Fix: ust-fork: reverse order of "after" callbacks

The "after" callbacks restore the pthread cancelstate to the prior
state, and warn on the application console when LTTNG_UST_DEBUG=1 is set
if the cancelstate restored does not match the cancelstate saved.

It is therefore important that we keep the following order:

  - begin callback (2.13)
  - begin callback (2.12)
    ...
  - after callback (2.12)
  - after callback (2.13)

to preserve the correct nesting of saved/restored pthread cancelstate.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Id95792654d514e0dcd09c00ff5dc0d220fb27f87

diff --git a/src/lib/lttng-ust-fork/ustfork.c b/src/lib/lttng-ust-fork/ustfork.c
index ec6974b0cbf020c396c26540095a9a9e3d66565b..b3b182dd74ee240db741805adb2dca84c53fa671 100644 (file)
--- a/src/lib/lttng-ust-fork/ustfork.c
+++ b/src/lib/lttng-ust-fork/ustfork.c
@@ -263,19 +263,19 @@ pid_t fork(void)
        saved_errno = errno;
        if (retval == 0) {
                /* child */
-               lttng_ust_after_fork_child(&sigset);
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
                if (_init_ust_after_fork_child()) {
                        __ust_after_fork_child(&sigset);
                }
 #endif
+               lttng_ust_after_fork_child(&sigset);
        } else {
-               lttng_ust_after_fork_parent(&sigset);
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
                if (_init_ust_after_fork_parent()) {
                        __ust_after_fork_parent(&sigset);
                }
 #endif
+               lttng_ust_after_fork_parent(&sigset);
        }
        errno = saved_errno;
        return retval;
@@ -309,20 +309,20 @@ int daemon(int nochdir, int noclose)
        saved_errno = errno;
        if (retval == 0) {
                /* child, parent called _exit() directly */
-               lttng_ust_after_fork_child(&sigset);
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
                if (_init_ust_after_fork_child()) {
                        __ust_after_fork_child(&sigset);
                }
 #endif
+               lttng_ust_after_fork_child(&sigset);
        } else {
                /* on error in the parent */
-               lttng_ust_after_fork_parent(&sigset);
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
                if (_init_ust_after_fork_parent()) {
                        __ust_after_fork_parent(&sigset);
                }
 #endif
+               lttng_ust_after_fork_parent(&sigset);
        }
        errno = saved_errno;
        return retval;
@@ -347,12 +347,12 @@ int setuid(uid_t uid)
        retval = plibc_func(uid);
        saved_errno = errno;
 
-       lttng_ust_after_setuid();
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
        if (_init_ust_after_setuid()) {
                __ust_after_setuid();
        }
 #endif
+       lttng_ust_after_setuid();
 
        errno = saved_errno;
        return retval;
@@ -377,12 +377,12 @@ int setgid(gid_t gid)
        retval = plibc_func(gid);
        saved_errno = errno;
 
-       lttng_ust_after_setgid();
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
        if (_init_ust_after_setgid()) {
                __ust_after_setgid();
        }
 #endif
+       lttng_ust_after_setgid();
 
        errno = saved_errno;
        return retval;
@@ -407,12 +407,12 @@ int seteuid(uid_t euid)
        retval = plibc_func(euid);
        saved_errno = errno;
 
-       lttng_ust_after_seteuid();
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
        if (_init_ust_after_seteuid()) {
                __ust_after_seteuid();
        }
 #endif
+       lttng_ust_after_seteuid();
 
        errno = saved_errno;
        return retval;
@@ -437,12 +437,12 @@ int setegid(gid_t egid)
        retval = plibc_func(egid);
        saved_errno = errno;
 
-       lttng_ust_after_setegid();
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
        if (_init_ust_after_setegid()) {
                __ust_after_setegid();
        }
 #endif
+       lttng_ust_after_setegid();
 
        errno = saved_errno;
        return retval;
@@ -467,12 +467,12 @@ int setreuid(uid_t ruid, uid_t euid)
        retval = plibc_func(ruid, euid);
        saved_errno = errno;
 
-       lttng_ust_after_setreuid();
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
        if (_init_ust_after_setreuid()) {
                __ust_after_setreuid();
        }
 #endif
+       lttng_ust_after_setreuid();
 
        errno = saved_errno;
        return retval;
@@ -497,12 +497,12 @@ int setregid(gid_t rgid, gid_t egid)
        retval = plibc_func(rgid, egid);
        saved_errno = errno;
 
-       lttng_ust_after_setregid();
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
        if (_init_ust_after_setregid()) {
                __ust_after_setregid();
        }
 #endif
+       lttng_ust_after_setregid();
 
        errno = saved_errno;
        return retval;
@@ -523,12 +523,12 @@ static int clone_fn(void *arg)
        struct ustfork_clone_info *info = (struct ustfork_clone_info *) arg;
 
        /* clone is now done and we are in child */
-       lttng_ust_after_fork_child(&info->sigset);
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
        if (_init_ust_after_fork_child()) {
                __ust_after_fork_child(&info->sigset);
        }
 #endif
+       lttng_ust_after_fork_child(&info->sigset);
        return info->fn(info->arg);
 }
 
@@ -583,12 +583,12 @@ int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...)
                                ptid, tls, ctid);
                saved_errno = errno;
                /* The child doesn't get here. */
-               lttng_ust_after_fork_parent(&info.sigset);
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
                if (_init_ust_after_fork_parent()) {
                        __ust_after_fork_parent(&info.sigset);
                }
 #endif
+               lttng_ust_after_fork_parent(&info.sigset);
        }
        errno = saved_errno;
        return retval;
@@ -613,12 +613,12 @@ int setns(int fd, int nstype)
        retval = plibc_func(fd, nstype);
        saved_errno = errno;
 
-       lttng_ust_after_setns();
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
        if (_init_ust_after_setns()) {
                __ust_after_setns();
        }
 #endif
+       lttng_ust_after_setns();
 
        errno = saved_errno;
        return retval;
@@ -643,12 +643,12 @@ int unshare(int flags)
        retval = plibc_func(flags);
        saved_errno = errno;
 
-       lttng_ust_after_unshare();
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
        if (_init_ust_after_unshare()) {
                __ust_after_unshare();
        }
 #endif
+       lttng_ust_after_unshare();
 
        errno = saved_errno;
        return retval;
@@ -673,12 +673,12 @@ int setresuid(uid_t ruid, uid_t euid, uid_t suid)
        retval = plibc_func(ruid, euid, suid);
        saved_errno = errno;
 
-       lttng_ust_after_setresuid();
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
        if (_init_ust_after_setresuid()) {
                __ust_after_setresuid();
        }
 #endif
+       lttng_ust_after_setresuid();
 
        errno = saved_errno;
        return retval;
@@ -703,12 +703,12 @@ int setresgid(gid_t rgid, gid_t egid, gid_t sgid)
        retval = plibc_func(rgid, egid, sgid);
        saved_errno = errno;
 
-       lttng_ust_after_setresgid();
 #if !defined(LTTNG_UST_CUSTOM_UPGRADE_CONFLICTING_SYMBOLS)
        if (_init_ust_after_setresgid()) {
                __ust_after_setresgid();
        }
 #endif
+       lttng_ust_after_setresgid();
 
        errno = saved_errno;
        return retval;