patch.file

diff -uprN -X kernel/Documentation/dontdiff kernel2/kernel/arch/x86/syscalls/syscall_32.tbl kernel/arch/x86/syscalls/syscall_32.tbl
--- kernel2/kernel/arch/x86/syscalls/syscall_32.tbl	2017-06-17 10:44:31.000000000 -0700
+++ kernel/arch/x86/syscalls/syscall_32.tbl	2018-12-02 12:21:29.421165242 -0700
@@ -365,3 +365,5 @@
 356	i386	memfd_create		sys_memfd_create
 357	i386	bpf			sys_bpf
 358	i386	execveat		sys_execveat			stub32_execveat
+359	i386	insdump			sys_insdump
+360	i386	rmdump			sys_rmdump
diff -uprN -X kernel/Documentation/dontdiff kernel2/kernel/include/linux/syscalls.h kernel/include/linux/syscalls.h
--- kernel2/kernel/include/linux/syscalls.h	2017-06-17 10:44:57.000000000 -0700
+++ kernel/include/linux/syscalls.h	2018-12-02 15:32:54.326122304 -0700
@@ -67,6 +67,8 @@ struct file_handle;
 struct sigaltstack;
 union bpf_attr;
 
+struct dumpmode_t;
+
 #include <linux/types.h>
 #include <linux/aio_abi.h>
 #include <linux/capability.h>
@@ -882,4 +884,10 @@ asmlinkage long sys_execveat(int dfd, co
 			const char __user *const __user *argv,
 			const char __user *const __user *envp, int flags);
 
+
+asmlinkage long sys_insdump(const char __user *symbolname, struct dumpmode_t __user * dumpmode);
+
+asmlinkage long sys_rmdump(int dumpid);
+
+
 #endif
ddiff -uprN -X kernel/Documentation/dontdiff kernel2/kernel/kernel/exit.c kernel/kernel/exit.c
--- kernel2/kernel/kernel/exit.c	2017-06-17 10:44:58.000000000 -0700
+++ kernel/kernel/exit.c	2018-12-02 15:21:57.057985017 -0700
@@ -59,6 +59,8 @@
 #include <asm/pgtable.h>
 #include <asm/mmu_context.h>
 
+#include <linux/dynamic_dump_stack.h>
+
 static void exit_mm(struct task_struct *tsk);
 
 static void __unhash_process(struct task_struct *p, bool group_dead)
@@ -654,7 +656,9 @@ void do_exit(long code)
 	struct task_struct *tsk = current;
 	int group_dead;
 	TASKS_RCU(int tasks_rcu_i);
-
+#ifdef CONFIG_DYNAMIC_DUMP_STACK
+	remove_krpobes(tsk->pid);
+#endif
 	profile_task_exit(tsk);
 
 	WARN_ON(blk_needs_flush_plug(tsk));
diff -uprN -X kernel/Documentation/dontdiff kernel2/kernel/lib/dynamic_dump_stack.c kernel/lib/dynamic_dump_stack.c
--- kernel2/kernel/lib/dynamic_dump_stack.c	1969-12-31 17:00:00.000000000 -0700
+++ kernel/lib/dynamic_dump_stack.c	2018-12-02 15:44:53.109352512 -0700
@@ -0,0 +1,186 @@
+#include<linux/kernel.h>
+#include<linux/init.h>
+#include<linux/sched.h>
+#include<linux/syscalls.h>
+#include<linux/string.h>
+#include<linux/kprobes.h>
+#include<linux/kallsyms.h>
+#include<linux/module.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+
+#include <linux/dynamic_dump_stack.h>
+
+#define MAX_SYMBOL_LEN 40
+
+int dumpstackid;
+struct list_head dump_stack_list = LIST_HEAD_INIT(dump_stack_list);
+struct dump_stack_struct *node;
+
+struct dump_stack_struct{
+
+	int dumpstackid;
+	char symbol_name[40];
+	struct kprobe p;
+	pid_t pid;
+	pid_t threadgid;
+	int dumpstackmode;
+	struct list_head dlist;
+
+};
+
+struct delete_node {
+	struct list_head listnode;
+	struct list_head* address;	
+};
+
+int remove_krpobes(pid_t pid) {
+
+    
+    struct list_head* iter = NULL;
+    struct dump_stack_struct* struct_iter = NULL;
+
+    struct delete_node *delList, *temp = NULL;
+    struct list_head nodes_to_delete = LIST_HEAD_INIT(nodes_to_delete);
+  
+    pr_info("PROCESS %d IS EXITED. REMOVING THE KRPOBES\n", pid);
+  
+    list_for_each(iter, &dump_stack_list) {
+	struct_iter = list_entry(iter, struct dump_stack_struct, dlist);
+	//pr_info("PROBES - symbol %s pid %d\n", struct_iter->symbol_name, struct_iter->pid);
+	if(struct_iter->pid == pid) {
+		unregister_kprobe(&struct_iter->p);
+		delList = kmalloc(sizeof(struct delete_node), GFP_KERNEL);
+		memset(delList, 0, sizeof(struct delete_node));
+		delList->address = iter;
+		list_add(&delList->listnode, &nodes_to_delete);
+	}
+    }
+     
+   list_for_each(iter, &nodes_to_delete) {
+	temp = list_entry(iter, struct delete_node, listnode);
+	list_del(temp->address);
+   }
+
+    pr_info("REMOVED THE KRPOBES\n");
+    
+    return 1;
+}
+
+int Pre_Handler(struct kprobe *probe, struct pt_regs *regs){
+	
+    struct dump_stack_struct *current_struct;
+    struct task_struct* task = current;
+    pid_t tgid;
+    pid_t pid;
+    tgid = task->tgid;
+    pid = task->pid;
+	
+    current_struct = container_of(probe, struct dump_stack_struct, p);
+
+    if(current_struct->dumpstackmode > 1){   
+   	 dump_stack();
+    }
+    else if(current_struct->dumpstackmode == 0 && pid == current_struct->pid){   
+   	 dump_stack();
+    }
+    else if(current_struct->dumpstackmode == 1 && (pid == current_struct->pid || tgid == current_struct->threadgid)){            
+   	 dump_stack();
+    }
+   	
+    return 0;
+}
+
+
+SYSCALL_DEFINE1(rmdump, int, dumpid){
+
+#ifdef CONFIG_DYNAMIC_DUMP_STACK
+	
+    
+    struct list_head* iter = NULL;
+    bool dump_stack_id_exists = false;
+    struct dump_stack_struct* struct_iter = NULL;
+    struct task_struct* task = current;
+    pid_t pid = task->pid;
+    pr_info("IN THE SYSCALL RMDUMP\n");	
+    list_for_each(iter, &dump_stack_list) {
+	struct_iter = list_entry(iter, struct dump_stack_struct, dlist);
+	if(struct_iter->dumpstackid == dumpid && struct_iter->pid == pid) {
+		dump_stack_id_exists = true;
+		break;
+	}
+    }
+   
+    if(dump_stack_id_exists){
+	printk(KERN_INFO "DUMPSTACK FOUND!! REMOVING\n");
+	unregister_kprobe(&struct_iter->p);
+	list_del(iter);
+    }else{
+	printk(KERN_INFO "DUMPSTACK NOT FOUND\n");
