linux/tools/perf/util/machine.c, branch v4.5

perf thread: Fix reference count initial state

2015-12-14T15:08:55Z

We should always return from thread__new(), the constructor, with the object with a reference count of one, so that: struct thread *thread = thread__new(); thread__put(thread); Will call thread__delete(). If any reference is made to that 'thread' variable, it better use thread__get(thread) to hold a reference. We were returning with thread->refcnt set to zero, fix it and some cases where thread__delete() was being called, which were not a problem because just one reference was being used, now that we set it to 1, use thread__put() instead. Reported-by: Masami Hiramatsu Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-4b9mkuk66to4ecckpmpvqx6s@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Clear struct machine during machine__init()

2015-12-11T12:32:41Z

There are so many test cases use stack allocated 'struct machine'. Including: test__hists_link test__hists_filter test__mmap_thread_lookup test__thread_mg_share test__hists_output test__hists_cumulate Also, in non-test code (for example, machine__new_host()) there are code use 'malloc()' to alloc struct machine. These are dangerous operations, cause some tests fail or hung in machines__exit(). For example, in machines__exit -> machine__destroy_kernel_maps -> map_groups__remove -> maps__remove -> pthread_rwlock_wrlock a incorrectly initialized lock causes unintended behavior. This patch memset(0) that structure in machine__init() to ensure all fields in 'struct machine' are initialized to zero. Signed-off-by: Wang Nan Cc: Jiri Olsa Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1449541544-67621-17-git-send-email-wangnan0@huawei.com [ Use memset, see 'man bzero' ] Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Fix machine.vmlinux_maps to make sure to clear the old one

2015-12-09T16:42:00Z

Fix machine.vmlinux_maps to make sure to clear the old one if it is renewal. This can leak the previous maps on the vmlinux_maps because those are just overwritten. Signed-off-by: Masami Hiramatsu Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20151209021133.10245.93730.stgit@localhost.localdomain [ Simplified the memset, same end result ] Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Pass correct string to dso__adjust_kmod_long_name

2015-12-07T21:12:45Z

There's a mistake in dso__adjust_kmod_long_name() that it use strdup() to dup the new long_name of a dso, but passes the original string to dso__set_long_name(). Which causes random crash during cleanup. Signed-off-by: Wang Nan Reviewed-by: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Fixes: c03d5184f0e9 ("perf machine: Adjust dso->long_name for offline module") Link: http://lkml.kernel.org/r/1449455785-42020-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Adjust dso->long_name for offline module

