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[RFA] Change maybe_disable_address_space_randomization to a class
- From: Tom Tromey <tom at tromey dot com>
- To: gdb-patches at sourceware dot org
- Cc: Tom Tromey <tom at tromey dot com>
- Date: Sat, 25 Nov 2017 14:11:13 -0700
- Subject: [RFA] Change maybe_disable_address_space_randomization to a class
- Authentication-results: sourceware.org; auth=none
This changes maybe_disable_address_space_randomization to be an RAII
class, rather than having it return a cleanup.
Regression tested by the buildbot.
ChangeLog
2017-11-25 Tom Tromey <tom@tromey.com>
* nat/linux-personality.h (class
maybe_disable_address_space_randomization): New class.
(maybe_disable_address_space_randomization): Don't declare
function.
* nat/linux-personality.c (restore_personality)
(make_disable_asr_cleanup): Remove.
(maybe_disable_address_space_randomization): Now a constructor.
(~maybe_disable_address_space_randomization): New destructor.
* linux-nat.c (linux_nat_create_inferior): Update.
gdbserver/ChangeLog
2017-11-25 Tom Tromey <tom@tromey.com>
* linux-low.c (linux_create_inferior): Update.
---
gdb/ChangeLog | 12 ++++++++
gdb/gdbserver/ChangeLog | 4 +++
gdb/gdbserver/linux-low.c | 19 ++++++------
gdb/linux-nat.c | 6 ++--
gdb/nat/linux-personality.c | 71 +++++++++++++++------------------------------
gdb/nat/linux-personality.h | 27 +++++++++++++----
6 files changed, 72 insertions(+), 67 deletions(-)
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 274263a947..c2420fdf57 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -998,16 +998,17 @@ linux_create_inferior (const char *program,
struct lwp_info *new_lwp;
int pid;
ptid_t ptid;
- struct cleanup *restore_personality
- = maybe_disable_address_space_randomization (disable_randomization);
- std::string str_program_args = stringify_argv (program_args);
- pid = fork_inferior (program,
- str_program_args.c_str (),
- get_environ ()->envp (), linux_ptrace_fun,
- NULL, NULL, NULL, NULL);
-
- do_cleanups (restore_personality);
+ {
+ maybe_disable_address_space_randomization restore_personality
+ (disable_randomization);
+ std::string str_program_args = stringify_argv (program_args);
+
+ pid = fork_inferior (program,
+ str_program_args.c_str (),
+ get_environ ()->envp (), linux_ptrace_fun,
+ NULL, NULL, NULL, NULL);
+ }
linux_add_process (pid, 0);
diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index a6395f4b5e..96cb21a2cf 100644
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -1118,8 +1118,8 @@ linux_nat_create_inferior (struct target_ops *ops,
const char *exec_file, const std::string &allargs,
char **env, int from_tty)
{
- struct cleanup *restore_personality
- = maybe_disable_address_space_randomization (disable_randomization);
+ maybe_disable_address_space_randomization restore_personality
+ (disable_randomization);
/* The fork_child mechanism is synchronous and calls target_wait, so
we have to mask the async mode. */
@@ -1128,8 +1128,6 @@ linux_nat_create_inferior (struct target_ops *ops,
linux_nat_pass_signals (ops, 0, NULL);
linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
-
- do_cleanups (restore_personality);
}
/* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
diff --git a/gdb/nat/linux-personality.c b/gdb/nat/linux-personality.c
index 21a9ca9d83..bcec2ce5f3 100644
--- a/gdb/nat/linux-personality.c
+++ b/gdb/nat/linux-personality.c
@@ -27,68 +27,43 @@
# endif /* ! HAVE_DECL_ADDR_NO_RANDOMIZE */
#endif /* HAVE_PERSONALITY */
-#ifdef HAVE_PERSONALITY
-
-/* Restore address space randomization of the inferior. ARG is the
- original inferior's personality value before the address space
- randomization was disabled. */
-
-static void
-restore_personality (void *arg)
-{
- int personality_orig = (int) (uintptr_t) arg;
-
- errno = 0;
- personality (personality_orig);
- if (errno != 0)
- warning (_("Error restoring address space randomization: %s"),
- safe_strerror (errno));
-}
-#endif /* HAVE_PERSONALITY */
-
-/* Return a cleanup responsible for restoring the inferior's
- personality (and restoring the inferior's address space
- randomization) if HAVE_PERSONALITY and if PERSONALITY_SET is not
- zero; return a null cleanup if not HAVE_PERSONALITY or if
- PERSONALITY_SET is zero. */
-
-static struct cleanup *
-make_disable_asr_cleanup (int personality_set, int personality_orig)
-{
-#ifdef HAVE_PERSONALITY
- if (personality_set != 0)
- return make_cleanup (restore_personality,
- (void *) (uintptr_t) personality_orig);
-#endif /* HAVE_PERSONALITY */
-
- return make_cleanup (null_cleanup, NULL);
-}
-
/* See comment on nat/linux-personality.h. */
-struct cleanup *
+maybe_disable_address_space_randomization::
maybe_disable_address_space_randomization (int disable_randomization)
+ : m_personality_set (false),
+ m_personality_orig (0)
{
- int personality_orig = 0;
- int personality_set = 0;
-
#ifdef HAVE_PERSONALITY
if (disable_randomization)
{
errno = 0;
- personality_orig = personality (0xffffffff);
- if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
+ m_personality_orig = personality (0xffffffff);
+ if (errno == 0 && !(m_personality_orig & ADDR_NO_RANDOMIZE))
{
- personality_set = 1;
- personality (personality_orig | ADDR_NO_RANDOMIZE);
+ m_personality_set = true;
+ personality (m_personality_orig | ADDR_NO_RANDOMIZE);
}
- if (errno != 0 || (personality_set
+ if (errno != 0 || (m_personality_set
&& !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
warning (_("Error disabling address space randomization: %s"),
safe_strerror (errno));
}
#endif /* HAVE_PERSONALITY */
+}
+
+maybe_disable_address_space_randomization::
+~maybe_disable_address_space_randomization ()
+{
+#ifdef HAVE_PERSONALITY
- return make_disable_asr_cleanup (personality_set,
- personality_orig);
+ if (m_personality_set)
+ {
+ errno = 0;
+ personality (m_personality_orig);
+ if (errno != 0)
+ warning (_("Error restoring address space randomization: %s"),
+ safe_strerror (errno));
+ }
+#endif /* HAVE_PERSONALITY */
}
diff --git a/gdb/nat/linux-personality.h b/gdb/nat/linux-personality.h
index 687086e68b..fcea02a67d 100644
--- a/gdb/nat/linux-personality.h
+++ b/gdb/nat/linux-personality.h
@@ -20,12 +20,27 @@
#ifndef NAT_LINUX_PERSONALITY_H
#define NAT_LINUX_PERSONALITY_H
-/* Disable the inferior's address space randomization if
- DISABLE_RANDOMIZATION is not zero and if we have
- <sys/personality.h>. Return a cleanup which, when called, will
- re-enable the inferior's address space randomization. */
+class maybe_disable_address_space_randomization
+{
+public:
-extern struct cleanup *maybe_disable_address_space_randomization
- (int disable_randomization);
+ /* Disable the inferior's address space randomization if
+ DISABLE_RANDOMIZATION is not zero and if we have
+ <sys/personality.h>. */
+ maybe_disable_address_space_randomization (int disable_randomization);
+
+ /* On destruction, re-enable address space randomization. */
+ ~maybe_disable_address_space_randomization ();
+
+ DISABLE_COPY_AND_ASSIGN (maybe_disable_address_space_randomization);
+
+private:
+
+ /* True if the personality was set in the constructor. */
+ bool m_personality_set;
+
+ /* If m_personality_set is true, the original personality value. */
+ int m_personality_orig;
+};
#endif /* ! NAT_LINUX_PERSONALITY_H */
--
2.13.6