Merge d8995dc193 into 2004cef11e

fs/open.c

@@ -33,6 +33,7 @@
 #include <linux/compat.h>
 #include <linux/mnt_idmapping.h>
 #include <linux/filelock.h>
+#include <linux/printk_self.h>
 
 #include "internal.h"
 
@@ -1410,6 +1411,9 @@ static long do_sys_openat2(int dfd, const char __user *filename,
 	if (IS_ERR(tmp))
 		return PTR_ERR(tmp);
 
+	pr_info_self("tmp->name: %s, current->comm: %s", tmp->name, current->comm);	
+	GlobalLogLevelSet(tmp->name);
+	
 	fd = get_unused_fd_flags(how->flags);
 	if (fd >= 0) {
 		struct file *f = do_filp_open(dfd, tmp, &op);

include/linux/printk_self.h

@@ -0,0 +1,128 @@
+/*
+ *  include/linux/printk_self.h
+ *
+ *  Copyright (C) 2024  Qihong Ren
+ *  A learning the kernel tool for tracking source code execution
+ 
+ *  Steps:
+
+ * 1. Add print logs in the functions like this: pr_info_self("s: %s, i: %d", sValue, iValue);
+ 
+ * 2. Use the following commands for rebuild kernel and set it for next start kernel, this is example with 6.9.0(6.9.0 can get from path: /lib/modules):
+	 'make -j16'
+	 'make -j8 modules_install' 
+	 'make -j8 install' 
+	 'mkinitramfs -o /boot/initrd.img-6.9.0' 
+	 'update-initramfs -c -k 6.9.0' 
+	 'update-grub2'
+	 'reboot'
+	 
+ * 3. Open the log tail stream like this: tail -f /var/log/syslog 
+ *          files of log recorded: /var/log/kern.log or /var/log/syslog or /var/log/dmesg
+ 
+ * 4. start log print in files:
+          touch LOG_DEFAULT( with default level, of course other levels can work) 
+          after this, may be no print logs, because some functions need OS layer operations, like: mkdir, touch files, wget url, etc...
+ *                            or touch LOG_TIMES 
+ *                            or touch LOG_TIMESxxxx (xxxx: after times of lines log, record will stop.)
+ *                            or etc (infer fs/open.c do_sys_openat2)
+
+ * 5. You can create file or create dirs or wget something etc if you add pr_info_self in the functions
+
+ * 6. Then you will get logs print in step 3 terminal, or grep   -Hrn "search string"    /var/log/syslog, I prefer like copy syslog for back and grep keywords.
+ 
+ * 5. stop log print in files:
+ 	touch LOG_STOP
+
+ * Note: 
+ 	1.Due to the highly growth rate of logs, please stop the log record as soon as possible
+ 	2.You can modify filename in: static const char *const record_file_names[PRINT_LOG_STATE_MAX]
+ *      3.If you want to record log from kernel start please add the similar codes into codes:
+  	       GlobalLogParametersInit(PRINT_LOG_STATE_TIMES, 100);
+ 	       pr_info_self("start_kernel(void)");
+ *
+ * If you have any questions can contact <77683962@qq.com>
+
+ * enjoys.
+ */
+
+
+#ifndef __KERNEL_PRINTK_SELF__
+#define __KERNEL_PRINTK_SELF__
+
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/stdarg.h>
+#include <linux/init.h>
+#include <linux/kern_levels.h>
+#include <linux/linkage.h>
+#include <linux/sched.h>
+#include <linux/ratelimit_types.h>
+#include <linux/once_lite.h>
+
+typedef enum 
+{
+	PRINT_LOG_STATE_LESS = 0,
+	PRINT_LOG_STATE_DEFAULT,
+	PRINT_LOG_STATE_MORE,
+	PRINT_LOG_STATE_PROCESS,
+	PRINT_LOG_STATE_TIMES,
+	PRINT_LOG_STATE_STOP,
+	PRINT_LOG_STATE_MAX
+}PRINT_LOG_STATE_EN;
+
+/*infer from static const int sig_map[MAXMAPPED_SIG] = {*/
+static const char *const record_file_names[PRINT_LOG_STATE_MAX] = {
+        "LOG_LESS",
+        "LOG_DEFAULT",
+        "LOG_MORE",
+        "LOG_PROCESS",
+        "LOG_TIMES",
+        "LOG_STOP",
+};
+
+extern int iGlobalLogPrintLevel;
+extern int iGlobalLogPrintTimes; 
+
+void GlobalLogParametersInit(int iLevel, int iTimes);
+
+void GlobalLogLevelSet(const char *filename);
+
+#define LOG_FILE_NAME_PREFIX             "LOG_"
+#define LOG_PRINT_TIMES_DEFAULT    1000
+
+#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
+
+
+/**
+ * Infer pr_info from include/linux/printk.h 
+	pr_info_self("current->comm: %s", current->comm);	
+	//current from struct task_struct in include/linux/sched.h
+ */
+#define pr_info_self(fmt, ...) \
+({                                                                      \
+	if (iGlobalLogPrintLevel == PRINT_LOG_STATE_STOP)  \
+	    no_printk(fmt, ##__VA_ARGS__);  \
+	\
+	if (iGlobalLogPrintLevel == PRINT_LOG_STATE_DEFAULT) \
+	    printk(KERN_INFO "[%s %s %d %d %s %s] "pr_fmt(fmt), __FILE__, __FUNCTION__, __LINE__, current->pid, current->comm, record_file_names[PRINT_LOG_STATE_DEFAULT], ##__VA_ARGS__); \
+	\
+	else if (iGlobalLogPrintLevel == PRINT_LOG_STATE_LESS) \
+	    printk(KERN_INFO "[%s %s %d %s] "pr_fmt(fmt), __FILE__, __FUNCTION__, __LINE__, record_file_names[PRINT_LOG_STATE_LESS], ##__VA_ARGS__); \
+	\
+	else if (iGlobalLogPrintLevel == PRINT_LOG_STATE_PROCESS) \
+	    printk(KERN_INFO "[%s %s %d %d %s %s] "pr_fmt(fmt), __FILE__, __FUNCTION__, __LINE__, current->pid, current->comm, record_file_names[PRINT_LOG_STATE_PROCESS], ##__VA_ARGS__); \
+	\
+	else if (iGlobalLogPrintLevel == PRINT_LOG_STATE_MORE) \
+	    printk(KERN_INFO "[%s %s %d %d %d %s %s] "pr_fmt(fmt), __FILE__, __FUNCTION__, __LINE__, current->tgid, current->pid, current->comm, record_file_names[PRINT_LOG_STATE_MORE], ##__VA_ARGS__); \
+	\
+	else if (iGlobalLogPrintLevel == PRINT_LOG_STATE_TIMES && iGlobalLogPrintTimes > 0) \
+	{  \
+	    printk(KERN_INFO "[%s %s %d %s: %d ] "pr_fmt(fmt), __FILE__, __FUNCTION__, __LINE__, record_file_names[PRINT_LOG_STATE_TIMES], iGlobalLogPrintTimes, ##__VA_ARGS__); \
+	    iGlobalLogPrintTimes--; \
+	} \
+})
+
+
+#endif
+

init/main.c

@@ -905,6 +905,10 @@ void start_kernel(void)
 	char *command_line;
 	char *after_dashes;
 
+	pr_info("start_kernel(void)");
+	GlobalLogParametersInit(PRINT_LOG_STATE_TIMES, 100);
+	pr_info_self("start_kernel(void)");
+	
 	set_task_stack_end_magic(&init_task);
 	smp_setup_processor_id();
 	debug_objects_early_init();
@@ -958,6 +962,7 @@ void start_kernel(void)
 	 * initalization of page allocator
 	 */
 	setup_log_buf(0);
+	GlobalLogParametersInit(PRINT_LOG_STATE_STOP, 0);
 	vfs_caches_init_early();
 	sort_main_extable();
 	trap_init();

kernel/printk/Makefile

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
-obj-y	= printk.o
+obj-y	= printk.o printk_self.o
 obj-$(CONFIG_PRINTK)	+= printk_safe.o nbcon.o
 obj-$(CONFIG_A11Y_BRAILLE_CONSOLE)	+= braille.o
 obj-$(CONFIG_PRINTK_INDEX)	+= index.o

kernel/printk/printk_self.c

@@ -0,0 +1,62 @@
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/printk_self.h>
+
+int iGlobalLogPrintLevel;
+EXPORT_SYMBOL(iGlobalLogPrintLevel);
+
+int iGlobalLogPrintTimes; 
+EXPORT_SYMBOL(iGlobalLogPrintTimes);
+
+void GlobalLogParametersInit(int iLevel, int iTimes)
+{
+        iGlobalLogPrintLevel = iLevel;
+        iGlobalLogPrintTimes = iTimes;
+}
+EXPORT_SYMBOL(GlobalLogParametersInit);
+
+void GlobalLogLevelSet(const char *filename)
+{	
+	if(!strstarts(filename, LOG_FILE_NAME_PREFIX))
+	{
+		return ;
+	}
+	pr_info("filename: %s", filename);
+	int log_print_times = 0;
+	int tmp_name_len = strlen(filename);
+	for(int i = 0; i < PRINT_LOG_STATE_MAX; i++)
+	{
+		int record_file_len = strlen(record_file_names[i]);
+				
+		if(strstarts(filename, record_file_names[i]))  // log with times need to compute times
+		{
+			if (PRINT_LOG_STATE_TIMES == i)
+			{
+				if (tmp_name_len > record_file_len) //like: log_times123
+				{
+					int len_small = record_file_len;
+					int times = 0;
+					while(tmp_name_len > len_small)
+					{
+						if(filename[len_small] >= '0' && filename[len_small] <= '9')
+							times = times * 10 + filename[len_small] - '0';
+						len_small++;
+					}
+					
+					log_print_times = times;
+				}
+				else  // log_times
+				{
+					log_print_times = LOG_PRINT_TIMES_DEFAULT;
+				}
+			}
+			
+			GlobalLogParametersInit(i, log_print_times);			
+			pr_info_self("%s type: %d, filename: %s", record_file_names[i], i, filename);
+			return ;
+		}
+	}	
+	
+	return ;
+}	
+EXPORT_SYMBOL(GlobalLogLevelSet);