[리눅스커널] 부팅 과정 유익한 패치

아래 패치도 정말 유용하다.

 

 * 유저 프로세스가 ASSET될 때 콜 스택 출력

 * 부팅 과정에 오픈하는 파일을 출력

 * 실행되는 파일 이름 출력

 

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c

index 9f5d818..4d6df0c 100644

--- a/arch/arm/kernel/traps.c

+++ b/arch/arm/kernel/traps.c

@@ -37,7 +37,8 @@

 #include <asm/tls.h>

 #include <asm/system_misc.h>

 #include <asm/opcodes.h>

-

+#include <linux/file.h>

+#include <linux/slab.h>

 

 static const char *handler[]= {

  "prefetch abort",

@@ -60,6 +61,48 @@ static int __init user_debug_setup(char *str)

 __setup("user_debug=", user_debug_setup);

 #endif

 

+

+void trace_exe_filename(void)

+{

+ struct file *exe_file;

+ char *pathbuf, *fname;

+

+ printk("[+][trace][%s][%s,%d] caller: %pS  \n",

+ current->comm, __func__,__LINE__,  (void *)__builtin_return_address(0));

+

+ exe_file = get_mm_exe_file(current->mm);

+

+ if (!exe_file)

+ {

+ printk("[-] path unknown: %s \n", current->comm);

+ return;

+ }

+

+ pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY);

+

+ if (!pathbuf) {

+ printk("[-] memory starved: %s \n", current->comm);

+ goto put_exe_file;

+ }

+

+ fname = d_path(&exe_file->f_path, pathbuf, PATH_MAX);

+

+ if (IS_ERR(fname)) {

+ printk("[-] path error: %s \n", current->comm);

+ goto free_buf;

+ }

+

+ printk("[+][%s]: exe_file: %s \n", current->comm, fname);

+

+free_buf:

+ kfree(pathbuf);

+put_exe_file:

+ fput(exe_file);

+

+ return;

+}

+

+

 static void dump_mem(const char *, const char *, unsigned long, unsigned long);

 

 void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)

@@ -409,6 +452,8 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)

  siginfo_t info;

  void __user *pc;

 

+ printk("[+][trace][%s][%s,%d]: \n", current->comm, __func__,__LINE__);

+

  pc = (void __user *)instruction_pointer(regs);

 

  if (processor_mode(regs) == SVC_MODE) {

@@ -444,14 +489,11 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)

  return;

 

 die_sig:

-#ifdef CONFIG_DEBUG_USER

- if (user_debug & UDBG_UNDEFINED) {

- printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",

+    printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",

  current->comm, task_pid_nr(current), pc);

- __show_regs(regs);

- dump_instr(KERN_INFO, regs);

- }

-#endif

+ __show_regs(regs);

+ dump_instr(KERN_INFO, regs);

+ trace_exe_filename();

 

  info.si_signo = SIGILL;

  info.si_errno = 0;

@@ -508,19 +550,18 @@ static int bad_syscall(int n, struct pt_regs *regs)

  struct thread_info *thread = current_thread_info();

  siginfo_t info;

 

+ printk("[+][trace][%s][%s,%d]: \n", current->comm, __func__,__LINE__);

+

  if ((current->personality & PER_MASK) != PER_LINUX &&

      thread->exec_domain->handler) {

  thread->exec_domain->handler(n, regs);

  return regs->ARM_r0;

  }

 

-#ifdef CONFIG_DEBUG_USER

- if (user_debug & UDBG_SYSCALL) {

- printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",

+ printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",

  task_pid_nr(current), current->comm, n);

- dump_instr(KERN_ERR, regs);

- }

-#endif

+ dump_instr(KERN_ERR, regs);

+ trace_exe_filename();

 

  info.si_signo = SIGILL;

  info.si_errno = 0;

@@ -688,21 +729,15 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)

  return -ENOSYS;

  break;

  }

-#ifdef CONFIG_DEBUG_USER

- /*

-  * experience shows that these seem to indicate that

-  * something catastrophic has happened

-  */

- if (user_debug & UDBG_SYSCALL) {

- printk("[%d] %s: arm syscall %d\n",

-        task_pid_nr(current), current->comm, no);

- dump_instr("", regs);

- if (user_mode(regs)) {

- __show_regs(regs);

- c_backtrace(frame_pointer(regs), processor_mode(regs));

- }

- }

-#endif

+

+  printk("[%d] %s: arm syscall %d\n",

+  task_pid_nr(current), current->comm, no);

+  dump_instr("", regs);

+  __show_regs(regs);

+  c_backtrace(frame_pointer(regs), processor_mode(regs));

+

+ trace_exe_filename();

+

  info.si_signo = SIGILL;

  info.si_errno = 0;

  info.si_code  = ILL_ILLTRP;

@@ -769,14 +804,11 @@ baddataabort(int code, unsigned long instr, struct pt_regs *regs)

  unsigned long addr = instruction_pointer(regs);

  siginfo_t info;

 

-#ifdef CONFIG_DEBUG_USER

- if (user_debug & UDBG_BADABORT) {

- printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",

+ printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",

  task_pid_nr(current), current->comm, code, instr);

- dump_instr(KERN_ERR, regs);

- show_pte(current->mm, addr);

- }

-#endif

+ dump_instr(KERN_ERR, regs);

+ show_pte(current->mm, addr);

+ trace_exe_filename();

 

  info.si_signo = SIGILL;

  info.si_errno = 0;

diff --git a/fs/exec.c b/fs/exec.c

index b7a5f46..b6089dc 100644

--- a/fs/exec.c

+++ b/fs/exec.c

@@ -1425,6 +1425,34 @@ int search_binary_handler(struct linux_binprm *bprm)

 }

 EXPORT_SYMBOL(search_binary_handler);

 

+#define PROCESS_ARG_BUFF_SIZE 128

+

+void trace_process_exec_profile(const char *fname)

+{

+       char process_arg_buf[PROCESS_ARG_BUFF_SIZE] = {0,};

+       int len = 0;

+

+       len = get_cmdline(current, process_arg_buf, PROCESS_ARG_BUFF_SIZE -1);

+

+       if(len == 0) {

+               pr_info("[-] Error: len: %d \n", len);

+               return;

+       }

+

+       if(!fname) {

+               pr_info("[-] Error: fname null \n");

+               return;

+       }

+

+       if (len > PROCESS_ARG_BUFF_SIZE)

+               len = PROCESS_ARG_BUFF_SIZE;

+

+       process_arg_buf[len] = '\0';

+

+       pr_info("[exec:%s-%d] exec_file: %s, arg: [%s] \n",

+                                       current->comm, current->pid, fname, process_arg_buf);

+}

+

 static int exec_binprm(struct linux_binprm *bprm)

 {

  pid_t old_pid, old_vpid;

@@ -1442,6 +1470,8 @@ static int exec_binprm(struct linux_binprm *bprm)

  trace_sched_process_exec(current, old_pid, bprm);

  ptrace_event(PTRACE_EVENT_EXEC, old_vpid);

  proc_exec_connector(current);

+

+ trace_process_exec_profile(bprm->filename);

  }

 

  return ret;