+	return -EINVAL;
+    }
+	return 1;
+#else
+	return 0;
+#endif
+    
+
+}
+
+SYSCALL_DEFINE2(insdump,const char __user *, symbolname, struct dumpmode_t __user *, dumpmode)
+{
+	  	
+#ifdef CONFIG_DYNAMIC_DUMP_STACK
+		
+        unsigned long address;
+	
+	char *symbol_name;
+	struct task_struct* task;
+	struct dumpmode_t input_mode;
+	pid_t tgid;
+ 	pid_t pid;
+	task = current;
+	tgid = task->tgid;
+	pid = task->pid;
+	pr_info("IN THE SYSCALL INSDUMP\n");
+	symbol_name = kmalloc(sizeof(char)*MAX_SYMBOL_LEN, GFP_KERNEL);
+        strncpy_from_user((char *)symbol_name,
+				symbolname, MAX_SYMBOL_LEN);
+    	address = kallsyms_lookup_name(symbol_name);
+	
+	if(address == 0/* && is_kernel_text(address)*/){
+		printk(KERN_INFO "SYMBOL NOT FOUND\n");
+		return -EINVAL;
+	}
+	
+	printk(KERN_INFO "SYMOBOL FOUND! ADDING THE KRPOBE\n");
+	node = (struct dump_stack_struct *)kmalloc(sizeof(struct dump_stack_struct), GFP_KERNEL);
+	memset(node, 0, sizeof(struct dump_stack_struct));
+	if (copy_from_user(&input_mode, dumpmode,sizeof(input_mode))){
+		return -EFAULT;
+	}
+	printk(KERN_INFO "DUMPSTACK MODE IS - %d\n", input_mode.mode);
+	node->pid = pid;
+	node->threadgid = tgid;
+	node->dumpstackmode = input_mode.mode;
+	snprintf(node->symbol_name, sizeof(char)*MAX_SYMBOL_LEN, "%s", symbol_name);
+	//node->p = (struct kprobe*)kmalloc(sizeof(struct kprobe), GFP_KERNEL);
+	memset(&node->p, 0, sizeof(struct kprobe));
+	node->p.pre_handler = Pre_Handler;
+    	node->p.addr = (kprobe_opcode_t *)address;
+	node->dumpstackid = dumpstackid++;
+
+	if(register_kprobe(&node->p)){
+		printk(KERN_INFO "Error while setting kprobe on address %p\n", (void*)(address));\
+		return -EINVAL;
+	}
+
+	list_add(&node->dlist, &dump_stack_list);
+	printk(KERN_INFO "KPROBE INSERTED\n");
+	return node->dumpstackid;
+#else	
+	return 0;
+	
+#endif
+        
+}
diff -uprN -X kernel/Documentation/dontdiff kernel2/kernel/include/linux/dynamic_dump_stack.h kernel/include/linux/dynamic_dump_stack.h
--- kernel2/kernel/include/linux/dynamic_dump_stack.h	1969-12-31 17:00:00.000000000 -0700
+++ kernel/include/linux/dynamic_dump_stack.h	2018-12-02 15:11:11.105969564 -0700
@@ -0,0 +1,10 @@
+
+
+
+extern struct list_head dump_stack_list;
+
+extern int remove_krpobes(pid_t pid);
+
+struct dumpmode_t {
+	unsigned int mode;
+};
diff -uprN -X kernel/Documentation/dontdiff kernel2/kernel/lib/Kconfig.debug kernel/lib/Kconfig.debug
--- kernel2/kernel/lib/Kconfig.debug	2017-06-17 10:44:58.000000000 -0700
+++ kernel/lib/Kconfig.debug	2018-12-02 14:02:14.213286585 -0700
@@ -1595,6 +1595,14 @@ config TEST_RHASHTABLE
 
 endmenu # runtime tests
 
+config DYNAMIC_DUMP_STACK
+	bool "Enable dynamic dump stack"
+	default n
+	help
+	  Enable this option to test the dyanamically adding the dump stack.
+
+	  If unsure, say N.
+
 config PROVIDE_OHCI1394_DMA_INIT
 	bool "Remote debugging over FireWire early on boot"
 	depends on PCI && X86
diff -uprN -X kernel/Documentation/dontdiff kernel2/kernel/lib/Makefile kernel/lib/Makefile
--- kernel2/kernel/lib/Makefile	2017-06-17 10:44:58.000000000 -0700
+++ kernel/lib/Makefile	2018-12-02 15:14:07.295498933 -0700
@@ -21,7 +21,7 @@ lib-$(CONFIG_SMP) += cpumask.o
 
 lib-y	+= kobject.o klist.o
 obj-y	+= lockref.o
-
+obj-y   += dynamic_dump_stack.o	
 obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
 	 bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
 	 gcd.o lcm.o list_sort.o uuid.o flex_array.o iovec.o clz_ctz.o \