Re: PATCH: ptrace support for fork/vfork/clone events [1/3]

From: Daniel Jacobowitz (dan@debian.org)
Date: Thu Oct 31 2002 - 15:02:36 EST


And the interesting one, #3.

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.857 -> 1.858
# include/linux/sched.h 1.95.1.2 -> 1.98
# kernel/fork.c 1.77.1.12 -> 1.81
# include/linux/ptrace.h 1.4 -> 1.5
# fs/binfmt_aout.c 1.12.1.1 -> 1.14
# fs/binfmt_elf.c 1.29 -> 1.30
# kernel/ptrace.c 1.19 -> 1.20
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/10/31 drow@nevyn.them.org 1.858
# Merge nevyn.them.org:/nevyn/big/kernel/test/linux-2.5-trace2
# into nevyn.them.org:/nevyn/big/kernel/test/linux-2.5-trace3
# --------------------------------------------
#
diff -Nru a/fs/binfmt_aout.c b/fs/binfmt_aout.c
--- a/fs/binfmt_aout.c Thu Oct 31 14:02:04 2002
+++ b/fs/binfmt_aout.c Thu Oct 31 14:02:04 2002
@@ -425,8 +425,12 @@
         regs->gp = ex.a_gpvalue;
 #endif
         start_thread(regs, ex.a_entry, current->mm->start_stack);
- if (current->ptrace & PT_PTRACED)
- send_sig(SIGTRAP, current, 0);
+ if (unlikely(current->ptrace & PT_PTRACED)) {
+ if (current->ptrace & PT_TRACE_EXEC)
+ ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
+ else
+ send_sig(SIGTRAP, current, 0);
+ }
         return 0;
 }
 
diff -Nru a/fs/binfmt_elf.c b/fs/binfmt_elf.c
--- a/fs/binfmt_elf.c Thu Oct 31 14:02:04 2002
+++ b/fs/binfmt_elf.c Thu Oct 31 14:02:04 2002
@@ -792,8 +792,12 @@
 #endif
 
         start_thread(regs, elf_entry, bprm->p);
- if (current->ptrace & PT_PTRACED)
- send_sig(SIGTRAP, current, 0);
+ if (unlikely(current->ptrace & PT_PTRACED)) {
+ if (current->ptrace & PT_TRACE_EXEC)
+ ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
+ else
+ send_sig(SIGTRAP, current, 0);
+ }
         retval = 0;
 out:
         return retval;
diff -Nru a/include/linux/ptrace.h b/include/linux/ptrace.h
--- a/include/linux/ptrace.h Thu Oct 31 14:02:04 2002
+++ b/include/linux/ptrace.h Thu Oct 31 14:02:04 2002
@@ -25,9 +25,20 @@
 
 /* 0x4200-0x4300 are reserved for architecture-independent additions. */
 #define PTRACE_SETOPTIONS 0x4200
+#define PTRACE_GETEVENTMSG 0x4201
 
 /* options set using PTRACE_SETOPTIONS */
 #define PTRACE_O_TRACESYSGOOD 0x00000001
+#define PTRACE_O_TRACEFORK 0x00000002
+#define PTRACE_O_TRACEVFORK 0x00000004
+#define PTRACE_O_TRACECLONE 0x00000008
+#define PTRACE_O_TRACEEXEC 0x00000010
+
+/* Wait extended result codes for the above trace options. */
+#define PTRACE_EVENT_FORK 1
+#define PTRACE_EVENT_VFORK 2
+#define PTRACE_EVENT_CLONE 3
+#define PTRACE_EVENT_EXEC 4
 
 #include <asm/ptrace.h>
 #include <linux/sched.h>
@@ -39,6 +50,7 @@
 extern void ptrace_disable(struct task_struct *);
 extern int ptrace_check_attach(struct task_struct *task, int kill);
 extern int ptrace_request(struct task_struct *child, long request, long addr, long data);
+extern void ptrace_notify(int exit_code);
 extern void __ptrace_link(struct task_struct *child,
                                 struct task_struct *new_parent);
 extern void __ptrace_unlink(struct task_struct *child);
diff -Nru a/include/linux/sched.h b/include/linux/sched.h
--- a/include/linux/sched.h Thu Oct 31 14:02:04 2002
+++ b/include/linux/sched.h Thu Oct 31 14:02:04 2002
@@ -389,6 +389,8 @@
         void *journal_info;
         struct dentry *proc_dentry;
         struct backing_dev_info *backing_dev_info;
+
+ unsigned long ptrace_message;
 };
 
 extern void __put_task_struct(struct task_struct *tsk);
@@ -427,6 +429,10 @@
 #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
 #define PT_TRACESYSGOOD 0x00000004
 #define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */
+#define PT_TRACE_FORK 0x00000010
+#define PT_TRACE_VFORK 0x00000020
+#define PT_TRACE_CLONE 0x00000040
+#define PT_TRACE_EXEC 0x00000080
 
 /*
  * Limit the stack by to some sane default: root can always
diff -Nru a/kernel/fork.c b/kernel/fork.c
--- a/kernel/fork.c Thu Oct 31 14:02:04 2002
+++ b/kernel/fork.c Thu Oct 31 14:02:04 2002
@@ -943,6 +943,22 @@
         goto fork_out;
 }
 
+static inline int fork_traceflag (unsigned clone_flags)
+{
+ if (clone_flags & (CLONE_UNTRACED | CLONE_IDLETASK))
+ return 0;
+ else if (clone_flags & CLONE_VFORK) {
+ if (current->ptrace & PT_TRACE_VFORK)
+ return PTRACE_EVENT_VFORK;
+ } else if ((clone_flags & CSIGNAL) != SIGCHLD) {
+ if (current->ptrace & PT_TRACE_CLONE)
+ return PTRACE_EVENT_CLONE;
+ } else if (current->ptrace & PT_TRACE_FORK)
+ return PTRACE_EVENT_FORK;
+
+ return 0;
+}
+
 /*
  * Ok, this is the main fork-routine.
  *
@@ -956,6 +972,13 @@
                             int *user_tid)
 {
         struct task_struct *p;
+ int trace = 0;
+
+ if (unlikely(current->ptrace)) {
+ trace = fork_traceflag (clone_flags);
+ if (trace)
+ clone_flags |= CLONE_PTRACE;
+ }
 
         p = copy_process(clone_flags, stack_start, regs, stack_size, user_tid);
         if (!IS_ERR(p)) {
@@ -971,6 +994,12 @@
 
                 wake_up_forked_process(p); /* do this last */
                 ++total_forks;
+
+ if (unlikely (trace)) {
+ current->ptrace_message = (unsigned long) p->pid;
+ ptrace_notify ((trace << 8) | SIGTRAP);
+ }
+
                 if (clone_flags & CLONE_VFORK)
                         wait_for_completion(&vfork);
                 else
diff -Nru a/kernel/ptrace.c b/kernel/ptrace.c
--- a/kernel/ptrace.c Thu Oct 31 14:02:04 2002
+++ b/kernel/ptrace.c Thu Oct 31 14:02:04 2002
@@ -249,14 +249,37 @@
         return copied;
 }
 
-int ptrace_setoptions(struct task_struct *child, long data)
+static int ptrace_setoptions(struct task_struct *child, long data)
 {
         if (data & PTRACE_O_TRACESYSGOOD)
                 child->ptrace |= PT_TRACESYSGOOD;
         else
                 child->ptrace &= ~PT_TRACESYSGOOD;
 
- if ((data & PTRACE_O_TRACESYSGOOD) != data)
+ if (data & PTRACE_O_TRACEFORK)
+ child->ptrace |= PT_TRACE_FORK;
+ else
+ child->ptrace &= ~PT_TRACE_FORK;
+
+ if (data & PTRACE_O_TRACEVFORK)
+ child->ptrace |= PT_TRACE_VFORK;
+ else
+ child->ptrace &= ~PT_TRACE_VFORK;
+
+ if (data & PTRACE_O_TRACECLONE)
+ child->ptrace |= PT_TRACE_CLONE;
+ else
+ child->ptrace &= ~PT_TRACE_CLONE;
+
+ if (data & PTRACE_O_TRACEEXEC)
+ child->ptrace |= PT_TRACE_EXEC;
+ else
+ child->ptrace &= ~PT_TRACE_EXEC;
+
+ if ((data & (PTRACE_O_TRACESYSGOOD | PTRACE_O_TRACEFORK
+ | PTRACE_O_TRACEVFORK | PTRACE_O_TRACECLONE
+ | PTRACE_O_TRACEEXEC))
+ != data)
                 return -EINVAL;
 
         return 0;
@@ -274,9 +297,23 @@
         case PTRACE_SETOPTIONS:
                 ret = ptrace_setoptions(child, data);
                 break;
+ case PTRACE_GETEVENTMSG:
+ ret = put_user(child->ptrace_message, (unsigned long *) data);
+ break;
         default:
                 break;
         }
 
         return ret;
+}
+
+void ptrace_notify(int exit_code)
+{
+ BUG_ON (!(current->ptrace & PT_PTRACED));
+
+ /* Let the debugger run. */
+ current->exit_code = exit_code;
+ set_current_state(TASK_STOPPED);
+ notify_parent(current, SIGCHLD);
+ schedule();
 }

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer
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This archive was generated by hypermail 2b29 : Thu Oct 31 2002 - 22:00:56 EST