diff mbox series

[1/3] tracing/probes: support '%pd' type for print struct dentry's name

Message ID 20240119013848.3111364-2-yebin10@huawei.com (mailing list archive)
State Superseded
Headers show
Series support '%pd' and '%pD' for print file name | expand

Commit Message

yebin (H) Jan. 19, 2024, 1:38 a.m. UTC 
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

Masami Hiramatsu (Google) Jan. 19, 2024, 2:57 p.m. UTC | #1 
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
>
kernel test robot Jan. 20, 2024, 12:59 a.m. UTC | #2 
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
kernel test robot Jan. 20, 2024, 6:27 a.m. UTC | #3 
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
diff mbox series

Patch

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[]"),
 	/* 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;
 }