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2016-05-10perf probe: Check the return value of strbuf APIsMasami Hiramatsu1-28/+24
Check the return value of strbuf APIs in perf-probe related code, so that it can handle errors in strbuf. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20160510054707.6158.69861.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-06perf probe: Check if dwarf_getlocations() is availableArnaldo Carvalho de Melo1-0/+9
If not, tell the user that: config/Makefile:273: Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157 And return -ENOTSUPP in die_get_var_range(), failing features that need it, like the one pointed out above. This fixes the build on older systems, such as Ubuntu 12.04.5. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Vinson Lee <vlee@freedesktop.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-9l7luqkq4gfnx7vrklkq4obs@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-23perf probe: No need to use formatting strbuf methodArnaldo Carvalho de Melo1-5/+5
We have addch() for chars, add() for fixed size data, and addstr() for variable length strings, use them. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-0ap02fn2xtvpduj2j6b2o1j4@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-13perf probe: Fix to add missed brace around if blockMasami Hiramatsu1-1/+2
The commit 75186a9b09e4 (perf probe: Fix to show lines of sys_ functions correctly) introduced a bug by a missed brace around if block. This fixes to add it. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Fixes: 75186a9b09e4 ("perf probe: Fix to show lines of sys_ functions correctly") Link: http://lkml.kernel.org/r/20150812215541.9088.62425.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-12perf probe: Fix to show lines of sys_ functions correctlyMasami Hiramatsu1-5/+13
"perf probe --lines sys_poll" shows only the first line of sys_poll, because the SYSCALL_DEFINE macro: ---- SYSCALL_DEFINE*(foo,...) { body; } ---- is expanded as below (on debuginfo) ---- static inline int SYSC_foo(...) { body; } int SyS_foo(...) <- is an alias of sys_foo. { return SYSC_foo(...); } ---- So, "perf probe --lines sys_foo" decodes SyS_foo function and it also skips inlined functions(SYSC_foo) inside the target function because those functions are usually defined somewhere else. To fix this issue, this fix checks whether the inlined function is defined at the same point of the target function, and if so, it doesn't skip the inline function. Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20150812012406.11811.94691.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-05-15perf tools: Fix dwarf-aux.c compilation on i386Jiri Olsa1-4/+4
Replacing %lu format strings for Dwarf_Addr type with PRIu64 as it fits for Dwarf_Addr (defined as uint64_t) type and works also on both 32/64 bits. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1431706991-15646-1-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-05-14perf probe: Ignore tail calls to probed functionsNaveen N. Rao1-0/+37
perf probe currently errors out if there are any tail calls to probed functions: [root@rhel71be]# perf probe do_fork Failed to find probe point in any functions. Error: Failed to add events. Fix this by teaching perf to ignore tail calls. Without patch: [root@rhel71be perf]# ./perf probe -v do_fork probe-definition(0): do_fork symbol:do_fork file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Looking at the vmlinux_path (7 entries long) symsrc__init: build id mismatch for /boot/vmlinux. Using /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux for symbols Open Debuginfo file: /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux Try to find probe point from debuginfo. found inline addr: 0xc0000000000bb9b0 Probe point found: do_fork+0 found inline addr: 0xc0000000000bbe20 Probe point found: kernel_thread+48 found inline addr: 0xc0000000000bbe5c Probe point found: sys_fork+28 found inline addr: 0xc0000000000bbfac Probe point found: sys_vfork+44 found inline addr: 0xc0000000000bc27c Failed to find probe point in any functions. An error occurred in debuginfo analysis (-2). Error: Failed to add events. Reason: No such file or directory (Code: -2) With patch: [root@rhel71be perf]# ./perf probe -v do_fork probe-definition(0): do_fork symbol:do_fork file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Looking at the vmlinux_path (7 entries long) symsrc__init: build id mismatch for /boot/vmlinux. Using /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux for symbols Open Debuginfo file: /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux Try to find probe point from debuginfo. found inline addr: 0xc0000000000bb9b0 Probe point found: do_fork+0 found inline addr: 0xc0000000000bbe20 Probe point found: kernel_thread+48 found inline addr: 0xc0000000000bbe5c Probe point found: sys_fork+28 found inline addr: 0xc0000000000bbfac Probe point found: sys_vfork+44 