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. Add a new type named 'char' to do it.
For example:
echo 'p:myprobe xxxx $arg1:char' > kprobe_events
Signed-off-by: Donglin Peng <[email protected]>
---
Documentation/trace/kprobetrace.rst | 3 ++-
kernel/trace/trace_probe.c | 2 ++
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst
index 4274cc6a2f94..007972a3c5c4 100644
--- a/Documentation/trace/kprobetrace.rst
+++ b/Documentation/trace/kprobetrace.rst
@@ -58,7 +58,7 @@ Synopsis of kprobe_events
NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
(u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types
- (x8/x16/x32/x64), "string", "ustring" and bitfield
+ (x8/x16/x32/x64), "char", "string", "ustring" and bitfield
are supported.
(\*1) only for the probe on function entry (offs == 0).
@@ -80,6 +80,7 @@ E.g. 'x16[4]' means an array of x16 (2bytes hex) with 4 elements.
Note that the array can be applied to memory type fetchargs, you can not
apply it to registers/stack-entries etc. (for example, '$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_probe.c b/kernel/trace/trace_probe.c
index 36dff277de46..a4abf7f6c295 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
--
2.25.1
Hi Donglin,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on rostedt-trace/for-next v6.1 next-20221213]
[cannot apply to rostedt-trace/for-next-urgent]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Donglin-Peng/tracing-probe-add-a-char-type-to-print-the-character-value-of-traced-arguments/20221213-195552
patch link: https://lore.kernel.org/r/20221213115304.3964458-1-dolinux.peng%40gmail.com
patch subject: [PATCH] tracing/probe: add a char type to print the character value of traced arguments
config: parisc-allyesconfig
compiler: hppa-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/c09eb24f0c2c27ce649aed5360dcf3299b636de6
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Donglin-Peng/tracing-probe-add-a-char-type-to-print-the-character-value-of-traced-arguments/20221213-195552
git checkout c09eb24f0c2c27ce649aed5360dcf3299b636de6
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=parisc SHELL=/bin/bash kernel/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email protected]>
All warnings (new ones prefixed by >>):
In file included from kernel/trace/trace_probe.c:14:
>> kernel/trace/trace_probe.h:146:41: warning: no previous prototype for 'print_type_char' [-Wmissing-prototypes]
146 | #define PRINT_TYPE_FUNC_NAME(type) print_type_##type
| ^~~~~~~~~~~
kernel/trace/trace_probe.c:34:5: note: in expansion of macro 'PRINT_TYPE_FUNC_NAME'
34 | int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
| ^~~~~~~~~~~~~~~~~~~~
kernel/trace/trace_probe.c:53:1: note: in expansion of macro 'DEFINE_BASIC_PRINT_TYPE_FUNC'
53 | DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "%c")
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +/print_type_char +146 kernel/trace/trace_probe.h
34fee3a104cea1 Namhyung Kim 2013-11-26 145
b26c74e116ad84 Namhyung Kim 2013-11-26 @146 #define PRINT_TYPE_FUNC_NAME(type) print_type_##type
b26c74e116ad84 Namhyung Kim 2013-11-26 147 #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
b26c74e116ad84 Namhyung Kim 2013-11-26 148
--
0-DAY CI Kernel Test Service
https://01.org/lkp
Hi Donglin,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on rostedt-trace/for-next]
[cannot apply to rostedt-trace/for-next-urgent]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Donglin-Peng/tracing-probe-add-a-char-type-to-print-the-character-value-of-traced-arguments/20221213-195552
patch link: https://lore.kernel.org/r/20221213115304.3964458-1-dolinux.peng%40gmail.com
patch subject: [PATCH] tracing/probe: add a char type to print the character value of traced arguments
config: s390-randconfig-r044-20221213
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 6e4cea55f0d1104408b26ac574566a0e4de48036)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install s390 cross compiling tool for clang build
# apt-get install binutils-s390x-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/c09eb24f0c2c27ce649aed5360dcf3299b636de6
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Donglin-Peng/tracing-probe-add-a-char-type-to-print-the-character-value-of-traced-arguments/20221213-195552
git checkout c09eb24f0c2c27ce649aed5360dcf3299b636de6
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash kernel/trace/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email protected]>
All warnings (new ones prefixed by >>):
In file included from kernel/trace/trace_probe.c:14:
In file included from kernel/trace/trace_probe.h:28:
In file included from kernel/trace/trace.h:9:
In file included from include/linux/clocksource.h:22:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
^
include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16'
#define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
^
In file included from kernel/trace/trace_probe.c:14:
In file included from kernel/trace/trace_probe.h:28:
In file included from kernel/trace/trace.h:9:
In file included from include/linux/clocksource.h:22:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32'
#define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
^
In file included from kernel/trace/trace_probe.c:14:
In file included from kernel/trace/trace_probe.h:28:
In file included from kernel/trace/trace.h:9:
In file included from include/linux/clocksource.h:22:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
>> kernel/trace/trace_probe.c:53:1: warning: no previous prototype for function 'print_type_char' [-Wmissing-prototypes]
DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "%c")
^
kernel/trace/trace_probe.c:34:5: note: expanded from macro 'DEFINE_BASIC_PRINT_TYPE_FUNC'
int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
^
kernel/trace/trace_probe.h:146:36: note: expanded from macro 'PRINT_TYPE_FUNC_NAME'
#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
^
<scratch space>:93:1: note: expanded from here
print_type_char
^
kernel/trace/trace_probe.c:53:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "%c")
^
static
kernel/trace/trace_probe.c:33:58: note: expanded from macro 'DEFINE_BASIC_PRINT_TYPE_FUNC'
#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
^
13 warnings generated.
vim +/print_type_char +53 kernel/trace/trace_probe.c
40
41 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
42 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
43 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
44 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
45 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
46 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
47 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
48 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
49 DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
50 DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
51 DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
52 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
> 53 DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "%c")
54
--
0-DAY CI Kernel Test Service
https://01.org/lkp