Bug 88051
| Summary: | vmpressure_work_fn is not multi-thread safe | ||
|---|---|---|---|
| Product: | Memory Management | Reporter: | ji_ang |
| Component: | Other | Assignee: | Andrew Morton (akpm) |
| Status: | RESOLVED CODE_FIX | ||
| Severity: | high | ||
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 3.18-rc4 and all earlier versions | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
Thanks, I queued that fix. |
static void vmpressure_work_fn(struct work_struct *work) { ... if (!vmpr->scanned) return; spin_lock(&vmpr->sr_lock); scanned = vmpr->scanned; In some android devices, there will be a "divided by zero" expection. the vmpr->scanned could be zero before “spin_lock(&vmpr->sr_lock)” So the above source code should be changed to: spin_lock(&vmpr->sr_lock); scanned = vmpr->scanned; if (!scanned) { spin_unlock(&vmpr->sr_lock); return; }