found inline addr: 0xc0000000000bc27c Ignoring tail call from SyS_clone Found 4 probe_trace_events. Opening /sys/kernel/debug/tracing/kprobe_events write=1 No kprobe blacklist support, ignored Added new events: Writing event: p:probe/do_fork _text+768432 Failed to write event: Invalid argument Error: Failed to add events. Reason: Invalid argument (Code: -22) [Ignore the error about failure to write event - this kernel is missing a patch to resolve _text properly] The reason to ignore tail calls is that the address does not belong to any function frame. In the example above, the address in SyS_clone is 0xc0000000000bc27c, but looking at the debug-info: <1><830081>: Abbrev Number: 133 (DW_TAG_subprogram) <830083> DW_AT_external : 1 <830083> DW_AT_name : (indirect string, offset: 0x3cea3): SyS_clone <830087> DW_AT_decl_file : 7 <830088> DW_AT_decl_line : 1689 <83008a> DW_AT_prototyped : 1 <83008a> DW_AT_type : <0x8110eb> <83008e> DW_AT_low_pc : 0xc0000000000bc270 <830096> DW_AT_high_pc : 0xc <83009e> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa) <8300a0> DW_AT_GNU_all_call_sites: 1 <8300a0> DW_AT_sibling : <0x830178> <snip> <3><830147>: Abbrev Number: 125 (DW_TAG_GNU_call_site) <830148> DW_AT_low_pc : 0xc0000000000bc27c <830150> DW_AT_GNU_tail_call: 1 <830150> DW_AT_abstract_origin: <0x82e7e1> The frame ends at 0xc0000000000bc27c. I suppose this is why this particular call is a "tail" call. FWIW, systemtap seems to ignore these as well and requires users to explicitly place probes at these call sites if necessary. I print out the caller so that users know. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/1430394151-15928-1-git-send-email-naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-05-12perf probe: Add --range option to show a variable's location rangeHe Kuang1-0/+121
It is not easy for users to get the accurate byte offset or the line number where a local variable can be probed. With '--range' option, local variables in the scope of the probe point are showed with a byte offset range, and can be added according to this range information. For example, there are some variables in the function generic_perform_write(): <generic_perform_write@mm/filemap.c:0> 0 ssize_t generic_perform_write(struct file *file, 1 struct iov_iter *i, loff_t pos) 2 { 3 struct address_space *mapping = file->f_mapping; 4 const struct address_space_operations *a_ops = mapping->a_ops; ... 42 status = a_ops->write_begin(file, mapping, pos, bytes, flags, &page, &fsdata); 44 if (unlikely(status < 0)) But we fail when we try to probe the variable 'a_ops' at line 42 or 44. $ perf probe --add 'generic_perform_write:42 a_ops' Failed to find the location of a_ops at this address. Perhaps, it has been optimized out. This is because the source code do not match the assembly, so a variable may not be available in the source code line where it appears. After this patch, we can lookup the accurate byte offset range of a variable, 'INV' indicates that this variable is not valid at the given point, but available in the scope: $ perf probe --vars 'generic_perform_write:42' --range Available variables at generic_perform_write:42 @<generic_perform_write+141> [INV] ssize_t written @<generic_perform_write+[324-331]> [INV] struct address_space_operations* a_ops @<generic_perform_write+[55-61,170-176,223-246]> [VAL] (unknown_type) fsdata @<generic_perform_write+[70-307,346-411]> [VAL] loff_t pos @<generic_perform_write+[0-286,286-336,346-411]> [VAL] long int status @<generic_perform_write+[83-342,346-411]> [VAL] long unsigned int bytes @<generic_perform_write+[122-311,320-338,346-403,403-411]> [VAL] struct address_space* mapping @<generic_perform_write+[35-344,346-411]> [VAL] struct iov_iter* i @<generic_perform_write+[0-340,346-411]> [VAL] struct page* page @<generic_perform_write+[70-307,346-411]> Then it is more clear for us to add a probe with this variable: $ perf probe --add 'generic_perform_write+170 a_ops' Added new event: probe:generic_perform_write (on generic_perform_write+170 with a_ops) Signed-off-by: He Kuang <hekuang@huawei.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1431336304-16863-2-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-05-12perf probe: Remove length limitation for showing available variablesHe Kuang1-28/+22
Use struct strbuf instead of bare char[] to remove the length limitation of variables in variable_list, so they will not disappear due to overlength, and make preparation for adding more description for variables. Signed-off-by: He Kuang <hekuang@huawei.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1431336304-16863-1-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-05-08perf probe: Support glob wildcards for function nameMasami Hiramatsu1-0/+16
Support glob wildcards for function name when adding new probes. This will allow us to build caches of function-entry level information with $params. e.g. ---- # perf probe --no-inlines --add 'kmalloc* $params' Added new events: probe:kmalloc_slab (on kmalloc* with $params) probe:kmalloc_large_node (on kmalloc* with $params) probe:kmalloc_order_trace (on kmalloc* with $params) You can now use it in all perf tools, such as: perf record -e probe:kmalloc_order_trace -aR sleep 1 # perf probe --list probe:kmalloc_large_node (on kmalloc_large_node@mm/slub.c with size flags node) probe:kmalloc_order_trace (on kmalloc_order_trace@mm/slub.c with size flags order) probe:kmalloc_slab (on kmalloc_slab@mm/slab_common.c with size flags) ---- Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20150508010335.24812.19972.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-04-02perf probe: Fix to track down unnamed union/structure membersMasami Hiramatsu1-4/+10
Fix 'perf probe' to track down unnamed union/structure members. perf probe did not track down the tree of unnamed union/structure members, since it just failed to find given "name" in a parent structure/union. To solve this issue, I've introduced 2 changes. - Fix die_find_member() to track down the type-DIE if it is unnamed, and if it contains the specified member, returns the unnamed member. (note that we don't return found member, since unnamed member has the offset in the parent structure) - Fix convert_variable_fields() to track down the unnamed union/ structure (one-by-one). With this patch, perf probe can access unnamed fields: ----- #./perf probe -nfx ./perf lock__delete ops 'locked_ops=ops->locked.ops' Added new event: probe_perf:lock__delete (on lock__delete in /home/mhiramat/ksrc/linux-3/tools/perf/perf with ops locked_ops=ops->locked.ops) You can now use it in all perf tools, such as: perf record -e probe_perf:lock__delete -aR sleep 1 ----- Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Report-Link: https://lkml.org/lkml/2015/3/5/431 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20150402073312.14482.37942.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-02-06perf probe: Fix to handle optimized not-inlined functionsMasami Hiramatsu1-0/+15
Fix to handle optimized no-inline functions which have only function definition but no actual instance at that point. To fix this problem, we need to find actual instance of the function. Without this patch: ---- # perf probe -a __up Failed to get entry address of __up. Error: Failed to add events. # perf probe -L __up Specified source line is not found. Error: Failed to show lines. ---- With this patch: ---- # perf probe -a __up Added new event: probe:__up (on __up) You can now use it in all perf tools, such as: perf record -e probe:__up -aR sleep 1 # perf probe -L __up <__up@/home/fedora/ksrc/linux-3/kernel/locking/semaphore.c:0> 0 static noinline void __sched __up(struct semaphore *sem) { struct semaphore_waiter *waiter = list_first_entry(&sem->wait_ struct semaphore_waite 4 list_del(&waiter->list); 5 waiter->up = true; 6 wake_up_process(waiter->task); 7 } ---- Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20150130093744.30575.43290.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-06-04perf probe: Fix perf probe to find correct variable DIEMasami Hiramatsu1-2/+5
Fix perf probe to find correct variable DIE which has location or external instance by tracking down the lexical blocks. Current die_find_variable() expects that the all variable DIEs which has DW_TAG_variable have a location. However, since recent dwarf information may have declaration variable DIEs at the entry of function (subprogram), die_find_variable() returns it. To solve this problem, it must track down the DIE tree to find a DIE which has an actual location or a reference for external instance. e.g. finding a DIE which origin is <0xdc73>; <1><11496>: Abbrev Number: 95 (DW_TAG_subprogram) <11497> DW_AT_abstract_origin: <0xdc42> <1149b> DW_AT_low_pc : 0x1850 [...] <2><114cc>: Abbrev Number: 119 (DW_TAG_variable) <- this is a declaration <114cd> DW_AT_abstract_origin: <0xdc73> <2><114d1>: Abbrev Number: 119 (DW_TAG_variable) [...] <3><115a7>: Abbrev Number: 105 (DW_TAG_lexical_block) <115a8> DW_AT_ranges : 0xaa0 <4><115ac>: Abbrev Number: 96 (DW_TAG_variable) <- this has a location <115ad> DW_AT_abstract_origin: <0xdc73> <115b1> DW_AT_location : 0x486c (location list) Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org> Acked-by: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20140529121930.30879.87092.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Jiri Olsa <jolsa@kernel.org>
2013-10-04perf probe: Fix to find line information for probe listMasami Hiramatsu1-4/+21