2015-11-26T16:47:43Z

Something unexpected may happen if copy statically linked perf to a production environment: # ./perf probe -m ./mymodule.ko my_func [mymodule] with build id 326ab42550ef3d24944f53c817533728367effeb not found, continuing without symbols Failed to find symbol my_func in /home/wangnan/kmodule/mymodule.ko Error: Failed to add events. # ./perf buildid-cache -a ./mymodule.ko # ./perf probe -m ./mymodule.ko my_func Added new event: probe:my_func (on my_func in /home/wangnan/kmodule/mymodule.ko) You can now use it in all perf tools, such as: perf record -e probe:my_func -aR sleep 1 Where: # ldd ./perf not a dynamic executable # strace -e open ./perf probe -m ./mymodule.ko my_func ... open("/home/wangnan/kmodule/mymodule.ko", O_RDONLY) = 3 open("/home/wangnan/kmodule/../lib64/elfutils/libebl_x86_64.so", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) ... open("/lib64/tls/libebl_x86_64.so", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/lib64/libebl_x86_64.so", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib64/tls/libebl_x86_64.so", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/lib64/libebl_x86_64.so", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("[mymodule]", O_RDONLY) = -1 ENOENT (No such file or directory) open("/home/wangnan/.debug/.build-id/32/6ab42550ef3d24944f53c817533728367effeb", O_RDONLY) = -1 ENOENT (No such file or directory) open("[mymodule]", O_RDONLY) = -1 ENOENT (No such file or directory) In the above example, probe fails before we put the module into buildid-cache. However, user would expect it success in both case because perf is able to find probe points actually. The reason is because perf won't utilize module's full path if it failed to open debuginfo. In: convert_to_probe_trace_events -> find_probe_trace_events_from_map -> get_target_map -> kernel_get_module_map -> machine__findnew_module_map -> map_groups__find_by_name map_groups__find_by_name() is able to find the map of that module, but this information is found from /proc/module before it knows the real path of the offline module. Therefore, the map->dso->long_name is set to something like '[mymodule]', which prevent dso__load() find the real path of the module file. In another aspect, if dso__load() can get the offline module through buildid cache, it can read symble table from that ko. Even if debuginfo is not available, 'perf probe' can success if the '.symtab' can be found. This patch improves machine__findnew_module_map(): when dso->long_name is leading with '[' (doesn't find path of module when parsing /proc/modules), fixes it by dso__set_long_name(), so following dso__load() is possible to find the symbol table. This patch won't interfere with buildid matching. Here is the test result: # ./perf probe -m ./mymodule.ko my_func Added new event: probe:my_func (on my_func in /home/wangnan/kmodule/mymodule.ko) You can now use it in all perf tools, such as: perf record -e probe:my_func -aR sleep 1 # ./perf probe -d '*' Removed event: probe:my_func # mv ./mymodule.{ko,.bak} # mv ./moduleb.ko mymodule.ko # ./perf probe -m ./mymodule.ko my_func /home/wangnan/kmodule/mymodule.ko with build id 326ab42550ef3d24944f53c817533728367effeb not found, continuing without symbols Failed to find symbol my_func in /home/wangnan/kmodule/mymodule.ko Error: Failed to add events. # ./perf probe -v -m ./mymodule.ko my_func probe-definition(0): my_func symbol:my_func file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Could not open debuginfo. Try to use symbols. symsrc__init: build id mismatch for /home/wangnan/kmodule/mymodule.ko. /home/wangnan/kmodule/mymodule.ko with build id 326ab42550ef3d24944f53c817533728367effeb not found, continuing without symbols Failed to find symbol my_func in /home/wangnan/kmodule/mymodule.ko Error: Failed to add events. Reason: No such file or directory (Code: -2) Signed-off-by: Wang Nan Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1448510397-187965-1-git-send-email-wangnan0@huawei.com [ Renamed adjust_dso_long_name() do dso__adjust_kmod_long_name() ] Signed-off-by: Arnaldo Carvalho de Melo

perf callchain: Honor hide_unresolved

2015-11-26T16:19:39Z

If user requested to hide unresolved entries, skip unresolved callchains as well as hist entries. Signed-off-by: Namhyung Kim Acked-by: Jiri Olsa Cc: Andi Kleen Cc: David Ahern Cc: Frederic Weisbecker Cc: Kan Liang Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1448521700-32062-3-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Fix machine__findnew_module_map to put dso

