[Ltrace-devel] r75 - in ltrace/trunk: . sysdeps/linux-gnu

[Petr Machata]

Author: pmachata-guest
Date: 2007-01-25 18:05:44 +0100 (Thu, 25 Jan 2007)
New Revision: 75

Modified:
   ltrace/trunk/ChangeLog
   ltrace/trunk/breakpoints.c
   ltrace/trunk/proc.c
   ltrace/trunk/sysdeps/linux-gnu/trace.c
Log:
- fix -p behavior: wait for process to stop after PTRACE_ATTACH
- fix -L behavior: always initialize the breakpoint dictionary,
  and thus aviod NULL dereference.


Modified: ltrace/trunk/ChangeLog
===================================================================
--- ltrace/trunk/ChangeLog	2006-12-28 15:16:56 UTC (rev 74)
+++ ltrace/trunk/ChangeLog	2007-01-25 17:05:44 UTC (rev 75)
@@ -1,3 +1,13 @@
+2007-01-19  Petr Machata  <pmachata at redhat.com>
+
+	* sysdeps/linux-gnu/trace.c (trace_pid): wait for child to stop,
+	as indicated by ptrace documentation.
+	* proc.c (open_pid): start the traced child again, it will have
+	been stopped after trace_pid.  Fixes tracing with -p.
+	* breakpoints.c: initialize proc->breakpoints always, don't wait
+	untill it might be needed.  This renders a check in insert_breakpoint
+	superfluous.  Fixes a sigsegvs experienced with -L.
+
 2006-12-28  Eric Vaitl  <evaitl at cisco.com>
 
 	* sysdeps/linux-gnu/mipsel/* Added mipsel support

Modified: ltrace/trunk/breakpoints.c
===================================================================
--- ltrace/trunk/breakpoints.c	2006-12-28 15:16:56 UTC (rev 74)
+++ ltrace/trunk/breakpoints.c	2007-01-25 17:05:44 UTC (rev 75)
@@ -30,12 +30,6 @@
 	struct breakpoint *sbp;
 	debug(1, "symbol=%s, addr=%p", libsym?libsym->name:"(nil)", addr);
 
-	if (!proc->breakpoints) {
-		proc->breakpoints =
-		    dict_init(dict_key2hash_int, dict_key_cmp_int);
-		/* atexit(brk_dict_clear); *//* why bother to do this on exit? */
-	}
-
 	if (!addr)
 		return;
 
@@ -169,6 +163,7 @@
 		dict_clear(proc->breakpoints);
 		proc->breakpoints = NULL;
 	}
+	proc->breakpoints = dict_init(dict_key2hash_int, dict_key_cmp_int);
 
 	if (opt_L && proc->filename) {
 		proc->list_of_symbols = read_elf(proc);

Modified: ltrace/trunk/proc.c
===================================================================
--- ltrace/trunk/proc.c	2006-12-28 15:16:56 UTC (rev 74)
+++ ltrace/trunk/proc.c	2007-01-25 17:05:44 UTC (rev 75)
@@ -56,5 +56,6 @@
 #endif
 
 	proc = open_program(filename, pid);
+	continue_process (pid);
 	proc->breakpoints_enabled = 1;
 }

Modified: ltrace/trunk/sysdeps/linux-gnu/trace.c
===================================================================
--- ltrace/trunk/sysdeps/linux-gnu/trace.c	2006-12-28 15:16:56 UTC (rev 74)
+++ ltrace/trunk/sysdeps/linux-gnu/trace.c	2007-01-25 17:05:44 UTC (rev 75)
@@ -4,6 +4,7 @@
 #include <errno.h>
 #include <unistd.h>
 #include <sys/types.h>
+#include <sys/wait.h>
 #include "ptrace.h"
 #include <asm/unistd.h>
 
@@ -87,6 +88,16 @@
 	if (ptrace(PTRACE_ATTACH, pid, 1, 0) < 0) {
 		return -1;
 	}
+
+	/* man ptrace: PTRACE_ATTACH attaches to the process specified
+	   in pid.  The child is sent a SIGSTOP, but will not
+	   necessarily have stopped by the completion of this call;
+	   use wait() to wait for the child to stop. */
+	if (waitpid (pid, NULL, 0) != pid) {
+		perror ("trace_pid: waitpid");
+		exit (1);
+	}
+
 	return 0;
 }