Evolution-X-Devices/kernel_google_wahoo
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

binder: make FIFO inheritance a per-context option

Browse Source 
Add a new ioctl to binder to control whether FIFO inheritance should happen.
In particular, hwbinder should inherit FIFO priority from callers, but standard
binder threads should not.

Test: boots

bug 36516194

Signed-off-by: Tim Murray <timmurray@google.com>
Change-Id: I8100c4364b7d15d1bf00a8ca5c286e4d4b23ce85
This commit is contained in:
Tim Murray
2017-03-22 22:02:20 -07:00
committed by Todd Kjos
parent 333086d0cb
commit d668aac7f1
2 changed files with 39 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
drivers/android/binder.c
View File

@@ -244,6 +244,7 @@ struct binder_context {
struct binder_node *binder_context_mgr_node;
kuid_t binder_context_mgr_uid;
const char *name;
bool inherit_fifo_prio;
};
struct binder_device {
@@ -622,11 +623,12 @@ static void binder_set_priority(
struct binder_transaction *t, struct binder_node *target_node)
{
bool oneway = !!(t->flags & TF_ONE_WAY);
bool inherit_fifo = target_node->proc->context->inherit_fifo_prio;
t->saved_sched_policy = current->policy;
t->saved_priority = task_nice(current);
if (!oneway && is_rt_policy(t->sched_policy) &&
if (!oneway && inherit_fifo && is_rt_policy(t->sched_policy) &&
!is_rt_policy(current->policy)) {
/* Transaction was initiated with a real-time policy,
* but we are not; temporarily upgrade this thread to RT.
@@ -3613,6 +3615,34 @@ out:
return ret;
}
static int binder_ioctl_set_inherit_fifo_prio(struct file *filp)
{
int ret = 0;
struct binder_proc *proc = filp->private_data;
struct binder_context *context = proc->context;
kuid_t curr_euid = current_euid();
mutex_lock(&binder_context_mgr_node_lock);
if (uid_valid(context->binder_context_mgr_uid)) {
if (!uid_eq(context->binder_context_mgr_uid, curr_euid)) {
pr_err("BINDER_SET_INHERIT_FIFO_PRIO bad uid %d != %d\n",
from_kuid(&init_user_ns, curr_euid),
from_kuid(&init_user_ns,
context->binder_context_mgr_uid));
ret = -EPERM;
goto out;
}
}
context->inherit_fifo_prio = true;
out:
mutex_unlock(&binder_context_mgr_node_lock);
return ret;
}
static int binder_ioctl_set_ctx_mgr(struct file *filp)
{
int ret = 0;
@@ -3726,6 +3756,12 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
if (ret)
goto err;
break;
case BINDER_SET_INHERIT_FIFO_PRIO:
ret = binder_ioctl_set_inherit_fifo_prio(filp);
if (ret)
goto err;
break;
case BINDER_THREAD_EXIT:
binder_debug(BINDER_DEBUG_THREADS, "%d:%d exit\n",
proc->pid, thread->pid);
@@ -4624,6 +4660,7 @@ static void print_binder_proc_stats(struct seq_file *m,
seq_printf(m, "proc %d%s\n", proc->pid,
proc->is_zombie ? " (ZOMBIE)" : "");
seq_printf(m, "context %s\n", proc->context->name);
seq_printf(m, "context FIFO: %d\n", proc->context->inherit_fifo_prio);
seq_printf(m, " cleared: procs=%d nodes=%d threads=%d\n",
cleared_procs, cleared_nodes, cleared_threads);
zombie_threads = zombie_nodes = zombie_refs = count = 0;

1
include/uapi/linux/android/binder.h
View File

@@ -191,6 +191,7 @@ struct binder_version {
#define BINDER_SET_CONTEXT_MGR _IOW('b', 7, __s32)
#define BINDER_THREAD_EXIT _IOW('b', 8, __s32)
#define BINDER_VERSION _IOWR('b', 9, struct binder_version)
#define BINDER_SET_INHERIT_FIFO_PRIO _IO('b', 10)
/*
* NOTE: Two special error codes you should check for when calling