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* bpf: fix panic in stack_map_get_build_id() on i386 and arm32Song Liu2019-01-101-1/+2
| | | | | | | | | | | | | | As Naresh reported, test_stacktrace_build_id() causes panic on i386 and arm32 systems. This is caused by page_address() returns NULL in certain cases. This patch fixes this error by using kmap_atomic/kunmap_atomic instead of page_address. Fixes: 615755a77b24 (" bpf: extend stackmap to save binary_build_id+offset instead of address") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: fix sanitation of alu op with pointer / scalar type from different pathsDaniel Borkmann2019-01-061-13/+48
| | | | | | | | | | | | | | | | | While 979d63d50c0c ("bpf: prevent out of bounds speculation on pointer arithmetic") took care of rejecting alu op on pointer when e.g. pointer came from two different map values with different map properties such as value size, Jann reported that a case was not covered yet when a given alu op is used in both "ptr_reg += reg" and "numeric_reg += reg" from different branches where we would incorrectly try to sanitize based on the pointer's limit. Catch this corner case and reject the program instead. Fixes: 979d63d50c0c ("bpf: prevent out of bounds speculation on pointer arithmetic") Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* Remove 'type' argument from access_ok() functionLinus Torvalds2019-01-0412-42/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2019-01-032-78/+312
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: "Several fixes here. Basically split down the line between newly introduced regressions and long existing problems: 1) Double free in tipc_enable_bearer(), from Cong Wang. 2) Many fixes to nf_conncount, from Florian Westphal. 3) op->get_regs_len() can throw an error, check it, from Yunsheng Lin. 4) Need to use GFP_ATOMIC in *_add_hash_mac_address() of fsl/fman driver, from Scott Wood. 5) Inifnite loop in fib_empty_table(), from Yue Haibing. 6) Use after free in ax25_fillin_cb(), from Cong Wang. 7) Fix socket locking in nr_find_socket(), also from Cong Wang. 8) Fix WoL wakeup enable in r8169, from Heiner Kallweit. 9) On 32-bit sock->sk_stamp is not thread-safe, from Deepa Dinamani. 10) Fix ptr_ring wrap during queue swap, from Cong Wang. 11) Missing shutdown callback in hinic driver, from Xue Chaojing. 12) Need to return NULL on error from ip6_neigh_lookup(), from Stefano Brivio. 13) BPF out of bounds speculation fixes from Daniel Borkmann" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (57 commits) ipv6: Consider sk_bound_dev_if when binding a socket to an address ipv6: Fix dump of specific table with strict checking bpf: add various test cases to selftests bpf: prevent out of bounds speculation on pointer arithmetic bpf: fix check_map_access smin_value test when pointer contains offset bpf: restrict unknown scalars of mixed signed bounds for unprivileged bpf: restrict stack pointer arithmetic for unprivileged bpf: restrict map value pointer arithmetic for unprivileged bpf: enable access to ax register also from verifier rewrite bpf: move tmp variable into ax register in interpreter bpf: move {prev_,}insn_idx into verifier env isdn: fix kernel-infoleak in capi_unlocked_ioctl ipv6: route: Fix return value of ip6_neigh_lookup() on neigh_create() error net/hamradio/6pack: use mod_timer() to rearm timers net-next/hinic:add shutdown callback net: hns3: call hns3_nic_net_open() while doing HNAE3_UP_CLIENT ip: validate header length on virtual device xmit tap: call skb_probe_transport_header after setting skb->dev ptr_ring: wrap back ->producer in __ptr_ring_swap_queue() net: rds: remove unnecessary NULL check ...
| * bpf: prevent out of bounds speculation on pointer arithmeticDaniel Borkmann2019-01-031-6/+179
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jann reported that the original commit back in b2157399cc98 ("bpf: prevent out-of-bounds speculation") was not sufficient to stop CPU from speculating out of bounds memory access: While b2157399cc98 only focussed on masking array map access for unprivileged users for tail calls and data access such that the user provided index gets sanitized from BPF program and syscall side, there is still a more generic form affected from BPF programs that applies to most maps that hold user data in relation to dynamic map access when dealing with unknown scalars or "slow" known scalars as access offset, for example: - Load a map value pointer into R6 - Load an index into R7 - Do a slow computation (e.g. with a memory dependency) that loads a limit into R8 (e.g. load the limit from a map for high latency, then mask it to make the verifier happy) - Exit if R7 >= R8 (mispredicted branch) - Load R0 = R6[R7] - Load R0 = R6[R0] For unknown scalars there are two options in the BPF verifier where we could derive knowledge from in order to guarantee safe access to the memory: i) While </>/<=/>= variants won't allow to derive any lower or upper bounds from the unknown scalar where it would be safe to add it to the map value pointer, it is possible through ==/!= test however. ii) another option is to transform the unknown scalar into a known scalar, for example, through ALU ops combination such as R &= <imm> followed by R |= <imm> or any similar combination where the original information from the unknown scalar would be destroyed entirely leaving R with a constant. The initial slow load still precedes the latter ALU ops on that register, so the CPU executes speculatively from that point. Once we have the known scalar, any compare operation would work then. A third option only involving registers with known scalars could be crafted as described in [0] where a CPU port (e.g. Slow Int unit) would be filled with many dependent computations such that the subsequent condition depending on its outcome has to wait for evaluation on its execution port and thereby executing speculatively if the speculated code can be scheduled on a different execution port, or any other form of mistraining as described in [1], for example. Given this is not limited to only unknown scalars, not only map but also stack access is affected since both is accessible for unprivileged users and could potentially be used for out of bounds access under speculation. In order to prevent any of these cases, the verifier is now sanitizing pointer arithmetic on the offset such that any out of bounds speculation would be masked in a way where the pointer arithmetic result in the destination register will stay unchanged, meaning offset masked into zero similar as in array_index_nospec() case. With regards to implementation, there are three options that were considered: i) new insn for sanitation, ii) push/pop insn and sanitation as inlined BPF, iii) reuse of ax register and sanitation as inlined BPF. Option i) has the downside that we end up using from reserved bits in the opcode space, but also that we would require each JIT to emit masking as native arch opcodes meaning mitigation would have slow adoption till everyone implements it eventually which is counter-productive. Option ii) and iii) have both in common that a temporary register is needed in order to implement the sanitation as inlined BPF since we are not allowed to modify the source register. While a push / pop insn in ii) would be useful to have in any case, it requires once again that every JIT needs to implement it first. While possible, amount of changes needed would also be unsuitable for a -stable patch. Therefore, the path which has fewer changes, less BPF instructions for the mitigation and does not require anything to be changed in the JITs is option iii) which this work is pursuing. The ax register is already mapped to a register in all JITs (modulo arm32 where it's mapped to stack as various other BPF registers there) and used in constant blinding for JITs-only so far. It can be reused for verifier rewrites under certain constraints. The interpreter's tmp "register" has therefore been remapped into extending the register set with hidden ax register and reusing that for a number of instructions that needed the prior temporary variable internally (e.g. div, mod). This allows for zero increase in stack space usage in the interpreter, and enables (restricted) generic use in rewrites otherwise as long as such a patchlet does not make use of these instructions. The sanitation mask is dynamic and relative to the offset the map value or stack pointer currently holds. There are various cases that need to be taken under consideration for the masking, e.g. such operation could look as follows: ptr += val or val += ptr or ptr -= val. Thus, the value to be sanitized could reside either in source or in destination register, and the limit is different depending on whether the ALU op is addition or subtraction and depending on the current known and bounded offset. The limit is derived as follows: limit := max_value_size - (smin_value + off). For subtraction: limit := umax_value + off. This holds because we do not allow any pointer arithmetic that would temporarily go out of bounds or would have an unknown value with mixed signed bounds where it is unclear at verification time whether the actual runtime value would be either negative or positive. For example, we have a derived map pointer value with constant offset and bounded one, so limit based on smin_value works because the verifier requires that statically analyzed arithmetic on the pointer must be in bounds, and thus it checks if resulting smin_value + off and umax_value + off is still within map value bounds at time of arithmetic in addition to time of access. Similarly, for the case of stack access we derive the limit as follows: MAX_BPF_STACK + off for subtraction and -off for the case of addition where off := ptr_reg->off + ptr_reg->var_off.value. Subtraction is a special case for the masking which can be in form of ptr += -val, ptr -= -val, or ptr -= val. In the first two cases where we know that the value is negative, we need to temporarily negate the value in order to do the sanitation on a positive value where we later swap the ALU op, and restore original source register if the value was in source. The sanitation of pointer arithmetic alone is still not fully sufficient as is, since a scenario like the following could happen ... PTR += 0x1000 (e.g. K-based imm) PTR -= BIG_NUMBER_WITH_SLOW_COMPARISON PTR += 0x1000 PTR -= BIG_NUMBER_WITH_SLOW_COMPARISON [...] ... which under speculation could end up as ... PTR += 0x1000 PTR -= 0 [ truncated by mitigation ] PTR += 0x1000 PTR -= 0 [ truncated by mitigation ] [...] ... and therefore still access out of bounds. To prevent such case, the verifier is also analyzing safety for potential out of bounds access under speculative execution. Meaning, it is also simulating pointer access under truncation. We therefore "branch off" and push the current verification state after the ALU operation with known 0 to the verification stack for later analysis. Given the current path analysis succeeded it is likely that the one under speculation can be pruned. In any case, it is also subject to existing complexity limits and therefore anything beyond this point will be rejected. In terms of pruning, it needs to be ensured that the verification state from speculative execution simulation must never prune a non-speculative execution path, therefore, we mark verifier state accordingly at the time of push_stack(). If verifier detects out of bounds access under speculative execution from one of the possible paths that includes a truncation, it will reject such program. Given we mask every reg-based pointer arithmetic for unprivileged programs, we've been looking into how it could affect real-world programs in terms of size increase. As the majority of programs are targeted for privileged-only use case, we've unconditionally enabled masking (with its alu restrictions on top of it) for privileged programs for the sake of testing in order to check i) whether they get rejected in its current form, and ii) by how much the number of instructions and size will increase. We've tested this by using Katran, Cilium and test_l4lb from the kernel selftests. For Katran we've evaluated balancer_kern.o, Cilium bpf_lxc.o and an older test object bpf_lxc_opt_-DUNKNOWN.o and l4lb we've used test_l4lb.o as well as test_l4lb_noinline.o. We found that none of the programs got rejected by the verifier with this change, and that impact is rather minimal to none. balancer_kern.o had 13,904 bytes (1,738 insns) xlated and 7,797 bytes JITed before and after the change. Most complex program in bpf_lxc.o had 30,544 bytes (3,817 insns) xlated and 18,538 bytes JITed before and after and none of the other tail call programs in bpf_lxc.o had any changes either. For the older bpf_lxc_opt_-DUNKNOWN.o object we found a small increase from 20,616 bytes (2,576 insns) and 12,536 bytes JITed before to 20,664 bytes (2,582 insns) and 12,558 bytes JITed after the change. Other programs from that object file had similar small increase. Both test_l4lb.o had no change and remained at 6,544 bytes (817 insns) xlated and 3,401 bytes JITed and for test_l4lb_noinline.o constant at 5,080 bytes (634 insns) xlated and 3,313 bytes JITed. This can be explained in that LLVM typically optimizes stack based pointer arithmetic by using K-based operations and that use of dynamic map access is not overly frequent. However, in future we may decide to optimize the algorithm further under known guarantees from branch and value speculation. Latter seems also unclear in terms of prediction heuristics that today's CPUs apply as well as whether there could be collisions in e.g. the predictor's Value History/Pattern Table for triggering out of bounds access, thus masking is performed unconditionally at this point but could be subject to relaxation later on. We were generally also brainstorming various other approaches for mitigation, but the blocker was always lack of available registers at runtime and/or overhead for runtime tracking of limits belonging to a specific pointer. Thus, we found this to be minimally intrusive under given constraints. With that in place, a simple example with sanitized access on unprivileged load at post-verification time looks as follows: # bpftool prog dump xlated id 282 [...] 28: (79) r1 = *(u64 *)(r7 +0) 29: (79) r2 = *(u64 *)(r7 +8) 30: (57) r1 &= 15 31: (79) r3 = *(u64 *)(r0 +4608) 32: (57) r3 &= 1 33: (47) r3 |= 1 34: (2d) if r2 > r3 goto pc+19 35: (b4) (u32) r11 = (u32) 20479 | 36: (1f) r11 -= r2 | Dynamic sanitation for pointer 37: (4f) r11 |= r2 | arithmetic with registers 38: (87) r11 = -r11 | containing bounded or known 39: (c7) r11 s>>= 63 | scalars in order to prevent 40: (5f) r11 &= r2 | out of bounds speculation. 41: (0f) r4 += r11 | 42: (71) r4 = *(u8 *)(r4 +0) 43: (6f) r4 <<= r1 [...] For the case where the scalar sits in the destination register as opposed to the source register, the following code is emitted for the above example: [...] 16: (b4) (u32) r11 = (u32) 20479 17: (1f) r11 -= r2 18: (4f) r11 |= r2 19: (87) r11 = -r11 20: (c7) r11 s>>= 63 21: (5f) r2 &= r11 22: (0f) r2 += r0 23: (61) r0 = *(u32 *)(r2 +0) [...] JIT blinding example with non-conflicting use of r10: [...] d5: je 0x0000000000000106 _ d7: mov 0x0(%rax),%edi | da: mov $0xf153246,%r10d | Index load from map value and e0: xor $0xf153259,%r10 | (const blinded) mask with 0x1f. e7: and %r10,%rdi |_ ea: mov $0x2f,%r10d | f0: sub %rdi,%r10 | Sanitized addition. Both use r10 f3: or %rdi,%r10 | but do not interfere with each f6: neg %r10 | other. (Neither do these instructions f9: sar $0x3f,%r10 | interfere with the use of ax as temp fd: and %r10,%rdi | in interpreter.) 100: add %rax,%rdi |_ 103: mov 0x0(%rdi),%eax [...] Tested that it fixes Jann's reproducer, and also checked that test_verifier and test_progs suite with interpreter, JIT and JIT with hardening enabled on x86-64 and arm64 runs successfully. [0] Speculose: Analyzing the Security Implications of Speculative Execution in CPUs, Giorgi Maisuradze and Christian Rossow, https://arxiv.org/pdf/1801.04084.pdf [1] A Systematic Evaluation of Transient Execution Attacks and Defenses, Claudio Canella, Jo Van Bulck, Michael Schwarz, Moritz Lipp, Benjamin von Berg, Philipp Ortner, Frank Piessens, Dmitry Evtyushkin, Daniel Gruss, https://arxiv.org/pdf/1811.05441.pdf Fixes: b2157399cc98 ("bpf: prevent out-of-bounds speculation") Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: fix check_map_access smin_value test when pointer contains offsetDaniel Borkmann2019-01-031-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In check_map_access() we probe actual bounds through __check_map_access() with offset of reg->smin_value + off for lower bound and offset of reg->umax_value + off for the upper bound. However, even though the reg->smin_value could have a negative value, the final result of the sum with off could be positive when pointer arithmetic with known and unknown scalars is combined. In this case we reject the program with an error such as "R<x> min value is negative, either use unsigned index or do a if (index >=0) check." even though the access itself would be fine. Therefore extend the check to probe whether the actual resulting reg->smin_value + off is less than zero. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: restrict unknown scalars of mixed signed bounds for unprivilegedDaniel Borkmann2019-01-031-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | For unknown scalars of mixed signed bounds, meaning their smin_value is negative and their smax_value is positive, we need to reject arithmetic with pointer to map value. For unprivileged the goal is to mask every map pointer arithmetic and this cannot reliably be done when it is unknown at verification time whether the scalar value is negative or positive. Given this is a corner case, the likelihood of breaking should be very small. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: restrict stack pointer arithmetic for unprivilegedDaniel Borkmann2019-01-031-22/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Restrict stack pointer arithmetic for unprivileged users in that arithmetic itself must not go out of bounds as opposed to the actual access later on. Therefore after each adjust_ptr_min_max_vals() with a stack pointer as a destination we simulate a check_stack_access() of 1 byte on the destination and once that fails the program is rejected for unprivileged program loads. This is analog to map value pointer arithmetic and needed for masking later on. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: restrict map value pointer arithmetic for unprivilegedDaniel Borkmann2019-01-031-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Restrict map value pointer arithmetic for unprivileged users in that arithmetic itself must not go out of bounds as opposed to the actual access later on. Therefore after each adjust_ptr_min_max_vals() with a map value pointer as a destination it will simulate a check_map_access() of 1 byte on the destination and once that fails the program is rejected for unprivileged program loads. We use this later on for masking any pointer arithmetic with the remainder of the map value space. The likelihood of breaking any existing real-world unprivileged eBPF program is very small for this corner case. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: enable access to ax register also from verifier rewriteDaniel Borkmann2019-01-031-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now we are using BPF ax register in JIT for constant blinding as well as in interpreter as temporary variable. Verifier will not be able to use it simply because its use will get overridden from the former in bpf_jit_blind_insn(). However, it can be made to work in that blinding will be skipped if there is prior use in either source or destination register on the instruction. Taking constraints of ax into account, the verifier is then open to use it in rewrites under some constraints. Note, ax register already has mappings in every eBPF JIT. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: move tmp variable into ax register in interpreterDaniel Borkmann2019-01-031-17/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | This change moves the on-stack 64 bit tmp variable in ___bpf_prog_run() into the hidden ax register. The latter is currently only used in JITs for constant blinding as a temporary scratch register, meaning the BPF interpreter will never see the use of ax. Therefore it is safe to use it for the cases where tmp has been used earlier. This is needed to later on allow restricted hidden use of ax in both interpreter and JITs. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: move {prev_,}insn_idx into verifier envDaniel Borkmann2019-01-031-38/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | Move prev_insn_idx and insn_idx from the do_check() function into the verifier environment, so they can be read inside the various helper functions for handling the instructions. It's easier to put this into the environment rather than changing all call-sites only to pass it along. insn_idx is useful in particular since this later on allows to hold state in env->insn_aux_data[env->insn_idx]. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | Merge tag 'nfs-for-4.21-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds2019-01-031-1/+57
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull NFS client updates from Anna Schumaker: "Stable bugfixes: - xprtrdma: Yet another double DMA-unmap # v4.20 Features: - Allow some /proc/sys/sunrpc entries without CONFIG_SUNRPC_DEBUG - Per-xprt rdma receive workqueues - Drop support for FMR memory registration - Make port= mount option optional for RDMA mounts Other bugfixes and cleanups: - Remove unused nfs4_xdev_fs_type declaration - Fix comments for behavior that has changed - Remove generic RPC credentials by switching to 'struct cred' - Fix crossing mountpoints with different auth flavors - Various xprtrdma fixes from testing and auditing the close code - Fixes for disconnect issues when using xprtrdma with krb5 - Clean up and improve xprtrdma trace points - Fix NFS v4.2 async copy reboot recovery" * tag 'nfs-for-4.21-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (63 commits) sunrpc: convert to DEFINE_SHOW_ATTRIBUTE sunrpc: Add xprt after nfs4_test_session_trunk() sunrpc: convert unnecessary GFP_ATOMIC to GFP_NOFS sunrpc: handle ENOMEM in rpcb_getport_async NFS: remove unnecessary test for IS_ERR(cred) xprtrdma: Prevent leak of rpcrdma_rep objects NFSv4.2 fix async copy reboot recovery xprtrdma: Don't leak freed MRs xprtrdma: Add documenting comment for rpcrdma_buffer_destroy xprtrdma: Replace outdated comment for rpcrdma_ep_post xprtrdma: Update comments in frwr_op_send SUNRPC: Fix some kernel doc complaints SUNRPC: Simplify defining common RPC trace events NFS: Fix NFSv4 symbolic trace point output xprtrdma: Trace mapping, alloc, and dereg failures xprtrdma: Add trace points for calls to transport switch methods xprtrdma: Relocate the xprtrdma_mr_map trace points xprtrdma: Clean up of xprtrdma chunk trace points xprtrdma: Remove unused fields from rpcrdma_ia xprtrdma: Cull dprintk() call sites ...
| * | cred: export get_task_cred().NeilBrown2018-12-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | There is no reason that modules should not be able to use this, and NFS will need it when converted to use 'struct cred'. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * | cred: add get_cred_rcu()NeilBrown2018-12-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sometimes we want to opportunistically get a ref to a cred in an rcu_read_lock protected section. get_task_cred() does this, and NFS does as similar thing with its own credential structures. To prepare for NFS converting to use 'struct cred' more uniformly, define get_cred_rcu(), and use it in get_task_cred(). Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| * | cred: add cred_fscmp() for comparing creds.NeilBrown2018-12-191-0/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | NFS needs to compare to credentials, to see if they can be treated the same w.r.t. filesystem access. Sometimes an ordering is needed when credentials are used as a key to an rbtree. NFS currently has its own private credential management from before 'struct cred' existed. To move it over to more consistent use of 'struct cred' we need a comparison function. This patch adds that function. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* | | Merge branch 'next-seccomp' of ↵Linus Torvalds2019-01-021-12/+455
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull seccomp updates from James Morris: - Add SECCOMP_RET_USER_NOTIF - seccomp fixes for sparse warnings and s390 build (Tycho) * 'next-seccomp' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: seccomp, s390: fix build for syscall type change seccomp: fix poor type promotion samples: add an example of seccomp user trap seccomp: add a return code to trap to userspace seccomp: switch system call argument type to void * seccomp: hoist struct seccomp_data recalculation higher
| * | | seccomp: fix poor type promotionTycho Andersen2018-12-141-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sparse complains, kernel/seccomp.c:1172:13: warning: incorrect type in assignment (different base types) kernel/seccomp.c:1172:13: expected restricted __poll_t [usertype] ret kernel/seccomp.c:1172:13: got int kernel/seccomp.c:1173:13: warning: restricted __poll_t degrades to integer Instead of assigning this to ret, since we don't use this anywhere, let's just test it against 0 directly. Signed-off-by: Tycho Andersen <tycho@tycho.ws> Reported-by: 0day robot <lkp@intel.com> Fixes: 6a21cc50f0c7 ("seccomp: add a return code to trap to userspace") Signed-off-by: Kees Cook <keescook@chromium.org>
| * | | seccomp: add a return code to trap to userspaceTycho Andersen2018-12-121-2/+446
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces a means for syscalls matched in seccomp to notify some other task that a particular filter has been triggered. The motivation for this is primarily for use with containers. For example, if a container does an init_module(), we obviously don't want to load this untrusted code, which may be compiled for the wrong version of the kernel anyway. Instead, we could parse the module image, figure out which module the container is trying to load and load it on the host. As another example, containers cannot mount() in general since various filesystems assume a trusted image. However, if an orchestrator knows that e.g. a particular block device has not been exposed to a container for writing, it want to allow the container to mount that block device (that is, handle the mount for it). This patch adds functionality that is already possible via at least two other means that I know about, both of which involve ptrace(): first, one could ptrace attach, and then iterate through syscalls via PTRACE_SYSCALL. Unfortunately this is slow, so a faster version would be to install a filter that does SECCOMP_RET_TRACE, which triggers a PTRACE_EVENT_SECCOMP. Since ptrace allows only one tracer, if the container runtime is that tracer, users inside the container (or outside) trying to debug it will not be able to use ptrace, which is annoying. It also means that older distributions based on Upstart cannot boot inside containers using ptrace, since upstart itself uses ptrace to monitor services while starting. The actual implementation of this is fairly small, although getting the synchronization right was/is slightly complex. Finally, it's worth noting that the classic seccomp TOCTOU of reading memory data from the task still applies here, but can be avoided with careful design of the userspace handler: if the userspace handler reads all of the task memory that is necessary before applying its security policy, the tracee's subsequent memory edits will not be read by the tracer. Signed-off-by: Tycho Andersen <tycho@tycho.ws> CC: Kees Cook <keescook@chromium.org> CC: Andy Lutomirski <luto@amacapital.net> CC: Oleg Nesterov <oleg@redhat.com> CC: Eric W. Biederman <ebiederm@xmission.com> CC: "Serge E. Hallyn" <serge@hallyn.com> Acked-by: Serge Hallyn <serge@hallyn.com> CC: Christian Brauner <christian@brauner.io> CC: Tyler Hicks <tyhicks@canonical.com> CC: Akihiro Suda <suda.akihiro@lab.ntt.co.jp> Signed-off-by: Kees Cook <keescook@chromium.org>
| * | | seccomp: switch system call argument type to void *Tycho Andersen2018-12-121-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The const qualifier causes problems for any code that wants to write to the third argument of the seccomp syscall, as we will do in a future patch in this series. The third argument to the seccomp syscall is documented as void *, so rather than just dropping the const, let's switch everything to use void * as well. I believe this is safe because of 1. the documentation above, 2. there's no real type information exported about syscalls anywhere besides the man pages. Signed-off-by: Tycho Andersen <tycho@tycho.ws> CC: Kees Cook <keescook@chromium.org> CC: Andy Lutomirski <luto@amacapital.net> CC: Oleg Nesterov <oleg@redhat.com> CC: Eric W. Biederman <ebiederm@xmission.com> CC: "Serge E. Hallyn" <serge@hallyn.com> Acked-by: Serge Hallyn <serge@hallyn.com> CC: Christian Brauner <christian@brauner.io> CC: Tyler Hicks <tyhicks@canonical.com> CC: Akihiro Suda <suda.akihiro@lab.ntt.co.jp> Signed-off-by: Kees Cook <keescook@chromium.org>
| * | | seccomp: hoist struct seccomp_data recalculation higherTycho Andersen2018-12-121-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the next patch, we're going to use the sd pointer passed to __seccomp_filter() as the data to pass to userspace. Except that in some cases (__seccomp_filter(SECCOMP_RET_TRACE), emulate_vsyscall(), every time seccomp is inovked on power, etc.) the sd pointer will be NULL in order to force seccomp to recompute the register data. Previously this recomputation happened one level lower, in seccomp_run_filters(); this patch just moves it up a level higher to __seccomp_filter(). Thanks Oleg for spotting this. Signed-off-by: Tycho Andersen <tycho@tycho.ws> CC: Kees Cook <keescook@chromium.org> CC: Andy Lutomirski <luto@amacapital.net> CC: Oleg Nesterov <oleg@redhat.com> CC: Eric W. Biederman <ebiederm@xmission.com> CC: "Serge E. Hallyn" <serge@hallyn.com> Acked-by: Serge Hallyn <serge@hallyn.com> CC: Christian Brauner <christian@brauner.io> CC: Tyler Hicks <tyhicks@canonical.com> CC: Akihiro Suda <suda.akihiro@lab.ntt.co.jp> Signed-off-by: Kees Cook <keescook@chromium.org>
* | | | Merge tag 'kgdb-4.21-rc1' of ↵Linus Torvalds2019-01-025-16/+82
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux Pull kgdb updates from Daniel Thompson: "Mostly clean ups although while Doug's was chasing down a odd lockdep warning he also did some work to improved debugger resilience when some CPUs fail to respond to the round up request. The main changes are: - Fixing a lockdep warning on architectures that cannot use an NMI for the round up plus related changes to make CPU round up and all CPU backtrace more resilient. - Constify the arch ops tables - A couple of other small clean ups Two of the three patchsets here include changes that spill over into arch/. Changes in the arch space are relatively narrow in scope (and directly related to kgdb). Didn't get comprehensive acks but all impacted maintainers were Cc:ed in good time" * tag 'kgdb-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux: kgdb/treewide: constify struct kgdb_arch arch_kgdb_ops mips/kgdb: prepare arch_kgdb_ops for constness kdb: use bool for binary state indicators kdb: Don't back trace on a cpu that didn't round up kgdb: Don't round up a CPU that failed rounding up before kgdb: Fix kgdb_roundup_cpus() for arches who used smp_call_function() kgdb: Remove irq flags from roundup
| * | | | kdb: use bool for binary state indicatorsNicholas Mc Guire2018-12-301-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | defcmd_in_progress is the state trace for command group processing - within a command group or not - usable is an indicator if a command set is valid (allocated/non-empty) - so use a bool for those binary indication here. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
| * | | | kdb: Don't back trace on a cpu that didn't round upDouglas Anderson2018-12-303-8/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If you have a CPU that fails to round up and then run 'btc' you'll end up crashing in kdb becaue we dereferenced NULL. Let's add a check. It's wise to also set the task to NULL when leaving the debugger so that if we fail to round up on a later entry into the debugger we won't backtrace a stale task. Signed-off-by: Douglas Anderson <dianders@chromium.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
| * | | | kgdb: Don't round up a CPU that failed rounding up beforeDouglas Anderson2018-12-302-1/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we're using the default implementation of kgdb_roundup_cpus() that uses smp_call_function_single_async() we can end up hanging kgdb_roundup_cpus() if we try to round up a CPU that failed to round up before. Specifically smp_call_function_single_async() will try to wait on the csd lock for the CPU that we're trying to round up. If the previous round up never finished then that lock could still be held and we'll just sit there hanging. There's not a lot of use trying to round up a CPU that failed to round up before. Let's keep a flag that indicates whether the CPU started but didn't finish to round up before. If we see that flag set then we'll skip the next round up. In general we have a few goals here: - We never want to end up calling smp_call_function_single_async() when the csd is still locked. This is accomplished because flush_smp_call_function_queue() unlocks the csd _before_ invoking the callback. That means that when kgdb_nmicallback() runs we know for sure the the csd is no longer locked. Thus when we set "rounding_up = false" we know for sure that the csd is unlocked. - If there are no timeouts rounding up we should never skip a round up. NOTE #1: In general trying to continue running after failing to round up CPUs doesn't appear to be supported in the debugger. When I simulate this I find that kdb reports "Catastrophic error detected" when I try to continue. I can overrule and continue anyway, but it should be noted that we may be entering the land of dragons here. Possibly the "Catastrophic error detected" was added _because_ of the future failure to round up, but even so this is an area of the code that hasn't been strongly tested. NOTE #2: I did a bit of testing