kernel.git/tools/perf/util/probe-event.c, branch linux-4.4.y

perf probe: Fix to check blacklist address correctly

2020-07-31T14:43:17Z

commit 80526491c2ca6abc028c0f0dbb0707a1f35fb18a upstream. Fix to check kprobe blacklist address correctly with relocated address by adjusting debuginfo address. Since the address in the debuginfo is same as objdump, it is different from relocated kernel address with KASLR. Thus, 'perf probe' always misses to catch the blacklisted addresses. Without this patch, 'perf probe' can not detect the blacklist addresses on a KASLR enabled kernel. # perf probe kprobe_dispatcher Failed to write event: Invalid argument Error: Failed to add events. # With this patch, it correctly shows the error message. # perf probe kprobe_dispatcher kprobe_dispatcher is blacklisted function, skip it. Probe point 'kprobe_dispatcher' not found. Error: Failed to add events. # Fixes: 9aaf5a5f479b ("perf probe: Check kprobes blacklist when adding new events") Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: stable@vger.kernel.org Link: http://lore.kernel.org/lkml/158763966411.30755.5882376357738273695.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

perf probe: Add warning message if there is unexpected event name

2018-04-13T17:50:12Z

[ Upstream commit 9f5c6d8777a2d962b0eeacb2a16f37da6bea545b ] This improve the error message so that user can know event-name error before writing new events to kprobe-events interface. E.g. ====== #./perf probe -x /lib64/libc-2.25.so malloc_get_state* Internal error: "malloc_get_state@GLIBC_2" is an invalid event name. Error: Failed to add events. ====== Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Masami Hiramatsu Acked-by: Ravi Bangoria Reviewed-by: Thomas Richter Tested-by: Arnaldo Carvalho de Melo Cc: Paul Clarke Cc: bhargavb Cc: linux-rt-users@vger.kernel.org Link: http://lkml.kernel.org/r/151275040665.24652.5188568529237584489.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

perf probe: Cleanup find_perf_probe_point_from_map to reduce redundancy

2015-11-06T13:47:33Z

In find_perf_probe_point_from_map(), the 'ret' variable is initialized with -ENOENT but overwritten by the return code of kernel_get_symbol_address_by_name(), and after that it is re-initialized with -ENOENT again. Setting ret=-ENOENT twice looks a bit redundant. This avoids the overwriting and just returns -ENOENT if some error happens to simplify the code. Signed-off-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Cc: Zefan Li Link: http://lkml.kernel.org/n/tip-ufp1zgbktzmttcputozneomd@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix find_perf_probe_point_from_map() which incorrectly returns success

2015-11-05T15:47:52Z

It is possible that find_perf_probe_point_from_map() fails to find a symbol but still returns 0 because of an small error when coding: find_perf_probe_point_from_map() set 'ret' to error code at first, but also use it to hold return value of kernel_get_symbol_address_by_name(). This patch resets 'ret' to error even kernel_get_symbol_address_by_name() success, so if !sym, the whole function returns error correctly. Signed-off-by: Wang Nan Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446729565-27592-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Allow probing on kmodules without dwarf

2015-10-02T18:59:23Z

Allow probing on kernel modules when 'perf' is built without debuginfo support. Currently perf-probe --module requires linking with libdw, but this doesn't make sense. E.g. ---- # make NO_DWARF=1 # ./perf probe -m pcspkr pcspkr_event%return Error: unknown switch `m' ---- With this patch ---- # ./perf probe -m pcspkr pcspkr_event%return Added new event: probe:pcspkr_event (on pcspkr_event%return in pcspkr) You can now use it in all perf tools, such as: perf record -e probe:pcspkr_event -aR sleep 1 ---- Signed-off-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/20151002125832.18617.78721.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix a segfault bug in debuginfo_cache

2015-09-30T21:34:36Z

perf probe --list will get a segfault if the first kprobe event is on a module and the second or latter one is on the kernel. e.g. ---- # ./perf probe -q -m pcspkr pcspkr_event # ./perf probe -q vfs_read # ./perf probe -l Segmentation fault (core dumped) ---- This is because the debuginfo_cache fails to handle NULL module name, which causes segfault on strcmp. (Note that strcmp("something", NULL) always causes segfault) To fix this debuginfo_cache__open always translates the NULL module name to "kernel" (this is correct, because NULL module name means opening the debuginfo for the kernel) ---- # ./perf probe -l probe:pcspkr_event (on pcspkr_event@drivers/input/misc/pcspkr.c in pcspkr) probe:vfs_read (on vfs_read@ksrc/linux-3/fs/read_write.c) ---- Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/20150930164135.3733.23993.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Show correct source lines of probes on kmodules

2015-09-30T21:34:35Z

Perf probe always failed to find appropriate line numbers because of failing to find .text start address offset from debuginfo. e.g. ---- # ./perf probe -m pcspkr pcspkr_event:5 Added new events: probe:pcspkr_event (on pcspkr_event:5 in pcspkr) probe:pcspkr_event_1 (on pcspkr_event:5 in pcspkr) You can now use it in all perf tools, such as: perf record -e probe:pcspkr_event_1 -aR sleep 1 # ./perf probe -l Failed to find debug information for address ffffffffa031f006 Failed to find debug information for address ffffffffa031f016 probe:pcspkr_event (on pcspkr_event+6 in pcspkr) probe:pcspkr_event_1 (on pcspkr_event+22 in pcspkr) ---- This fixes the above issue as below. 1. Get the relative address of the symbol in .text by using map->start. 2. Adjust the address by adding the offset of .text section in the kernel module binary. With this fix, perf probe -l shows lines correctly. ---- # ./perf probe -l probe:pcspkr_event (on pcspkr_event:5@drivers/input/misc/pcspkr.c in pcspkr) probe:pcspkr_event_1 (on pcspkr_event:5@drivers/input/misc/pcspkr.c in pcspkr) ---- Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/20150930164132.3733.24643.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Fix to remove dot suffix from second or latter events

2015-09-30T21:34:33Z

Fix to remove dot suffix (e.g. .const, .isra) from the second or latter events which has suffix numbers. Since the previous commit 35a23ff928b0 ("perf probe: Cut off the gcc optimization postfixes from function name") didn't care about the suffix numbered events, therefore we'll have an error when we add additional events on the same dot suffix functions. e.g. ---- # ./perf probe -f -a get_sigframe.isra.2.constprop.3 \ -a get_sigframe.isra.2.constprop.3 Failed to write event: Invalid argument Error: Failed to add events. ---- This fixes above issue as below: ---- # ./perf probe -f -a get_sigframe.isra.2.constprop.3 \ -a get_sigframe.isra.2.constprop.3 Added new events: probe:get_sigframe (on get_sigframe.isra.2.constprop.3) probe:get_sigframe_1 (on get_sigframe.isra.2.constprop.3) You can now use it in all perf tools, such as: perf record -e probe:get_sigframe_1 -aR sleep 1 ---- Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/20150930164130.3733.26573.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Add method for common kernel_map(FUNCTION) operation

2015-09-30T21:34:29Z

And it is also a step in the direction of killing the separation of data and text maps in map_groups. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-rrds86kb3wx5wk8v38v56gw8@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Use machine__kernel_map() thoroughly

2015-09-30T21:34:28Z

In places where we were using its open coded equivalent. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-khkdugcdoqy3tkszm3jdxgbe@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo