[1/3] tracing/probes: support '%pd' type for print struct dentry's name
Commit Message
Similar to '%pd' for printk, use 'pd' for print struct dentry's name.
Signed-off-by: Ye Bin <yebin10@huawei.com>
---
kernel/trace/trace_probe.c | 38 ++++++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)
Comments
On Fri, 19 Jan 2024 09:38:46 +0800
Ye Bin <yebin10@huawei.com> wrote:
> Similar to '%pd' for printk, use 'pd' for print struct dentry's name.
No, please use '%pd' as a type instead.
>
> Signed-off-by: Ye Bin <yebin10@huawei.com>
> ---
> kernel/trace/trace_probe.c | 38 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 38 insertions(+)
>
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index 4dc74d73fc1d..460f98b85b1c 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -11,6 +11,7 @@
> */
> #define pr_fmt(fmt) "trace_probe: " fmt
>
> +#include <linux/dcache.h>
> #include <linux/bpf.h>
> #include "trace_btf.h"
>
> @@ -86,6 +87,8 @@ static const struct fetch_type probe_fetch_types[] = {
> "__data_loc char[]"),
> __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1,
> "__data_loc char[]"),
> + __ASSIGN_FETCH_TYPE("pd", string, string, sizeof(u32), 1, 1,
> + "__data_loc char[]"),
And you don't need to add a new type.
Similar to the preprocessor macro, this should be done before parsing the
args. See traceprobe_expand_meta_args(), you can scan the args and search
argument end with ':%pd'. If you find that, you can replace it with
"+0x%lx(%s):string". Then, you don't need any of these complex fetch type.
Thank you,
> /* Basic types */
> ASSIGN_FETCH_TYPE(u8, u8, 0),
> ASSIGN_FETCH_TYPE(u16, u16, 0),
> @@ -1090,6 +1093,25 @@ static int __parse_bitfield_probe_arg(const char *bf,
> return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
> }
>
> +static char* traceprobe_expand_dentry(const char *argv)
> +{
> + #define DENTRY_EXPAND_LEN 7 /* +0xXX() */
> + char *new_argv;
> + int len = strlen(argv) + 1 + DENTRY_EXPAND_LEN;
> +
> + new_argv = kmalloc(len, GFP_KERNEL);
> + if (!new_argv)
> + return NULL;
> +
> + if (snprintf(new_argv, len, "+0x%lx(%s)",
> + offsetof(struct dentry, d_name.name), argv) >= len) {
> + kfree(new_argv);
> + return NULL;
> + }
> +
> + return new_argv;
> +}
> +
> /* String length checking wrapper */
> static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
> struct probe_arg *parg,
> @@ -1099,6 +1121,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
> char *t, *t2, *t3;
> int ret, len;
> char *arg;
> + char *org_arg = NULL;
>
> arg = kstrdup(argv, GFP_KERNEL);
> if (!arg)
> @@ -1182,6 +1205,16 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
> parg->count);
> }
>
> + if (!strcmp("pd", parg->type->name)) {
> + char *temp;
> +
> + temp = traceprobe_expand_dentry(arg);
> + if (!temp)
> + goto out;
> + org_arg = arg;
> + arg = temp;
> + }
> +
> code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
> if (!code)
> goto out;
> @@ -1243,6 +1276,10 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
> goto fail;
> }
> }
> +
> + if (!strcmp(parg->type->name, "pd"))
> + code++;
> +
> /* If op == DEREF, replace it with STRING */
> if (!strcmp(parg->type->name, "ustring") ||
> code->op == FETCH_OP_UDEREF)
> @@ -1321,6 +1358,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
> kfree(tmp);
> out:
> kfree(arg);
> + kfree(org_arg);
>
> return ret;
> }
> --
> 2.31.1
>
Hi Ye,
kernel test robot noticed the following build warnings:
[auto build test WARNING on linus/master]
[also build test WARNING on v6.7 next-20240119]
[cannot apply to rostedt-trace/for-next 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/Ye-Bin/tracing-probes-support-pd-type-for-print-struct-dentry-s-name/20240119-093912
base: linus/master
patch link: https://lore.kernel.org/r/20240119013848.3111364-2-yebin10%40huawei.com
patch subject: [PATCH 1/3] tracing/probes: support '%pd' type for print struct dentry's name
config: i386-defconfig (https://download.01.org/0day-ci/archive/20240120/202401200837.b9DEGdBT-lkp@intel.com/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240120/202401200837.b9DEGdBT-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401200837.b9DEGdBT-lkp@intel.com/
All warnings (new ones prefixed by >>):
kernel/trace/trace_probe.c: In function 'traceprobe_expand_dentry':
>> kernel/trace/trace_probe.c:1106:36: warning: format '%lx' expects argument of type 'long unsigned int', but argument 4 has type 'unsigned int' [-Wformat=]
if (snprintf(new_argv, len, "+0x%lx(%s)",
~~^
%x
vim +1106 kernel/trace/trace_probe.c
1095
1096 static char* traceprobe_expand_dentry(const char *argv)
1097 {
1098 #define DENTRY_EXPAND_LEN 7 /* +0xXX() */
1099 char *new_argv;
1100 int len = strlen(argv) + 1 + DENTRY_EXPAND_LEN;
1101
1102 new_argv = kmalloc(len, GFP_KERNEL);
1103 if (!new_argv)
1104 return NULL;
1105
> 1106 if (snprintf(new_argv, len, "+0x%lx(%s)",
1107 offsetof(struct dentry, d_name.name), argv) >= len) {
1108 kfree(new_argv);
1109 return NULL;
1110 }
1111
1112 return new_argv;
1113 }
1114
Hi Ye,
kernel test robot noticed the following build warnings:
[auto build test WARNING on linus/master]
[also build test WARNING on v6.7 next-20240119]
[cannot apply to rostedt-trace/for-next 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/Ye-Bin/tracing-probes-support-pd-type-for-print-struct-dentry-s-name/20240119-093912
base: linus/master
patch link: https://lore.kernel.org/r/20240119013848.3111364-2-yebin10%40huawei.com
patch subject: [PATCH 1/3] tracing/probes: support '%pd' type for print struct dentry's name
config: i386-randconfig-051-20240120 (https://download.01.org/0day-ci/archive/20240120/202401201403.aTEbo79S-lkp@intel.com/config)
compiler: ClangBuiltLinux clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240120/202401201403.aTEbo79S-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401201403.aTEbo79S-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> kernel/trace/trace_probe.c:1107:8: warning: format specifies type 'unsigned long' but the argument has type 'unsigned int' [-Wformat]
1106 | if (snprintf(new_argv, len, "+0x%lx(%s)",
| ~~~
| %x
1107 | offsetof(struct dentry, d_name.name), argv) >= len) {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/stddef.h:16:32: note: expanded from macro 'offsetof'
16 | #define offsetof(TYPE, MEMBER) __builtin_offsetof(TYPE, MEMBER)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
vim +1107 kernel/trace/trace_probe.c
1095
1096 static char* traceprobe_expand_dentry(const char *argv)
1097 {
1098 #define DENTRY_EXPAND_LEN 7 /* +0xXX() */
1099 char *new_argv;
1100 int len = strlen(argv) + 1 + DENTRY_EXPAND_LEN;
1101
1102 new_argv = kmalloc(len, GFP_KERNEL);
1103 if (!new_argv)
1104 return NULL;
1105
1106 if (snprintf(new_argv, len, "+0x%lx(%s)",
> 1107 offsetof(struct dentry, d_name.name), argv) >= len) {
1108 kfree(new_argv);
1109 return NULL;
1110 }
1111
1112 return new_argv;
1113 }
1114
@@ -11,6 +11,7 @@
*/
#define pr_fmt(fmt) "trace_probe: " fmt
+#include <linux/dcache.h>
#include <linux/bpf.h>
#include "trace_btf.h"
@@ -86,6 +87,8 @@ static const struct fetch_type probe_fetch_types[] = {
"__data_loc char[]"),
__ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1,
"__data_loc char[]"),
+ __ASSIGN_FETCH_TYPE("pd", string, string, sizeof(u32), 1, 1,
+ "__data_loc char[]"),
/* Basic types */
ASSIGN_FETCH_TYPE(u8, u8, 0),
ASSIGN_FETCH_TYPE(u16, u16, 0),
@@ -1090,6 +1093,25 @@ static int __parse_bitfield_probe_arg(const char *bf,
return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
}
+static char* traceprobe_expand_dentry(const char *argv)
+{
+ #define DENTRY_EXPAND_LEN 7 /* +0xXX() */
+ char *new_argv;
+ int len = strlen(argv) + 1 + DENTRY_EXPAND_LEN;
+
+ new_argv = kmalloc(len, GFP_KERNEL);
+ if (!new_argv)
+ return NULL;
+
+ if (snprintf(new_argv, len, "+0x%lx(%s)",
+ offsetof(struct dentry, d_name.name), argv) >= len) {
+ kfree(new_argv);
+ return NULL;
+ }
+
+ return new_argv;
+}
+
/* String length checking wrapper */
static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
struct probe_arg *parg,
@@ -1099,6 +1121,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
char *t, *t2, *t3;
int ret, len;
char *arg;
+ char *org_arg = NULL;
arg = kstrdup(argv, GFP_KERNEL);
if (!arg)
@@ -1182,6 +1205,16 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
parg->count);
}
+ if (!strcmp("pd", parg->type->name)) {
+ char *temp;
+
+ temp = traceprobe_expand_dentry(arg);
+ if (!temp)
+ goto out;
+ org_arg = arg;
+ arg = temp;
+ }
+
code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
if (!code)
goto out;
@@ -1243,6 +1276,10 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
goto fail;
}
}
+
+ if (!strcmp(parg->type->name, "pd"))
+ code++;
+
/* If op == DEREF, replace it with STRING */
if (!strcmp(parg->type->name, "ustring") ||
code->op == FETCH_OP_UDEREF)
@@ -1321,6 +1358,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
kfree(tmp);
out:
kfree(arg);
+ kfree(org_arg);
return ret;
}