kernel/tools/perf/util/probe-event.h, branch linux-4.3.y

perf probe: Support probing at absolute address

2015-08-26T13:41:12Z

It should be useful to allow 'perf probe' probe at absolute offset of a target. For example, when (u)probing at a instruction of a shared object in a embedded system where debuginfo is not avaliable but we know the offset of that instruction by manually digging. This patch enables following perf probe command syntax: # perf probe 0xffffffff811e6615 And # perf probe /lib/x86_64-linux-gnu/libc-2.19.so 0xeb860 In the above example, we don't need a anchor symbol, so it is possible to compute absolute addresses using other methods and then use 'perf probe' to create the probing points. v1 -> v2: Drop the leading '+' in cmdline; Allow uprobing at offset 0x0; Improve 'perf probe -l' result when uprobe at area without debuginfo. v2 -> v3: Split bugfix to a separated patch. Test result: # perf probe 0xffffffff8119d175 %ax # perf probe sys_write %ax # perf probe /lib64/libc-2.18.so 0x0 %ax # perf probe /lib64/libc-2.18.so 0x5 %ax # perf probe /lib64/libc-2.18.so 0xd8e40 %ax # perf probe /lib64/libc-2.18.so __write %ax # perf probe /lib64/libc-2.18.so 0xd8e49 %ax # cat /sys/kernel/debug/tracing/uprobe_events p:probe_libc/abs_0 /lib64/libc-2.18.so:0x (null) arg1=%ax p:probe_libc/abs_5 /lib64/libc-2.18.so:0x0000000000000005 arg1=%ax p:probe_libc/abs_d8e40 /lib64/libc-2.18.so:0x00000000000d8e40 arg1=%ax p:probe_libc/__write /lib64/libc-2.18.so:0x00000000000d8e40 arg1=%ax p:probe_libc/abs_d8e49 /lib64/libc-2.18.so:0x00000000000d8e49 arg1=%ax # cat /sys/kernel/debug/tracing/kprobe_events p:probe/abs_ffffffff8119d175 0xffffffff8119d175 arg1=%ax p:probe/sys_write _text+1692016 arg1=%ax # perf probe -l Failed to find debug information for address 5 probe:abs_ffffffff8119d175 (on sys_write+5 with arg1) probe:sys_write (on sys_write with arg1) probe_libc:__write (on @unix/syscall-template.S:81 in /lib64/libc-2.18.so with arg1) probe_libc:abs_0 (on 0x0 in /lib64/libc-2.18.so with arg1) probe_libc:abs_5 (on 0x5 in /lib64/libc-2.18.so with arg1) probe_libc:abs_d8e40 (on @unix/syscall-template.S:81 in /lib64/libc-2.18.so with arg1) probe_libc:abs_d8e49 (on __GI___libc_write+9 in /lib64/libc-2.18.so with arg1) Signed-off-by: Wang Nan Acked-by: Masami Hiramatsu Cc: Namhyung Kim Cc: Steven Rostedt Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1440586666-235233-7-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add missing forward declaration of struct map to probe-event.h

2015-08-06T18:38:40Z

Commit 7b6ff0bdbf4f7f429c2116cca92a6d171217449e ("perf probe ppc64le: Fixup function entry if using kallsyms lookup") adds 'struct map' into probe-event.h but not forward declares it. This patch fixes it. Signed-off-by: Wang Nan Cc: Alexei Starovoitov Cc: Brendan Gregg Cc: Daniel Borkmann Cc: David Ahern Cc: He Kuang Cc: Jiri Olsa Cc: Kaixu Xia Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Fixes: 7b6ff0bdbf4f ("perf probe ppc64le: Fixup function entry if using kallsyms lookup") Link: http://lkml.kernel.org/n/1436445342-1402-30-git-send-email-wangnan0@huawei.com [ No need to include map.h, just forward declare 'struct map' ] Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Move ftrace probe-event operations to probe-file.c

2015-07-20T20:49:49Z

Move ftrace probe-event operations to probe-file.c from probe-event.c. Signed-off-by: Masami Hiramatsu Cc: Adrian Hunter Cc: Borislav Petkov Cc: Hemant Kumar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150715091407.8915.14316.stgit@localhost.localdomain [ Fixed up strlist__new() calls wrt 4a77e2183fc0 ("perf strlist: Make dupstr be the...") ] Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Show the error reason comes from invalid DSO

2015-05-27T15:21:45Z

Show the reason of error when dso__load* fails. This shows when user gives wrong kernel image or wrong path. Without this, perf probe shows an obscure message: ---- $ perf probe -k ~/kbin/linux-3.x86_64/vmlinux -L vfs_read Failed to find path of kernel module. Error: Failed to show lines. ---- With this, perf shows appropriate error message: ---- $ perf probe -k ~/kbin/linux-3.x86_64/vmlinux -L vfs_read Failed to find the path for kernel: Mismatching build id Error: Failed to show lines. ---- And: ---- $ perf probe -k /non-exist/kernel/vmlinux -L vfs_read Failed to find the path for kernel: No such file or directory Error: Failed to show lines. ---- Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Richard Weinberger Link: http://lkml.kernel.org/r/20150527083718.23880.84100.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Add --range option to show a variable's location range

2015-05-12T12:59:50Z

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(): 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 @ [INV] ssize_t written @ [INV] struct address_space_operations* a_ops @ [VAL] (unknown_type) fsdata @ [VAL] loff_t pos @ [VAL] long int status @ [VAL] long unsigned int bytes @ [VAL] struct address_space* mapping @ [VAL] struct iov_iter* i @ [VAL] struct page* page @ 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 Acked-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1431336304-16863-2-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Support glob wildcards for function name

2015-05-08T19:31:02Z

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 Tested-by: Arnaldo Carvalho de Melo Cc: Ananth N Mavinakayanahalli Cc: David Ahern Cc: Hemant Kumar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150508010335.24812.19972.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Add --no-inlines option to avoid searching inline functions

2015-05-08T19:26:44Z

Add --no-inlines(--inlines) option to avoid searching inline functions. Searching all functions which matches glob pattern can take a long time and find a lot of inline functions. With this option perf-probe searches target on the non-inlined functions. Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: David Ahern Cc: Hemant Kumar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150508010333.24812.86568.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Introduce probe_conf global configs

2015-05-08T19:26:26Z

Introduce probe_conf global configuration parameters for probe-event and probe-finder, and removes related parameters from APIs. Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: David Ahern Cc: Hemant Kumar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150508010330.24812.21095.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Use perf_probe_event.target instead of passing as an argument

2015-05-08T19:25:21Z

Use perf_probe_event.target field for the target binary instead of passing it as an argument. Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: David Ahern Cc: Hemant Kumar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150508010328.24812.67887.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Allow to use filter on --del command

2015-05-05T21:13:02Z

This makes perf-probe --del option to accept filter rules not only simple glob pattern. This simplifies the code and improve the flexibility. E.g. if we remove 2 different pattern events, we need 2 -d options. ---- # ./perf probe -d vfs\* -d malloc Removed event: probe_libc:malloc Removed event: probe:vfs_read ---- This allows you to joint the 2 patterns with '|'. ---- # ./perf probe -d 'vfs*|malloc' Removed event: probe:vfs_read Removed event: probe_libc:malloc ---- Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150505022948.23399.4197.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo