- 17 Dec, 2017 6 commits
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Alexei Starovoitov authored
- recognize relocation emitted by llvm - since all regular function will be kept in .text section and llvm takes care of pc-relative offsets in bpf_call instruction simply copy all of .text to relevant program section while adjusting bpf_call instructions in program section to point to newly copied body of instructions from .text - do so for all programs in the elf file - set all programs types to the one passed to bpf_prog_load() Note for elf files with multiple programs that use different functions in .text section we need to do 'linker' style logic. This work is still TBD Signed-off-by:
Alexei Starovoitov <ast@kernel.org> Acked-by:
Daniel Borkmann <daniel@iogearbox.net> Signed-off-by:
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Alexei Starovoitov authored
adjust two tests, since verifier got smarter and add new one to test stack_zero logic Signed-off-by:
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Alexei Starovoitov authored
programs with function calls are often passing various pointers via stack. When all calls are inlined llvm flattens stack accesses and optimizes away extra branches. When functions are not inlined it becomes the job of the verifier to recognize zero initialized stack to avoid exploring paths that program will not take. The following program would fail otherwise: ptr = &buffer_on_stack; *ptr = 0; ... func_call(.., ptr, ...) { if (..) *ptr = bpf_map_lookup(); } ... if (*ptr != 0) { // Access (*ptr)->field is valid. // Without stack_zero tracking such (*ptr)->field access // will be rejected } since stack slots are no longer uniform invalid | spill | misc add liveness marking to all slots, but do it in 8 byte chunks. So if nothing was read or written in [fp-16, fp-9] range it will be marked as LIVE_NONE. If any byte in that range was read, it will be marked LIVE_READ and stacksafe() check will perform byte-by-byte verification. If all bytes in the range were written the slot will be marked as LIVE_WRITTEN. This significantly speeds up state equality comparison and reduces total number of states processed. before after bpf_lb-DLB_L3.o 2051 2003 bpf_lb-DLB_L4.o 3287 3164 bpf_lb-DUNKNOWN.o 1080 1080 bpf_lxc-DDROP_ALL.o 24980 12361 bpf_lxc-DUNKNOWN.o 34308 16605 bpf_netdev.o 15404 10962 bpf_overlay.o 7191 6679 Signed-off-by: -
Alexei Starovoitov authored
Add extensive set of tests for bpf_call verification logic: calls: basic sanity calls: using r0 returned by callee calls: callee is using r1 calls: callee using args1 calls: callee using wrong args2 calls: callee using two args calls: callee changing pkt pointers calls: two calls with args calls: two calls with bad jump calls: recursive call. test1 calls: recursive call. test2 calls: unreachable code calls: invalid call calls: jumping across function bodies. test1 calls: jumping across function bodies. test2 calls: call without exit calls: call into middle of ld_imm64 calls: call into middle of other call calls: two calls with bad fallthrough calls: two calls with stack read calls: two calls with stack write calls: spill into caller stack frame calls: two calls with stack write and void return calls: ambiguous return value calls: two calls that return map_value calls: two calls that return map_value with bool condition calls: two calls that return map_value with incorrect bool check calls: two calls that receive map_value via arg=ptr_stack_of_caller. test1 calls: two calls that receive map_value via arg=ptr_stack_of_caller. test2 calls: two jumps that receive map_value via arg=ptr_stack_of_jumper. test3 calls: two calls that receive map_value_ptr_or_null via arg. test1 calls: two calls that receive map_value_ptr_or_null via arg. test2 calls: pkt_ptr spill into caller stack Signed-off-by:
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Alexei Starovoitov authored
Allow arbitrary function calls from bpf function to another bpf function. To recognize such set of bpf functions the verifier does: 1. runs control flow analysis to detect function boundaries 2. proceeds with verification of all functions starting from main(root) function It recognizes that the stack of the caller can be accessed by the callee (if the caller passed a pointer to its stack to the callee) and the callee can store map_value and other pointers into the stack of the caller. 3. keeps track of the stack_depth of each function to make sure that total stack depth is still less than 512 bytes 4. disallows pointers to the callee stack to be stored into the caller stack, since they will be invalid as soon as the callee returns 5. to reuse all of the existing state_pruning logic each function call is considered to be independent call from the verifier point of view. The verifier pretends to inline all function calls it sees are being called. It stores the callsite instruction index as part of the state to make sure that two calls to the same callee from two different places in the caller will be different from state pruning point of view 6. more safety checks are added to liveness analysis Implementation details: . struct bpf_verifier_state is now consists of all stack frames that led to this function . struct bpf_func_state represent one stack frame. It consists of registers in the given frame and its stack . propagate_liveness() logic had a premature optimization where mark_reg_read() and mark_stack_slot_read() were manually inlined with loop iterating over parents for each register or stack slot. Undo this optimization to reuse more complex mark_*_read() logic . skip_callee() logic is not necessary from safety point of view, but without it mark_*_read() markings become too conservative, since after returning from the funciton call a read of r6-r9 will incorrectly propagate the read marks into callee causing inefficient pruning later . mark_*_read() logic is now aware of control flow which makes it more complex. In the future the plan is to rewrite liveness to be hierarchical. So that liveness can be done within basic block only and control flow will be responsible for propagation of liveness information along cfg and between calls. . tail_calls and ld_abs insns are not allowed in the programs with bpf-to-bpf calls . returning stack pointers to the caller or storing them into stack frame of the caller is not allowed Testing: . no difference in cilium processed_insn numbers . large number of tests follows in next patches Signed-off-by:
John Fastabend <john.fastabend@gmail.com> Acked-by:
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Alexei Starovoitov authored
Allow arbitrary function calls from bpf function to another bpf function. Since the beginning of bpf all bpf programs were represented as a single function and program authors were forced to use always_inline for all functions in their C code. That was causing llvm to unnecessary inflate the code size and forcing developers to move code to header files with little code reuse. With a bit of additional complexity teach verifier to recognize arbitrary function calls from one bpf function to another as long as all of functions are presented to the verifier as a single bpf program. New program layout: r6 = r1 // some code .. r1 = .. // arg1 r2 = .. // arg2 call pc+1 // function call pc-relative exit .. = r1 // access arg1 .. = r2 // access arg2 .. call pc+20 // second level of function call ... It allows for better optimized code and finally allows to introduce the core bpf libraries that can be reused in different projects, since programs are no longer limited by single elf file. With function calls bpf can be compiled into multiple .o files. This patch is the first step. It detects programs that contain multiple functions and checks that calls between them are valid. It splits the sequence of bpf instructions (one program) into a set of bpf functions that call each other. Calls to only known functions are allowed. In the future the verifier may allow calls to unresolved functions and will do dynamic linking. This logic supports statically linked bpf functions only. Such function boundary detection could have been done as part of control flow graph building in check_cfg(), but it's cleaner to separate function boundary detection vs control flow checks within a subprogram (function) into logically indepedent steps. Follow up patches may split check_cfg() further, but not check_subprogs(). Only allow bpf-to-bpf calls for root only and for non-hw-offloaded programs. These restrictions can be relaxed in the future. Signed-off-by:
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- 15 Dec, 2017 7 commits
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Jakub Kicinski authored
Build bot reported warning about invalid printk formats on 32bit architectures. Use %zu for size_t and %zd ptr diff. Signed-off-by:
Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by:
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Daniel Borkmann authored
Jakub Kicinski says: ==================== This small set adds support for bpf_xdp_adjust_head() to the offload. Since we have access to unmodified BPF bytecode translating calls is pretty trivial. First part of the series adds handling of BPF capabilities included in the FW in TLV format. The last two patches add adjust head support in the nfp verifier and jit, and a small optimization in case we can guarantee the constant adjustment will always meet adjustment constaints. ==================== Signed-off-by: -
Jakub Kicinski authored
If the program is simple and has only one adjust head call with constant parameters, we can check that the call will always succeed at translation time. We need to track the location of the call and make sure parameters are always the same. We also have to check the parameters against datapath constraints and ETH_HLEN. Signed-off-by:
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Jakub Kicinski authored
Support bpf_xdp_adjust_head(). We need to check whether the packet offset after adjustment is within datapath's limits. We also check if the frame is at least ETH_HLEN long (similar to the kernel implementation). Signed-off-by:
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Jakub Kicinski authored
Add skeleton of verifier checks and translation handler for call instructions. Make sure jump target resolution will not treat them as jumps. Signed-off-by:
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Jakub Kicinski authored
BPF FW creates a run time symbol called bpf_capabilities which contains TLV-formatted capability information. Allocate app private structure to store parsed capabilities and add a skeleton of parsing logic. Signed-off-by:
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Jakub Kicinski authored
Allow users outside of core reading area sizes. This was not needed previously because whatever entity created the area would usually know what size it asked for. The nfp_rtsym_map() helper, however, will allocate the area based on the size of an RT-symbol with given name. Signed-off-by:
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- 14 Dec, 2017 5 commits
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Daniel Borkmann authored
Roman Gushchin says: ==================== This patchset adds basic cgroup bpf operations to bpftool. Right now there is no convenient way to perform these operations. The /samples/bpf/load_sock_ops.c implements attach/detacg operations, but only for BPF_CGROUP_SOCK_OPS programs. Bps (part of bcc) implements bpf introspection, but lacks any cgroup-related specific. I find having a tool to perform these basic operations in the kernel tree very useful, as it can be used in the corresponding bpf documentation without creating additional dependencies. And bpftool seems to be a right tool to extend with such functionality. v4: - ATTACH_FLAGS and ATTACH_TYPE are listed and described in docs and usage - ATTACH_FLAG names converted to "multi" and "override" - do_attach() recognizes ATTACH_FLAG abbreviations, e.g "mul" - Local variables sorted ("reverse Christmas tree") - unknown attach flags value will be never truncated v3: - SRC replaced with OBJ in prog load docs - Output unknown attach type in hex - License header in SPDX format - Minor style fixes (e.g. variable reordering) v2: - Added prog load operations - All cgroup operations are looking like bpftool cgroup <command> - All cgroup-related stuff is moved to a separate file - Added support for attach flags - Added support for attaching/detaching programs by id, pinned name, etc - Changed cgroup detach arguments order - Added empty json output for succesful programs - Style fixed: includes order, strncmp and macroses, error handling - Added man pages v1: https://lwn.net/Articles/740366/ ==================== Reviewed-by:Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by:
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Roman Gushchin authored
This patch adds basic cgroup bpf operations to bpftool: cgroup list, attach and detach commands. Usage is described in the corresponding man pages, and examples are provided. Syntax: $ bpftool cgroup list CGROUP $ bpftool cgroup attach CGROUP ATTACH_TYPE PROG [ATTACH_FLAGS] $ bpftool cgroup detach CGROUP ATTACH_TYPE PROG Signed-off-by:
Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by:
David Ahern <dsahern@gmail.com> Reviewed-by:
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Roman Gushchin authored
Add the prog load command to load a bpf program from a specified binary file and pin it to bpffs. Usage description and examples are given in the corresponding man page. Syntax: $ bpftool prog load OBJ FILE FILE is a non-existing file on bpffs. Signed-off-by:
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Roman Gushchin authored
Libbpf picks the name of the first symbol in the corresponding elf section to use as a program name. But without taking symbol's scope into account it may end's up with some local label as a program name. E.g.: $ bpftool prog 1: type 15 name LBB0_10 tag 0390a5136ba23f5c loaded_at Dec 07/17:22 uid 0 xlated 456B not jited memlock 4096B Fix this by preferring global symbols as program name. For instance: $ bpftool prog 1: type 15 name bpf_prog1 tag 0390a5136ba23f5c loaded_at Dec 07/17:26 uid 0 xlated 456B not jited memlock 4096B Signed-off-by:
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Roman Gushchin authored
The bpf_prog_load() function will guess program type if it's not specified explicitly. This functionality will be used to implement loading of different programs without asking a user to specify the program type. In first order it will be used by bpftool. Signed-off-by:
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- 13 Dec, 2017 1 commit
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Yonghong Song authored
Commit f371b304 ("bpf/tracing: allow user space to query prog array on the same tp") introduced a perf ioctl command to query prog array attached to the same perf tracepoint. The commit introduced a compilation error under certain config conditions, e.g., (1). CONFIG_BPF_SYSCALL is not defined, or (2). CONFIG_TRACING is defined but neither CONFIG_UPROBE_EVENTS nor CONFIG_KPROBE_EVENTS is defined. Error message: kernel/events/core.o: In function `perf_ioctl': core.c:(.text+0x98c4): undefined reference to `bpf_event_query_prog_array' This patch fixed this error by guarding the real definition under CONFIG_BPF_EVENTS and provided static inline dummy function if CONFIG_BPF_EVENTS was not defined. It renamed the function from bpf_event_query_prog_array to perf_event_query_prog_array and moved the definition from linux/bpf.h to linux/trace_events.h so the definition is in proximity to other prog_array related functions. Fixes: f371b304 ("bpf/tracing: allow user space to query prog array on the same tp") Reported-by:
Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by:
Yonghong Song <yhs@fb.com> Signed-off-by:
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- 12 Dec, 2017 10 commits
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Alexei Starovoitov authored
Josef Bacik says: ==================== This is the same as v8, just rebased onto the bpf tree. v8->v9: - rebased onto the bpf tree. v7->v8: - removed the _ASM_KPROBE_ERROR_INJECT since it was not needed. v6->v7: - moved the opt-in macro to bpf.h out of kprobes.h. v5->v6: - add BPF_ALLOW_ERROR_INJECTION() tagging for functions that will support this feature. This way only functions that opt-in will be allowed to be overridden. - added a btrfs patch to allow error injection for open_ctree() so that the bpf sample actually works. v4->v5: - disallow kprobe_override programs from being put in the prog map array so we don't tail call into something we didn't check. This allows us to make the normal path still fast without a bunch of percpu operations. v3->v4: - fix a build error found by kbuild test bot (I didn't wait long enough apparently.) - Added a warning message as per Daniels suggestion. v2->v3: - added a ->kprobe_override flag to bpf_prog. - added some sanity checks to disallow attaching bpf progs that have ->kprobe_override set that aren't for ftrace kprobes. - added the trace_kprobe_ftrace helper to check if the trace_event_call is a ftrace kprobe. - renamed bpf_kprobe_state to bpf_kprobe_override, fixed it so we only read this value in the kprobe path, and thus only write to it if we're overriding or clearing the override. v1->v2: - moved things around to make sure that bpf_override_return could really only be used for an ftrace kprobe. - killed the special return values from trace_call_bpf. - renamed pc_modified to bpf_kprobe_state so bpf_override_return could tell if it was being called from an ftrace kprobe context. - reworked the logic in kprobe_perf_func to take advantage of bpf_kprobe_state. - updated the test as per Alexei's review. - Original message - A lot of our error paths are not well tested because we have no good way of injecting errors generically. Some subystems (block, memory) have ways to inject errors, but they are random so it's hard to get reproduceable results. With BPF we can add determinism to our error injection. We can use kprobes and other things to verify we are injecting errors at the exact case we are trying to test. This patch gives us the tool to actual do the error injection part. It is very simple, we just set the return value of the pt_regs we're given to whatever we provide, and then override the PC with a dummy function that simply returns. Right now this only works on x86, but it would be simple enough to expand to other architectures. Thanks, Josef ==================== In patch "bpf: add a bpf_override_function helper" Alexei moved "ifdef CONFIG_BPF_KPROBE_OVERRIDE" few lines to fail program loading when kprobe_override is not available instead of failing at run-time. Signed-off-by: -
Josef Bacik authored
This was instrumental in reproducing a space cache bug. Signed-off-by:
Josef Bacik <jbacik@fb.com> Acked-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Josef Bacik authored
This adds a basic test for bpf_override_return to verify it works. We override the main function for mounting a btrfs fs so it'll return -ENOMEM and then make sure that trying to mount a btrfs fs will fail. Acked-by:
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Josef Bacik authored
Error injection is sloppy and very ad-hoc. BPF could fill this niche perfectly with it's kprobe functionality. We could make sure errors are only triggered in specific call chains that we care about with very specific situations. Accomplish this with the bpf_override_funciton helper. This will modify the probe'd callers return value to the specified value and set the PC to an override function that simply returns, bypassing the originally probed function. This gives us a nice clean way to implement systematic error injection for all of our code paths. Acked-by:
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Josef Bacik authored
This allows us to do error injection with BPF for open_ctree. Signed-off-by:
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Josef Bacik authored
Using BPF we can override kprob'ed functions and return arbitrary values. Obviously this can be a bit unsafe, so make this feature opt-in for functions. Simply tag a function with KPROBE_ERROR_INJECT_SYMBOL in order to give BPF access to that function for error injection purposes. Signed-off-by:
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Alexei Starovoitov authored
Yonghong Song says: ==================== Commit e87c6bc3 ("bpf: permit multiple bpf attachments for a single perf event") added support to attach multiple bpf programs to a single perf event. Given a perf event (kprobe, uprobe, or kernel tracepoint), the perf ioctl interface is used to query bpf programs attached to the same trace event. There already exists a BPF_PROG_QUERY command for introspection currently used by cgroup+bpf. We did have an implementation for querying tracepoint+bpf through the same interface. However, it looks cleaner to use ioctl() style of api here, since attaching bpf prog to tracepoint/kuprobe is also done via ioctl. Patch #1 had the core implementation and patch #2 added a test case in tools bpf selftests suite. Changelogs: v3 -> v4: - Fix a compilation error with newer gcc like 6.3.1 while old gcc 4.8.5 is okay. I was using &uquery->ids to represent the address to the ids array to make it explicit that the address is passed, and this syntax is rightly rejected by gcc 6.3.1. v2 -> v3: - Change uapi structure perf_event_query_bpf to be more clearer based on Peter's suggestion, and adjust other codes accordingly. v1 -> v2: - Rebase on top of net-next. - Use existing bpf_prog_array_length function instead of implementing the same functionality in function bpf_prog_array_copy_info. ==================== Signed-off-by:
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Yonghong Song authored
Added a subtest in test_progs. The tracepoint is sched/sched_switch. Multiple bpf programs are attached to this tracepoint and the query interface is exercised. Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by:
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Yonghong Song authored
Commit e87c6bc3 ("bpf: permit multiple bpf attachments for a single perf event") added support to attach multiple bpf programs to a single perf event. Although this provides flexibility, users may want to know what other bpf programs attached to the same tp interface. Besides getting visibility for the underlying bpf system, such information may also help consolidate multiple bpf programs, understand potential performance issues due to a large array, and debug (e.g., one bpf program which overwrites return code may impact subsequent program results). Commit 2541517c ("tracing, perf: Implement BPF programs attached to kprobes") utilized the existing perf ioctl interface and added the command PERF_EVENT_IOC_SET_BPF to attach a bpf program to a tracepoint. This patch adds a new ioctl command, given a perf event fd, to query the bpf program array attached to the same perf tracepoint event. The new uapi ioctl command: PERF_EVENT_IOC_QUERY_BPF The new uapi/linux/perf_event.h structure: struct perf_event_query_bpf { __u32 ids_len; __u32 prog_cnt; __u32 ids[0]; }; User space provides buffer "ids" for kernel to copy to. When returning from the kernel, the number of available programs in the array is set in "prog_cnt". The usage: struct perf_event_query_bpf *query = malloc(sizeof(*query) + sizeof(u32) * ids_len); query.ids_len = ids_len; err = ioctl(pmu_efd, PERF_EVENT_IOC_QUERY_BPF, query); if (err == 0) { /* query.prog_cnt is the number of available progs, * number of progs in ids: (ids_len == 0) ? 0 : query.prog_cnt */ } else if (errno == ENOSPC) { /* query.ids_len number of progs copied, * query.prog_cnt is the number of available progs */ } else { /* other errors */ } Signed-off-by:
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Naresh Kamboju authored
CONFIG_CGROUP_BPF=y is required for test_dev_cgroup test case. Signed-off-by:
Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by:
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- 08 Dec, 2017 5 commits
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Daniel Borkmann authored
Quentin Monnet says: ==================== First patch of this series cleans up the two Makefiles (Makefile and Documentation/Makefile) and make their contents more consistent. The second one add "uninstall" and "doc-uninstall" targets, to remove files previously installed on the system with "install" and "doc-install" targets. ==================== Signed-off-by: -
Quentin Monnet authored
Create two targets to remove executable and documentation that would have been previously installed with `make install` and `make doc-install`. Also create a "QUIET_UNINST" helper in tools/scripts/Makefile.include. Do not attempt to remove directories /usr/local/sbin and /usr/share/bash-completions/completions, even if they are empty, as those specific directories probably already existed on the system before we installed the program, and we do not wish to break other makefiles that might assume their existence. Do remvoe /usr/local/share/man/man8 if empty however, as this directory does not seem to exist by default. Signed-off-by:
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Quentin Monnet authored
Several minor fixes and harmonisation items for Makefiles: * Use the same mechanism for verbose/non-verbose output in two files ("$(Q)"), for all commands. * Use calls to "QUIET_INSTALL" and equivalent in Makefile. In particular, use "call(descend, ...)" instead of "make -C" to run documentation targets. * Add a "doc-clean" target, aligned on "doc" and "doc-install". * Make "install" target in Makefile depend on "bpftool". * Remove condition on DESTDIR to initialise prefix in doc Makefile. * Remove modification of VPATH based on OUTPUT, it is unused. * Formatting: harmonise spaces around equal signs. * Make install path for man pages /usr/local/man instead of /usr/local/share/man (respects the Makefile conventions, and the latter is usually a symbolic link to the former anyway). * Do not erase prefix if set by user in bpftool Makefile. * Fix install target for bpftool: append DESTDIR to install path. Signed-off-by: -
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller authored
Alexei Starovoitov says: ==================== pull-request: bpf-next 2017-12-07 The following pull-request contains BPF updates for your net-next tree. The main changes are: 1) Detailed documentation of BPF development process from Daniel. 2) Addition of is_fullsock, snd_cwnd and srtt_us fields to bpf_sock_ops from Lawrence. 3) Minor follow up for bpf_skb_set_tunnel_key() from William. ==================== Signed-off-by:David S. Miller <davem@davemloft.net>
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Jason Wang authored
Private destructor could be called when register_netdev() fail with rtnl lock held. This will lead deadlock in tun_free_netdev() who tries to hold rtnl_lock. Fixing this by switching to use spinlock to synchronize. Fixes: 96f84061 ("tun: add eBPF based queue selection method") Reported-by:
Eric Dumazet <eric.dumazet@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by:
Jason Wang <jasowang@redhat.com> Acked-by:
Michael S. Tsirkin <mst@redhat.com> Reviewed-by:
Eric Dumazet <edumazet@google.com> Signed-off-by:
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- 07 Dec, 2017 6 commits
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David S. Miller authored
Ursula Braun says: ==================== smc: fixes 2017-12-07 here are some smc-patches. The initial 4 patches are cleanups. Patch 5 gets rid of ib_post_sends in tasklet context to avoid peer drops due to out-of-order receivals. Patch 6 makes sure, the Linux SMC code understands variable sized CLC proposal messages built according to RFC7609. ==================== Signed-off-by: -
Ursula Braun authored
According to RFC7609 [1] the CLC proposal message contains an area of unknown length for future growth. Additionally it may contain up to 8 IPv6 prefixes. The current version of the SMC-code does not understand CLC proposal messages using these variable length fields and, thus, is incompatible with SMC implementations in other operating systems. This patch makes sure, SMC understands incoming CLC proposals * with arbitrary length values for future growth * with up to 8 IPv6 prefixes [1] SMC-R Informational RFC: http://www.rfc-editor.org/info/rfc7609Signed-off-by:
Ursula Braun <ubraun@linux.vnet.ibm.com> Reviewed-by:
Hans Wippel <hwippel@linux.vnet.ibm.com> Signed-off-by:
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Ursula Braun authored
The SMC protocol requires to send a separate consumer cursor update, if it cannot be piggybacked to updates of the producer cursor. When receiving a blocked signal from the sender, this update is sent already in tasklet context. In addition consumer cursor updates are sent after data receival. Sending of cursor updates is controlled by sequence numbers. Assuming receiving stray messages the receiver drops updates with older sequence numbers than an already received cursor update with a higher sequence number. Sending consumer cursor updates in tasklet context may result in wrong order sends and its corresponding drops at the receiver. Since it is sufficient to send consumer cursor updates once the data is received, this patch gets rid of the consumer cursor update in tasklet context to guarantee in-sequence arrival of cursor updates. Signed-off-by:
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Ursula Braun authored
When waiting for data to be received it must be checked if the peer signals shutdown. The SMC code uses two different checks for this purpose, even though just one check is sufficient. This patch removes the superfluous test for SOCK_DONE. Signed-off-by:
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Ursula Braun authored
The smc code never checks the sk_write_pending sock field. Thus there is no need to update it. Signed-off-by:
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Ursula Braun authored
Let smc_clc_send_decline() return with an error, if the amount sent is smaller than the length of an smc decline message. Signed-off-by:
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