2015-11-19T16:19:21Z

Fix machine__findnew_module_map to drop the reference to the dso because it is already referenced by both machine__findnew_module_dso() and map__new2(). Refcnt debugger shows: ==== [1] ==== Unreclaimed dso: 0x1ffd980 Refcount +1 => 1 at ./perf(dso__new+0x1ff) [0x4a62df] ./perf(__dsos__addnew+0x29) [0x4a6e19] ./perf() [0x4b8b91] ./perf(modules__parse+0xfc) [0x4a9d5c] ./perf() [0x4b8460] ./perf(machine__create_kernel_maps+0x150) [0x4bb550] ./perf(machine__new_host+0xfa) [0x4bb75a] ./perf(init_probe_symbol_maps+0x93) [0x506623] ./perf() [0x455ffa] ./perf(cmd_probe+0x6c) [0x4566bc] ./perf() [0x47abc5] ./perf(main+0x610) [0x421f90] /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f1345a8eaf5] ./perf() [0x4220a9] This map_groups__insert(0x4b8b91) already gets a reference to the new dso: ---- eu-addr2line -e ./perf -f 0x4b8b91 map_groups__insert inlined at util/machine.c:586 in machine__create_module util/map.h:207 ---- So this dso refcnt will be released when map_groups gets released. [snip] Refcount +1 => 2 at ./perf(dso__get+0x34) [0x4a65f4] ./perf() [0x4b8b35] ./perf(modules__parse+0xfc) [0x4a9d5c] ./perf() [0x4b8460] ./perf(machine__create_kernel_maps+0x150) [0x4bb550] ./perf(machine__new_host+0xfa) [0x4bb75a] ./perf(init_probe_symbol_maps+0x93) [0x506623] ./perf() [0x455ffa] ./perf(cmd_probe+0x6c) [0x4566bc] ./perf() [0x47abc5] ./perf(main+0x610) [0x421f90] /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f1345a8eaf5] ./perf() [0x4220a9] Here, machine__findnew_module_dso(0x4b8b35) gets the dso (and stores it in a local variable): ---- # eu-addr2line -e ./perf -f 0x4b8b35 machine__findnew_module_dso inlined at util/machine.c:578 in machine__create_module util/machine.c:514 ---- Refcount +1 => 3 at ./perf(dso__get+0x34) [0x4a65f4] ./perf(map__new2+0x76) [0x4be1c6] ./perf() [0x4b8b4f] ./perf(modules__parse+0xfc) [0x4a9d5c] ./perf() [0x4b8460] ./perf(machine__create_kernel_maps+0x150) [0x4bb550] ./perf(machine__new_host+0xfa) [0x4bb75a] ./perf(init_probe_symbol_maps+0x93) [0x506623] ./perf() [0x455ffa] ./perf(cmd_probe+0x6c) [0x4566bc] ./perf() [0x47abc5] ./perf(main+0x610) [0x421f90] /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f1345a8eaf5] ./perf() [0x4220a9] But also map__new2() gets the dso which will be put when the map is released. So, we have to drop the constructor reference obtained in machine__findnew_module_dso(). Signed-off-by: Masami Hiramatsu Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20151118064035.30709.58824.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix machine__create_kernel_maps to put kernel dso refcount

2015-11-19T16:19:21Z

Fix machine__create_kernel_maps() to put kernel dso because the dso has been gotten via __machine__create_kernel_maps(). Refcnt debugger shows: ==== [0] ==== Unreclaimed dso: 0x3036ab0 Refcount +1 => 1 at ./perf(dso__new+0x1ff) [0x4a62df] ./perf(__dsos__addnew+0x29) [0x4a6e19] ./perf(dsos__findnew+0xd1) [0x4a7181] ./perf(machine__findnew_kernel+0x27) [0x4a5e17] ./perf() [0x4b8cf2] ./perf(machine__create_kernel_maps+0x28) [0x4bb428] ./perf(machine__new_host+0xfa) [0x4bb74a] ./perf(init_probe_symbol_maps+0x93) [0x506613] ./perf() [0x455ffa] ./perf(cmd_probe+0x6c) [0x4566bc] ./perf() [0x47abc5] ./perf(main+0x610) [0x421f90] /lib64/libc.so.6(__libc_start_main+0xf5) [0x7ffa6809eaf5] ./perf() [0x4220a9] [snip] Refcount +1 => 2 at ./perf(dsos__findnew+0x7e) [0x4a712e] ./perf(machine__findnew_kernel+0x27) [0x4a5e17] ./perf() [0x4b8cf2] ./perf(machine__create_kernel_maps+0x28) [0x4bb428] ./perf(machine__new_host+0xfa) [0x4bb74a] ./perf(init_probe_symbol_maps+0x93) [0x506613] ./perf() [0x455ffa] ./perf(cmd_probe+0x6c) [0x4566bc] ./perf() [0x47abc5] ./perf(main+0x610) [0x421f90] /lib64/libc.so.6(__libc_start_main+0xf5) [0x7ffa6809eaf5] ./perf() [0x4220a9] [snip] Refcount -1 => 1 at ./perf(dso__put+0x2f) [0x4a664f] ./perf(machine__delete+0xfe) [0x4b93ee] ./perf(exit_probe_symbol_maps+0x28) [0x5066b8] ./perf() [0x45628a] ./perf(cmd_probe+0x6c) [0x4566bc] ./perf() [0x47abc5] ./perf(main+0x610) [0x421f90] /lib64/libc.so.6(__libc_start_main+0xf5) [0x7ffa6809eaf5] ./perf() [0x4220a9] Actually, dsos__findnew gets the dso before returning it, so the dso user (in this case machine__create_kernel_maps) has to put the dso after used. Signed-off-by: Masami Hiramatsu Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20151118064033.30709.98954.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Fix to destroy kernel maps when machine exits

