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2015-04-29perf probe: Remove all probes matches given pattern at onceMasami Hiramatsu1-9/+17
Fix perf-probe --del option to delete all matched probes in both of kprobes and uprobes at once. When we have 2 or more events on different binaries as below, ---- # ./perf probe -l probe:vfs_read (on vfs_read@ksrc/linux-3/fs/read_write.c) probe_libc:malloc (on __libc_malloc@malloc/malloc.c in /usr/lib64/libc-2.17 ---- Trying to remove all event with '*' just removes kprobe events at first. ---- # ./perf probe -d \* Removed event: probe:vfs_read ---- And in 2nd try, it removes all uprobe events. ---- # ./perf probe -d \* Removed event: probe_libc:malloc ---- This fixes to remove all event at once as below. ---- # ./perf probe -d \* Removed event: probe:vfs_read Removed event: probe_libc:malloc ---- Reported-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-04-13perf probe: Find compilation directory path for lazy matchingNaohiro Aota1-59/+0
If we use lazy matching, it failed to open a souce file if perf command is invoked outside of compilation directory: $ perf probe -a '__schedule;clear_*' Failed to open kernel/sched/core.c: No such file or directory Error: Failed to add events. (-2) OTOH, other commands like "probe -L" can solve the souce directory by themselves. Let's make it possible for lazy matching too! Signed-off-by: Naohiro Aota <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Cc: He Kuang <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-04-13perf probe: Set retprobe flag when probe in address-based alternative modeHe Kuang1-0/+1
When perf probe searched in a debuginfo file and failed, it tried with an alternative, in function get_alternative_probe_event(): memcpy(tmp, &pev->point, sizeof(*tmp)); memset(&pev->point, 0, sizeof(pev->point)); In this case, it drops the retprobe flag and forgets to set it back in find_alternative_probe_point(), so the problem occurs. Can be reproduced as following: $ perf probe -v -k vmlinux --add='sys_write%return' ... Added new event: Writing event: p:probe/sys_write _stext+1584952 probe:sys_write (on sys_write%return) $ cat /sys/kernel/debug/tracing/kprobe_events p:probe/sys_write _stext+1584952 After this patch: $ perf probe -v -k vmlinux --add='sys_write%return' Added new event: Writing event: r:probe/sys_write SyS_write+0 probe:sys_write (on sys_write%return) $ cat /sys/kernel/debug/tracing/kprobe_events r:probe/sys_write SyS_write Signed-off-by: He Kuang <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-04-10perf probe: Support multiple probes on different binariesMasami Hiramatsu1-2/+3
Support multiple probes on different binaries with just one command. In the result, this example sets up the probes on icmp_rcv in kernel, on main and set_target in perf, and on pcspkr_event in pcspker.ko driver. ----- # perf probe -a icmp_rcv -x ./perf -a main -a set_target \ -m /lib/modules/4.0.0-rc5+/kernel/drivers/input/misc/pcspkr.ko \ -a pcspkr_event Added new event: probe:icmp_rcv (on icmp_rcv) You can now use it in all perf tools, such as: perf record -e probe:icmp_rcv -aR sleep 1 Added new event: probe_perf:main (on main in /home/mhiramat/ksrc/linux-3/tools/perf/perf) You can now use it in all perf tools, such as: perf record -e probe_perf:main -aR sleep 1 Added new event: probe_perf:set_target (on set_target in /home/mhiramat/ksrc/linux-3/tools/perf/perf) You can now use it in all perf tools, such as: perf record -e probe_perf:set_target -aR sleep 1 Added new event: probe:pcspkr_event (on pcspkr_event in pcspkr) You can now use it in all perf tools, such as: perf record -e probe:pcspkr_event -aR sleep 1 ----- Reported-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-04-08perf probe: Fix ARM 32 building errorWang Nan1-1/+2
Commit 9b118acae310f57baee770b5db402500d8695e50 ("perf probe: Fix to handle aliased symbols in glibc") uses an absolute format '%lx' to print u64 argument, which causes compiling error on ARM 32. This patch replaces it with PRIx64. Signed-off-by: Wang Nan <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Zefan Li <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-04-08perf kmaps: Check kmaps to make code more robustWang Nan1-0/+2
This patch add checks in places where map__kmap is used to get kmaps from struct kmap. Error messages are added at map__kmap to warn invalid accessing of kmap (for the case of !map->dso->kernel, kmap(map) does not exists at all). Also, introduces map__kmaps() to warn uninitialized kmaps. Reviewed-by: Ingo Molnar <[email protected]> Signed-off-by: Wang Nan <[email protected]> Cc: [email protected] Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Zefan Li <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-03-24perf probe: Fix to get ummapped symbol address on kernelMasami Hiramatsu1-1/+4
Fix to get correctly unmapped symbol address on kernel. This allows us to probe on syscall symbols which are aliases of SyS_ functions with using debuginfo. Without this fix: ---- # ./perf probe -a sys_write Failed to find debug information for address 3b0100 Probe point 'sys_write' not found. Error: Failed to add events. ---- The address 0x3b0100 is a mapped address, and not usable in debuginfo. With this fix: ---- # ./perf probe -a sys_write Added new event: probe:sys_write (on sys_write) You can now use it in all perf tools, such as: perf record -e probe:sys_write -aR sleep 1 ---- Signed-off-by: Masami Hiramatsu <[email protected]> Cc: He Kuang <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-03-21perf probe: Fix failure to add multiple probes without debuginfoHe Kuang1-3/+1
Perf tries to find probe function addresses from map when debuginfo could not be found. To the first added function, the value of ref_reloc_sym was set in maps__set_kallsyms_ref_reloc_sym() and can be obtained from host_machine->kmaps->maps. After that, new maps are added to host_machine->kmaps->maps in dso__load_kcore(), all these new added maps do not have a valid ref_reloc_sym. When adding a second function, get_target_map() may get a map without valid ref_reloc_sym, and raise the error "Relocated base symbol is not found". Fix this by using kernel_get_ref_reloc_sym() to get ref_reloc_sym. This problem can be reproduced as following: $ perf probe --add='sys_write' --add='sys_open' Relocated base symbol is not found! Error: Failed to add events. After this patch: $ perf probe --add='sys_write' --add='sys_open' Added new event: probe:sys_write (on sys_write) You can now use it in all perf tools, such as: perf record -e probe:sys_write -aR sleep 1 Added new event: probe:sys_open (on sys_open) You can now use it in all perf tools, such as: perf record -e probe:sys_open -aR sleep 1 Signed-off-by: He Kuang <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Tested-by: Masami Hiramatsu <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-03-12perf probe: Fix compiles due to declarations using perf_probe_pointDavid Ahern1-4/+6
perf fails to build with gcc "(GCC) 4.4.7 20120313 (Red Hat 4.4.7-4.0.9)" (a.k.a., RHEL6 / CentOS 6 / OL 6): cc1: warnings being treated as errors util/probe-event.c: In function ‘get_alternative_line_range’: util/probe-event.c:359: error: missing initializer util/probe-event.c:359: error: (near initialization for ‘pp.file’) util/probe-event.c:359: error: missing initializer util/probe-event.c:359: error: (near initialization for ‘result.function’) Fix by bringing in initializers to declaration. Signed-off-by: David Ahern <[email protected]> Cc: Masami Hiramatsu <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-03-12perf probe: Fix possible double free on errorHe Kuang1-1/+5
A double free occurred when get source file path failed. If lr->path failed to assign a new value, it will be freed as the old path and then be freed again during line_range__clear(), and causes this: $ perf probe -L do_execve -k vmlinux *** Error in `/usr/bin/perf': double free or corruption (fasttop): 0x0000000000a9ac50 *** ======= Backtrace: ========= ../lib64/libc.so.6(+0x6eeef)[0x7ffff5e44eef] ../lib64/libc.so.6(+0x78cae)[0x7ffff5e4ecae] ../lib64/libc.so.6(+0x79987)[0x7ffff5e4f987] ../bin/perf[0x4ab41f] ... This patch fix this problem. Signed-off-by: He Kuang <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-03-12perf probe: Allow weak symbols to be probedNamhyung Kim1-8/+4
It currently prevents adding probes in weak symbols. But there're cases that given name is an only weak symbol so that we cannot add probe. $ perf probe -x /usr/lib/libc.so.6 -a calloc Failed to find symbol calloc in /usr/lib/libc-2.21.so Error: Failed to add events. $ nm /usr/lib/libc.so.6 | grep calloc 000000000007b1f0 t __calloc 000000000007b1f0 T __libc_calloc 000000000007b1f0 W calloc This change will result in duplicate probes when strong and weak symbols co-exist in a binary. But I think it's not a big problem since probes at the weak symbol will never be hit anyway. Signed-off-by: Namhyung Kim <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Naohiro Aota <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Masami Hiramatsu <[email protected]> Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-03-12perf symbols: Allow symbol alias when loading map for symbol nameNamhyung Kim1-0/+1
When perf probe tries to add a probe in a binary using symbol name, it sometimes failed since some symbols were discard during loading dso. When it resolves an address to symbol, it'd be better to have just one symbol at given address. But for finding address from symbol, it'd be better to keep all names (including aliases). So allow tools to state that they want to allow aliases via symbol_conf.allow_aliases. Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Naohiro Aota <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] [ Original patch passwd allow_alias to many functions, use symbol_conf.allow_aliases instead ] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-03-12Revert "perf probe: Fix to fall back to find probe point in symbols"Masami Hiramatsu1-4/+2
This reverts commit 906451b98b67 ("perf probe: Fix to fall back to find probe point in symbols"). Since 'perf probe' now retries with the address of given symbol searched from map before this path, this fall back routine isn't needed anymore. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Naohiro Aota <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-03-12perf probe: Fix --line to handle aliased symbols in glibcMasami Hiramatsu1-2/+33
Fix perf probe --line to handle aliased symbols correctly in glibc. This makes line_range search failing back to address-based alternative search as same as --add and --vars. Without this patch; ----- # ./perf probe -x /usr/lib64/libc-2.17.so -L malloc Specified source line is not found. Error: Failed to show lines. ----- With this patch; ----- # ./perf probe -x /usr/lib64/libc-2.17.so -L malloc <__libc_malloc@/usr/src/debug/glibc-2.17-c758a686/malloc/malloc.c:0> 0 __libc_malloc(size_t bytes) 1 { mstate ar_ptr; void *victim; __malloc_ptr_t (*hook) (size_t, const __malloc_ptr_t) 6 = force_reg (__malloc_hook); 7 if (__builtin_expect (hook != NULL, 0)) 8 return (*hook)(bytes, RETURN_ADDRESS (0)); 10 arena_lookup(ar_ptr); 12 arena_lock(ar_ptr, bytes); ----- Note that this actually shows __libc_malloc, since it is the real instance of malloc. User can use both __libc_malloc and malloc for --line. Signed-off-by: Masami Hiramatsu <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Naohiro Aota <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-03-12perf probe: Fix to handle aliased symbols in glibcMasami Hiramatsu1-16/+124
Fix perf probe to handle aliased symbols correctly in glibc. In the glibc, several symbols are defined as an alias of __libc_XXX, e.g. malloc is an alias of __libc_malloc. In such cases, dwarf has no subroutine instances of the alias functions (e.g. no "malloc" instance), but the map has that symbol and its address. Thus, if we search the alieased symbol in debuginfo, we always fail to find it, but it is in the map. To solve this problem, this fails back to address-based alternative search, which searches the symbol in the map, translates its address to alternative (correct) function name by using debuginfo, and retry to find the alternative function point from debuginfo. This adds fail-back process to --vars, --lines and --add options. So, now you can use those on malloc@libc :) Without this patch; ----- # ./perf probe -x /usr/lib64/libc-2.17.so -V malloc Failed to find the address of malloc Error: Failed to show vars. # ./perf probe -x /usr/lib64/libc-2.17.so -a "malloc bytes" Probe point 'malloc' not found in debuginfo. Error: Failed to add events. ----- With this patch; ----- # ./perf probe -x /usr/lib64/libc-2.17.so -V malloc Available variables at malloc @<__libc_malloc+0> size_t bytes # ./perf probe -x /usr/lib64/libc-2.17.so -a "malloc bytes" Added new event: probe_libc:malloc (on malloc in /usr/lib64/libc-2.17.so with bytes) You can now use it in all perf tools, such as: perf record -e probe_libc:malloc -aR sleep 1 ----- Reported-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Naohiro Aota <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-03-02perf probe: Warn if given uprobe event accesses memory on older kernelMasami Hiramatsu1-0/+23
Warn if given uprobe event accesses memory on older kernel. Until 3.14, uprobe event only supports accessing registers so this warns to upgrade kernel if uprobe-event returns -EINVAL and an argument of the event accesses memory ($stack, @+offset, and +|-offs() symtax). With this patch (on 3.10.0-123.13.2.el7.x86_64); ----- # ./perf probe -x ./perf warn_uprobe_event_compat stack=-0\(%sp\) Added new event: Failed to write event: Invalid argument Please upgrade your kernel to at least 3.14 to have access to feature -0(%sp) Error: Failed to add events. ----- Suggested-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-02-27perf probe: Fix a precedence bugHe Kuang1-1/+1
The minus operator has higher precedence than ?: Add parentheses around ?: fix this. Before this patch: $ echo 'p:myprobe do_sys_open' > /sys/kernel/debug/tracing/kprobe_events $ perf probe -l -k ../vmlinux kprobes:myprobe (on do_sys_open) After this patch: $ echo 'p:myprobe do_sys_open' > /sys/kernel/debug/tracing/kprobe_events $ perf probe -l -k ../vmlinux kprobes:myprobe (on [email protected]/fs/open.c) Signed-off-by: He Kuang <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-02-27perf probe: Handle strdup() failureArnaldo Carvalho de Melo1-1/+1
We could end up returning 0 (Ok) with a NULL raw_path. Fix it. Acked-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Naohiro Aota <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-02-26perf probe: Fix get_real_path to free allocated memory in error pathMasami Hiramatsu1-1/+3
Fix get_real_path to free allocated memory when comp_dir is used for complementing path and getting an error. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Naohiro Aota <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-02-26perf probe: Check kprobes blacklist when adding new eventsMasami Hiramatsu1-1/+108
Recent linux kernel provides a blacklist of the functions which can not be probed. perf probe can now check this blacklist before setting new events and indicate better error message for users. Without this patch, ---- # perf probe --add vmalloc_fault Added new event: Failed to write event: Invalid argument Error: Failed to add events. ---- With this patch ---- # perf probe --add vmalloc_fault Added new event: Warning: Skipped probing on blacklisted function: vmalloc_fault ---- Reported-by: Arnaldo Carvalho de Melo <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Masami Hiramatsu <[email protected]> Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-02-11perf tools: Make perf aware of tracefsSteven Rostedt (Red Hat)1-8/+16
As tracefs may be mounted instead of debugfs to get to the event directories, have perf know about tracefs, and use that file system over debugfs if it is present. Signed-off-by: Steven Rostedt <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Namhyung Kim <[email protected]> Link: http://lkml.kernel.org/r/[email protected] [ Fixed up error messages about tracefs pointed out by Namhyung ] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-01-21perf probe: Fix probing kretprobesNamhyung Kim1-2/+2
The commit dfef99cd0b2c ("perf probe: Use ref_reloc_sym based address instead of the symbol name") converts kprobes to use ref_reloc_sym (i.e. _stext) and offset instead of using symbol's name directly. So on my system, adding do_fork ends up with like below: $ sudo perf probe -v --add do_fork%return probe-definition(0): do_fork%return symbol:do_fork file:(null) line:0 offset:0 return:1 lazy:(null) 0 arguments Looking at the vmlinux_path (7 entries long) Using /lib/modules/3.17.6-1-ARCH/build/vmlinux for symbols Could not open debuginfo. Try to use symbols. Opening /sys/kernel/debug/tracing/kprobe_events write=1 Added new event: Writing event: r:probe/do_fork _stext+456136 Failed to write event: Invalid argument Error: Failed to add events. Reason: Operation not permitted (Code: -1) As you can see, the do_fork was translated to _stext+456136. This was because to support (local) symbols that have same name. But the problem is that kretprobe requires to be inserted at function start point so it simply checks whether it's called with offset 0. And if not, it'll return with -EINVAL. You can see it with dmesg. $ dmesg | tail -1 [125621.764103] Return probe must be used without offset. So we need to use the symbol name instead of ref_reloc_sym in case of return probes. Reported-by: Jiri Olsa <[email protected]> Signed-off-by: Namhyung Kim <[email protected]> Tested-by: Jiri Olsa <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-01-21perf symbols: Introduce 'for' method to iterate over the symbols with a ↵Arnaldo Carvalho de Melo1-11/+3
given name Removing boilerplate from two places, where one would have to find the first entry, then iterate using symbol__next_by_name + strcmp to see if the next member had the same name. Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Masami Hiramatsu <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-01-21perf probe: Do not rely on map__load() filter to find symbolsNamhyung Kim1-16/+22
The find_probe_trace_events_from_map() searches matching symbol from a map (so from a backing dso). For uprobes, it'll create a new map (and dso) and loads it using a filter. It's a little bit inefficient in that it'll read out the symbol table everytime but works well anyway. For kprobes however, it'll reuse existing kernel map which might be loaded before. In this case map__load() just returns with no result. It makes kprobes always failed to find symbol even if it exists in the map (dso). To fix it, use map__find_symbol_by_name() instead. It'll load a map with full symbols and sorts them by name. It needs to search sibing nodes since there can be multiple (local) symbols with same name. Signed-off-by: Namhyung Kim <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Masami Hiramatsu <[email protected]> Link: http://lkml.kernel.org/r/[email protected] [ Use symbol__next_by_name ] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-01-16perf probe: Propagate error code when write(2) failedNamhyung Kim1-1/+3
When it failed to write probe commands to the probe_event file in debugfs, it needs to propagate the error code properly. Current code blindly uses the return value of the write(2) so it always uses -1 (-EPERM) and it might confuse users. Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2015-01-02perf probe: Fix to fall back to find probe point in symbolsMasami Hiramatsu1-2/+4
Fix to fall back to find a probe point in symbols if perf fails to find it in debuginfo. This can happen when the target function is an alias of another function. Such alias doesn't have an entry in debuginfo but in symbols. David Ahern reported this problem in https://lkml.org/lkml/2014/12/29/355 I ensured the problem and deeper investigation discovers it. ----- eu-readelf --debug-dump=info /usr/lib/debug/lib/x86_64-linux-gnu/libc-2.19.so | grep \"malloc\" -A6 name (strp) "malloc" decl_file (data1) 25 decl_line (data2) 466 prototyped (flag_present) type (ref4) [ 81b5] declaration (flag_present) [ 8f58] formal_parameter -- name (strp) "malloc" decl_file (data1) 23 decl_line (data2) 466 prototyped (flag_present) type (ref4) [ 9f4a] declaration (flag_present) sibling (ref4) [ bb29] ... ----- All these entires have no instances (all of them are declarations) This is why the perf probe failed to find it in debuginfo. However, there are some malloc instances in symbols. ----- eu-readelf --symbols /usr/lib/debug/lib/x86_64-linux-gnu/libc-2.19.so | grep malloc$ 1181: 0000000000080700 5332 FUNC LOCAL DEFAULT 12 _int_malloc 4537: 00000000000831d0 339 FUNC LOCAL DEFAULT 12 __GI___libc_malloc 5545: 00000000000831d0 339 FUNC LOCAL DEFAULT 12 __malloc 6063: 00000000000831d0 339 FUNC GLOBAL DEFAULT 12 malloc 7302: 00000000000831d0 339 FUNC GLOBAL DEFAULT 12 __libc_malloc ----- As you an see, malloc and __libc_malloc have same address, and actually __libc_malloc has an entry in debuginfo. So you can set up a probe on __libc_malloc. To fix this problem shortly, perf probe simply falls back to find probe point(malloc) in symbols if it is not found in debuginfo. Reported-by: David Ahern <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Acked-by: Namhyung Kim <[email protected]> Cc: David Ahern <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-10-29perf probe: Add --quiet option to suppress output result messageMasami Hiramatsu1-9/+9
Add --quiet(-q) option to suppress output result message for --add, and --del options (Note that --lines/funcs/vars are not affected). This option is useful if you run the perf probe inside your scripts. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Hemant Kumar <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Srikar Dronamraju <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-09-30perf symbols: Encapsulate dsos list head into struct dsosWaiman Long1-1/+2
This is a precursor patch to enable long name searching of DSOs using a rbtree. In this patch, a new dsos structure is created which contains only a list head structure for the moment. The new dsos structure is used, in turn, in the machine structure for the user_dsos and kernel_dsos fields. Only the following 3 dsos functions are modified to accept the new dsos structure parameter instead of list_head: - dsos__add() - dsos__find() - __dsos__findnew() Signed-off-by: Waiman Long <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Don Zickus <[email protected]> Cc: Douglas Hatch <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Scott J Norton <[email protected]> Link: http://lkml.kernel.org/r/[email protected] [ Move struct dsos to dso.h to reduce the dso methods depends on machine.h ] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-09-17perf probe: Do not access kallsyms when analyzing user binariesMasami Hiramatsu1-4/+5
Do not access kallsyms to show available variables and show source lines in user binaries. This behavior always requires the root privilege when sysctl sets kernel.kptr_restrict=1, but we don't need it just for analyzing user binaries. Without this patch (by normal user, kptr_restrict=1): ---- $ perf probe -x ./perf -V add_cmdname Failed to init vmlinux path. Error: Failed to show vars. $ perf probe -x ./perf -L add_cmdname Failed to init vmlinux path. Error: Failed to show lines. ---- With this patch: ---- $ perf probe -x ./perf -V add_cmdname Available variables at add_cmdname @<perf_unknown_cmd_config+144> (No matched variables) @<list_commands_in_dir+160> (No matched variables) @<add_cmdname+0> char* name size_t len struct cmdnames* cmds $ perf probe -x ./perf -L add_cmdname <add_cmdname@/home/fedora/ksrc/linux-3/tools/perf/util/help.c:0> 0 void add_cmdname(struct cmdnames *cmds, const char *name, size_t len) 1 { 2 struct cmdname *ent = malloc(sizeof(*ent) + len + 1); 4 ent->len = len; 5 memcpy(ent->name, name, len); 6 ent->name[len] = 0; ... ---- Signed-off-by: Masami Hiramatsu <[email protected]> Cc: david lerner <[email protected]> Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] [ Added missing 'bool user' argument to the !DWARF show_line_range() stub ] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-08-15perf probe: Make error messages thread-safeMasami Hiramatsu1-13/+15
To make error messages thread-safe, this replaces strerror with strerror_r for warnings, and just shows the return value instead of using strerror for debug messages. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Naohiro Aota <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-08-15perf probe: Don't use strerror if strlist__add failedMasami Hiramatsu1-2/+4
Since the strlist__add doesn't involves any IO, the failure reason must be ENOMEM or EINVAL, moreover this is just a debug message, we don't need to show the error string. And also, if get_probe_trace_command_rawlist() returns NULL, it doesn't mean the rawlist is empty, there is an error. So caller must use -ENOMEM for the error. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Naohiro Aota <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-08-15perf probe: Warn user to rebuild target with debuginfoMasami Hiramatsu1-18/+23
Warn user to rebuild target with debuginfo when the perf probe fails to find debug information in the target binary. Without this, perf probe just reports the failure, but it's no hint for users. This gives more hint for users. Without this: $ strip perf $ ./perf probe -x perf -L argv_split Failed to open debuginfo file. Error: Failed to show lines. With this: $ strip perf $ ./perf probe -x perf -L argv_split The /home/fedora/ksrc/linux-3/tools/perf/perf file has no debug information. Rebuild with -g, or install an appropriate debuginfo package. Error: Failed to show lines. The "rebuild with ..." part changes to "rebuild with CONFIG_DEBUG_INFO" if the target is the kernel or a kernel module. Suggested-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Brendan Gregg <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-08-13perf tools: Check recorded kernel version when finding vmlinuxNamhyung Kim1-1/+1
Currently vmlinux_path__init() only tries to find vmlinux file from current directory, /boot and some canonical directories with version number of the running kernel. This can be a problem when reporting old data recorded on a kernel version not running currently. We can use --symfs option for this but it's annoying for user to do it always. As we already have the info in the perf.data file, it can be changed to use it for the search automatically. Before: $ perf report ... # Samples: 4K of event 'cpu-clock' # Event count (approx.): 1067250000 # # Overhead Command Shared Object Symbol # ........ .......... ................. .............................. 71.87% swapper [kernel.kallsyms] [k] recover_probed_instruction After: # Overhead Command Shared Object Symbol # ........ .......... ................. .................... 71.87% swapper [kernel.kallsyms] [k] native_safe_halt This requires to change signature of symbol__init() to receive struct perf_session_env *. Reported-by: Minchan Kim <[email protected]> Signed-off-by: Namhyung Kim <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: David Ahern <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Minchan Kim <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-08-13perf probe: Fix --del option to delete events only with uprobe eventsMasami Hiramatsu1-23/+26
Current perf probe --del doesn't work if only CONFIG_UPROBE_EVENTS=y because it aborts when it fails to open kprobe_events file before checking uprobe_events file. This fixes --del option to delete dynamic events if it can open either kprobe_events or uprobe_events. Only if it failed to open both of them, it shows an error message and aborts. Without this patch, if we run perf probe -d on the kernel configured with CONFIG_KPROBE_EVENTS=n and CONFIG_UPROBE_EVENTS=y, # perf probe -d \* kprobe_events file does not exist - please rebuild kernel with CONFIG_KPROBE_EVENTS. Error: Failed to delete events. With this patch, # perf probe -d \* Removed event: probe_perf:alloc_event Changes in v2: - Use strerror_r instead of strerror. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Naohiro Aota <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-08-13perf probe: Fix --list option to show events only with uprobe eventsMasami Hiramatsu1-30/+59
Current perf probe --list doesn't work if only CONFIG_UPROBE_EVENTS=y because it aborts when it fails to open kprobe_events file before checking uprobe_events file. This fixes --list option to show dynamic events if it can open either kprobe_events or uprobe_events. Only if it failed to open both of them, it shows an error message and aborts. Without this patch, if we run perf probe -l on the kernel configured with CONFIG_KPROBE_EVENTS=n and CONFIG_UPROBE_EVENTS=y, # perf probe -l /sys/kernel/debug/tracing/kprobe_events file does not exist - please rebuild ker Error: Failed to show event list. With this patch, # perf probe -l probe_perf:alloc_event (on alloc_event@lib/traceevent/event-parse.c in /home/fedora/ksrc/linux-3/tools/perf/perf) Changes in v2: - Use strerror_r instead of strerror. Reported-by: Naohiro Aota <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Naohiro Aota <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-06-10perf probe: Improve error messages in --line optionMasami Hiramatsu1-3/+3
Improve error messages of 'perf probe --line' mode. Currently 'perf probe' shows the "Debuginfo analysis failed" message with an error code when the given symbol is not found: ----- # perf probe -L page_cgroup_init_flatmem Debuginfo analysis failed. (-2) Error: Failed to show lines. ----- But -2 (-ENOENT) means that the given source line or function was not found. With this patch, 'perf probe' shows the correct error message: ----- # perf probe -L page_cgroup_init_flatmem Specified source line is not found. Error: Failed to show lines. ----- There is also another debug error code is shown in the same function after get_real_path(). This removes that too. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-06-09perf probe: Improve an error message of perf probe --vars modeMasami Hiramatsu1-1/+6
Fix an error message when failed to find given address in --vars mode. Without this fix, perf probe -V doesn't show the final "Error" message if it fails to find given source line. Moreover, it tells it fails to find "variables" instead of the source line. ----- # perf probe -V foo@bar Failed to find variables at foo@bar (0) ----- The result also shows mysterious error code. Actually the error returns 0 or -ENOENT means that it just fails to find the address of given source line. (0 means there is no matching address, and -ENOENT means there is an entry(DIE) but it has no instance, e.g. an empty inlined function) This fixes it to show what happened and the final error message as below. ----- # perf probe -V foo@bar Failed to find the address of foo@bar Error: Failed to show vars. ----- Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-18perf probe: Support distro-style debuginfo for uprobeMasami Hiramatsu1-6/+3
Support distro-style debuginfo supported by dso for setting uprobes. Note that this tries to find a debuginfo file based on the real path of the target binary. If the debuginfo is not correctly installed on the system, this can not find it. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: "David A. Long" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140206053227.29635.54434.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-18perf probe: Allow to add events on the local functionsMasami Hiramatsu1-205/+173
Allow to add events on the local functions without debuginfo. (With the debuginfo, we can add events even on inlined functions) Currently, probing on local functions requires debuginfo to locate actual address. It is also possible without debuginfo since we have symbol maps. Without this change; ---- # ./perf probe -a t_show Added new event: probe:t_show (on t_show) You can now use it in all perf tools, such as: perf record -e probe:t_show -aR sleep 1 # ./perf probe -x perf -a identity__map_ip no symbols found in /kbuild/ksrc/linux-3/tools/perf/perf, maybe install a debug package? Failed to load map. Error: Failed to add events. (-22) ---- As the above results, perf probe just put one event on the first found symbol for kprobe event. Moreover, for uprobe event, perf probe failed to find local functions. With this change; ---- # ./perf probe -a t_show Added new events: probe:t_show (on t_show) probe:t_show_1 (on t_show) probe:t_show_2 (on t_show) probe:t_show_3 (on t_show) You can now use it in all perf tools, such as: perf record -e probe:t_show_3 -aR sleep 1 # ./perf probe -x perf -a identity__map_ip Added new events: probe_perf:identity__map_ip (on identity__map_ip in /kbuild/ksrc/linux-3/tools/perf/perf) probe_perf:identity__map_ip_1 (on identity__map_ip in /kbuild/ksrc/linux-3/tools/perf/perf) probe_perf:identity__map_ip_2 (on identity__map_ip in /kbuild/ksrc/linux-3/tools/perf/perf) probe_perf:identity__map_ip_3 (on identity__map_ip in /kbuild/ksrc/linux-3/tools/perf/perf) You can now use it in all perf tools, such as: perf record -e probe_perf:identity__map_ip_3 -aR sleep 1 ---- Now we succeed to put events on every given local functions for both kprobes and uprobes. :) Note that this also introduces some symbol rbtree iteration macros; symbols__for_each, dso__for_each_symbol, and map__for_each_symbol. These are for walking through the symbol list in a map. Changes from v2: - Fix add_exec_to_probe_trace_events() not to convert address to tp->symbol any more. - Fix to set kernel probes based on ref_reloc_sym. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: "David A. Long" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140206053225.29635.15026.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-18perf probe: Show source-level or symbol-level info for uprobesMasami Hiramatsu1-83/+144
Show source-level or symbol-level information for uprobe events. Without this change; # ./perf probe -l probe_perf:dso__load_vmlinux (on 0x000000000006d110 in /kbuild/ksrc/linux-3/tools/perf/perf) With this change; # ./perf probe -l probe_perf:dso__load_vmlinux (on dso__load_vmlinux@util/symbol.c in /kbuild/ksrc/linux-3/tools/perf/perf) Changes from v2: - Update according to previous patches. Changes from v1: - Rewrite the code based on new series. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: "David A. Long" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140206053223.29635.51280.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-18perf probe: Show appropriate symbol for ref_reloc_sym based kprobesMasami Hiramatsu1-28/+55
Show appropriate symbol for ref_reloc_sym based kprobes instead of refpoint+offset when perf-probe -l runs without debuginfo. Without this change: # ./perf probe -l probe:t_show (on _stext+889880 with m v) probe:t_show_1 (on _stext+928568 with m v t) probe:t_show_2 (on _stext+969512 with m v fmt) probe:t_show_3 (on _stext+1001416 with m v file) With this change: # ./perf probe -l probe:t_show (on t_show with m v) probe:t_show_1 (on t_show with m v t) probe:t_show_2 (on t_show with m v fmt) probe:t_show_3 (on t_show with m v file) Changes from v2: - Check ref_reloc_sym to find correct unrelocated address. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: "David A. Long" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140206053220.29635.81819.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-18perf probe: Find given address from offline dwarfMasami Hiramatsu1-14/+26
Find the given address from offline dwarfs instead of online kernel dwarfs. On the KASLR enabled kernel, the kernel text section is loaded with random offset, and the debuginfo__new_online_kernel can't handle it. So let's move to the offline dwarf loader instead of using the online dwarf loader. As a result, since we don't need debuginfo__new_online_kernel any more, this also removes the functions related to that. Without this change; # ./perf probe -l probe:t_show (on _stext+901288 with m v) probe:t_show_1 (on _stext+939624 with m v t) probe:t_show_2 (on _stext+980296 with m v fmt) probe:t_show_3 (on _stext+1014392 with m v file) With this change; # ./perf probe -l probe:t_show (on t_show@linux-3/kernel/trace/ftrace.c with m v) probe:t_show_1 (on t_show@linux-3/kernel/trace/trace.c with m v t) probe:t_show_2 (on t_show@kernel/trace/trace_printk.c with m v fmt) probe:t_show_3 (on t_show@kernel/trace/trace_events.c with m v file) Changes from v2: - Instead of retrying, directly opens offline dwarf. - Remove debuginfo__new_online_kernel and related functions. - Refer map->reloc to get the correct address of a symbol. - Add a special case for handling ref_reloc_sym based address. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: "David A. Long" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140206053218.29635.74821.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-18perf probe: Use ref_reloc_sym based address instead of the symbol nameMasami Hiramatsu1-9/+49
Since several local symbols can have same name (e.g. t_show), we need to use the relative address from the symbol referred by kmap->ref_reloc_sym instead of the target symbol name itself. Because the kernel address space layout randomize (kASLR) changes the absolute address of kernel symbols, we can't rely on the absolute address. Note that this works only with debuginfo. E.g. without this change; ---- # ./perf probe -a "t_show \$vars" Added new events: probe:t_show (on t_show with $vars) probe:t_show_1 (on t_show with $vars) probe:t_show_2 (on t_show with $vars) probe:t_show_3 (on t_show with $vars) You can now use it in all perf tools, such as: perf record -e probe:t_show_3 -aR sleep 1 ---- OK, we have 4 different t_show()s. All functions have different arguments as below; ---- # cat /sys/kernel/debug/tracing/kprobe_events p:probe/t_show t_show m=%di:u64 v=%si:u64 p:probe/t_show_1 t_show m=%di:u64 v=%si:u64 t=%si:u64 p:probe/t_show_2 t_show m=%di:u64 v=%si:u64 fmt=%si:u64 p:probe/t_show_3 t_show m=%di:u64 v=%si:u64 file=%si:u64 ---- However, all of them have been put on the *same* address. ---- # cat /sys/kernel/debug/kprobes/list ffffffff810d9720 k t_show+0x0 [DISABLED] ffffffff810d9720 k t_show+0x0 [DISABLED] ffffffff810d9720 k t_show+0x0 [DISABLED] ffffffff810d9720 k t_show+0x0 [DISABLED] ---- With this change; ---- # ./perf probe -a "t_show \$vars" Added new events: probe:t_show (on t_show with $vars) probe:t_show_1 (on t_show with $vars) probe:t_show_2 (on t_show with $vars) probe:t_show_3 (on t_show with $vars) You can now use it in all perf tools, such as: perf record -e probe:t_show_3 -aR sleep 1 # cat /sys/kernel/debug/tracing/kprobe_events p:probe/t_show _stext+889880 m=%di:u64 v=%si:u64 p:probe/t_show_1 _stext+928568 m=%di:u64 v=%si:u64 t=%si:u64 p:probe/t_show_2 _stext+969512 m=%di:u64 v=%si:u64 fmt=%si:u64 p:probe/t_show_3 _stext+1001416 m=%di:u64 v=%si:u64 file=%si:u64 # cat /sys/kernel/debug/kprobes/list ffffffffb50d95e0 k t_show+0x0 [DISABLED] ffffffffb50e2d00 k t_show+0x0 [DISABLED] ffffffffb50f4990 k t_show+0x0 [DISABLED] ffffffffb50eccf0 k t_show+0x0 [DISABLED] ---- This time, each event is put in different address correctly. Note that currently this doesn't support address-based probe on modules (thus the probes on modules are symbol based), since it requires relative address probe syntax for kprobe-tracer, and it isn't implemented yet. One more note, this allows us to put events on correct address, but --list option should be updated to show correct corresponding source code. Changes from v2: - Refer kmap->ref_reloc_sym instead of "_stext". - Refer map->reloc to catch up the kASLR perf fix. Changes from v1: - Use _stext relative address instead of actual absolute address recorded in debuginfo. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: "David A. Long" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140206053216.29635.22584.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-18perf probe: Show in what binaries/modules probes are setMasami Hiramatsu1-3/+7
Show the name of binary file or modules in which the probes are set with --list option. Without this change; # ./perf probe -m drm drm_av_sync_delay # ./perf probe -x perf dso__load_vmlinux # ./perf probe -l probe:drm_av_sync_delay (on drm_av_sync_delay) probe_perf:dso__load_vmlinux (on 0x000000000006d110) With this change; # ./perf probe -l probe:drm_av_sync_delay (on drm_av_sync_delay in drm) probe_perf:dso__load_vmlinux (on 0x000000000006d110 in /kbuild/ksrc/linux-3/tools/perf/perf) Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: "David A. Long" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140206053213.29635.69948.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-18perf probe: Unify show_available_functions for uprobes/kprobesMasami Hiramatsu1-46/+26
Unify show_available_functions for uprobes/kprobes to cleanup and reduce the code. This also improves error messages. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: "David A. Long" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140206053211.29635.20563.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-18perf probe: Replace line_list with intlistMasami Hiramatsu1-12/+10
Replace line_list (struct line_node) with intlist for reducing similar codes. Signed-off-by: Masami Hiramatsu <[email protected]> Acked-by: Namhyung Kim <[email protected]> Cc: David Ahern <[email protected]> Cc: "David A. Long" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140206053209.29635.81043.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-18perf probe: Remove incorrect symbol check for --listMasami Hiramatsu1-8/+0
Remove unneeded symbol check for --list option. This code actually checks whether the given symbol exists in the kernel. But this is incorrect for online kernel/module and offline module too: - For online kernel/module, the kprobes itself already ensured the symbol exist in the kernel. - For offline module, this code can't access the offlined modules. Ignore it. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: "David A. Long" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140206053206.29635.7453.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-18perf probe: Fix to do exit call for symbol mapsMasami Hiramatsu1-48/+56
Some perf-probe commands do symbol_init() but doesn't do exit call. This fixes that to call symbol_exit() and releases machine if needed. This also merges init_vmlinux() and init_user_exec() because both of them are doing similar things. (init_user_exec() just skips init vmlinux related symbol maps) Changes from v2: - Not to set symbol_conf.try_vmlinux_path in init_symbol_maps() (Thanks to Namhyung Kim!) Signed-off-by: Masami Hiramatsu <[email protected]> Cc: David Ahern <[email protected]> Cc: "David A. Long" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140206053204.29635.28334.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-02-10perf probe: Do not add offset twice to uprobe addressMasami Hiramatsu1-1/+1
Fix perf-probe not to add offset value twice to uprobe probe address when post processing. The tevs[i].point.address struct member is the address of symbol+offset, but current perf-probe adjusts the point.address by adding the offset. As a result, the probe address becomes symbol+offset+offset. This may cause unexpected code corruption. Urgent fix is needed. Without this fix: --- # ./perf probe -x ./perf dso__load_vmlinux+4 # ./perf probe -l probe_perf:dso__load_vmlinux (on 0x000000000006d2b8) # nm ./perf.orig | grep dso__load_vmlinux\$ 000000000046d0a0 T dso__load_vmlinux --- You can see the given offset is 3 but the actual probed address is dso__load_vmlinux+8. With this fix: --- # ./perf probe -x ./perf dso__load_vmlinux+4 # ./perf probe -l probe_perf:dso__load_vmlinux (on 0x000000000006d2b4) --- Now the problem is fixed. Note: This bug is introduced by commit fb7345bbf7fad9bf72ef63a19c707970b9685812 Signed-off-by: Masami Hiramatsu <[email protected]> Cc: "David A. Long" <[email protected]> Cc: David Ahern <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/20140205051858.6519.27314.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2014-01-16perf symbols: Export elf_section_by_name and reuseMasami Hiramatsu1-48/+28
Remove duplicated elf_section_by_name() functions from unwind.c and probe-event.c and use one exported elf_section_by_name() instance defined in symbol-elf.c. Note that this also moves get_text_start_address() to merge HAVE_DWARF_SUPPORT defined area. Reported-by: David Ahern <[email protected]> Signed-off-by: Masami Hiramatsu <[email protected]> Cc: "David A. Long" <[email protected]> Cc: "Steven Rostedt (Red Hat)" <[email protected]> Cc: David Ahern <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Srikar Dronamraju <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>