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linux-next/tools/perf/util/probe-finder.h

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perf: Add perf probe subcommand, a kprobe-event setup helper Add perf probe subcommand that implements a kprobe-event setup helper to the perf command. This allows user to define kprobe events using C expressions (C line numbers, C function names, and C local variables). Usage ----- perf probe [<options>] -P 'PROBEDEF' [-P 'PROBEDEF' ...] -k, --vmlinux <file> vmlinux/module pathname -P, --probe <p|r:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]> probe point definition, where p: kprobe probe r: kretprobe probe GRP: Group name (optional) NAME: Event name FUNC: Function name OFFS: Offset from function entry (in byte) SRC: Source code path LINE: Line number ARG: Probe argument (local variable name or kprobe-tracer argument format is supported.) Changes in v4: - Add _GNU_SOURCE macro for strndup(). Changes in v3: - Remove -r option because perf always be used for online kernel. - Check malloc/calloc results. Changes in v2: - Check synthesized string length. - Rename perf kprobe to perf probe. - Use spaces for separator and update usage comment. - Check error paths in parse_probepoint(). - Check optimized-out variables. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Frank Ch. Eigler <fche@redhat.com> LKML-Reference: <20091008211737.29299.14784.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-10-09 05:17:38 +08:00
#ifndef _PROBE_FINDER_H
#define _PROBE_FINDER_H
#include <stdbool.h>
#include "util.h"
#include "probe-event.h"
#define MAX_PROBE_BUFFER 1024
#define MAX_PROBES 128
#define MAX_PROBE_ARGS 128
perf: Add perf probe subcommand, a kprobe-event setup helper Add perf probe subcommand that implements a kprobe-event setup helper to the perf command. This allows user to define kprobe events using C expressions (C line numbers, C function names, and C local variables). Usage ----- perf probe [<options>] -P 'PROBEDEF' [-P 'PROBEDEF' ...] -k, --vmlinux <file> vmlinux/module pathname -P, --probe <p|r:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]> probe point definition, where p: kprobe probe r: kretprobe probe GRP: Group name (optional) NAME: Event name FUNC: Function name OFFS: Offset from function entry (in byte) SRC: Source code path LINE: Line number ARG: Probe argument (local variable name or kprobe-tracer argument format is supported.) Changes in v4: - Add _GNU_SOURCE macro for strndup(). Changes in v3: - Remove -r option because perf always be used for online kernel. - Check malloc/calloc results. Changes in v2: - Check synthesized string length. - Rename perf kprobe to perf probe. - Use spaces for separator and update usage comment. - Check error paths in parse_probepoint(). - Check optimized-out variables. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Frank Ch. Eigler <fche@redhat.com> LKML-Reference: <20091008211737.29299.14784.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-10-09 05:17:38 +08:00
static inline int is_c_varname(const char *name)
{
/* TODO */
return isalpha(name[0]) || name[0] == '_';
}
#ifdef HAVE_DWARF_SUPPORT
#include "dwarf-aux.h"
/* TODO: export debuginfo data structure even if no dwarf support */
/* debug information structure */
struct debuginfo {
Dwarf *dbg;
perf probe: Fix probing symbols with optimization suffix Fix perf probe to probe on some symbols which have some optimzation suffixes, e.g. ".part", ".isra", and ".constprop". To fix this issue, instead of using the DIE name, perf probe uses the symbol name found by dwfl_module_addrsym(). This also involves a perf probe --vars operation update which now shows the symbol name instead of the DIE name. Without this patch, putting a probe on an inlined function which was compiled with a suffixed symbol will fail like this: $ perf probe -v getname_flags probe-definition(0): getname_flags symbol:getname_flags file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Looking at the vmlinux_path (6 entries long) Using /lib/modules/3.11.0+/build/vmlinux for symbols found inline addr: 0xffffffff8119bb70 Probe point found: getname_flags+0 found inline addr: 0xffffffff8119bcb6 Probe point found: getname+6 found inline addr: 0xffffffff811a06a6 Probe point found: user_path_at_empty+6 find 3 probe_trace_events. Opening /sys/kernel/debug//tracing/kprobe_events write=1 Added new events: Writing event: p:probe/getname_flags getname_flags+0 Failed to write event: No such file or directory Error: Failed to add events. (-1) Because the debuginfo knows only the original (non suffix) symbol name, it uses the original symbol for probe address but the kernel (kallsyms) knows only suffixed symbol. Then, the kernel rejects that original symbol. This patch uses dwfl_module_addrsym() to get the correct (suffixed) symbol from symtab when a probe point is found. Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20130925131616.31632.46658.stgit@udc4-manage.rcp.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-09-25 21:16:16 +08:00
Dwfl_Module *mod;
Dwfl *dwfl;
Dwarf_Addr bias;
};
extern struct debuginfo *debuginfo__new(const char *path);
extern struct debuginfo *debuginfo__new_online_kernel(unsigned long addr);
extern void debuginfo__delete(struct debuginfo *self);
/* Find probe_trace_events specified by perf_probe_event from debuginfo */
extern int debuginfo__find_trace_events(struct debuginfo *self,
struct perf_probe_event *pev,
struct probe_trace_event **tevs,
int max_tevs);
/* Find a perf_probe_point from debuginfo */
extern int debuginfo__find_probe_point(struct debuginfo *self,
unsigned long addr,
struct perf_probe_point *ppt);
/* Find a line range */
extern int debuginfo__find_line_range(struct debuginfo *self,
struct line_range *lr);
perf: Add perf probe subcommand, a kprobe-event setup helper Add perf probe subcommand that implements a kprobe-event setup helper to the perf command. This allows user to define kprobe events using C expressions (C line numbers, C function names, and C local variables). Usage ----- perf probe [<options>] -P 'PROBEDEF' [-P 'PROBEDEF' ...] -k, --vmlinux <file> vmlinux/module pathname -P, --probe <p|r:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]> probe point definition, where p: kprobe probe r: kretprobe probe GRP: Group name (optional) NAME: Event name FUNC: Function name OFFS: Offset from function entry (in byte) SRC: Source code path LINE: Line number ARG: Probe argument (local variable name or kprobe-tracer argument format is supported.) Changes in v4: - Add _GNU_SOURCE macro for strndup(). Changes in v3: - Remove -r option because perf always be used for online kernel. - Check malloc/calloc results. Changes in v2: - Check synthesized string length. - Rename perf kprobe to perf probe. - Use spaces for separator and update usage comment. - Check error paths in parse_probepoint(). - Check optimized-out variables. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Frank Ch. Eigler <fche@redhat.com> LKML-Reference: <20091008211737.29299.14784.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-10-09 05:17:38 +08:00
/* Find available variables */
extern int debuginfo__find_available_vars_at(struct debuginfo *self,
struct perf_probe_event *pev,
struct variable_list **vls,
int max_points, bool externs);
perf: Add perf probe subcommand, a kprobe-event setup helper Add perf probe subcommand that implements a kprobe-event setup helper to the perf command. This allows user to define kprobe events using C expressions (C line numbers, C function names, and C local variables). Usage ----- perf probe [<options>] -P 'PROBEDEF' [-P 'PROBEDEF' ...] -k, --vmlinux <file> vmlinux/module pathname -P, --probe <p|r:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]> probe point definition, where p: kprobe probe r: kretprobe probe GRP: Group name (optional) NAME: Event name FUNC: Function name OFFS: Offset from function entry (in byte) SRC: Source code path LINE: Line number ARG: Probe argument (local variable name or kprobe-tracer argument format is supported.) Changes in v4: - Add _GNU_SOURCE macro for strndup(). Changes in v3: - Remove -r option because perf always be used for online kernel. - Check malloc/calloc results. Changes in v2: - Check synthesized string length. - Rename perf kprobe to perf probe. - Use spaces for separator and update usage comment. - Check error paths in parse_probepoint(). - Check optimized-out variables. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Frank Ch. Eigler <fche@redhat.com> LKML-Reference: <20091008211737.29299.14784.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-10-09 05:17:38 +08:00
struct probe_finder {
struct perf_probe_event *pev; /* Target probe event */
/* Callback when a probe point is found */
int (*callback)(Dwarf_Die *sc_die, struct probe_finder *pf);
perf: Add perf probe subcommand, a kprobe-event setup helper Add perf probe subcommand that implements a kprobe-event setup helper to the perf command. This allows user to define kprobe events using C expressions (C line numbers, C function names, and C local variables). Usage ----- perf probe [<options>] -P 'PROBEDEF' [-P 'PROBEDEF' ...] -k, --vmlinux <file> vmlinux/module pathname -P, --probe <p|r:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]> probe point definition, where p: kprobe probe r: kretprobe probe GRP: Group name (optional) NAME: Event name FUNC: Function name OFFS: Offset from function entry (in byte) SRC: Source code path LINE: Line number ARG: Probe argument (local variable name or kprobe-tracer argument format is supported.) Changes in v4: - Add _GNU_SOURCE macro for strndup(). Changes in v3: - Remove -r option because perf always be used for online kernel. - Check malloc/calloc results. Changes in v2: - Check synthesized string length. - Rename perf kprobe to perf probe. - Use spaces for separator and update usage comment. - Check error paths in parse_probepoint(). - Check optimized-out variables. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Frank Ch. Eigler <fche@redhat.com> LKML-Reference: <20091008211737.29299.14784.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-10-09 05:17:38 +08:00
/* For function searching */
int lno; /* Line number */
Dwarf_Addr addr; /* Address */
const char *fname; /* Real file name */
Dwarf_Die cu_die; /* Current CU */
perf probe: Add fastpath to do lookup by function name v3 -> v2: - Make pubname_search_cb more generic - Add fastpath to find_probes also v2 -> v1: - Don't compare file names with cu_find_realpath(...), instead, compare them with the name returned by dwarf_decl_file(sp_die) The vmlinux file may have thousands of CUs. We can lookup function name from .debug_pubnames section to avoid the slow loop on CUs. 1. Improvement data for find_line_range ./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \ -s /home/mlin/linux-2.6 \ --line csum_partial_copy_to_user > tmp.log before patch applied ===================== 847,988,276 cycles 0.355075856 seconds time elapsed after patch applied ===================== 206,102,622 cycles 0.086883555 seconds time elapsed 2. Improvement data for find_probes ./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \ -s /home/mlin/linux-2.6 \ --vars csum_partial_copy_to_user > tmp.log before patch applied ===================== 848,490,844 cycles 0.355307901 seconds time elapsed after patch applied ===================== 205,684,469 cycles 0.086694010 seconds time elapsed Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: linux-kernel <linux-kernel@vger.kernel.org> LKML-Reference: <1301041668.14111.52.camel@minggr.sh.intel.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-03-25 16:27:48 +08:00
Dwarf_Die sp_die;
struct list_head lcache; /* Line cache for lazy match */
perf: Add perf probe subcommand, a kprobe-event setup helper Add perf probe subcommand that implements a kprobe-event setup helper to the perf command. This allows user to define kprobe events using C expressions (C line numbers, C function names, and C local variables). Usage ----- perf probe [<options>] -P 'PROBEDEF' [-P 'PROBEDEF' ...] -k, --vmlinux <file> vmlinux/module pathname -P, --probe <p|r:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]> probe point definition, where p: kprobe probe r: kretprobe probe GRP: Group name (optional) NAME: Event name FUNC: Function name OFFS: Offset from function entry (in byte) SRC: Source code path LINE: Line number ARG: Probe argument (local variable name or kprobe-tracer argument format is supported.) Changes in v4: - Add _GNU_SOURCE macro for strndup(). Changes in v3: - Remove -r option because perf always be used for online kernel. - Check malloc/calloc results. Changes in v2: - Check synthesized string length. - Rename perf kprobe to perf probe. - Use spaces for separator and update usage comment. - Check error paths in parse_probepoint(). - Check optimized-out variables. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Frank Ch. Eigler <fche@redhat.com> LKML-Reference: <20091008211737.29299.14784.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-10-09 05:17:38 +08:00
/* For variable searching */
#if _ELFUTILS_PREREQ(0, 142)
Dwarf_CFI *cfi; /* Call Frame Information */
#endif
Dwarf_Op *fb_ops; /* Frame base attribute */
struct perf_probe_arg *pvar; /* Current target variable */
struct probe_trace_arg *tvar; /* Current result variable */
perf: Add perf probe subcommand, a kprobe-event setup helper Add perf probe subcommand that implements a kprobe-event setup helper to the perf command. This allows user to define kprobe events using C expressions (C line numbers, C function names, and C local variables). Usage ----- perf probe [<options>] -P 'PROBEDEF' [-P 'PROBEDEF' ...] -k, --vmlinux <file> vmlinux/module pathname -P, --probe <p|r:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]> probe point definition, where p: kprobe probe r: kretprobe probe GRP: Group name (optional) NAME: Event name FUNC: Function name OFFS: Offset from function entry (in byte) SRC: Source code path LINE: Line number ARG: Probe argument (local variable name or kprobe-tracer argument format is supported.) Changes in v4: - Add _GNU_SOURCE macro for strndup(). Changes in v3: - Remove -r option because perf always be used for online kernel. - Check malloc/calloc results. Changes in v2: - Check synthesized string length. - Rename perf kprobe to perf probe. - Use spaces for separator and update usage comment. - Check error paths in parse_probepoint(). - Check optimized-out variables. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Frank Ch. Eigler <fche@redhat.com> LKML-Reference: <20091008211737.29299.14784.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-10-09 05:17:38 +08:00
};
perf probe: Support --line option to show probable source-code lines Add --line option to support showing probable source-code lines. perf probe --line SRC:LN[-LN|+NUM] or perf probe --line FUNC[:LN[-LN|+NUM]] This option shows source-code with line number if the line can be probed. Lines without line number (and blue color) means that the line can not be probed, because debuginfo doesn't have the information of those lines. The argument specifies the range of lines, "source.c:100-120" shows lines between 100th to l20th in source.c file. And "func:10+20" shows 20 lines from 10th line of func function. e.g. # ./perf probe --line kernel/sched.c:1080 <kernel/sched.c:1080> * * called with rq->lock held and irqs disabled */ static void hrtick_start(struct rq *rq, u64 delay) { struct hrtimer *timer = &rq->hrtick_timer; 1086 ktime_t time = ktime_add_ns(timer->base->get_time(), delay); hrtimer_set_expires(timer, time); 1090 if (rq == this_rq()) { 1091 hrtimer_restart(timer); 1092 } else if (!rq->hrtick_csd_pending) { 1093 __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 1094 rq->hrtick_csd_pending = 1; If you specifying function name, this shows function-relative line number. # ./perf probe --line schedule <schedule:0> asmlinkage void __sched schedule(void) 1 { struct task_struct *prev, *next; unsigned long *switch_count; struct rq *rq; int cpu; need_resched: preempt_disable(); 9 cpu = smp_processor_id(); 10 rq = cpu_rq(cpu); 11 rcu_sched_qs(cpu); 12 prev = rq->curr; 13 switch_count = &prev->nivcsw; Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20100106144534.27218.77939.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-06 22:45:34 +08:00
struct trace_event_finder {
struct probe_finder pf;
perf probe: Fix probing symbols with optimization suffix Fix perf probe to probe on some symbols which have some optimzation suffixes, e.g. ".part", ".isra", and ".constprop". To fix this issue, instead of using the DIE name, perf probe uses the symbol name found by dwfl_module_addrsym(). This also involves a perf probe --vars operation update which now shows the symbol name instead of the DIE name. Without this patch, putting a probe on an inlined function which was compiled with a suffixed symbol will fail like this: $ perf probe -v getname_flags probe-definition(0): getname_flags symbol:getname_flags file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Looking at the vmlinux_path (6 entries long) Using /lib/modules/3.11.0+/build/vmlinux for symbols found inline addr: 0xffffffff8119bb70 Probe point found: getname_flags+0 found inline addr: 0xffffffff8119bcb6 Probe point found: getname+6 found inline addr: 0xffffffff811a06a6 Probe point found: user_path_at_empty+6 find 3 probe_trace_events. Opening /sys/kernel/debug//tracing/kprobe_events write=1 Added new events: Writing event: p:probe/getname_flags getname_flags+0 Failed to write event: No such file or directory Error: Failed to add events. (-1) Because the debuginfo knows only the original (non suffix) symbol name, it uses the original symbol for probe address but the kernel (kallsyms) knows only suffixed symbol. Then, the kernel rejects that original symbol. This patch uses dwfl_module_addrsym() to get the correct (suffixed) symbol from symtab when a probe point is found. Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20130925131616.31632.46658.stgit@udc4-manage.rcp.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-09-25 21:16:16 +08:00