2015-11-19T16:19:19Z

Actually machine__exit forgot to call machine__destroy_kernel_maps. This fixes some memory leaks on map as below. Without this fix. ---- ./perf probe vfs_read Added new event: probe:vfs_read (on vfs_read) You can now use it in all perf tools, such as: perf record -e probe:vfs_read -aR sleep 1 REFCNT: BUG: Unreclaimed objects found. REFCNT: Total 4 objects are not reclaimed. To see all backtraces, rerun with -v option ---- With this fix. ---- ./perf probe vfs_read Added new event: probe:vfs_read (on vfs_read) You can now use it in all perf tools, such as: perf record -e probe:vfs_read -aR sleep 1 REFCNT: BUG: Unreclaimed objects found. REFCNT: Total 2 objects are not reclaimed. To see all backtraces, rerun with -v option ---- Signed-off-by: Masami Hiramatsu Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20151118064024.30709.43577.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Fix machine__destroy_kernel_maps to drop vmlinux_maps references

2015-11-19T16:19:18Z

Fix machine__destroy_kernel_maps() to drop vmlinux_maps references before filling it with NULL. Refcnt debugger shows ==== [1] ==== Unreclaimed map: 0x36b1070 Refcount +1 => 1 at ./perf(map__new2+0xb5) [0x4bdec5] ./perf(machine__create_kernel_maps+0x72) [0x4bb152] ./perf(machine__new_host+0xfa) [0x4bb41a] ./perf(init_probe_symbol_maps+0x93) [0x5062d3] ./perf() [0x455ffa] ./perf(cmd_probe+0x6c) [0x4566bc] ./perf() [0x47abc5] ./perf(main+0x610) [0x421f90] /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f1fc9fc4af5] ./perf() [0x4220a9] Refcount +1 => 2 at ./perf(maps__insert+0x9a) [0x4bfd6a] ./perf(machine__create_kernel_maps+0xc3) [0x4bb1a3] ./perf(machine__new_host+0xfa) [0x4bb41a] ./perf(init_probe_symbol_maps+0x93) [0x5062d3] ./perf() [0x455ffa] ./perf(cmd_probe+0x6c) [0x4566bc] ./perf() [0x47abc5] ./perf(main+0x610) [0x421f90] /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f1fc9fc4af5] ./perf() [0x4220a9] Refcount -1 => 1 at ./perf(map_groups__exit+0x94) [0x4bea74] ./perf(machine__delete+0x3d) [0x4b91fd] ./perf(exit_probe_symbol_maps+0x28) [0x506378] ./perf() [0x45628a] ./perf(cmd_probe+0x6c) [0x4566bc] ./perf() [0x47abc5] ./perf(main+0x610) [0x421f90] /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f1fc9fc4af5] ./perf() [0x4220a9] map__new2() returns map with refcnt = 1, and also map_groups__insert gets it again in__machine__create_kernel_maps(). machine__destroy_kernel_maps() calls map_groups__remove() to decrement the refcnt, but before decrement it again (corresponding to map__new2), it makes vmlinux_maps[type] = NULL. And this may cause a refcnt leak. Signed-off-by: Masami Hiramatsu Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20151118064022.30709.3897.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo