diff options
| author | Brian Behlendorf <[email protected]> | 2011-06-24 11:57:14 -0700 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2011-06-24 13:00:08 -0700 |
| commit | 86fd39f354778eb10e77a7c1660b59ca16ffcc16 (patch) | |
| tree | ddba0bbdcc45babd1863a732c96bc475a19251a7 /config/spl-build.m4 | |
| parent | 79593b0dec57ee94c5bb56cdc2770ebde81ecea9 (diff) | |
Linux 2.6.39 compat, mutex owner
Prior to Linux 2.6.39 when CONFIG_DEBUG_MUTEXES was defined
the kernel stored a thread_info pointer as the mutex owner.
From this you could get the pointer of the current task_struct
to compare with get_current().
As of Linux 2.6.39 this behavior has changed and now the mutex
stores a pointer to the task_struct. This commit detects the
type of pointer stored in the mutex and adjusts the mutex_owner()
and mutex_owned() functions to perform the correct comparision.
Diffstat (limited to 'config/spl-build.m4')
| -rw-r--r-- | config/spl-build.m4 | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/config/spl-build.m4 b/config/spl-build.m4 index 75267bb83..ea5078507 100644 --- a/config/spl-build.m4 +++ b/config/spl-build.m4 @@ -48,6 +48,7 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [ SPL_AC_MONOTONIC_CLOCK SPL_AC_INODE_I_MUTEX SPL_AC_MUTEX_OWNER + SPL_AC_MUTEX_OWNER_TASK_STRUCT SPL_AC_MUTEX_LOCK_NESTED SPL_AC_3ARGS_ON_EACH_CPU SPL_AC_KALLSYMS_LOOKUP_NAME @@ -1129,6 +1130,32 @@ AC_DEFUN([SPL_AC_MUTEX_OWNER], [ ]) dnl # +dnl # 2.6.39 API change, +dnl # Owner type change. A Linux mutex prior to 2.6.39 would store +dnl # the owner as a thread_info pointer when CONFIG_DEBUG_MUTEXES +dnl # was defined. As of 2.6.39 this was changed to a task_struct +dnl # pointer which frankly makes a lot more sense. +dnl # +AC_DEFUN([SPL_AC_MUTEX_OWNER_TASK_STRUCT], [ + AC_MSG_CHECKING([whether struct mutex owner is a task_struct]) + tmp_flags="$EXTRA_KCFLAGS" + EXTRA_KCFLAGS="-Werror" + SPL_LINUX_TRY_COMPILE([ + #include <linux/mutex.h> + ],[ + struct mutex mtx __attribute__ ((unused)); + mtx.owner = current; + ],[ + AC_MSG_RESULT(yes) + AC_DEFINE(HAVE_MUTEX_OWNER_TASK_STRUCT, 1, + [struct mutex owner is a task_struct]) + ],[ + AC_MSG_RESULT(no) + ]) + EXTRA_KCFLAGS="$tmp_flags" +]) + +dnl # dnl # 2.6.18 API change, dnl # First introduced 'mutex_lock_nested()' in include/linux/mutex.h, dnl # as part of the mutex validator. Fallback to using 'mutex_lock()' |