diff options
| author | Robin Holt <holt@sgi.com> | 2007-05-18 20:46:52 +0200 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2007-05-22 19:16:07 +0200 |
| commit | 6ae384884d936cb39ab20238af34689933e44525 (patch) | |
| tree | 41fdde5596919fb7f987f637a4578792ef39ea4e /arch/ia64/kernel/process.c | |
| parent | [IA64] Improve unwind checking. (diff) | |
| download | linux-6ae384884d936cb39ab20238af34689933e44525.tar.xz linux-6ae384884d936cb39ab20238af34689933e44525.zip | |
[IA64] Only unwind non-running tasks.
Unwinding a running task has proven problematic.
In one instance, the running task was attempting to unwind itself and
received an interrupt between when get_wchan allocated local variables on
the stack and when unw_init_from_blocked_task was called which resulted
in unw_init_frame_info to place this tasks task_struct pointer over the
switch stack's ar_bspstore entry.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64/kernel/process.c')
| -rw-r--r-- | arch/ia64/kernel/process.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index d1c3ed9943e5..af73b8dfde28 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -763,6 +763,9 @@ get_wchan (struct task_struct *p) unsigned long ip; int count = 0; + if (!p || p == current || p->state == TASK_RUNNING) + return 0; + /* * Note: p may not be a blocked task (it could be current or * another process running on some other CPU. Rather than @@ -773,6 +776,8 @@ get_wchan (struct task_struct *p) */ unw_init_from_blocked_task(&info, p); do { + if (p->state == TASK_RUNNING) + return 0; if (unw_unwind(&info) < 0) return 0; unw_get_ip(&info, &ip); |