- 18 Nov, 2015 11 commits
-
-
Wang Nan authored
By extending the syntax of BPF object section names, this patch allows users to config probing options like what they can do in 'perf probe'. The error message in 'perf probe' is also updated. Test result: For following BPF file test_probe_glob.c: # cat test_probe_glob.c __attribute__((section("inlines=no;func=SyS_dup?"), used)) int func(void *ctx) { return 1; } char _license[] __attribute__((section("license"), used)) = "GPL"; int _version __attribute__((section("version"), used)) = 0x40300; # # ./perf record -e ./test_probe_glob.c ls / ... [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.013 MB perf.data ] # ./perf evlist perf_bpf_probe:func_1 perf_bpf_probe:func After changing "inlines=no" to "inlines=yes": # ./perf record -e ./test_probe_glob.c ls / ... [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.013 MB perf.data ] # ./perf evlist perf_bpf_probe:func_3 perf_bpf_probe:func_2 perf_bpf_probe:func_1 perf_bpf_probe:func Then test 'force': Use following program: # cat test_probe_force.c __attribute__((section("func=sys_write"), used)) int funca(void *ctx) { return 1; } __attribute__((section("force=yes;func=sys_write"), used)) int funcb(void *ctx) { return 1; } char _license[] __attribute__((section("license"), used)) = "GPL"; int _version __attribute__((section("version"), used)) = 0x40300; # # perf record -e ./test_probe_force.c usleep 1 Error: event "func" already exists. Hint: Remove existing event by 'perf probe -d' or force duplicates by 'perf probe -f' or set 'force=yes' in BPF source. event syntax error: './test_probe_force.c' \___ Probe point exist. Try 'perf probe -d "*"' and set 'force=yes' (add -v to see detail) ... Then replace 'force=no' to 'force=yes': # vim test_probe_force.c # perf record -e ./test_probe_force.c usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.017 MB perf.data ] # perf evlist perf_bpf_probe:func_1 perf_bpf_probe:func # Signed-off-by:Wang Nan <wangnan0@huawei.com> Tested-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1447675815-166222-7-git-send-email-wangnan0@huawei.comSigned-off-by:
-
Wang Nan authored
By extending the syntax of BPF object section names, this patch allows users to attach BPF programs to symbols in modules. For example: SEC("module=i915;" "parse_cmds=i915_parse_cmds") int parse_cmds(void *ctx) { return 1; } The implementation is very simple: like what 'perf probe' does, for module, fill 'uprobe' field in 'struct perf_probe_event'. Other parts will be done automatically. Signed-off-by: -
Wang Nan authored
This patch adds a new syntax to the BPF object section name to support probing at uprobe event. Now we can use BPF program like this: SEC( "exec=/lib64/libc.so.6;" "libcwrite=__write" ) int libcwrite(void *ctx) { return 1; } Where, in section name of a program, before the main config string, we can use 'key=value' style options. Now the only option key is "exec", for uprobes. Signed-off-by: -
Wang Nan authored
regs_query_register_offset() in dwarf-regs.c is required by BPF prologue. This patch compiles it if CONFIG_BPF_PROLOGUE is on to avoid build failure when CONFIG_BPF_PROLOGUE is on but CONFIG_DWARF is not set. Signed-off-by:
He Kuang <hekuang@huawei.com> Acked-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: He Kuang <hekuang@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1447675815-166222-10-git-send-email-wangnan0@huawei.comSigned-off-by:
-
Wang Nan authored
If both LIBBPF and DWARF are detected, it is possible to create prologue for eBPF programs to help them access kernel data. HAVE_BPF_PROLOGUE and CONFIG_BPF_PROLOGUE are added as flags for this feature. PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET is introduced in commit 63ab024a ("perf tools: regs_query_register_offset() infrastructure"), which indicates that an architecture supports converting name of a register to its offset in 'struct pt_regs'. Without this support, BPF_PROLOGUE should be turned off. Signed-off-by:
-
Wang Nan authored
This patch is a preparation for BPF prologue support which allows generating a series of BPF bytecode for fetching kernel data before calling program code. With the newly introduced multiple instances support, perf is able to create different prologues for different kprobe points. Before this patch, a bpf_program can be loaded into kernel only once, and get the only resulting fd. What this patch does is to allow creating and loading different variants of one bpf_program, then fetching their fds. Here we describe the basic idea in this patch. The detailed description of the newly introduced APIs can be found in comments in the patch body. The key of this patch is the new mechanism in bpf_program__load(). Instead of loading BPF program into kernel directly, it calls a 'pre-processor' to generate program instances which would be finally loaded into the kernel based on the original code. To enable the generation of multiple instances, libbpf passes an index to the pre-processor so it know which instance is being loaded. Pre-processor should be called from libbpf's user (perf) using bpf_program__set_prep(). The number of instances and the relationship between indices and the target instance should be clear when calling bpf_program__set_prep(). To retrieve a fd for a specific instance of a program, bpf_program__nth_fd() is introduced. It returns the resulting fd according to index. Signed-off-by:
-
Wang Nan authored
Copying it to tools/lib/string.c, the counterpart to the kernel's lib/string.c. This is preparation for enhancing BPF program configuration, which will allow config string like 'inlines=yes'. Signed-off-by:
-
Arnaldo Carvalho de Melo authored
That will contain more string functions with counterparts, sometimes verbatim copies, in the kernel. Acked-by:
-
Kevin Hilman authored
Fix copy/paste error in selftests_install rule which was copy-pasted from the clean rule but not properly changed. Signed-off-by:
Kevin Hilman <khilman@linaro.org> Cc: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Pali Rohar <pali.rohar@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Roberta Dobrescu <roberta.dobrescu@gmail.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: linaro-kernel@lists.linaro.org Link: http://lkml.kernel.org/r/1447797261-1775-1-git-send-email-khilman@kernel.orgSigned-off-by:
-
Arnaldo Carvalho de Melo authored
$ rpm -q glibc glibc-2.12-1.166.el6_7.1.x86_64 <SNIP> CC /tmp/build/perf/tests/llvm.o cc1: warnings being treated as errors tests/llvm.c: In function ‘test_llvm__fetch_bpf_obj’: tests/llvm.c:53: error: declaration of ‘index’ shadows a global declaration /usr/include/string.h:489: error: shadowed declaration is here <SNIP> CC /tmp/build/perf/tests/bpf.o cc1: warnings being treated as errors tests/bpf.c: In function ‘__test__bpf’: tests/bpf.c:149: error: declaration of ‘index’ shadows a global declaration /usr/include/string.h:489: error: shadowed declaration is here <SNIP> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: pi3orama@163.com Cc: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Fixes: b31de018 ("perf test: Enhance the LLVM test: update basic BPF test program") Fixes: ba1fae43 ("perf test: Add 'perf test BPF'") Link: http://lkml.kernel.org/n/tip-akpo4r750oya2phxoh9e3447@git.kernel.orgSigned-off-by: -
Ingo Molnar authored
Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes from Arnaldo Carvalho de Melo: - Do not change the key of an object in a rbtree, this time it was the one for DSOs lookup by its long_name, and the noticed symptom was with 'perf buildid-list --with-hits' (Adrian Hunter) - 'perf inject' is a pipe, events it doesn't touch should be passed on, PERF_RECORD_LOST wasn't, fix it (Adrian Hunter) - Make 'perf buildid-list' request event ordering, as it needs to first get the mmap events to be able to mark wich DSOs had hits (Adrian Hunter) - Fix memory leaks on failure in 'perf probe' (Masami Hiramatsu, Wang Nan) Signed-off-by:
Ingo Molnar <mingo@kernel.org>
-
- 13 Nov, 2015 6 commits
-
-
Wang Nan authored
When probing with a glob, errors in add_probe_trace_event() won't be passed to debuginfo__find_trace_events() because it would be modified by probe_point_search_cb(). It causes a segfault if perf fails to find an argument for a probe point matched by the glob. For example: # ./perf probe -v -n 'SyS_dup? oldfd' probe-definition(0): SyS_dup? oldfd symbol:SyS_dup? file:(null) line:0 offset:0 return:0 lazy:(null) parsing arg: oldfd into oldfd 1 arguments Looking at the vmlinux_path (7 entries long) Using /lib/modules/4.3.0-rc4+/build/vmlinux for symbols Open Debuginfo file: /lib/modules/4.3.0-rc4+/build/vmlinux Try to find probe point from debuginfo. Matched function: SyS_dup3 found inline addr: 0xffffffff812095c0 Probe point found: SyS_dup3+0 Searching 'oldfd' variable in context. Converting variable oldfd into trace event. oldfd type is long int. found inline addr: 0xffffffff812096d4 Probe point found: SyS_dup2+36 Searching 'oldfd' variable in context. Failed to find 'oldfd' in this function. Matched function: SyS_dup3 Probe point found: SyS_dup3+0 Searching 'oldfd' variable in context. Converting variable oldfd into trace event. oldfd type is long int. Matched function: SyS_dup2 Probe point found: SyS_dup2+0 Searching 'oldfd' variable in context. Converting variable oldfd into trace event. oldfd type is long int. Found 4 probe_trace_events. Opening /sys/kernel/debug/tracing//kprobe_events write=1 Writing event: p:probe/SyS_dup3 _text+2135488 oldfd=%di:s64 Segmentation fault (core dumped) # This patch ensures that add_probe_trace_event() doesn't touches tf->ntevs and tf->tevs if those functions fail. After the patch: # perf probe 'SyS_dup? oldfd' Failed to find 'oldfd' in this function. Added new events: probe:SyS_dup3 (on SyS_dup? with oldfd) probe:SyS_dup3_1 (on SyS_dup? with oldfd) probe:SyS_dup2 (on SyS_dup? with oldfd) You can now use it in all perf tools, such as: perf record -e probe:SyS_dup2 -aR sleep 1 Signed-off-by: -
Masami Hiramatsu authored
Fix memory leaking on the debuginfo__find_trace_events() failure path which frees an array of probe_trace_events but doesn't clears all the allocated sub-structures and strings. So, before doing zfree(tevs), clear all the array elements which may have allocated resources. Reported-by:
-
Adrian Hunter authored
perf inject must re-pipe all events otherwise they get dropped from the output file. Signed-off-by:
Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/1447408112-1920-4-git-send-email-adrian.hunter@intel.comSigned-off-by:
-
Adrian Hunter authored
'perf buildid-list' processes events to determine hits (i.e. with-hits option). That may not work if events are not sorted in order. i.e. MMAP events must be processed before the samples that depend on them so that sample processing can 'hit' the DSO to which the MMAP refers. Signed-off-by:
-
Adrian Hunter authored
Commit 4598a0a6 ("perf symbols: Improve DSO long names lookup speed with rbtree") Added a tree to lookup dsos by long name. That tree gets corrupted whenever a dso long name is changed because the tree is not updated. One effect of that is buildid-list does not work with the 'with-hits' option because dso lookup fails and results in two structs for the same dso. The first has the buildid but no hits, the second has hits but no buildid. e.g. Before: $ tools/perf/perf record ls arch certs CREDITS Documentation firmware include ipc Kconfig lib Makefile net REPORTING-BUGS scripts sound usr block COPYING crypto drivers fs init Kbuild kernel MAINTAINERS mm README samples security tools virt [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.012 MB perf.data (11 samples) ] $ tools/perf/perf buildid-list 574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms] 30c94dc66a1fe95180c3d68d2b89e576d5ae213c /lib/x86_64-linux-gnu/libc-2.19.so $ tools/perf/perf buildid-list -H 574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms] 0000000000000000000000000000000000000000 /lib/x86_64-linux-gnu/libc-2.19.so After: $ tools/perf/perf buildid-list -H 574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms] 30c94dc66a1fe95180c3d68d2b89e576d5ae213c /lib/x86_64-linux-gnu/libc-2.19.so The fix is to record the root of the tree on the dso so that dso__set_long_name() can update the tree when the long name changes. Signed-off-by:
-
Ingo Molnar authored
Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes from Arnaldo Carvalho de Melo: - Fix 'd' hotkey for filtering by DSO in the top/report TUI browser (Arnaldo Carvalho de Melo) - Allow forcing reading of non-root owned /tmp/perf-PID JIT symbol maps (Arnaldo Carvalho de Melo) - Rebuild rbtree when adjusting symbols for kcore (Adrian Hunter) - Actually install tmon in the tools/ install rule (Kamal Mostafa) Signed-off-by:
-
- 12 Nov, 2015 8 commits
-
-
Arnaldo Carvalho de Melo authored
When the root user tries to read a file owned by some other user we get: # ls -la perf.data -rw-------. 1 acme acme 20032 Nov 12 15:50 perf.data # perf report File perf.data not owned by current user or root (use -f to override) # perf report -f | grep -v ^# | head -2 30.96% ls [kernel.vmlinux] [k] do_set_pte 28.24% ls libc-2.20.so [.] intel_check_word # That wasn't happening when the symbol code tried to read a JIT map, where the same check was done but no forcing was possible, fix it. Reported-by:Brendan Gregg <brendan.d.gregg@gmail.com> Tested-by:
-
Arnaldo Carvalho de Melo authored
So no need to have a 'dso' member in 'popup_action', remove it as no code is using it, already. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-76a6s0007slug0op0wkl6o8b@git.kernel.orgSigned-off-by:
-
Arnaldo Carvalho de Melo authored
When pressing 'd' the expected action is to filter all entries by the DSO in the current entry, but for that the action->map needs to be set, and only action->dso was being set, fix it. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Fixes: 045b80dd ("perf hists browser: Use the map to determine if a DSO is being used as a kernel") Link: http://lkml.kernel.org/n/tip-xqhfzgoblq49lk5h5u82atro@git.kernel.orgSigned-off-by:
-
Adrian Hunter authored
Normally symbols are read from the DSO and adjusted, if need be, so that the symbol start matches the file offset in the DSO file (we want the file offset because that is what we know from MMAP events). That is done by dso__load_sym() which inserts the symbols *after* adjusting them. In the case of kcore, the symbols have been read from kallsyms and the symbol start is the memory address. The symbols have to be adjusted to match the kcore file offsets. dso__split_kallsyms_for_kcore() does that, but now the adjustment is being done *after* the symbols have been inserted. It appears dso__split_kallsyms_for_kcore() was assuming that changing the symbol start would not change the order in the rbtree - which is, of course, not guaranteed. Signed-off-by:
-
Kamal Mostafa authored
Signed-off-by:
Kamal Mostafa <kamal@canonical.com> Acked-by:
Pavel Machek <pavel@ucw.cz> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Pali Rohar <pali.rohar@gmail.com> Cc: Roberta Dobrescu <roberta.dobrescu@gmail.com> Link: http://lkml.kernel.org/r/1447280736-2161-2-git-send-email-kamal@canonical.comSigned-off-by:
-
Kamal Mostafa authored
Signed-off-by:
-
Huang Rui authored
Signed-off-by:
Huang Rui <ray.huang@amd.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Li <tony.li@amd.com> Link: http://lkml.kernel.org/r/1446630233-3166-1-git-send-email-ray.huang@amd.comSigned-off-by:
-
Ingo Molnar authored
Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes from Arnaldo Carvalho de Melo: - Add missing newlines to some pr_err() calls (Arnaldo Carvalho de Melo) - Print full source file paths when using 'perf annotate --print-line --full-paths' (Michael Petlan) - Fix 'perf probe -d' when just one out of uprobes and kprobes is enabled (Wang Nan) - Add compiler.h to list.h to fix 'make perf-tar-src-pkg' generated tarballs, i.e. out of tree building (Arnaldo Carvalho de Melo) - Add the llvm-src-base.c and llvm-src-kbuild.c files, generated by the 'perf test' LLVM entries, when running it in-tree, to .gitignore (Yunlong Song) Signed-off-by:
-
- 11 Nov, 2015 5 commits
-
-
Arnaldo Carvalho de Melo authored
list.h needs WRITE_ONCE() since 7f5f873c ("rculist: Use WRITE_ONCE() when deleting from reader-visible list") add it before including the kernel's list.h file. This fixes builds of 'make perf-tar-src-pkg' perf tool tarball builds, i.e. out of tree builds. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-e0rb8f7jwz0jn24ttyick9u6@git.kernel.orgSigned-off-by:
-
Wang Nan authored
On kernel with only one out of CONFIG_KPROBE_EVENTS and CONFIG_UPROBE_EVENTS enabled, 'perf probe -d' causes a segfault because perf_del_probe_events() calls probe_file__get_events() with a negative fd. This patch fixes it by adding parameter validation at the entry of probe_file__get_events() and probe_file__get_rawlist(). Since they are both non-static public functions (in .h file), parameter verifying is required. v1 -> v2: Verify fd at the head of probe_file__get_rawlist() instead of checking at call site (suggested by Masami and Arnaldo at [1,2]). [1] http://lkml.kernel.org/r/50399556C9727B4D88A595C8584AAB37526048E3@GSjpTKYDCembx32.service.hitachi.net [2] http://lkml.kernel.org/r/20151105155830.GV13236@kernel.orgSigned-off-by: -
Arnaldo Carvalho de Melo authored
Before: [acme@zoo linux]$ perf evlist WARNING: The perf.data file's data size field is 0 which is unexpected. Was the 'perf record' command properly terminated? non matching sample_type[acme@zoo linux]$ After: [acme@zoo linux]$ perf evlist WARNING: The perf.data file's data size field is 0 which is unexpected. Was the 'perf record' command properly terminated? non matching sample_type [acme@zoo linux]$ Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-wscok3a2s7yrj8156oc2r6qe@git.kernel.orgSigned-off-by:
-
Michael Petlan authored
The --full-paths option did not show the full source file paths in the 'perf annotate' tool, because the value of the option was not propagated into the related functions. With this patch the value of the --full-paths option is known to the function that composes the srcline string, so it prints the full path when necessary. Committer Note: This affects annotate when the --print-line option is used: # perf annotate -h 2>&1 | grep print-line -l, --print-line print matching source lines (may be slow) Looking just at the lines that should be affected by this change: Before: # perf annotate --print-line --full-paths --stdio fput | grep '\.[ch]:[0-9]\+' 94.44 atomic64_64.h:114 5.56 file_table.c:265 file_table.c:265 5.56 : ffffffff81219a00: callq ffffffff81769360 <__fentry__> atomic64_64.h:114 94.44 : ffffffff81219a05: lock decq 0x38(%rdi) After: # perf annotate --print-line --full-paths --stdio fput | grep '\.[ch]:[0-9]\+' 94.44 /home/git/linux/arch/x86/include/asm/atomic64_64.h:114 5.56 /home/git/linux/fs/file_table.c:265 /home/git/linux/fs/file_table.c:265 5.56 : ffffffff81219a00: callq ffffffff81769360 <__fentry__> /home/git/linux/arch/x86/include/asm/atomic64_64.h:114 94.44 : ffffffff81219a05: lock decq 0x38(%rdi) # Signed-off-by:Michael Petlan <mpetlan@redhat.com> Tested-by:
-
Yunlong Song authored
Commit b31de018 ("perf test: Enhance the LLVM test: update basic BPF test program") dynamically creates file llvm-src-base.c during the perf building. Similarly, the commit 7af3f3d5 ("perf test: Enhance the LLVM tests: add kbuild test") dynamically creates file llvm-src-kbuild.c during the perf building. Add them to .gitignore. Signed-off-by:
Yunlong Song <yunlong.song@huawei.com> Tested-by:
-
- 09 Nov, 2015 2 commits
-
-
Peter Zijlstra authored
Arnaldo reported that tracepoint filters seem to misbehave (ie. not apply) on inherited events. The fix is obvious; filters are only set on the actual (parent) event, use the normal pattern of using this parent event for filters. This is safe because each child event has a reference to it. Reported-by:
Arnaldo Carvalho de Melo <acme@kernel.org> Tested-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wang Nan <wangnan0@huawei.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20151102095051.GN17308@twins.programming.kicks-ass.netSigned-off-by:
-
Paul E. McKenney authored
The perf_lock_task_context() function disables preemption across its RCU read-side critical section because that critical section acquires a scheduler lock. If there was a preemption during that RCU read-side critical section, the rcu_read_unlock() could attempt to acquire scheduler locks, resulting in deadlock. However, recent optimizations to expedited grace periods mean that IPI handlers that execute during preemptible RCU read-side critical sections can now cause the subsequent rcu_read_unlock() to acquire scheduler locks. Disabling preemption does nothiing to prevent these IPI handlers from executing, so these optimizations introduced a deadlock. In theory, this deadlock could be avoided by pulling all wakeups and printk()s out from rnp->lock critical sections, but in practice this would re-introduce some RCU CPU stall warning bugs. Given that acquiring scheduler locks entails disabling interrupts, these deadlocks can be avoided by disabling interrupts (instead of disabling preemption) across any RCU read-side critical that acquires scheduler locks and holds them across the rcu_read_unlock(). This commit therefore makes this change for perf_lock_task_context(). Reported-by:
Dave Jones <davej@codemonkey.org.uk> Reported-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by:
-
- 08 Nov, 2015 1 commit
-
-
Ingo Molnar authored
Merge tag 'perf-core-for-mingo-2' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: Fixes: - libbpf error reporting improvements, using a strerror interface to more precisely tell the user about problems with the provided scriptlet, be it in C or as a ready made object file (Wang Nan) - Do not be case sensitive when searching for matching 'perf test' entries (Arnaldo Carvalho de Melo) - Inform the user about objdump failures in 'perf annotate' (Andi Kleen) Infrastructure changes: - Improve the LLVM 'perf test' entry, introduce a new ones for BPF and kbuild tests to check the environment used by clang to compile .c scriptlets (Wang Nan) Signed-off-by:
-
- 06 Nov, 2015 7 commits
-
-
Arnaldo Carvalho de Melo authored
Before: # perf test llvm # perf test LLVM 35: Test LLVM searching and compiling : Ok # After # perf test llvm 35: Test LLVM searching and compiling : Ok # Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-c1u05npqbf6epse17ovfejoj@git.kernel.orgSigned-off-by:
-
Wang Nan authored
This patch adds BPF testcase for testing BPF event filtering. By utilizing the result of 'perf test LLVM', this patch compiles the eBPF sample program then test its ability. The BPF script in 'perf test LLVM' lets only 50% samples generated by epoll_pwait() to be captured. This patch runs that system call for 111 times, so the result should contain 56 samples. Signed-off-by:
-
Wang Nan authored
This patch adds a kbuild testcase to check whether kernel headers can be correctly found. For example: # mv /lib/modules/4.3.0-rc5{,.bak} # perf test LLVM 38: Test LLVM searching and compiling : Skip # perf test -v LLVM ... <stdin>:11:10: fatal error: 'uapi/linux/fs.h' file not found #include <uapi/linux/fs.h> ^ 1 error generated. ERROR: unable to compile - Hint: Check error message shown above. Hint: You can also pre-compile it into .o using: clang -target bpf -O2 -c - with proper -I and -D options. Failed to compile test case: 'Test kbuild searching' test child finished with -2 Signed-off-by: -
Wang Nan authored
This patch replaces the original toy BPF program with the previously introduced bpf-script-example.c. Dynamically embeddeding it into 'llvm-src-base.c'. The newly introduced BPF program attaches a BPF program to 'sys_epoll_pwait()'. perf itself never use that syscall, so further test can verify their result with it. The program would generate 1 sample in every 2 calls of epoll_pwait() system call. Since the resulting BPF object is useful per se for further tests, test_llvm__fetch_bpf_obj() is introduced for creating BPF objects from source. The LLVM test was rewritten to use it. Committer note: Running it: [root@zoo wb]# perf test -v LLVM 35: Test LLVM searching and compiling : --- start --- test child forked, pid 17740 Kernel