| Message ID | 20221219110613.367098-1-dolinux.peng@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v6] tracing/probe: add a char type to show the character value of traced arguments | expand |
Looking back at emails that happened when I was off ;-) Masami, what's you thoughts about this patch? -- Steve On Mon, 19 Dec 2022 03:06:13 -0800 Donglin Peng <dolinux.peng@gmail.com> wrote: > There are scenes that we want to show the character value of traced > arguments other than a decimal or hexadecimal or string value for debug > convinience. I add a new type named 'char' to do it and a new test case > file named 'kprobe_args_char.tc' to do selftest for char type. > > For example: > > The to be traced function is 'void demo_func(char type, char *name);', we > can add a kprobe event as follows to show argument values as we want: > > echo 'p:myprobe demo_func $arg1:char +0($arg2):char[5]' > kprobe_events > > we will get the following trace log: > > ... myprobe: (demo_func+0x0/0x29) arg1='A' arg2={'b','p','f','1',''} > > Signed-off-by: Donglin Peng <dolinux.peng@gmail.com> > Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> > Reported-by: kernel test robot <lkp@intel.com> > --- > Changes in v6: > - change "\'%c\'" to "'%c'" in trace_probe.c > > Changes in v5: > - wrap the output character with single quotes > - add a test case named kprobe_args_char.tc to do selftest > > Changes in v4: > - update the example in the commit log > > Changes in v3: > - update readme_msg > > Changes in v2: > - fix build warnings reported by kernel test robot > - modify commit log > --- > Documentation/trace/kprobetrace.rst | 3 +- > kernel/trace/trace.c | 2 +- > kernel/trace/trace_probe.c | 2 + > kernel/trace/trace_probe.h | 1 + > .../ftrace/test.d/kprobe/kprobe_args_char.tc | 47 +++++++++++++++++++ > 5 files changed, 53 insertions(+), 2 deletions(-) > create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc > > diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst > index 4274cc6a2f94..007972a3c5c4 100644 > --- a/Documentation/trace/kprobetrace.rst > +++ b/Documentation/trace/kprobetrace.rst > @@ -58,7 +58,7 @@ Synopsis of kprobe_events > NAME=FETCHARG : Set NAME as the argument name of FETCHARG. > FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types > (u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types > - (x8/x16/x32/x64), "string", "ustring" and bitfield > + (x8/x16/x32/x64), "char", "string", "ustring" and bitfield > are supported. > > (\*1) only for the probe on function entry (offs == 0). > @@ -80,6 +80,7 @@ E.g. 'x16[4]' means an array of x16 (2bytes hex) with 4 elements. > Note that the array can be applied to memory type fetchargs, you can not > apply it to registers/stack-entries etc. (for example, '$stack1:x8[8]' is > wrong, but '+8($stack):x8[8]' is OK.) > +Char type can be used to show the character value of traced arguments. > String type is a special type, which fetches a "null-terminated" string from > kernel space. This means it will fail and store NULL if the string container > has been paged out. "ustring" type is an alternative of string for user-space. > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 6d7ef130f57e..c602081e64c8 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -5615,7 +5615,7 @@ static const char readme_msg[] = > "\t $stack<index>, $stack, $retval, $comm,\n" > #endif > "\t +|-[u]<offset>(<fetcharg>), \\imm-value, \\\"imm-string\"\n" > - "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" > + "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, char, string, symbol,\n" > "\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n" > "\t <type>\\[<array-size>\\]\n" > #ifdef CONFIG_HIST_TRIGGERS > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c > index bb2f95d7175c..794a21455396 100644 > --- a/kernel/trace/trace_probe.c > +++ b/kernel/trace/trace_probe.c > @@ -50,6 +50,7 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") > DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") > DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") > DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") > +DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'") > > int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) > { > @@ -93,6 +94,7 @@ static const struct fetch_type probe_fetch_types[] = { > ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), > ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), > ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), > + ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0), > ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0), > > ASSIGN_FETCH_TYPE_END > diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h > index de38f1c03776..8c86aaa8b0c9 100644 > --- a/kernel/trace/trace_probe.h > +++ b/kernel/trace/trace_probe.h > @@ -164,6 +164,7 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x16); > DECLARE_BASIC_PRINT_TYPE_FUNC(x32); > DECLARE_BASIC_PRINT_TYPE_FUNC(x64); > > +DECLARE_BASIC_PRINT_TYPE_FUNC(char); > DECLARE_BASIC_PRINT_TYPE_FUNC(string); > DECLARE_BASIC_PRINT_TYPE_FUNC(symbol); > > diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc > new file mode 100644 > index 000000000000..285b4770efad > --- /dev/null > +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc > @@ -0,0 +1,47 @@ > +#!/bin/sh > +# SPDX-License-Identifier: GPL-2.0 > +# description: Kprobe event char type argument > +# requires: kprobe_events > + > +case `uname -m` in > +x86_64) > + ARG1=%di > +;; > +i[3456]86) > + ARG1=%ax > +;; > +aarch64) > + ARG1=%x0 > +;; > +arm*) > + ARG1=%r0 > +;; > +ppc64*) > + ARG1=%r3 > +;; > +ppc*) > + ARG1=%r3 > +;; > +s390*) > + ARG1=%r2 > +;; > +mips*) > + ARG1=%r4 > +;; > +*) > + echo "Please implement other architecture here" > + exit_untested > +esac > + > +: "Test get argument (1)" > +echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):char" > kprobe_events > +echo 1 > events/kprobes/testprobe/enable > +echo "p:test $FUNCTION_FORK" >> kprobe_events > +grep -qe "testprobe.* arg1='t'" trace > + > +echo 0 > events/kprobes/testprobe/enable > +: "Test get argument (2)" > +echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):char arg2=+0(${ARG1}):char[4]" > kprobe_events > +echo 1 > events/kprobes/testprobe/enable > +echo "p:test $FUNCTION_FORK" >> kprobe_events > +grep -qe "testprobe.* arg1='t' arg2={'t','e','s','t'}" trace
On Tue, 24 Jan 2023 17:38:00 -0500 Steven Rostedt <rostedt@goodmis.org> wrote: > > Looking back at emails that happened when I was off ;-) > > Masami, what's you thoughts about this patch? Oops, I also missed this. Thanks for updating the patch! Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> I'll pick this to the for-next. Thank you! > > -- Steve > > > On Mon, 19 Dec 2022 03:06:13 -0800 > Donglin Peng <dolinux.peng@gmail.com> wrote: > > > There are scenes that we want to show the character value of traced > > arguments other than a decimal or hexadecimal or string value for debug > > convinience. I add a new type named 'char' to do it and a new test case > > file named 'kprobe_args_char.tc' to do selftest for char type. > > > > For example: > > > > The to be traced function is 'void demo_func(char type, char *name);', we > > can add a kprobe event as follows to show argument values as we want: > > > > echo 'p:myprobe demo_func $arg1:char +0($arg2):char[5]' > kprobe_events > > > > we will get the following trace log: > > > > ... myprobe: (demo_func+0x0/0x29) arg1='A' arg2={'b','p','f','1',''} > > > > Signed-off-by: Donglin Peng <dolinux.peng@gmail.com> > > Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> > > Reported-by: kernel test robot <lkp@intel.com> > > --- > > Changes in v6: > > - change "\'%c\'" to "'%c'" in trace_probe.c > > > > Changes in v5: > > - wrap the output character with single quotes > > - add a test case named kprobe_args_char.tc to do selftest > > > > Changes in v4: > > - update the example in the commit log > > > > Changes in v3: > > - update readme_msg > > > > Changes in v2: > > - fix build warnings reported by kernel test robot > > - modify commit log > > --- > > Documentation/trace/kprobetrace.rst | 3 +- > > kernel/trace/trace.c | 2 +- > > kernel/trace/trace_probe.c | 2 + > > kernel/trace/trace_probe.h | 1 + > > .../ftrace/test.d/kprobe/kprobe_args_char.tc | 47 +++++++++++++++++++ > > 5 files changed, 53 insertions(+), 2 deletions(-) > > create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc > > > > diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst > > index 4274cc6a2f94..007972a3c5c4 100644 > > --- a/Documentation/trace/kprobetrace.rst > > +++ b/Documentation/trace/kprobetrace.rst > > @@ -58,7 +58,7 @@ Synopsis of kprobe_events > > NAME=FETCHARG : Set NAME as the argument name of FETCHARG. > > FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types > > (u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types > > - (x8/x16/x32/x64), "string", "ustring" and bitfield > > + (x8/x16/x32/x64), "char", "string", "ustring" and bitfield > > are supported. > > > > (\*1) only for the probe on function entry (offs == 0). > > @@ -80,6 +80,7 @@ E.g. 'x16[4]' means an array of x16 (2bytes hex) with 4 elements. > > Note that the array can be applied to memory type fetchargs, you can not > > apply it to registers/stack-entries etc. (for example, '$stack1:x8[8]' is > > wrong, but '+8($stack):x8[8]' is OK.) > > +Char type can be used to show the character value of traced arguments. > > String type is a special type, which fetches a "null-terminated" string from > > kernel space. This means it will fail and store NULL if the string container > > has been paged out. "ustring" type is an alternative of string for user-space. > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > > index 6d7ef130f57e..c602081e64c8 100644 > > --- a/kernel/trace/trace.c > > +++ b/kernel/trace/trace.c > > @@ -5615,7 +5615,7 @@ static const char readme_msg[] = > > "\t $stack<index>, $stack, $retval, $comm,\n" > > #endif > > "\t +|-[u]<offset>(<fetcharg>), \\imm-value, \\\"imm-string\"\n" > > - "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" > > + "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, char, string, symbol,\n" > > "\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n" > > "\t <type>\\[<array-size>\\]\n" > > #ifdef CONFIG_HIST_TRIGGERS > > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c > > index bb2f95d7175c..794a21455396 100644 > > --- a/kernel/trace/trace_probe.c > > +++ b/kernel/trace/trace_probe.c > > @@ -50,6 +50,7 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") > > DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") > > DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") > > DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") > > +DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'") > > > > int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) > > { > > @@ -93,6 +94,7 @@ static const struct fetch_type probe_fetch_types[] = { > > ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), > > ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), > > ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), > > + ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0), > > ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0), > > > > ASSIGN_FETCH_TYPE_END > > diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h > > index de38f1c03776..8c86aaa8b0c9 100644 > > --- a/kernel/trace/trace_probe.h > > +++ b/kernel/trace/trace_probe.h > > @@ -164,6 +164,7 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x16); > > DECLARE_BASIC_PRINT_TYPE_FUNC(x32); > > DECLARE_BASIC_PRINT_TYPE_FUNC(x64); > > > > +DECLARE_BASIC_PRINT_TYPE_FUNC(char); > > DECLARE_BASIC_PRINT_TYPE_FUNC(string); > > DECLARE_BASIC_PRINT_TYPE_FUNC(symbol); > > > > diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc > > new file mode 100644 > > index 000000000000..285b4770efad > > --- /dev/null > > +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc > > @@ -0,0 +1,47 @@ > > +#!/bin/sh > > +# SPDX-License-Identifier: GPL-2.0 > > +# description: Kprobe event char type argument > > +# requires: kprobe_events > > + > > +case `uname -m` in > > +x86_64) > > + ARG1=%di > > +;; > > +i[3456]86) > > + ARG1=%ax > > +;; > > +aarch64) > > + ARG1=%x0 > > +;; > > +arm*) > > + ARG1=%r0 > > +;; > > +ppc64*) > > + ARG1=%r3 > > +;; > > +ppc*) > > + ARG1=%r3 > > +;; > > +s390*) > > + ARG1=%r2 > > +;; > > +mips*) > > + ARG1=%r4 > > +;; > > +*) > > + echo "Please implement other architecture here" > > + exit_untested > > +esac > > + > > +: "Test get argument (1)" > > +echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):char" > kprobe_events > > +echo 1 > events/kprobes/testprobe/enable > > +echo "p:test $FUNCTION_FORK" >> kprobe_events > > +grep -qe "testprobe.* arg1='t'" trace > > + > > +echo 0 > events/kprobes/testprobe/enable > > +: "Test get argument (2)" > > +echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):char arg2=+0(${ARG1}):char[4]" > kprobe_events > > +echo 1 > events/kprobes/testprobe/enable > > +echo "p:test $FUNCTION_FORK" >> kprobe_events > > +grep -qe "testprobe.* arg1='t' arg2={'t','e','s','t'}" trace >
diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst index 4274cc6a2f94..007972a3c5c4 100644 --- a/Documentation/trace/kprobetrace.rst +++ b/Documentation/trace/kprobetrace.rst @@ -58,7 +58,7 @@ Synopsis of kprobe_events NAME=FETCHARG : Set NAME as the argument name of FETCHARG. FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types (u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types - (x8/x16/x32/x64), "string", "ustring" and bitfield + (x8/x16/x32/x64), "char", "string", "ustring" and bitfield are supported. (\*1) only for the probe on function entry (offs == 0). @@ -80,6 +80,7 @@ E.g. 'x16[4]' means an array of x16 (2bytes hex) with 4 elements. Note that the array can be applied to memory type fetchargs, you can not apply it to registers/stack-entries etc. (for example, '$stack1:x8[8]' is wrong, but '+8($stack):x8[8]' is OK.) +Char type can be used to show the character value of traced arguments. String type is a special type, which fetches a "null-terminated" string from kernel space. This means it will fail and store NULL if the string container has been paged out. "ustring" type is an alternative of string for user-space. diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 6d7ef130f57e..c602081e64c8 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5615,7 +5615,7 @@ static const char readme_msg[] = "\t $stack<index>, $stack, $retval, $comm,\n" #endif "\t +|-[u]<offset>(<fetcharg>), \\imm-value, \\\"imm-string\"\n" - "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" + "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, char, string, symbol,\n" "\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n" "\t <type>\\[<array-size>\\]\n" #ifdef CONFIG_HIST_TRIGGERS diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index bb2f95d7175c..794a21455396 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -50,6 +50,7 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") +DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'") int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent) { @@ -93,6 +94,7 @@ static const struct fetch_type probe_fetch_types[] = { ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), + ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0), ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0), ASSIGN_FETCH_TYPE_END diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index de38f1c03776..8c86aaa8b0c9 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -164,6 +164,7 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x16); DECLARE_BASIC_PRINT_TYPE_FUNC(x32); DECLARE_BASIC_PRINT_TYPE_FUNC(x64); +DECLARE_BASIC_PRINT_TYPE_FUNC(char); DECLARE_BASIC_PRINT_TYPE_FUNC(string); DECLARE_BASIC_PRINT_TYPE_FUNC(symbol); diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc new file mode 100644 index 000000000000..285b4770efad --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc @@ -0,0 +1,47 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe event char type argument +# requires: kprobe_events + +case `uname -m` in +x86_64) + ARG1=%di +;; +i[3456]86) + ARG1=%ax +;; +aarch64) + ARG1=%x0 +;; +arm*) + ARG1=%r0 +;; +ppc64*) + ARG1=%r3 +;; +ppc*) + ARG1=%r3 +;; +s390*) + ARG1=%r2 +;; +mips*) + ARG1=%r4 +;; +*) + echo "Please implement other architecture here" + exit_untested +esac + +: "Test get argument (1)" +echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):char" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +echo "p:test $FUNCTION_FORK" >> kprobe_events +grep -qe "testprobe.* arg1='t'" trace + +echo 0 > events/kprobes/testprobe/enable +: "Test get argument (2)" +echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):char arg2=+0(${ARG1}):char[4]" > kprobe_events +echo 1 > events/kprobes/testprobe/enable +echo "p:test $FUNCTION_FORK" >> kprobe_events +grep -qe "testprobe.* arg1='t' arg2={'t','e','s','t'}" trace
There are scenes that we want to show the character value of traced arguments other than a decimal or hexadecimal or string value for debug convinience. I add a new type named 'char' to do it and a new test case file named 'kprobe_args_char.tc' to do selftest for char type. For example: The to be traced function is 'void demo_func(char type, char *name);', we can add a kprobe event as follows to show argument values as we want: echo 'p:myprobe demo_func $arg1:char +0($arg2):char[5]' > kprobe_events we will get the following trace log: ... myprobe: (demo_func+0x0/0x29) arg1='A' arg2={'b','p','f','1',''} Signed-off-by: Donglin Peng <dolinux.peng@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reported-by: kernel test robot <lkp@intel.com> --- Changes in v6: - change "\'%c\'" to "'%c'" in trace_probe.c Changes in v5: - wrap the output character with single quotes - add a test case named kprobe_args_char.tc to do selftest Changes in v4: - update the example in the commit log Changes in v3: - update readme_msg Changes in v2: - fix build warnings reported by kernel test robot - modify commit log --- Documentation/trace/kprobetrace.rst | 3 +- kernel/trace/trace.c | 2 +- kernel/trace/trace_probe.c | 2 + kernel/trace/trace_probe.h | 1 + .../ftrace/test.d/kprobe/kprobe_args_char.tc | 47 +++++++++++++++++++ 5 files changed, 53 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc