ipv6/GRE encapsulation, from Peter Dawson. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (43 commits) ipv4: add reference counting to metrics net: ethernet: ax88796: don't call free_irq without request_irq first ip6_tunnel, ip6_gre: fix setting of DSCP on encapsulated packets sctp: fix ICMP processing if skb is non-linear net: llc: add lock_sock in llc_ui_bind to avoid a race condition bonding: Don't update slave->link until ready to commit test_bpf: Add a couple of tests for BPF_JSGE. bpf: add various verifier test cases bpf: fix wrong exposure of map_flags into fdinfo for lpm bpf: add bpf_clone_redirect to bpf_helper_changes_pkt_data bpf: properly reset caller saved regs after helper call and ld_abs/ind bpf: fix incorrect pruning decision when alignment must be tracked arp: fixed -Wuninitialized compiler warning tcp: avoid fastopen API to be used on AF_UNSPEC net: move somaxconn init from sysctl code net: fix potential null pointer dereference geneve: fix fill_info when using collect_metadata virtio-net: enable TSO/checksum offloads for Q-in-Q vlans be2net: Fix offload features for Q-in-Q packets vlan: Fix tcp checksum offloads in Q-in-Q vlans ...
2017-05-25bpf: fix wrong exposure of map_flags into fdinfo for lpmDaniel Borkmann3-0/+3
trie_alloc() always needs to have BPF_F_NO_PREALLOC passed in via attr->map_flags, since it does not support preallocation yet. We check the flag, but we never copy the flag into trie->map.map_flags, which is later on exposed into fdinfo and used by loaders such as iproute2. Latter uses this in bpf_map_selfcheck_pinned() to test whether a pinned map has the same spec as the one from the BPF obj file and if not, bails out, which is currently the case for lpm since it exposes always 0 as flags. Also copy over flags in array_map_alloc() and stack_map_alloc(). They always have to be 0 right now, but we should make sure to not miss to copy them over at a later point in time when we add actual flags for them to use. Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation") Reported-by: Jarno Rajahalme <jarno@covalent.io> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-25bpf: properly reset caller saved regs after helper call and ld_abs/indDaniel Borkmann1-21/+16
Currently, after performing helper calls, we clear all caller saved registers, that is r0 - r5 and fill r0 depending on struct bpf_func_proto specification. The way we reset these regs can affect pruning decisions in later paths, since we only reset register's imm to 0 and type to NOT_INIT. However, we leave out clearing of other variables such as id, min_value, max_value, etc, which can later on lead to pruning mismatches due to stale data. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-25bpf: fix incorrect pruning decision when alignment must be trackedDaniel Borkmann1-9/+10
Currently, when we enforce alignment tracking on direct packet access, the verifier lets the following program pass despite doing a packet write with unaligned access: 0: (61) r2 = *(u32 *)(r1 +76) 1: (61) r3 = *(u32 *)(r1 +80) 2: (61) r7 = *(u32 *)(r1 +8) 3: (bf) r0 = r2 4: (07) r0 += 14 5: (25) if r7 > 0x1 goto pc+4 R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp 6: (2d) if r0 > r3 goto pc+1 R0=pkt(id=0,off=14,r=14) R1=ctx R2=pkt(id=0,off=0,r=14) R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp 7: (63) *(u32 *)(r0 -4) = r0 8: (b7) r0 = 0 9: (95) exit from 6 to 8: R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp 8: (b7) r0 = 0 9: (95) exit from 5 to 10: R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=2 R10=fp 10: (07) r0 += 1 11: (05) goto pc-6 6: safe <----- here, wrongly found safe processed 15 insns However, if we enforce a pruning mismatch by adding state into r8 which is then being mismatched in states_equal(), we find that for the otherwise same program, the verifier detects a misaligned packet access when actually walking that path: 0: (61) r2 = *(u32 *)(r1 +76) 1: (61) r3 = *(u32 *)(r1 +80) 2: (61) r7 = *(u32 *)(r1 +8) 3: (b7) r8 = 1 4: (bf) r0 = r2 5: (07) r0 += 14 6: (25) if r7 > 0x1 goto pc+4 R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=0,max_value=1 R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp 7: (2d) if r0 > r3 goto pc+1 R0=pkt(id=0,off=14,r=14) R1=ctx R2=pkt(id=0,off=0,r=14) R3=pkt_end R7=inv,min_value=0,max_value=1 R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp 8: (63) *(u32 *)(r0 -4) = r0 9: (b7) r0 = 0 10: (95) exit from 7 to 9: R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=0,max_value=1 R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp 9: (b7) r0 = 0 10: (95) exit from 6 to 11: R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0) R3=pkt_end R7=inv,min_value=2 R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp 11: (07) r0 += 1 12: (b7) r8 = 0 13: (05) goto pc-7 <----- mismatch due to r8 7: (2d) if r0 > r3 goto pc+1 R0=pkt(id=0,off=15,r=15) R1=ctx R2=pkt(id=0,off=0,r=15) R3=pkt_end R7=inv,min_value=2 R8=imm0,min_value=0,max_value=0,min_align=2147483648 R10=fp 8: (63) *(u32 *)(r0 -4) = r0 misaligned packet access off 2+15+-4 size 4 The reason why we fail to see it in states_equal() is that the third test in compare_ptrs_to_packet() ... if (old->off <= cur->off && old->off >= old->range && cur->off >= cur->range) return true; ... will let the above pass. The situation we run into is that old->off <= cur->off (14 <= 15), meaning that prior walked paths went with smaller offset, which was later used in the packet access after successful packet range check and found to be safe already. For example: Given is R0=pkt(id=0,off=0,r=0). Adding offset 14 as in above program to it, results in R0=pkt(id=0,off=14,r=0) before the packet range test. Now, testing this against R3=pkt_end with 'if r0 > r3 goto out' will transform R0 into R0=pkt(id=0,off=14,r=14) for the case when we're within bounds. A write into the packet at offset *(u32 *)(r0 -4), that is, 2 + 14 -4, is valid and aligned (2 is for NET_IP_ALIGN). After processing this with all fall-through paths, we later on check paths from branches. When the above skb->mark test is true, then we jump near the end of the program, perform r0 += 1, and jump back to the 'if r0 > r3 goto out' test we've visited earlier already. This time, R0 is of type R0=pkt(id=0,off=15,r=0), and we'll prune that part because this time we'll have a larger safe packet range, and we already found that with off=14 all further insn were already safe, so it's safe as well with a larger off. However, the problem is that the subsequent write into the packet with 2 + 15 -4 is then unaligned, and not caught by the alignment tracking. Note that min_align, aux_off, and aux_off_align were all 0 in this example. Since we cannot tell at this time what kind of packet access was performed in the prior walk and what minimal requirements it has (we might do so in the future, but that requires more complexity), fix it to disable this pruning case for strict alignment for now, and let the verifier do check such paths instead. With that applied, the test cases pass and reject the program due to misalignment. Fixes: d1174416747d ("bpf: Track alignment of register values in the verifier.") Reference: http://patchwork.ozlabs.org/patch/761909/ Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>