Fix to find the correct (as much as possible) line information for listing probes. Without this fix, perf probe --list action will show incorrect line information as below; probe:getname_flags (on getname_flags@ksrc/linux-3/fs/namei.c) probe:getname_flags_1 (on getname:-89@x86/include/asm/current.h) probe:getname_flags_2 (on user_path_at_empty:-2054@x86/include/asm/current.h) The minus line number is obviously wrong, and current.h is not related to the probe point. Deeper investigation discovered that there were 2 issues related to this bug, and minor typos too. The 1st issue is the rack of considering about nested inlined functions, which causes the wrong (relative) line number. The 2nd issue is that the dwarf line info is not correct at those points. It points 14th line of current.h. Since it seems that the line info includes somewhat unreliable information, this fixes perf to try to find correct line information from both of debuginfo and line info as below. 1) Probe address is the entry of a function instance In this case, the line is set as the function declared line. 2) Probe address is the entry of an expanded inline function block In this case, the line is set as the function call-site line. This means that the line number is relative from the entry line of caller function (which can be an inlined function if nested) 3) Probe address is inside a function instance or an expanded inline function block In this case, perf probe queries the line number from lineinfo and verify the function declared file is same as the file name queried from lineinfo. If the file name is different, it is a failure case. The probe address is shown as symbol+offset. 4) Probe address is not in the any function instance This is a failure case, the probe address is shown as symbol+offset. With this fix, perf probe -l shows correct probe lines as below; probe:getname_flags (on getname_flags@ksrc/linux-3/fs/namei.c) probe:getname_flags_1 (on getname:2@ksrc/linux-3/fs/namei.c) probe:getname_flags_2 (on user_path_at_empty:4@ksrc/linux-3/fs/namei.c) Changes at v2: - Fix typos in the function comments. (Thanks to Namhyung Kim) - Use die_find_top_inlinefunc instead of die_find_inlinefunc_next. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20130930092144.1693.11058.stgit@udc4-manage.rcp.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-09-19perf probe: Fix finder to find lines of given functionMasami Hiramatsu1-0/+19
The commit ba28c59bc9ed8fb7b9a753cd88ee54a2c4f6265b fixed a declaration entry bug in probe_point_search_cb(). There are same bugs in line finder and call_probe_finder(). This introduces a new dwarf utility function to determine given DIE is a function definition, not declaration. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20120423032435.8737.80064.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-09-27perf probe: Print an enum type variable in "enum variable-name" format when showing accessible variablesHyeoncheol Lee1-0/+2
When showing accessible variables, an enum type variable was printed in "variable-name" format. Change this format into "enum variable-name". Signed-off-by: Hyeoncheol Lee <hyc.lee@gmail.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/1348713399-4541-1-git-send-email-hyc.lee@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12perf probe: Filter out redundant inline-instancesMasami Hiramatsu1-0/+22
With gcc4.6, some instances of concrete inlined function looks redundant and broken, because it appears inside of a concrete instance and its call_file and call_line are same as the original abstruct's decl_file and decl_line respectively. e.g. [ d1aa] subprogram external (flag) Yes name (strp) "add_timer" decl_file (data1) 2 ;here is original decl_line (data2) 847 ;line and file prototyped (flag) Yes inline (data1) inlined (1) sibling (ref4) [ d1c6] ... [ 11d84] subprogram abstract_origin (ref4) [ d1aa] ; concrete instance low_pc (addr) .text+0x000000000000246f <add_timer> high_pc (addr) .text+0x000000000000248b <mod_timer_pending> frame_base (block1) [ 0] call_frame_cfa sibling (ref4) [ 11dd9] [ 11d9f] formal_parameter abstract_origin (ref4) [ d1b9] location (data4) location list [ 701b] [ 11da8] inlined_subroutine abstract_origin (ref4) [ d1aa] ; redundant instance low_pc (addr) .text+0x000000000000247e <add_timer+0xf> high_pc (addr) .text+0x0000000000002480 <add_timer+0x11> call_file (data1) 2 ; call line and file call_line (data2) 847 ; are same as above Those redundant instances leads unwilling results; e.g. find probe points inside of functions even if we specify a function entry as below; $ perf probe -V add_timer Available variables at add_timer @<add_timer+0> struct timer_list* timer @<add_timer+15> (No matched variables) So, this filters out those redundant instances based on call-site and decl-site information. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110317.19900.59525.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12perf probe: Search concrete out-of-line instancesMasami Hiramatsu1-0/+58
gcc 4.6 generates a concrete out-of-line instance when there is a function which is implicitly inlined somewhere but also has its own instance. The concrete out-of-line instance means that it has an abstract origin of the function which is referred by not only inlined-subroutines but also a concrete subprogram. Since current dwarf_func_inline_instances() can find only instances of inlined-subroutines, this introduces new die_walk_instances() to find both of subprogram and inlined-subroutines. e.g. without this, Available variables at sched_group_rt_period @<cpu_rt_period_read_uint+9> struct task_group* tg perf probe failed to find actual subprogram instance of sched_group_rt_period(). With this, Available variables at sched_group_rt_period @<cpu_rt_period_read_uint+9> struct task_group* tg @<sched_group_rt_period+0> struct task_group* tg Now it found the sched_group_rt_period() itself. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110311.19900.63997.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12perf probe: Fix to search local variables in appropriate scopeMasami Hiramatsu1-0/+33
Fix perf probe to search local variables in appropriate local inlined function scope. For example, pre_schedule() has only 2 local variables, as below; $ perf probe -L pre_schedule <pre_schedule@/home/mhiramat/ksrc/linux-2.6/kernel/sched.c:0> 0 static inline void pre_schedule(struct rq *rq, struct task_struct *prev) { 2 if (prev->sched_class->pre_schedule) 3 prev->sched_class->pre_schedule(rq, prev); } However, current perf probe shows 4 local variables on pre_schedule(), because it searches variables in the caller(schedule()) scope. $ perf probe -V pre_schedule Available variables at pre_schedule @<schedule+445> int cpu long unsigned int* switch_count struct rq* rq struct task_struct* prev This patch fixes this issue by searching variables in the local scope of the instance of inlined function. Here is the result. $ perf probe -V pre_schedule Available variables at pre_schedule @<schedule+445> struct rq* rq struct task_struct* prev Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110259.19900.85664.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12perf probe: Fix to search nested inlined functions in CUMasami Hiramatsu1-12/+79
Fix perf probe to walk through the lines of all nested inlined function call sites and declared lines when a whole CU is passed to the line walker. The die_walk_lines() can have two different type of DIEs, subprogram (or inlined-subroutine) DIE and CU DIE. If a caller passes a subprogram DIE, this means that the walker walk on lines of given subprogram. In this case, it just needs to search on direct children of DIE tree for finding call-site information of inlined function which directly called from given subprogram. On the other hand, if a caller passes a CU DIE to the walker, this means that the walker have to walk on all lines in the source files included in given CU DIE. In this case, it has to search whole DIE trees of all subprograms to find the call-site information of all nested inlined functions. Without this patch: $ perf probe --line kernel/cpu.c:151-157 </home/mhiramat/ksrc/linux-2.6/kernel/cpu.c:151> static int cpu_notify(unsigned long val, void *v) { 154 return __cpu_notify(val, v, -1, NULL); } With this: $ perf probe --line kernel/cpu.c:151-157 </home/mhiramat/ksrc/linux-2.6/kernel/cpu.c:151> 152 static int cpu_notify(unsigned long val, void *v) { 154 return __cpu_notify(val, v, -1, NULL); } As you can see, --line option with source line range shows the declared lines as probe-able. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110241.19900.34994.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12perf probe: Fix line walker to check CU correctlyMasami Hiramatsu1-3/+3
Fix line walker to check whether a given DIE is CU or not. Actually this function accepts CU, subprogram and inlined_subroutine DIEs. Without this fix, perf probe always fails to analyze lines on inlined functions; $ perf probe -L pre_schedule Debuginfo analysis failed. (-2) Error: Failed to show lines. (-2) This fixes that bug, as below. $ perf probe -L pre_schedule <pre_schedule@/home/mhiramat/ksrc/linux-2.6/kernel/sched.c:0> 0 static inline void pre_schedule(struct rq *rq, struct task_struct *prev { 2 if (prev->sched_class->pre_schedule) 3 prev->sched_class->pre_schedule(rq, prev); } /* rq->lock is NOT held, but preemption is disabled */ Changes from v1: - Update against current tip tree.(Fix dwarf-aux.c) Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20110811110235.19900.20614.stgit@fedora15 Signed-off-by: Masami Hiramatsu <masami.hiramatsu@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-07-15perf-probe: Move dwarf library routines to dwarf-aux.{c, h}Masami Hiramatsu1-0/+663
Move dwarf library related routines to dwarf-aux.{c,h}. This includes several minor changes. - Add simple documents for each API. - Rename die_find_real_subprogram() to die_find_realfunc() - Rename line_walk_handler_t to line_walk_callback_t. - Minor cleanups. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Link: http://lkml.kernel.org/r/20110627072727.6528.57647.stgit@fedora15 Signed-off-by: Steven Rostedt <rostedt@goodmis.org>