build dir is set to /lib/modules/4.3.0-rc1+/build set env: KBUILD_DIR=/lib/modules/4.3.0-rc1+/build unset env: KBUILD_OPTS include option is set to -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.9.2/include -I/home/git/linux/arch/x86/include -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated -I/home/git/linux/include -Iinclude -I/home/git/linux/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/home/git/linux/include/uapi -Iinclude/generated/uapi -include /home/git/linux/include/linux/kconfig.h set env: NR_CPUS=4 set env: LINUX_VERSION_CODE=0x40300 set env: CLANG_EXEC=/usr/libexec/icecc/bin/clang set env: CLANG_OPTIONS=-xc set env: KERNEL_INC_OPTIONS= -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.9.2/include -I/home/git/linux/arch/x86/include -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated -I/home/git/linux/include -Iinclude -I/home/git/linux/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/home/git/linux/include/uapi -Iinclude/generated/uapi -include /home/git/linux/include/linux/kconfig.h set env: WORKING_DIR=/lib/modules/4.3.0-rc1+/build set env: CLANG_SOURCE=- llvm compiling command template: echo '/* * bpf-script-example.c * Test basic LLVM building */ #ifndef LINUX_VERSION_CODE # error Need LINUX_VERSION_CODE # error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig' #endif #define BPF_ANY 0 #define BPF_MAP_TYPE_ARRAY 2 #define BPF_FUNC_map_lookup_elem 1 #define BPF_FUNC_map_update_elem 2 static void *(*bpf_map_lookup_elem)(void *map, void *key) = (void *) BPF_FUNC_map_lookup_elem; static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) = (void *) BPF_FUNC_map_update_elem; struct bpf_map_def { unsigned int type; unsigned int key_size; unsigned int value_size; unsigned int max_entries; }; #define SEC(NAME) __attribute__((section(NAME), used)) struct bpf_map_def SEC("maps") flip_table = { .type = BPF_MAP_TYPE_ARRAY, .key_size = sizeof(int), .value_size = sizeof(int), .max_entries = 1, }; SEC("func=sys_epoll_pwait") int bpf_func__sys_epoll_pwait(void *ctx) { int ind =0; int *flag = bpf_map_lookup_elem(&flip_table, &ind); int new_flag; if (!flag) return 0; /* flip flag and store back */ new_flag = !*flag; bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY); return new_flag; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; ' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o - test child finished with 0 ---- end ---- Test LLVM searching and compiling: Ok [root@zoo wb]# Signed-off-by: -
Wang Nan authored
A series of bpf loader related error codes were introduced to help error reporting. Functions were improved to return these new error codes. Functions which return pointers were adjusted to encode error codes into return value using the ERR_PTR() interface. bpf_loader_strerror() was improved to convert these error messages to strings. It checks the error codes and calls libbpf_strerror() and strerror_r() accordingly, so caller don't need to consider checking the range of the error code. In bpf__strerror_load(), print kernel version of running kernel and the object's 'version' section to notify user how to fix his/her program. v1 -> v2: Use macro for error code. Fetch error message based on array index, eliminate for-loop. Print version strings. Before: # perf record -e ./test_kversion_nomatch_program.o sleep 1 event syntax error: './test_kversion_nomatch_program.o' \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object SKIP After: # perf record -e ./test_kversion_nomatch_program.o ls event syntax error: './test_kversion_nomatch_program.o' \___ 'version' (4.4.0) doesn't match running kernel (4.3.0) SKIP Signed-off-by: -
Wang Nan authored
There are 2 places in llvm-utils.c which find kernel version information through uname. This patch extracts the uname related code into a fetch_kernel_version() function and puts it into util.h so it can be reused. Signed-off-by:
-
Wang Nan authored
bpf_object__get_kversion() can be used to fetch value of object's 'version' section. Following patch will use it for error reporting. Signed-off-by:
-