before and after this change. I introduced a 10 second hang in the kernel while holding a spinlock that I could invoke on a certain CPU with 'taskset -c 3 cat /sys/...". Before this change if I did: - Invoke hang - Enter debugger - g (which warns about Catastrophic error, g again to go anyway) - g - Enter debugger ...I'd hang the rest of the 10 seconds without getting a debugger prompt. After this change I end up in the debugger the 2nd time after only 1 second with the standard warning about 'Timed out waiting for secondary CPUs.' I'll also note that once the CPU finished waiting I could actually debug it (aka "btc" worked) I won't promise that everything works perfectly if the errant CPU comes back at just the wrong time (like as we're entering or exiting the debugger) but it certainly seems like an improvement. NOTE #3: setting 'kgdb_info[cpu].rounding_up = false' is in kgdb_nmicallback() instead of kgdb_call_nmi_hook() because some implementations override kgdb_call_nmi_hook(). It shouldn't hurt to have it in kgdb_nmicallback() in any case. NOTE #4: this logic is really only needed because there is no API call like "smp_try_call_function_single_async()" or "smp_csd_is_locked()". If such an API existed then we'd use it instead, but it seemed a bit much to add an API like this just for kgdb. Signed-off-by: Douglas Anderson <dianders@chromium.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
| * | | | kgdb: Fix kgdb_roundup_cpus() for arches who used smp_call_function()Douglas Anderson2018-12-301-0/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When I had lockdep turned on and dropped into kgdb I got a nice splat on my system. Specifically it hit: DEBUG_LOCKS_WARN_ON(current->hardirq_context) Specifically it looked like this: sysrq: SysRq : DEBUG ------------[ cut here ]------------ DEBUG_LOCKS_WARN_ON(current->hardirq_context) WARNING: CPU: 0 PID: 0 at .../kernel/locking/lockdep.c:2875 lockdep_hardirqs_on+0xf0/0x160 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0 #27 pstate: 604003c9 (nZCv DAIF +PAN -UAO) pc : lockdep_hardirqs_on+0xf0/0x160 ... Call trace: lockdep_hardirqs_on+0xf0/0x160 trace_hardirqs_on+0x188/0x1ac kgdb_roundup_cpus+0x14/0x3c kgdb_cpu_enter+0x53c/0x5cc kgdb_handle_exception+0x180/0x1d4 kgdb_compiled_brk_fn+0x30/0x3c brk_handler+0x134/0x178 do_debug_exception+0xfc/0x178 el1_dbg+0x18/0x78 kgdb_breakpoint+0x34/0x58 sysrq_handle_dbg+0x54/0x5c __handle_sysrq+0x114/0x21c handle_sysrq+0x30/0x3c qcom_geni_serial_isr+0x2dc/0x30c ... ... irq event stamp: ...45 hardirqs last enabled at (...44): [...] __do_softirq+0xd8/0x4e4 hardirqs last disabled at (...45): [...] el1_irq+0x74/0x130 softirqs last enabled at (...42): [...] _local_bh_enable+0x2c/0x34 softirqs last disabled at (...43): [...] irq_exit+0xa8/0x100 ---[ end trace adf21f830c46e638 ]--- Looking closely at it, it seems like a really bad idea to be calling local_irq_enable() in kgdb_roundup_cpus(). If nothing else that seems like it could violate spinlock semantics and cause a deadlock. Instead, let's use a private csd alongside smp_call_function_single_async() to round up the other CPUs. Using smp_call_function_single_async() doesn't require interrupts to be enabled so we can remove the offending bit of code. In order to avoid duplicating this across all the architectures that use the default kgdb_roundup_cpus(), we'll add a "weak" implementation to debug_core.c. Looking at all the people who previously had copies of this code, there were a few variants. I've attempted to keep the variants working like they used to. Specifically: * For arch/arc we passed NULL to kgdb_nmicallback() instead of get_irq_regs(). * For arch/mips there was a bit of extra code around kgdb_nmicallback() NOTE: In this patch we will still get into trouble if we try to round up a CPU that failed to round up before. We'll try to round it up again and potentially hang when we try to grab the csd lock. That's not new behavior but we'll still try to do better in a future patch. Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: James Hogan <jhogan@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
| * | | | kgdb: Remove irq flags from roundupDouglas Anderson2018-12-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function kgdb_roundup_cpus() was passed a parameter that was documented as: > the flags that will be used when restoring the interrupts. There is > local_irq_save() call before kgdb_roundup_cpus(). Nobody used those flags. Anyone who wanted to temporarily turn on interrupts just did local_irq_enable() and local_irq_disable() without looking at them. So we can definitely remove the flags. Signed-off-by: Douglas Anderson <dianders@chromium.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: James Hogan <jhogan@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
* | | | | Merge tag 'trace-v4.21' of ↵Linus Torvalds2018-12-3122-1562/+2199
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - Rework of the kprobe/uprobe and synthetic events to consolidate all the dynamic event code. This will make changes in the future easier. - Partial rewrite of the function graph tracing infrastructure. This will allow for multiple users of hooking onto functions to get the callback (return) of the function. This is the ground work for having kprobes and function graph tracer using one code base. - Clean up of the histogram code that will facilitate adding more features to the histograms in the future. - Addition of str_has_prefix() and a few use cases. There currently is a similar function strstart() that is used in a few places, but only returns a bool and not a length. These instances will be removed in the future to use str_has_prefix() instead. - A few other various clean ups as well. * tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits) tracing: Use the return of str_has_prefix() to remove open coded numbers tracing: Have the historgram use the result of str_has_prefix() for len of prefix tracing: Use str_has_prefix() instead of using fixed sizes tracing: Use str_has_prefix() helper for histogram code string.h: Add str_has_prefix() helper function tracing: Make function ‘ftrace_exports’ static tracing: Simplify printf'ing in seq_print_sym tracing: Avoid -Wformat-nonliteral warning tracing: Merge seq_print_sym_short() and seq_print_sym_offset() tracing: Add hist trigger comments for variable-related fields tracing: Remove hist trigger synth_var_refs tracing: Use hist trigger's var_ref array to destroy var_refs tracing: Remove open-coding of hist trigger var_ref management tracing: Use var_refs[] for hist trigger reference checking tracing: Change strlen to sizeof for hist trigger static strings tracing: Remove unnecessary hist trigger struct field tracing: Fix ftrace_graph_get_ret_stack() to use task and not current seq_buf: Use size_t for len in seq_buf_puts() seq_buf: Make seq_buf_puts() null-terminate the buffer arm64: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack ...