Dwfl_Module *mod; /* For solving symbols */
struct probe_trace_event *tevs; /* Found trace events */
int ntevs; /* Number of trace events */
int max_tevs; /* Max number of trace events */
};
struct available_var_finder {
struct probe_finder pf;
perf probe: Fix probing symbols with optimization suffix Fix perf probe to probe on some symbols which have some optimzation suffixes, e.g. ".part", ".isra", and ".constprop". To fix this issue, instead of using the DIE name, perf probe uses the symbol name found by dwfl_module_addrsym(). This also involves a perf probe --vars operation update which now shows the symbol name instead of the DIE name. Without this patch, putting a probe on an inlined function which was compiled with a suffixed symbol will fail like this: $ perf probe -v getname_flags probe-definition(0): getname_flags symbol:getname_flags file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Looking at the vmlinux_path (6 entries long) Using /lib/modules/3.11.0+/build/vmlinux for symbols found inline addr: 0xffffffff8119bb70 Probe point found: getname_flags+0 found inline addr: 0xffffffff8119bcb6 Probe point found: getname+6 found inline addr: 0xffffffff811a06a6 Probe point found: user_path_at_empty+6 find 3 probe_trace_events. Opening /sys/kernel/debug//tracing/kprobe_events write=1 Added new events: Writing event: p:probe/getname_flags getname_flags+0 Failed to write event: No such file or directory Error: Failed to add events. (-1) Because the debuginfo knows only the original (non suffix) symbol name, it uses the original symbol for probe address but the kernel (kallsyms) knows only suffixed symbol. Then, the kernel rejects that original symbol. This patch uses dwfl_module_addrsym() to get the correct (suffixed) symbol from symtab when a probe point is found. Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20130925131616.31632.46658.stgit@udc4-manage.rcp.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-09-25 21:16:16 +08:00
Dwfl_Module *mod; /* For solving symbols */
struct variable_list *vls; /* Found variable lists */
int nvls; /* Number of variable lists */
int max_vls; /* Max no. of variable lists */
bool externs; /* Find external vars too */
bool child; /* Search child scopes */
};
perf probe: Support --line option to show probable source-code lines Add --line option to support showing probable source-code lines. perf probe --line SRC:LN[-LN|+NUM] or perf probe --line FUNC[:LN[-LN|+NUM]] This option shows source-code with line number if the line can be probed. Lines without line number (and blue color) means that the line can not be probed, because debuginfo doesn't have the information of those lines. The argument specifies the range of lines, "source.c:100-120" shows lines between 100th to l20th in source.c file. And "func:10+20" shows 20 lines from 10th line of func function. e.g. # ./perf probe --line kernel/sched.c:1080 <kernel/sched.c:1080> * * called with rq->lock held and irqs disabled */ static void hrtick_start(struct rq *rq, u64 delay) { struct hrtimer *timer = &rq->hrtick_timer; 1086 ktime_t time = ktime_add_ns(timer->base->get_time(), delay); hrtimer_set_expires(timer, time); 1090 if (rq == this_rq()) { 1091 hrtimer_restart(timer); 1092 } else if (!rq->hrtick_csd_pending) { 1093 __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 1094 rq->hrtick_csd_pending = 1; If you specifying function name, this shows function-relative line number. # ./perf probe --line schedule <schedule:0> asmlinkage void __sched schedule(void) 1 { struct task_struct *prev, *next; unsigned long *switch_count; struct rq *rq; int cpu; need_resched: preempt_disable(); 9 cpu = smp_processor_id(); 10 rq = cpu_rq(cpu); 11 rcu_sched_qs(cpu); 12 prev = rq->curr; 13 switch_count = &prev->nivcsw; Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20100106144534.27218.77939.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-06 22:45:34 +08:00
struct line_finder {
struct line_range *lr; /* Target line range */
const char *fname; /* File name */
int lno_s; /* Start line number */
int lno_e; /* End line number */
Dwarf_Die cu_die; /* Current CU */
perf probe: Add fastpath to do lookup by function name v3 -> v2: - Make pubname_search_cb more generic - Add fastpath to find_probes also v2 -> v1: - Don't compare file names with cu_find_realpath(...), instead, compare them with the name returned by dwarf_decl_file(sp_die) The vmlinux file may have thousands of CUs. We can lookup function name from .debug_pubnames section to avoid the slow loop on CUs. 1. Improvement data for find_line_range ./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \ -s /home/mlin/linux-2.6 \ --line csum_partial_copy_to_user > tmp.log before patch applied ===================== 847,988,276 cycles 0.355075856 seconds time elapsed after patch applied ===================== 206,102,622 cycles 0.086883555 seconds time elapsed 2. Improvement data for find_probes ./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \ -s /home/mlin/linux-2.6 \ --vars csum_partial_copy_to_user > tmp.log before patch applied ===================== 848,490,844 cycles 0.355307901 seconds time elapsed after patch applied ===================== 205,684,469 cycles 0.086694010 seconds time elapsed Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: linux-kernel <linux-kernel@vger.kernel.org> LKML-Reference: <1301041668.14111.52.camel@minggr.sh.intel.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-03-25 16:27:48 +08:00
Dwarf_Die sp_die;
perf probe: Support --line option to show probable source-code lines Add --line option to support showing probable source-code lines. perf probe --line SRC:LN[-LN|+NUM] or perf probe --line FUNC[:LN[-LN|+NUM]] This option shows source-code with line number if the line can be probed. Lines without line number (and blue color) means that the line can not be probed, because debuginfo doesn't have the information of those lines. The argument specifies the range of lines, "source.c:100-120" shows lines between 100th to l20th in source.c file. And "func:10+20" shows 20 lines from 10th line of func function. e.g. # ./perf probe --line kernel/sched.c:1080 <kernel/sched.c:1080> * * called with rq->lock held and irqs disabled */ static void hrtick_start(struct rq *rq, u64 delay) { struct hrtimer *timer = &rq->hrtick_timer; 1086 ktime_t time = ktime_add_ns(timer->base->get_time(), delay); hrtimer_set_expires(timer, time); 1090 if (rq == this_rq()) { 1091 hrtimer_restart(timer); 1092 } else if (!rq->hrtick_csd_pending) { 1093 __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 1094 rq->hrtick_csd_pending = 1; If you specifying function name, this shows function-relative line number. # ./perf probe --line schedule <schedule:0> asmlinkage void __sched schedule(void) 1 { struct task_struct *prev, *next; unsigned long *switch_count; struct rq *rq; int cpu; need_resched: preempt_disable(); 9 cpu = smp_processor_id(); 10 rq = cpu_rq(cpu); 11 rcu_sched_qs(cpu); 12 prev = rq->curr; 13 switch_count = &prev->nivcsw; Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20100106144534.27218.77939.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-06 22:45:34 +08:00
int found;
};
#endif /* HAVE_DWARF_SUPPORT */
perf: Add perf probe subcommand, a kprobe-event setup helper Add perf probe subcommand that implements a kprobe-event setup helper to the perf command. This allows user to define kprobe events using C expressions (C line numbers, C function names, and C local variables). Usage ----- perf probe [<options>] -P 'PROBEDEF' [-P 'PROBEDEF' ...] -k, --vmlinux <file> vmlinux/module pathname -P, --probe <p|r:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]> probe point definition, where p: kprobe probe r: kretprobe probe GRP: Group name (optional) NAME: Event name FUNC: Function name OFFS: Offset from function entry (in byte) SRC: Source code path LINE: Line number ARG: Probe argument (local variable name or kprobe-tracer argument format is supported.) Changes in v4: - Add _GNU_SOURCE macro for strndup(). Changes in v3: - Remove -r option because perf always be used for online kernel. - Check malloc/calloc results. Changes in v2: - Check synthesized string length. - Rename perf kprobe to perf probe. - Use spaces for separator and update usage comment. - Check error paths in parse_probepoint(). - Check optimized-out variables. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Frank Ch. Eigler <fche@redhat.com> LKML-Reference: <20091008211737.29299.14784.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-10-09 05:17:38 +08:00
#endif /*_PROBE_FINDER_H */