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2022-02-25tracing: Fix selftest config check for function graph start up testChristophe Leroy
CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS is required to test direct tramp. Link: https://lkml.kernel.org/r/bdc7e594e13b0891c1d61bc8d56c94b1890eaed7.1640017960.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25tracing/osnoise: Make osnoise_main to sleep for microsecondsDaniel Bristot de Oliveira
osnoise's runtime and period are in the microseconds scale, but it is currently sleeping in the millisecond's scale. This behavior roots in the usage of hwlat as the skeleton for osnoise. Make osnoise to sleep in the microseconds scale. Also, move the sleep to a specialized function. Link: https://lkml.kernel.org/r/302aa6c7bdf2d131719b22901905e9da122a11b2.1645197336.git.bristot@kernel.org Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25ftrace: Remove unused ftrace_startup_enable() stubNathan Chancellor
When building with clang + CONFIG_DYNAMIC_FTRACE=n + W=1, there is a warning: kernel/trace/ftrace.c:7194:20: error: unused function 'ftrace_startup_enable' [-Werror,-Wunused-function] static inline void ftrace_startup_enable(int command) { } ^ 1 error generated. Clang warns on instances of static inline functions in .c files with W=1 after commit 6863f5643dd7 ("kbuild: allow Clang to find unused static inline functions for W=1 build"). The ftrace_startup_enable() stub has been unused since commit e1effa0144a1 ("ftrace: Annotate the ops operation on update"), where its use outside of the CONFIG_DYNAMIC_TRACE section was replaced by ftrace_startup_all(). Remove it to resolve the warning. Link: https://lkml.kernel.org/r/20220214192847.488166-1-nathan@kernel.org Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25tracing: Ensure trace buffer is at least 4096 bytes largeSven Schnelle
Booting the kernel with 'trace_buf_size=1' give a warning at boot during the ftrace selftests: [ 0.892809] Running postponed tracer tests: [ 0.892893] Testing tracer function: [ 0.901899] Callback from call_rcu_tasks_trace() invoked. [ 0.983829] Callback from call_rcu_tasks_rude() invoked. [ 1.072003] .. bad ring buffer .. corrupted trace buffer .. [ 1.091944] Callback from call_rcu_tasks() invoked. [ 1.097695] PASSED [ 1.097701] Testing dynamic ftrace: .. filter failed count=0 ..FAILED! [ 1.353474] ------------[ cut here ]------------ [ 1.353478] WARNING: CPU: 0 PID: 1 at kernel/trace/trace.c:1951 run_tracer_selftest+0x13c/0x1b0 Therefore enforce a minimum of 4096 bytes to make the selftest pass. Link: https://lkml.kernel.org/r/20220214134456.1751749-1-svens@linux.ibm.com Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25tracing: Uninline trace_trigger_soft_disabled() partlyChristophe Leroy
On a powerpc32 build with CONFIG_CC_OPTIMISE_FOR_SIZE, the inline keyword is not honored and trace_trigger_soft_disabled() appears approx 50 times in vmlinux. Adding -Winline to the build, the following message appears: ./include/linux/trace_events.h:712:1: error: inlining failed in call to 'trace_trigger_soft_disabled': call is unlikely and code size would grow [-Werror=inline] That function is rather big for an inlined function: c003df60 <trace_trigger_soft_disabled>: c003df60: 94 21 ff f0 stwu r1,-16(r1) c003df64: 7c 08 02 a6 mflr r0 c003df68: 90 01 00 14 stw r0,20(r1) c003df6c: bf c1 00 08 stmw r30,8(r1) c003df70: 83 e3 00 24 lwz r31,36(r3) c003df74: 73 e9 01 00 andi. r9,r31,256 c003df78: 41 82 00 10 beq c003df88 <trace_trigger_soft_disabled+0x28> c003df7c: 38 60 00 00 li r3,0 c003df80: 39 61 00 10 addi r11,r1,16 c003df84: 4b fd 60 ac b c0014030 <_rest32gpr_30_x> c003df88: 73 e9 00 80 andi. r9,r31,128 c003df8c: 7c 7e 1b 78 mr r30,r3 c003df90: 41 a2 00 14 beq c003dfa4 <trace_trigger_soft_disabled+0x44> c003df94: 38 c0 00 00 li r6,0 c003df98: 38 a0 00 00 li r5,0 c003df9c: 38 80 00 00 li r4,0 c003dfa0: 48 05 c5 f1 bl c009a590 <event_triggers_call> c003dfa4: 73 e9 00 40 andi. r9,r31,64 c003dfa8: 40 82 00 28 bne c003dfd0 <trace_trigger_soft_disabled+0x70> c003dfac: 73 ff 02 00 andi. r31,r31,512 c003dfb0: 41 82 ff cc beq c003df7c <trace_trigger_soft_disabled+0x1c> c003dfb4: 80 01 00 14 lwz r0,20(r1) c003dfb8: 83 e1 00 0c lwz r31,12(r1) c003dfbc: 7f c3 f3 78 mr r3,r30 c003dfc0: 83 c1 00 08 lwz r30,8(r1) c003dfc4: 7c 08 03 a6 mtlr r0 c003dfc8: 38 21 00 10 addi r1,r1,16 c003dfcc: 48 05 6f 6c b c0094f38 <trace_event_ignore_this_pid> c003dfd0: 38 60 00 01 li r3,1 c003dfd4: 4b ff ff ac b c003df80 <trace_trigger_soft_disabled+0x20> However it is located in a hot path so inlining it is important. But forcing inlining of the entire function by using __always_inline leads to increasing the text size by approx 20 kbytes. Instead, split the fonction in two parts, one part with the likely fast path, flagged __always_inline, and a second part out of line. With this change, on a powerpc32 with CONFIG_CC_OPTIMISE_FOR_SIZE vmlinux text increases by only 1,4 kbytes, which is partly compensated by a decrease of vmlinux data by 7 kbytes. On ppc64_defconfig which has CONFIG_CC_OPTIMISE_FOR_SPEED, this change reduces vmlinux text by more than 30 kbytes. Link: https://lkml.kernel.org/r/69ce0986a52d026d381d612801d978aa4f977460.1644563295.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25eprobes: Remove redundant event type informationSteven Rostedt (Google)
Currently, the event probes save the type of the event they are attached to when recording the event. For example: # echo 'e:switch sched/sched_switch prev_state=$prev_state prev_prio=$prev_prio next_pid=$next_pid next_prio=$next_prio' > dynamic_events # cat events/eprobes/switch/format name: switch ID: 1717 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:unsigned int __probe_type; offset:8; size:4; signed:0; field:u64 prev_state; offset:12; size:8; signed:0; field:u64 prev_prio; offset:20; size:8; signed:0; field:u64 next_pid; offset:28; size:8; signed:0; field:u64 next_prio; offset:36; size:8; signed:0; print fmt: "(%u) prev_state=0x%Lx prev_prio=0x%Lx next_pid=0x%Lx next_prio=0x%Lx", REC->__probe_type, REC->prev_state, REC->prev_prio, REC->next_pid, REC->next_prio The __probe_type adds 4 bytes to every event. One of the reasons for creating eprobes is to limit what is traced in an event to be able to limit what is written into the ring buffer. Having this redundant 4 bytes to every event takes away from this. The event that is recorded can be retrieved from the event probe itself, that is available when the trace is happening. For user space tools, it could simply read the dynamic_event file to find the event they are for. So there is really no reason to write this information into the ring buffer for every event. Link: https://lkml.kernel.org/r/20220218190057.2f5a19a8@gandalf.local.home Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Joel Fernandes <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25tracing: Have traceon and traceoff trigger honor the instanceSteven Rostedt (Google)
If a trigger is set on an event to disable or enable tracing within an instance, then tracing should be disabled or enabled in the instance and not at the top level, which is confusing to users. Link: https://lkml.kernel.org/r/20220223223837.14f94ec3@rorschach.local.home Cc: stable@vger.kernel.org Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables") Tested-by: Daniel Bristot de Oliveira <bristot@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25uaccess: remove CONFIG_SET_FSArnd Bergmann
There are no remaining callers of set_fs(), so CONFIG_SET_FS can be removed globally, along with the thread_info field and any references to it. This turns access_ok() into a cheaper check against TASK_SIZE_MAX. As CONFIG_SET_FS is now gone, drop all remaining references to set_fs()/get_fs(), mm_segment_t, user_addr_max() and uaccess_kernel(). Acked-by: Sam Ravnborg <sam@ravnborg.org> # for sparc32 changes Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Tested-by: Sergey Matyukevich <sergey.matyukevich@synopsys.com> # for arc changes Acked-by: Stafford Horne <shorne@gmail.com> # [openrisc, asm-generic] Acked-by: Dinh Nguyen <dinguyen@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-02-24tracing: Dump stacktrace trigger to the corresponding instanceDaniel Bristot de Oliveira
The stacktrace event trigger is not dumping the stacktrace to the instance where it was enabled, but to the global "instance." Use the private_data, pointing to the trigger file, to figure out the corresponding trace instance, and use it in the trigger action, like snapshot_trigger does. Link: https://lkml.kernel.org/r/afbb0b4f18ba92c276865bc97204d438473f4ebc.1645396236.git.bristot@kernel.org Cc: stable@vger.kernel.org Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables") Reviewed-by: Tom Zanussi <zanussi@kernel.org> Tested-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-23tracing: Fix allocation of last_cmd in last_cmd_set()Steven Rostedt (Google)
The strncat() used in last_cmd_set() includes the nul byte of length of the string being copied in, when it should only hold the size of the string being copied (not the nul byte). Change it to subtract the length of the allocated space and the nul byte to pass that into the strncat(). Also, assign "len" instead of initializing it to zero and its first update is to do a "+=". Link: https://lore.kernel.org/all/202202140628.fj6e4w4v-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-22scsi: block: Remove REQ_OP_WRITE_SAME supportChristoph Hellwig
No more users of REQ_OP_WRITE_SAME or drivers implementing it are left, so remove the infrastructure. [mkp: fold in and tweak sysfs reporting fix] Link: https://lore.kernel.org/r/20220209082828.2629273-8-hch@lst.de Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-02-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-10user_events: Validate user payloads for size and null terminationBeau Belgrave
Add validation to ensure data is at or greater than the min size for the fields of the event. If a dynamic array is used and is a type of char, ensure null termination of the array exists. Link: https://lkml.kernel.org/r/20220118204326.2169-7-beaub@linux.microsoft.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-10user_events: Optimize writing events by only copying data onceBeau Belgrave
Pass iterator through to probes to allow copying data directly to the probe buffers instead of taking multiple copies. Enables eBPF user and raw iterator types out to programs for no-copy scenarios. Link: https://lkml.kernel.org/r/20220118204326.2169-6-beaub@linux.microsoft.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-10user_events: Add basic perf and eBPF supportBeau Belgrave
Adds support to write out user_event data to perf_probe/perf files as well as to any attached eBPF program. Link: https://lkml.kernel.org/r/20220118204326.2169-5-beaub@linux.microsoft.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-10user_events: Handle matching arguments from dyn_eventsBeau Belgrave
Ensures that when dynamic events requests a match with arguments that they match what is in the user_event. Link: https://lkml.kernel.org/r/20220118204326.2169-4-beaub@linux.microsoft.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-10user_events: Add print_fmt generation support for basic typesBeau Belgrave
Addes print_fmt format generation for basic types that are supported for user processes. Only supports sizes that are the same on 32 and 64 bit. Link: https://lkml.kernel.org/r/20220118204326.2169-3-beaub@linux.microsoft.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-10user_events: Add minimal support for trace_event into ftraceBeau Belgrave
Minimal support for interacting with dynamic events, trace_event and ftrace. Core outline of flow between user process, ioctl and trace_event APIs. User mode processes that wish to use trace events to get data into ftrace, perf, eBPF, etc are limited to uprobes today. The user events features enables an ABI for user mode processes to create and write to trace events that are isolated from kernel level trace events. This enables a faster path for tracing from user mode data as well as opens managed code to participate in trace events, where stub locations are dynamic. User processes often want to trace only when it's useful. To enable this a set of pages are mapped into the user process space that indicate the current state of the user events that have been registered. User processes can check if their event is hooked to a trace/probe, and if it is, emit the event data out via the write() syscall. Two new files are introduced into tracefs to accomplish this: user_events_status - This file is mmap'd into participating user mode processes to indicate event status. user_events_data - This file is opened and register/delete ioctl's are issued to create/open/delete trace events that can be used for tracing. The typical scenario is on process start to mmap user_events_status. Processes then register the events they plan to use via the REG ioctl. The ioctl reads and updates the passed in user_reg struct. The status_index of the struct is used to know the byte in the status page to check for that event. The write_index of the struct is used to describe that event when writing out to the fd that was used for the ioctl call. The data must always include this index first when writing out data for an event. Data can be written either by write() or by writev(). For example, in memory: int index; char data[]; Psuedo code example of typical usage: struct user_reg reg; int page_fd = open("user_events_status", O_RDWR); char *page_data = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_SHARED, page_fd, 0); close(page_fd); int data_fd = open("user_events_data", O_RDWR); reg.size = sizeof(reg); reg.name_args = (__u64)"test"; ioctl(data_fd, DIAG_IOCSREG, &reg); int status_id = reg.status_index; int write_id = reg.write_index; struct iovec io[2]; io[0].iov_base = &write_id; io[0].iov_len = sizeof(write_id); io[1].iov_base = payload; io[1].iov_len = sizeof(payload); if (page_data[status_id]) writev(data_fd, io, 2); User events are also exposed via the dynamic_events tracefs file for both create and delete. Current status is exposed via the user_events_status tracefs file. Simple example to register a user event via dynamic_events: echo u:test >> dynamic_events cat dynamic_events u:test If an event is hooked to a probe, the probe hooked shows up: echo 1 > events/user_events/test/enable cat user_events_status 1:test # Used by ftrace Active: 1 Busy: 1 Max: 4096 If an event is not hooked to a probe, no probe status shows up: echo 0 > events/user_events/test/enable cat user_events_status 1:test Active: 1 Busy: 0 Max: 4096 Users can describe the trace event format via the following format: name[:FLAG1[,FLAG2...] [field1[;field2...]] Each field has the following format: type name Example for char array with a size of 20 named msg: echo 'u:detailed char[20] msg' >> dynamic_events cat dynamic_events u:detailed char[20] msg Data offsets are based on the data written out via write() and will be updated to reflect the correct offset in the trace_event fields. For dynamic data it is recommended to use the new __rel_loc data type. This type will be the same as __data_loc, but the offset is relative to this entry. This allows user_events to not worry about what common fields are being inserted before the data. The above format is valid for both the ioctl and the dynamic_events file. Link: https://lkml.kernel.org/r/20220118204326.2169-2-beaub@linux.microsoft.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-10tracing: Save both wakee and current on wakeup eventsSteven Rostedt (Google)
Use the sched_switch function to save both the wakee and the waker comms in the saved cmdlines list when sched_wakeup is done. Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-10tracing: Remove size restriction on synthetic event cmd error loggingTom Zanussi
Currently, synthetic event command error strings are restricted to a length of MAX_FILTER_STR_VAL (256), which is too short for some commands already seen in the wild (with cmd strings longer than that showing up truncated in err_log). Remove the restriction so that no synthetic event command error string is ever truncated. Link: https://lkml.kernel.org/r/0376692396a81d0b795127c66ea92ca5bf60f481.1643399022.git.zanussi@kernel.org Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-10tracing: Remove size restriction on hist trigger cmd error loggingTom Zanussi
Currently, hist trigger command error strings are restricted to a length of MAX_FILTER_STR_VAL (256), which is too short for some commands already seen in the wild (with cmd strings longer than that showing up truncated in err_log). Remove the restriction so that no hist trigger command error string is ever truncated. Link: https://lkml.kernel.org/r/0f9d46407222eaf6632cd3b417bc50a11f401b71.1643399022.git.zanussi@kernel.org Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-10tracing: Remove size restriction on tracing_log_err cmd stringsTom Zanussi
Currently, tracing_log_err.cmd strings are restricted to a length of MAX_FILTER_STR_VAL (256), which is too short for some commands already seen in the wild (with cmd strings longer than that showing up truncated). Remove the restriction so that no command string is ever truncated. Link: https://lkml.kernel.org/r/ca965f23256b350ebd94b3dc1a319f28e8267f5f.1643319703.git.zanussi@kernel.org Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-09Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski
Daniel Borkmann says: ==================== pull-request: bpf-next 2022-02-09 We've added 126 non-merge commits during the last 16 day(s) which contain a total of 201 files changed, 4049 insertions(+), 2215 deletions(-). The main changes are: 1) Add custom BPF allocator for JITs that pack multiple programs into a huge page to reduce iTLB pressure, from Song Liu. 2) Add __user tagging support in vmlinux BTF and utilize it from BPF verifier when generating loads, from Yonghong Song. 3) Add per-socket fast path check guarding from cgroup/BPF overhead when used by only some sockets, from Pavel Begunkov. 4) Continued libbpf deprecation work of APIs/features and removal of their usage from samples, selftests, libbpf & bpftool, from Andrii Nakryiko and various others. 5) Improve BPF instruction set documentation by adding byte swap instructions and cleaning up load/store section, from Christoph Hellwig. 6) Switch BPF preload infra to light skeleton and remove libbpf dependency from it, from Alexei Starovoitov. 7) Fix architecture-agnostic macros in libbpf for accessing syscall arguments from BPF progs for non-x86 architectures, from Ilya Leoshkevich. 8) Rework port members in struct bpf_sk_lookup and struct bpf_sock to be of 16-bit field with anonymous zero padding, from Jakub Sitnicki. 9) Add new bpf_copy_from_user_task() helper to read memory from a different task than current. Add ability to create sleepable BPF iterator progs, from Kenny Yu. 10) Implement XSK batching for ice's zero-copy driver used by AF_XDP and utilize TX batching API from XSK buffer pool, from Maciej Fijalkowski. 11) Generate temporary netns names for BPF selftests to avoid naming collisions, from Hangbin Liu. 12) Implement bpf_core_types_are_compat() with limited recursion for in-kernel usage, from Matteo Croce. 13) Simplify pahole version detection and finally enable CONFIG_DEBUG_INFO_DWARF5 to be selected with CONFIG_DEBUG_INFO_BTF, from Nathan Chancellor. 14) Misc minor fixes to libbpf and selftests from various folks. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (126 commits) selftests/bpf: Cover 4-byte load from remote_port in bpf_sk_lookup bpf: Make remote_port field in struct bpf_sk_lookup 16-bit wide libbpf: Fix compilation warning due to mismatched printf format selftests/bpf: Test BPF_KPROBE_SYSCALL macro libbpf: Add BPF_KPROBE_SYSCALL macro libbpf: Fix accessing the first syscall argument on s390 libbpf: Fix accessing the first syscall argument on arm64 libbpf: Allow overriding PT_REGS_PARM1{_CORE}_SYSCALL selftests/bpf: Skip test_bpf_syscall_macro's syscall_arg1 on arm64 and s390 libbpf: Fix accessing syscall arguments on riscv libbpf: Fix riscv register names libbpf: Fix accessing syscall arguments on powerpc selftests/bpf: Use PT_REGS_SYSCALL_REGS in bpf_syscall_macro libbpf: Add PT_REGS_SYSCALL_REGS macro selftests/bpf: Fix an endianness issue in bpf_syscall_macro test bpf: Fix bpf_prog_pack build HPAGE_PMD_SIZE bpf: Fix leftover header->pages in sparc and powerpc code. libbpf: Fix signedness bug in btf_dump_array_data() selftests/bpf: Do not export subtest as standalone test bpf, x86_64: Fail gracefully on bpf_jit_binary_pack_finalize failures ... ==================== Link: https://lore.kernel.org/r/20220209210050.8425-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-08tracing: Fix tp_printk option related with tp_printk_stop_on_bootJaeSang Yoo
The kernel parameter "tp_printk_stop_on_boot" starts with "tp_printk" which is the same as another kernel parameter "tp_printk". If "tp_printk" setup is called before the "tp_printk_stop_on_boot", it will override the latter and keep it from being set. This is similar to other kernel parameter issues, such as: Commit 745a600cf1a6 ("um: console: Ignore console= option") or init/do_mounts.c:45 (setup function of "ro" kernel param) Fix it by checking for a "_" right after the "tp_printk" and if that exists do not process the parameter. Link: https://lkml.kernel.org/r/20220208195421.969326-1-jsyoo5b@gmail.com Signed-off-by: JaeSang Yoo <jsyoo5b@gmail.com> [ Fixed up change log and added space after if condition ] Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-27tracing: Don't inc err_log entry count if entry allocation failsTom Zanussi
tr->n_err_log_entries should only be increased if entry allocation succeeds. Doing it when it fails won't cause any problems other than wasting an entry, but should be fixed anyway. Link: https://lkml.kernel.org/r/cad1ab28f75968db0f466925e7cba5970cec6c29.1643319703.git.zanussi@kernel.org Cc: stable@vger.kernel.org Fixes: 2f754e771b1a6 ("tracing: Don't inc err_log entry count if entry allocation fails") Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27tracing: Propagate is_signed to expressionTom Zanussi
During expression parsing, a new expression field is created which should inherit the properties of the operands, such as size and is_signed. is_signed propagation was missing, causing spurious errors with signed operands. Add it in parse_expr() and parse_unary() to fix the problem. Link: https://lkml.kernel.org/r/f4dac08742fd7a0920bf80a73c6c44042f5eaa40.1643319703.git.zanussi@kernel.org Cc: stable@vger.kernel.org Fixes: 100719dcef447 ("tracing: Add simple expression support to hist triggers") Reported-by: Yordan Karadzhov <ykaradzhov@vmware.com> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215513 Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27tracing: Fix smatch warning for do while check in event_hist_trigger_parse()Tom Zanussi
The patch ec5ce0987541: "tracing: Allow whitespace to surround hist trigger filter" from Jan 15, 2018, leads to the following Smatch static checker warning: kernel/trace/trace_events_hist.c:6199 event_hist_trigger_parse() warn: 'p' can't be NULL. Since p is always checked for a NULL value at the top of loop and nothing in the rest of the loop will set it to NULL, the warning is correct and might as well be 1 to silence the warning. Link: https://lkml.kernel.org/r/a1d4c79766c0cf61e20438dc35244d216633fef6.1643319703.git.zanussi@kernel.org Fixes: ec5ce09875410 ("tracing: Allow whitespace to surround hist trigger filter") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27tracing: Fix smatch warning for null glob in event_hist_trigger_parse()Tom Zanussi
The recent rename of event_hist_trigger_parse() caused smatch re-evaluation of trace_events_hist.c and as a result an old warning was found: kernel/trace/trace_events_hist.c:6174 event_hist_trigger_parse() error: we previously assumed 'glob' could be null (see line 6166) glob should never be null (and apparently smatch can also figure that out and skip the warning when using the cross-function DB (but which can't be used with a 0day build as it takes too much time to generate)). Nonetheless for clarity, remove the test but add a WARN_ON() in case the code ever changes. Link: https://lkml.kernel.org/r/96925e5c1f116654ada7ea0613d930b1266b5e1c.1643319703.git.zanussi@kernel.org Fixes: f404da6e1d46c ("tracing: Add 'last error' error facility for hist triggers") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27tracing/histogram: Fix a potential memory leak for kstrdup()Xiaoke Wang
kfree() is missing on an error path to free the memory allocated by kstrdup(): p = param = kstrdup(data->params[i], GFP_KERNEL); So it is better to free it via kfree(p). Link: https://lkml.kernel.org/r/tencent_C52895FD37802832A3E5B272D05008866F0A@qq.com Cc: stable@vger.kernel.org Fixes: d380dcde9a07c ("tracing: Fix now invalid var_ref_vals assumption in trace action") Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27ftrace: Have architectures opt-in for mcount build time sortingSteven Rostedt (Google)
First S390 complained that the sorting of the mcount sections at build time caused the kernel to crash on their architecture. Now PowerPC is complaining about it too. And also ARM64 appears to be having issues. It may be necessary to also update the relocation table for the values in the mcount table. Not only do we have to sort the table, but also update the relocations that may be applied to the items in the table. If the system is not relocatable, then it is fine to sort, but if it is, some architectures may have issues (although x86 does not as it shifts all addresses the same). Add a HAVE_BUILDTIME_MCOUNT_SORT that an architecture can set to say it is safe to do the sorting at build time. Also update the config to compile in build time sorting in the sorttable code in scripts/ to depend on CONFIG_BUILDTIME_MCOUNT_SORT. Link: https://lore.kernel.org/all/944D10DA-8200-4BA9-8D0A-3BED9AA99F82@linux.ibm.com/ Link: https://lkml.kernel.org/r/20220127153821.3bc1ac6e@gandalf.local.home Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Yinan Liu <yinan@linux.alibaba.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Kees Cook <keescook@chromium.org> Reported-by: Sachin Sant <sachinp@linux.ibm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64] Tested-by: Sachin Sant <sachinp@linux.ibm.com> Fixes: 72b3942a173c ("scripts: ftrace - move the sort-processing in ftrace_init") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-24bpf: Add bpf_copy_from_user_task() helperKenny Yu
This adds a helper for bpf programs to read the memory of other tasks. As an example use case at Meta, we are using a bpf task iterator program and this new helper to print C++ async stack traces for all threads of a given process. Signed-off-by: Kenny Yu <kennyyu@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220124185403.468466-3-kennyyu@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-24Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski
Daniel Borkmann says: ==================== pull-request: bpf-next 2022-01-24 We've added 80 non-merge commits during the last 14 day(s) which contain a total of 128 files changed, 4990 insertions(+), 895 deletions(-). The main changes are: 1) Add XDP multi-buffer support and implement it for the mvneta driver, from Lorenzo Bianconi, Eelco Chaudron and Toke Høiland-Jørgensen. 2) Add unstable conntrack lookup helpers for BPF by using the BPF kfunc infra, from Kumar Kartikeya Dwivedi. 3) Extend BPF cgroup programs to export custom ret value to userspace via two helpers bpf_get_retval() and bpf_set_retval(), from YiFei Zhu. 4) Add support for AF_UNIX iterator batching, from Kuniyuki Iwashima. 5) Complete missing UAPI BPF helper description and change bpf_doc.py script to enforce consistent & complete helper documentation, from Usama Arif. 6) Deprecate libbpf's legacy BPF map definitions and streamline XDP APIs to follow tc-based APIs, from Andrii Nakryiko. 7) Support BPF_PROG_QUERY for BPF programs attached to sockmap, from Di Zhu. 8) Deprecate libbpf's bpf_map__def() API and replace users with proper getters and setters, from Christy Lee. 9) Extend libbpf's btf__add_btf() with an additional hashmap for strings to reduce overhead, from Kui-Feng Lee. 10) Fix bpftool and libbpf error handling related to libbpf's hashmap__new() utility function, from Mauricio Vásquez. 11) Add support to BTF program names in bpftool's program dump, from Raman Shukhau. 12) Fix resolve_btfids build to pick up host flags, from Connor O'Brien. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (80 commits) selftests, bpf: Do not yet switch to new libbpf XDP APIs selftests, xsk: Fix rx_full stats test bpf: Fix flexible_array.cocci warnings xdp: disable XDP_REDIRECT for xdp frags bpf: selftests: add CPUMAP/DEVMAP selftests for xdp frags bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest net: xdp: introduce bpf_xdp_pointer utility routine bpf: generalise tail call map compatibility check libbpf: Add SEC name for xdp frags programs bpf: selftests: update xdp_adjust_tail selftest to include xdp frags bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature bpf: introduce frags support to bpf_prog_test_run_xdp() bpf: move user_size out of bpf_test_init bpf: add frags support to xdp copy helpers bpf: add frags support to the bpf_xdp_adjust_tail() API bpf: introduce bpf_xdp_get_buff_len helper net: mvneta: enable jumbo frames if the loaded XDP program support frags bpf: introduce BPF_F_XDP_HAS_FRAGS flag in prog_flags loading the ebpf program net: mvneta: add frags support to XDP_TX xdp: add frags support to xdp_return_{buff/frame} ... ==================== Link: https://lore.kernel.org/r/20220124221235.18993-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-23Merge tag 'trace-v5.17-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull ftrace fix from Steven Rostedt: "Fix s390 breakage from sorting mcount tables. The latest merge of the tracing tree sorts the mcount table at build time. But s390 appears to do things differently (like always) and replaces the sorted table back to the original unsorted one. As the ftrace algorithm depends on it being sorted, bad things happen when it is not, and s390 experienced those bad things. Add a new config to tell the boot if the mcount table is sorted or not, and allow s390 to opt out of it" * tag 'trace-v5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Fix assuming build time sort works for s390
2022-01-23ftrace: Fix assuming build time sort works for s390Steven Rostedt (Google)
To speed up the boot process, as mcount_loc needs to be sorted for ftrace to work properly, sorting it at build time is more efficient than boot up and can save milliseconds of time. Unfortunately, this change broke s390 as it will modify the mcount_loc location after the sorting takes place and will put back the unsorted locations. Since the sorting is skipped at boot up if it is believed that it was sorted at run time, ftrace can crash as its algorithms are dependent on the list being sorted. Add a new config BUILDTIME_MCOUNT_SORT that is set when BUILDTIME_TABLE_SORT but not if S390 is set. Use this config to determine if sorting should take place at boot up. Link: https://lore.kernel.org/all/yt9dee51ctfn.fsf@linux.ibm.com/ Fixes: 72b3942a173c ("scripts: ftrace - move the sort-processing in ftrace_init") Reported-by: Sven Schnelle <svens@linux.ibm.com> Tested-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-21bpf: add frags support to xdp copy helpersEelco Chaudron
This patch adds support for frags for the following helpers: - bpf_xdp_output() - bpf_perf_event_output() Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/340b4a99cdc24337b40eaf8bb597f9f9e7b0373e.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-16Merge tag 'trace-v5.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "New: - The Real Time Linux Analysis (RTLA) tool is added to the tools directory. - Can safely filter on user space pointers with: field.ustring ~ "match-string" - eprobes can now be filtered like any other event. - trace_marker(_raw) now uses stream_open() to allow multiple threads to safely write to it. Note, this could possibly break existing user space, but we will not know until we hear about it, and then can revert the change if need be. - New field in events to display when bottom halfs are disabled. - Sorting of the ftrace functions are now done at compile time instead of at bootup. Infrastructure changes to support future efforts: - Added __rel_loc type for trace events. Similar to __data_loc but the offset to the dynamic data is based off of the location of the descriptor and not the beginning of the event. Needed for user defined events. - Some simplification of event trigger code. - Make synthetic events process its callback better to not hinder other event callbacks that are registered. Needed for user defined events. And other small fixes and cleanups" * tag 'trace-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (50 commits) tracing: Add ustring operation to filtering string pointers rtla: Add rtla timerlat hist documentation rtla: Add rtla timerlat top documentation rtla: Add rtla timerlat documentation rtla: Add rtla osnoise hist documentation rtla: Add rtla osnoise top documentation rtla: Add rtla osnoise man page rtla: Add Documentation rtla/timerlat: Add timerlat hist mode rtla: Add timerlat tool and timelart top mode rtla/osnoise: Add the hist mode rtla/osnoise: Add osnoise top mode rtla: Add osnoise tool rtla: Helper functions for rtla rtla: Real-Time Linux Analysis tool tracing/osnoise: Properly unhook events if start_per_cpu_kthreads() fails tracing: Remove duplicate warnings when calling trace_create_file() tracing/kprobes: 'nmissed' not showed correctly for kretprobe tracing: Add test for user space strings when filtering on string pointers tracing: Have syscall trace events use trace_event_buffer_lock_reserve() ...
2022-01-15Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc updates from Andrew Morton: "146 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak, dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap, memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb, userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp, ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits) mm/damon: hide kernel pointer from tracepoint event mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging mm/damon/dbgfs: remove an unnecessary variable mm/damon: move the implementation of damon_insert_region to damon.h mm/damon: add access checking for hugetlb pages Docs/admin-guide/mm/damon/usage: update for schemes statistics mm/damon/dbgfs: support all DAMOS stats Docs/admin-guide/mm/damon/reclaim: document statistics parameters mm/damon/reclaim: provide reclamation statistics mm/damon/schemes: account how many times quota limit has exceeded mm/damon/schemes: account scheme actions that successfully applied mm/damon: remove a mistakenly added comment for a future feature Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning Docs/admin-guide/mm/damon/usage: remove redundant information Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks mm/damon: convert macro functions to static inline functions mm/damon: modify damon_rand() macro to static inline function mm/damon: move damon_rand() definition into damon.h ...
2022-01-15trace/hwlat: make use of the helper function kthread_run_on_cpu()Cai Huoqing
Replace kthread_create_on_cpu/wake_up_process() with kthread_run_on_cpu() to simplify the code. Link: https://lkml.kernel.org/r/20211022025711.3673-7-caihuoqing@baidu.com Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Cc: Bernard Metzler <bmt@zurich.ibm.com> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Doug Ledford <dledford@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15trace/osnoise: make use of the helper function kthread_run_on_cpu()Cai Huoqing
Replace kthread_create_on_cpu/wake_up_process() with kthread_run_on_cpu() to simplify the code. Link: https://lkml.kernel.org/r/20211022025711.3673-6-caihuoqing@baidu.com Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Cc: Bernard Metzler <bmt@zurich.ibm.com> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Doug Ledford <dledford@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15ring-buffer: make use of the helper function kthread_run_on_cpu()Cai Huoqing
Replace kthread_create/kthread_bind/wake_up_process() with kthread_run_on_cpu() to simplify the code. Link: https://lkml.kernel.org/r/20211022025711.3673-4-caihuoqing@baidu.com Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Cc: Bernard Metzler <bmt@zurich.ibm.com> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Doug Ledford <dledford@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-14tracing: Add ustring operation to filtering string pointersSteven Rostedt
Since referencing user space pointers is special, if the user wants to filter on a field that is a pointer to user space, then they need to specify it. Add a ".ustring" attribute to the field name for filters to state that the field is pointing to user space such that the kernel can take the appropriate action to read that pointer. Link: https://lore.kernel.org/all/yt9d8rvmt2jq.fsf@linux.ibm.com/ Fixes: 77360f9bbc7e ("tracing: Add test for user space strings when filtering on string pointers") Tested-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13tracing/osnoise: Properly unhook events if start_per_cpu_kthreads() failsNikita Yushchenko
If start_per_cpu_kthreads() called from osnoise_workload_start() returns error, event hooks are left in broken state: unhook_irq_events() called but unhook_thread_events() and unhook_softirq_events() not called, and trace_osnoise_callback_enabled flag not cleared. On the next tracer enable, hooks get not installed due to trace_osnoise_callback_enabled flag. And on the further tracer disable an attempt to remove non-installed hooks happened, hitting a WARN_ON_ONCE() in tracepoint_remove_func(). Fix the error path by adding the missing part of cleanup. While at this, introduce osnoise_unhook_events() to avoid code duplication between this error path and normal tracer disable. Link: https://lkml.kernel.org/r/20220109153459.3701773-1-nikita.yushchenko@virtuozzo.com Cc: stable@vger.kernel.org Fixes: bce29ac9ce0b ("trace: Add osnoise tracer") Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Nikita Yushchenko <nikita.yushchenko@virtuozzo.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13tracing: Remove duplicate warnings when calling trace_create_file()Yuntao Wang
Since the same warning message is already printed in the trace_create_file() function, there is no need to print it again. Link: https://lkml.kernel.org/r/20220109162232.361747-1-ytcoode@gmail.com Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13tracing/kprobes: 'nmissed' not showed correctly for kretprobeXiangyang Zhang
The 'nmissed' column of the 'kprobe_profile' file for kretprobe is not showed correctly, kretprobe can be skipped by two reasons, shortage of kretprobe_instance which is counted by tk->rp.nmissed, and kprobe itself is missed by some reason, so to show the sum. Link: https://lkml.kernel.org/r/20220107150242.5019-1-xyz.sun.ok@gmail.com Cc: stable@vger.kernel.org Fixes: 4a846b443b4e ("tracing/kprobes: Cleanup kprobe tracer code") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Xiangyang Zhang <xyz.sun.ok@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13tracing: Add test for user space strings when filtering on string pointersSteven Rostedt
Pingfan reported that the following causes a fault: echo "filename ~ \"cpu\"" > events/syscalls/sys_enter_openat/filter echo 1 > events/syscalls/sys_enter_at/enable The reason is that trace event filter treats the user space pointer defined by "filename" as a normal pointer to compare against the "cpu" string. The following bug happened: kvm-03-guest16 login: [72198.026181] BUG: unable to handle page fault for address: 00007fffaae8ef60 #PF: supervisor read access in kernel mode #PF: error_code(0x0001) - permissions violation PGD 80000001008b7067 P4D 80000001008b7067 PUD 2393f1067 PMD 2393ec067 PTE 8000000108f47867 Oops: 0001 [#1] PREEMPT SMP PTI CPU: 1 PID: 1 Comm: systemd Kdump: loaded Not tainted 5.14.0-32.el9.x86_64 #1 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:strlen+0x0/0x20 Code: 48 89 f9 74 09 48 83 c1 01 80 39 00 75 f7 31 d2 44 0f b6 04 16 44 88 04 11 48 83 c2 01 45 84 c0 75 ee c3 0f 1f 80 00 00 00 00 <80> 3f 00 74 10 48 89 f8 48 83 c0 01 80 38 00 75 f7 48 29 f8 c3 31 RSP: 0018:ffffb5b900013e48 EFLAGS: 00010246 RAX: 0000000000000018 RBX: ffff8fc1c49ede00 RCX: 0000000000000000 RDX: 0000000000000020 RSI: ffff8fc1c02d601c RDI: 00007fffaae8ef60 RBP: 00007fffaae8ef60 R08: 0005034f4ddb8ea4 R09: 0000000000000000 R10: ffff8fc1c02d601c R11: 0000000000000000 R12: ffff8fc1c8a6e380 R13: 0000000000000000 R14: ffff8fc1c02d6010 R15: ffff8fc1c00453c0 FS: 00007fa86123db40(0000) GS:ffff8fc2ffd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffaae8ef60 CR3: 0000000102880001 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: filter_pred_pchar+0x18/0x40 filter_match_preds+0x31/0x70 ftrace_syscall_enter+0x27a/0x2c0 syscall_trace_enter.constprop.0+0x1aa/0x1d0 do_syscall_64+0x16/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fa861d88664 The above happened because the kernel tried to access user space directly and triggered a "supervisor read access in kernel mode" fault. Worse yet, the memory could not even be loaded yet, and a SEGFAULT could happen as well. This could be true for kernel space accessing as well. To be even more robust, test both kernel and user space strings. If the string fails to read, then simply have the filter fail. Note, TASK_SIZE is used to determine if the pointer is user or kernel space and the appropriate strncpy_from_kernel/user_nofault() function is used to copy the memory. For some architectures, the compare to TASK_SIZE may always pick user space or kernel space. If it gets it wrong, the only thing is that the filter will fail to match. In the future, this needs to be fixed to have the event denote which should be used. But failing a filter is much better than panicing the machine, and that can be solved later. Link: https://lore.kernel.org/all/20220107044951.22080-1-kernelfans@gmail.com/ Link: https://lkml.kernel.org/r/20220110115532.536088fd@gandalf.local.home Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Tom Zanussi <zanussi@kernel.org> Reported-by: Pingfan Liu <kernelfans@gmail.com> Tested-by: Pingfan Liu <kernelfans@gmail.com> Fixes: 87a342f5db69d ("tracing/filters: Support filtering for char * strings") Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13tracing: Have syscall trace events use trace_event_buffer_lock_reserve()Steven Rostedt
Currently, the syscall trace events call trace_buffer_lock_reserve() directly, which means that it misses out on some of the filtering optimizations provided by the helper function trace_event_buffer_lock_reserve(). Have the syscall trace events call that instead, as it was missed when adding the update to use the temp buffer when filtering. Link: https://lkml.kernel.org/r/20220107225839.823118570@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tom Zanussi <zanussi@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 0fc1b09ff1ff4 ("tracing: Use temp buffer when filtering events") Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13ftrace: Add test to make sure compiled time sorts workSteven Rostedt (VMware)
Now that ftrace function pointers are sorted at compile time, add a test that makes sure they are sorted at run time. This test is only run if it is configured in. Link: https://lkml.kernel.org/r/20211206151858.4d21a24d@gandalf.local.home Cc: Yinan Liu <yinan@linux.alibaba.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2022-01-13scripts: ftrace - move the sort-processing in ftrace_initYinan Liu
When the kernel starts, the initialization of ftrace takes up a portion of the time (approximately 6~8ms) to sort mcount addresses. We can save this time by moving mcount-sorting to compile time. Link: https://lkml.kernel.org/r/20211212113358.34208-2-yinan@linux.alibaba.com Signed-off-by: Yinan Liu <yinan@linux.alibaba.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>