| * | | | | tracing: Use the return of str_has_prefix() to remove open coded numbersSteven Rostedt (VMware)2018-12-233-13/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are several locations that compare constants to the beginning of string variables to determine what commands should be done, then the constant length is used to index into the string. This is error prone as the hard coded numbers have to match the size of the constants. Instead, use the len returned from str_has_prefix() and remove the open coded string length sizes. Cc: Joe Perches <joe@perches.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> (for trace_probe part) Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Have the historgram use the result of str_has_prefix() for len of ↵Steven Rostedt (VMware)2018-12-231-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | prefix As str_has_prefix() returns the length on match, we can use that for the updating of the string pointer instead of recalculating the prefix size. Cc: Tom Zanussi <zanussi@kernel.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Use str_has_prefix() instead of using fixed sizesSteven Rostedt (VMware)2018-12-235-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are several instances of strncmp(str, "const", 123), where 123 is the strlen of the const string to check if "const" is the prefix of str. But this can be error prone. Use str_has_prefix() instead. Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Use str_has_prefix() helper for histogram codeSteven Rostedt (VMware)2018-12-231-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tracing histogram code contains a lot of instances of the construct: strncmp(str, "const", sizeof("const") - 1) This can be prone to bugs due to typos or bad cut and paste. Use the str_has_prefix() helper macro instead that removes the need for having two copies of the constant string. Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Make function ‘ftrace_exports’ staticMathieu Malaterre2018-12-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 478409dd683d ("tracing: Add hook to function tracing for other subsystems to use"), a new function ‘ftrace_exports’ was added. Since this function can be made static, make it so. Silence the following warning triggered using W=1: kernel/trace/trace.c:2451:6: warning: no previous prototype for ‘ftrace_exports’ [-Wmissing-prototypes] Link: http://lkml.kernel.org/r/20180516193012.25390-1-malat@debian.org Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Simplify printf'ing in seq_print_symRasmus Villemoes2018-12-221-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | trace_seq_printf(..., "%s", ...) can be done with trace_seq_puts() instead, avoiding printf overhead. In the second instance, the string we're copying was just created from an snprintf() to a stack buffer, so we might as well do that printf directly. This naturally leads to moving the declaration of the str buffer inside the CONFIG_KALLSYMS guard, which in turn will make gcc inline the function for !CONFIG_KALLSYMS (it only has a single caller, but the huge stack frame seems to make gcc not inline it for CONFIG_KALLSYMS). Link: http://lkml.kernel.org/r/20181029223542.26175-4-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Avoid -Wformat-nonliteral warningRasmus Villemoes2018-12-221-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Building with -Wformat-nonliteral, gcc complains kernel/trace/trace_output.c: In function ‘seq_print_sym’: kernel/trace/trace_output.c:356:3: warning: format not a string literal, argument types not checked [-Wformat-nonliteral] trace_seq_printf(s, fmt, name); But seq_print_sym only has a single caller which passes "%s" as fmt, so we might as well just use that directly. That also paves the way for further cleanups that will actually make that format string go away entirely. Link: http://lkml.kernel.org/r/20181029223542.26175-3-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Merge seq_print_sym_short() and seq_print_sym_offset()Rasmus Villemoes2018-12-221-27/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These two functions are nearly identical, so we can avoid some code duplication by moving the conditional into a common implementation. Link: http://lkml.kernel.org/r/20181029223542.26175-2-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Add hist trigger comments for variable-related fieldsTom Zanussi2018-12-221-0/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a few comments to help clarify how variable and variable reference fields are used in the code. Link: http://lkml.kernel.org/r/ea857ce948531d7bec712bbb0f38360aa1d378ec.1545161087.git.tom.zanussi@linux.intel.com Acked-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Remove hist trigger synth_var_refsTom Zanussi2018-12-221-18/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All var_refs are now handled uniformly and there's no reason to treat the synth_refs in a special way now, so remove them and associated functions. Link: http://lkml.kernel.org/r/b4d3470526b8f0426dcec125399dad9ad9b8589d.1545161087.git.tom.zanussi@linux.intel.com Acked-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Use hist trigger's var_ref array to destroy var_refsTom Zanussi2018-12-221-5/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since every var ref for a trigger has an entry in the var_ref[] array, use that to destroy the var_refs, instead of piecemeal via the field expressions. This allows us to avoid having to keep and treat differently separate lists for the action-related references, which future patches will remove. Link: http://lkml.kernel.org/r/fad1a164f0e257c158e70d6eadbf6c586e04b2a2.1545161087.git.tom.zanussi@linux.intel.com Acked-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Remove open-coding of hist trigger var_ref managementTom Zanussi2018-12-221-18/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Have create_var_ref() manage the hist trigger's var_ref list, rather than having similar code doing it in multiple places. This cleans up the code and makes sure var_refs are always accounted properly. Also, document the var_ref-related functions to make what their purpose clearer. Link: http://lkml.kernel.org/r/05ddae93ff514e66fc03897d6665231892939913.1545161087.git.tom.zanussi@linux.intel.com Acked-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Use var_refs[] for hist trigger reference checkingTom Zanussi2018-12-221-57/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since all the variable reference hist_fields are collected into hist_data->var_refs[] array, there's no need to go through all the fields looking for them, or in separate arrays like synth_var_refs[], which will be going away soon anyway. This also allows us to get rid of some unnecessary code and functions currently used for the same purpose. Link: http://lkml.kernel.org/r/1545246556.4239.7.camel@gmail.com Acked-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Change strlen to sizeof for hist trigger static stringsTom Zanussi2018-12-221-19/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no need to use strlen() for static strings when the length is already known, so update trace_events_hist.c with sizeof() for those cases. Link: http://lkml.kernel.org/r/e3e754f2bd18e56eaa8baf79bee619316ebf4cfc.1545161087.git.tom.zanussi@linux.intel.com Acked-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Remove unnecessary hist trigger struct fieldTom Zanussi2018-12-221-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hist_field.var_idx is completely unused, so remove it. Link: http://lkml.kernel.org/r/d4e066c0f509f5f13ad3babc8c33ca6e7ddc439a.1545161087.git.tom.zanussi@linux.intel.com Acked-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Fix ftrace_graph_get_ret_stack() to use task and not currentSteven Rostedt (VMware)2018-12-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function ftrace_graph_get_ret_stack() takes a task struct descriptor but uses current as the task to perform the operations on. In pretty much all cases the task decriptor is the same as current, so this wasn't an issue. But there is a case in the ARM architecture that passes in a task that is not current, and expects a result from that task, and this code breaks it. Fixes: 51584396cff5 ("arm64: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack") Reported-by: James Morse <james.morse@arm.com> Tested-by: James Morse <james.morse@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | fgraph: Add comment to describe ftrace_graph_get_ret_stackSteven Rostedt (VMware)2018-12-101-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ret_stack should not be accessed directly via the curr_ret_stack variable on the task_struct. This is because the ret_stack is going to be converted into a series of longs and not an array of ret_stack structures. The way that a ret_stack should be retrieved is via the ftrace_graph_get_ret_stack structure, but it needs to be documented on how to use it. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | ftrace: Allow ftrace_replace_code() to be schedulableSteven Rostedt (VMware)2018-12-101-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function ftrace_replace_code() is the ftrace engine that does the work to modify all the nops into the calls to the function callback in all the functions being traced. The generic version which is normally called from stop machine, but an architecture can implement a non stop machine version and still use the generic ftrace_replace_code(). When an architecture does this, ftrace_replace_code() may be called from a schedulable context, where it can allow the code to be preemptible, and schedule out. In order to allow an architecture to make ftrace_replace_code() schedulable, a new command flag is added called: FTRACE_MAY_SLEEP Which can be or'd to the command that is passed to ftrace_modify_all_code() that calls ftrace_replace_code() and will have it call cond_resched() in the loop that modifies the nops into the calls to the ftrace trampolines. Link: http://lkml.kernel.org/r/20181204192903.8193-1-anders.roxell@linaro.org Link: http://lkml.kernel.org/r/20181205183303.828422192@goodmis.org Reported-by: Anders Roxell <anders.roxell@linaro.org> Tested-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Add generic event-name based remove event methodMasami Hiramatsu2018-12-101-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a generic method to remove event from dynamic event list. This is same as other system under ftrace. You just need to pass the event name with '!', e.g. # echo p:new_grp/new_event _do_fork > dynamic_events This creates an event, and # echo '!p:new_grp/new_event _do_fork' > dynamic_events Or, # echo '!p:new_grp/new_event' > dynamic_events will remove new_grp/new_event event. Note that this doesn't check the event prefix (e.g. "p:") strictly, because the "group/event" name must be unique. Link: http://lkml.kernel.org/r/154140869774.17322.8887303560398645347.stgit@devbox Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Consolidate trace_add/remove_event_call back to the nolock functionsSteven Rostedt (VMware)2018-12-104-33/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The trace_add/remove_event_call_nolock() functions were added to allow the tace_add/remove_event_call() code be called when the event_mutex lock was already taken. Now that all callers are done within the event_mutex, there's no reason to have two different interfaces. Remove the current wrapper trace_add/remove_event_call()s and rename the _nolock versions back to the original names. Link: http://lkml.kernel.org/r/154140866955.17322.2081425494660638846.stgit@devbox Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Remove unneeded synth_event_mutexMasami Hiramatsu2018-12-091-23/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rmove unneeded synth_event_mutex. This mutex protects the reference count in synth_event, however, those operational points are already protected by event_mutex. 1. In __create_synth_event() and create_or_delete_synth_event(), those synth_event_mutex clearly obtained right after event_mutex. 2. event_hist_trigger_func() is trigger_hist_cmd.func() which is called by trigger_process_regex(), which is a part of event_trigger_regex_write() and this function takes event_mutex. 3. hist_unreg_all() is trigger_hist_cmd.unreg_all() which is called by event_trigger_regex_open() and it takes event_mutex. 4. onmatch_destroy() and onmatch_create() have long call tree, but both are finally invoked from event_trigger_regex_write() and event_trace_del_tracer(), former takes event_mutex, and latter ensures called under event_mutex locked. Finally, I ensured there is no resource conflict. For safety, I added lockdep_assert_held(&event_mutex) for each function. Link: http://lkml.kernel.org/r/154140864134.17322.4796059721306031894.stgit@devbox Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| * | | | | tracing: Use dyn_event framework for synthetic eventsMasami Hiramatsu2018-12-093-98/+176
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use dyn_event framework for synthetic events. This shows synthetic events on "tracing/dynamic_events" file in addition to tracing/synthetic_events interface. User can also define new events via tracing/dynamic_events with "s:" prefix. So, the new syntax is below; s:[synthetic/]EVENT_NAME TYPE ARG; [TYPE ARG;]... To remove events via tracing/dynamic_events, you can use "-:" prefix as same as other events. Link: http://lkml.kernel.org/r/154140861301.17322.15454611233735614508.stgit@devbox Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com> Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>