245 lines
8.3 KiB
Diff
245 lines
8.3 KiB
Diff
http://sourceware.org/ml/gdb-patches/2012-03/msg00171.html
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Subject: [patch 3/3] attach-fail-reasons: SELinux deny_ptrace
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Hi,
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and here is the last bit for new SELinux 'deny_ptrace':
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https://bugzilla.redhat.com/show_bug.cgi?id=786878
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As even PTRACE_TRACEME fails in such case it needs to install hook for even
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that event.
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Thanks,
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Jan
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gdb/
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2012-03-06 Jan Kratochvil <jan.kratochvil@redhat.com>
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* common/linux-ptrace.c [HAVE_SELINUX_SELINUX_H]: include
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selinux/selinux.h.
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(linux_ptrace_attach_warnings): Call linux_ptrace_create_warnings.
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(linux_ptrace_create_warnings): New.
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* common/linux-ptrace.h (linux_ptrace_create_warnings): New declaration.
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* config.in: Regenerate.
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* configure: Regenerate.
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* configure.ac: Check selinux/selinux.h and the selinux library.
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* inf-ptrace.c (inf_ptrace_me): Check the ptrace result.
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* linux-nat.c (linux_nat_create_inferior): New variable ex. Wrap
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to_create_inferior into TRY_CATCH, call linux_ptrace_create_warnings.
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gdb/gdbserver/
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* config.in: Regenerate.
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* configure: Regenerate.
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* configure.ac: Check selinux/selinux.h and the selinux library.
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* linux-low.c (linux_traceme): New function.
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(linux_create_inferior, linux_tracefork_child): Call it instead of
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direct ptrace.
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Index: gdb-7.5.50.20130118/gdb/common/linux-ptrace.c
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===================================================================
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--- gdb-7.5.50.20130118.orig/gdb/common/linux-ptrace.c 2013-01-18 23:18:47.313360065 +0100
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+++ gdb-7.5.50.20130118/gdb/common/linux-ptrace.c 2013-01-18 23:19:27.269417051 +0100
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@@ -29,6 +29,10 @@
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#include "gdb_assert.h"
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#include "gdb_wait.h"
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+#ifdef HAVE_SELINUX_SELINUX_H
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+# include <selinux/selinux.h>
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+#endif /* HAVE_SELINUX_SELINUX_H */
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+
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/* Find all possible reasons we could fail to attach PID and append these
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newline terminated reason strings to initialized BUFFER. '\0' termination
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of BUFFER must be done by the caller. */
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@@ -48,6 +52,8 @@ linux_ptrace_attach_warnings (pid_t pid,
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buffer_xml_printf (buffer, _("warning: process %d is a zombie "
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"- the process has already terminated\n"),
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(int) pid);
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+
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+ linux_ptrace_create_warnings (buffer);
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}
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#if defined __i386__ || defined __x86_64__
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@@ -243,3 +249,19 @@ linux_ptrace_init_warnings (void)
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linux_ptrace_test_ret_to_nx ();
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}
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+
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+/* Print all possible reasons we could fail to create a traced process. */
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+
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+void
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+linux_ptrace_create_warnings (struct buffer *buffer)
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+{
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+#ifdef HAVE_LIBSELINUX
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+ /* -1 is returned for errors, 0 if it has no effect, 1 if PTRACE_ATTACH is
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+ forbidden. */
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+ if (security_get_boolean_active ("deny_ptrace") == 1)
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+ buffer_xml_printf (buffer,
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+ _("the SELinux boolean 'deny_ptrace' is enabled, "
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+ "you can disable this process attach protection by: "
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+ "(gdb) shell sudo setsebool deny_ptrace=0"));
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+#endif /* HAVE_LIBSELINUX */
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+}
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Index: gdb-7.5.50.20130118/gdb/common/linux-ptrace.h
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===================================================================
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--- gdb-7.5.50.20130118.orig/gdb/common/linux-ptrace.h 2013-01-18 23:18:47.313360065 +0100
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+++ gdb-7.5.50.20130118/gdb/common/linux-ptrace.h 2013-01-18 23:19:04.990385360 +0100
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@@ -69,5 +69,6 @@ struct buffer;
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extern void linux_ptrace_attach_warnings (pid_t pid, struct buffer *buffer);
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extern void linux_ptrace_init_warnings (void);
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+extern void linux_ptrace_create_warnings (struct buffer *buffer);
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#endif /* COMMON_LINUX_PTRACE_H */
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Index: gdb-7.5.50.20130118/gdb/configure.ac
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===================================================================
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--- gdb-7.5.50.20130118.orig/gdb/configure.ac 2013-01-18 23:18:47.315360069 +0100
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+++ gdb-7.5.50.20130118/gdb/configure.ac 2013-01-18 23:19:04.991385362 +0100
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@@ -2068,6 +2068,10 @@ then
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[Define if you support the personality syscall.])
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fi
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+dnl Check security_get_boolean_active availability.
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+AC_CHECK_HEADERS(selinux/selinux.h)
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+AC_CHECK_LIB(selinux, security_get_boolean_active)
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+
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dnl Handle optional features that can be enabled.
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# Support for --with-sysroot is a copy of GDB_AC_WITH_DIR,
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Index: gdb-7.5.50.20130118/gdb/gdbserver/configure.ac
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===================================================================
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--- gdb-7.5.50.20130118.orig/gdb/gdbserver/configure.ac 2013-01-18 23:18:47.315360069 +0100
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+++ gdb-7.5.50.20130118/gdb/gdbserver/configure.ac 2013-01-18 23:19:04.991385362 +0100
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@@ -451,6 +451,10 @@ if $want_ipa ; then
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fi
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fi
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+dnl Check security_get_boolean_active availability.
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+AC_CHECK_HEADERS(selinux/selinux.h)
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+AC_CHECK_LIB(selinux, security_get_boolean_active)
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+
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AC_SUBST(GDBSERVER_DEPFILES)
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AC_SUBST(GDBSERVER_LIBS)
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AC_SUBST(USE_THREAD_DB)
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Index: gdb-7.5.50.20130118/gdb/gdbserver/linux-low.c
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===================================================================
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--- gdb-7.5.50.20130118.orig/gdb/gdbserver/linux-low.c 2013-01-18 23:18:47.317360073 +0100
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+++ gdb-7.5.50.20130118/gdb/gdbserver/linux-low.c 2013-01-18 23:19:04.993385366 +0100
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@@ -601,6 +601,28 @@ add_lwp (ptid_t ptid)
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return lwp;
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}
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+/* Execute PTRACE_TRACEME with error checking. */
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+
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+static void
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+linux_traceme (const char *program)
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+{
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+ int save_errno;
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+ struct buffer buffer;
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+
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+ errno = 0;
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+ if (ptrace (PTRACE_TRACEME, 0, NULL, NULL) == 0)
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+ return;
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+
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+ save_errno = errno;
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+ buffer_init (&buffer);
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+ linux_ptrace_create_warnings (&buffer);
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+ buffer_grow_str0 (&buffer, "");
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+ fprintf (stderr, _("%sCannot trace created process %s: %s.\n"),
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+ buffer_finish (&buffer), program, strerror (save_errno));
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+ fflush (stderr);
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+ _exit (0177);
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+}
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+
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/* Start an inferior process and returns its pid.
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ALLARGS is a vector of program-name and args. */
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@@ -641,7 +663,7 @@ linux_create_inferior (char *program, ch
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if (pid == 0)
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{
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- ptrace (PTRACE_TRACEME, 0, 0, 0);
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+ linux_traceme (program);
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#ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
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signal (__SIGRTMIN + 1, SIG_DFL);
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@@ -4574,7 +4596,7 @@ linux_tracefork_grandchild (void *arg)
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static int
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linux_tracefork_child (void *arg)
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{
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- ptrace (PTRACE_TRACEME, 0, 0, 0);
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+ linux_traceme ("PTRACE_O_TRACEFORK test");
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kill (getpid (), SIGSTOP);
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#if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
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Index: gdb-7.5.50.20130118/gdb/inf-ptrace.c
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===================================================================
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--- gdb-7.5.50.20130118.orig/gdb/inf-ptrace.c 2013-01-18 23:18:47.318360076 +0100
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+++ gdb-7.5.50.20130118/gdb/inf-ptrace.c 2013-01-18 23:19:04.993385366 +0100
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@@ -104,7 +104,15 @@ static void
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inf_ptrace_me (void)
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{
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/* "Trace me, Dr. Memory!" */
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+ errno = 0;
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ptrace (PT_TRACE_ME, 0, (PTRACE_TYPE_ARG3)0, 0);
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+ if (errno != 0)
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+ {
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+ fprintf_unfiltered (gdb_stderr, _("Cannot create process: %s\n"),
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+ safe_strerror (errno));
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+ gdb_flush (gdb_stderr);
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+ _exit (0177);
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+ }
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}
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/* Start a new inferior Unix child process. EXEC_FILE is the file to
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Index: gdb-7.5.50.20130118/gdb/linux-nat.c
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===================================================================
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--- gdb-7.5.50.20130118.orig/gdb/linux-nat.c 2013-01-18 23:18:47.320360083 +0100
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+++ gdb-7.5.50.20130118/gdb/linux-nat.c 2013-01-18 23:19:04.994385369 +0100
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@@ -1578,6 +1578,7 @@ linux_nat_create_inferior (struct target
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#ifdef HAVE_PERSONALITY
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int personality_orig = 0, personality_set = 0;
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#endif /* HAVE_PERSONALITY */
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+ volatile struct gdb_exception ex;
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/* The fork_child mechanism is synchronous and calls target_wait, so
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we have to mask the async mode. */
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@@ -1602,7 +1603,10 @@ linux_nat_create_inferior (struct target
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/* Make sure we report all signals during startup. */
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linux_nat_pass_signals (0, NULL);
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- linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
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+ TRY_CATCH (ex, RETURN_MASK_ERROR)
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+ {
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+ linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
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+ }
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#ifdef HAVE_PERSONALITY
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if (personality_set)
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@@ -1614,6 +1618,24 @@ linux_nat_create_inferior (struct target
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safe_strerror (errno));
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}
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#endif /* HAVE_PERSONALITY */
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+
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+ if (ex.reason < 0)
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+ {
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+ struct buffer buffer;
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+ char *message, *buffer_s;
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+
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+ message = xstrdup (ex.message);
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+ make_cleanup (xfree, message);
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+
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+ buffer_init (&buffer);
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+ linux_ptrace_create_warnings (&buffer);
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+
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+ buffer_grow_str0 (&buffer, "");
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+ buffer_s = buffer_finish (&buffer);
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+ make_cleanup (xfree, buffer_s);
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+
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+ throw_error (ex.error, "%s%s", buffer_s, message);
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+ }
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}
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static void
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