When user calls sys_setpriority(PRIO_PGRP ...) on a NPTL style multi-LWP
process, only the task leader of the process is affected, all other sibling
LWP threads didn't receive the setting. The problem was that the iterator
used in sys_setpriority() only iteartes over one task for each process,
ignoring all other sibling thread.
Introduce a new macro do_each_pid_thread / while_each_pid_thread to walk
each thread of a process. Convert 4 call sites in {set/get}priority and
ioprio_{set/get}.
Signed-off-by: Ken Chen <kenchen@google.com>
diff --git a/include/linux/pid.h b/include/linux/pid.h
index c21c7e8..6bea2be 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -163,4 +163,13 @@ pid_t pid_vnr(struct pid *pid);
} \
} while (0)
+#define do_each_pid_thread(pid, type, task) \
+ do_each_pid_task(pid, type, task) { \
+ struct task_struct *tg___ = task; \
+ do {
+
+#define while_each_pid_thread(pid, type, task) \
+ } while_each_thread(tg___, task); \
+ task = tg___; \
+ } while_each_pid_task(pid, type, task)
#endif /* _LINUX_PID_H */
diff --git a/kernel/sys.c b/kernel/sys.c
index 14e9728..fc58623 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -169,9 +169,9 @@ asmlinkage long sys_setpriority
pgrp = find_vpid(who);
else
pgrp = task_pgrp(current);
- do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
+ do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
error = set_one_prio(p, niceval, error);
- } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
+ } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case PRIO_USER:
user = current->user;
@@ -229,11 +229,11 @@ asmlinkage long sys_getpriority
pgrp = find_vpid(who);
else
pgrp = task_pgrp(current);
- do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
+ do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
niceval = 20 - task_nice(p);
if (niceval > retval)
retval = niceval;
- } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
+ } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case PRIO_USER:
user = current->user;
diff --git a/fs/ioprio.c b/fs/ioprio.c
index c4a1c3c..da3cc46 100644
--- a/fs/ioprio.c
+++ b/fs/ioprio.c
@@ -115,11 +115,11 @@ asmlinkage long sys_ioprio_set
pgrp = task_pgrp(current);
else
pgrp = find_vpid(who);
- do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
+ do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
ret = set_task_ioprio(p, ioprio);
if (ret)
break;
- } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
+ } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case IOPRIO_WHO_USER:
if (!who)
@@ -204,7 +204,7 @@ asmlinkage long sys_ioprio_get
pgrp = task_pgrp(current);
else
pgrp = find_vpid(who);
- do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
+ do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
tmpio = get_task_ioprio(p);
if (tmpio < 0)
continue;
@@ -212,7 +212,7 @@ asmlinkage long sys_ioprio_get
ret = tmpio;
else
ret = ioprio_best(ret, tmpio);
- } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
+ } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
break;
case IOPRIO_WHO_USER:
if (!who)
--
