Commit a968bed78b549b4c61d4a46e59161fc1f60f96a6
Committed by
Rafael J. Wysocki
Rafael J. Wysocki
1 parent
fe82dcec64
Exists in
ti-lsk-linux-4.1.y
and in
10 other branches
PM / clk: Fix crash in clocks management code if !CONFIG_PM_RUNTIME
Unlike the clocks management code for runtime PM, the code used for
system suspend does not check the pm_clock_entry.status field.
If pm_clk_acquire() failed, ce->status will be PCE_STATUS_ERROR, and
ce->clk will be a negative error code (e.g. 0xfffffffe = -2 = -ENOENT).
Depending on the clock implementation, suspend or resume may crash with:
Unable to handle kernel NULL pointer dereference at virtual address 00000026
(CCF clk_disable() has an IS_ERR_OR_NULL() check, while CCF clk_enable()
only has a NULL check; pre-CCF implementations may behave differently)
While just checking for PCE_STATUS_ERROR would be sufficient, it doesn't
hurt to use the same state machine as is done for runtime PM, as this
makes the two versions more similar, and eligible for a future
consolidation.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Showing 1 changed file with 15 additions and 4 deletions Side-by-side Diff
drivers/base/power/clock_ops.c
| ... | ... | @@ -368,8 +368,13 @@ |
| 368 | 368 | |
| 369 | 369 | spin_lock_irqsave(&psd->lock, flags); |
| 370 | 370 | |
| 371 | - list_for_each_entry_reverse(ce, &psd->clock_list, node) | |
| 372 | - clk_disable(ce->clk); | |
| 371 | + list_for_each_entry_reverse(ce, &psd->clock_list, node) { | |
| 372 | + if (ce->status < PCE_STATUS_ERROR) { | |
| 373 | + if (ce->status == PCE_STATUS_ENABLED) | |
| 374 | + clk_disable(ce->clk); | |
| 375 | + ce->status = PCE_STATUS_ACQUIRED; | |
| 376 | + } | |
| 377 | + } | |
| 373 | 378 | |
| 374 | 379 | spin_unlock_irqrestore(&psd->lock, flags); |
| 375 | 380 | |
| ... | ... | @@ -385,6 +390,7 @@ |
| 385 | 390 | struct pm_subsys_data *psd = dev_to_psd(dev); |
| 386 | 391 | struct pm_clock_entry *ce; |
| 387 | 392 | unsigned long flags; |
| 393 | + int ret; | |
| 388 | 394 | |
| 389 | 395 | dev_dbg(dev, "%s()\n", __func__); |
| 390 | 396 | |
| ... | ... | @@ -394,8 +400,13 @@ |
| 394 | 400 | |
| 395 | 401 | spin_lock_irqsave(&psd->lock, flags); |
| 396 | 402 | |
| 397 | - list_for_each_entry(ce, &psd->clock_list, node) | |
| 398 | - __pm_clk_enable(dev, ce->clk); | |
| 403 | + list_for_each_entry(ce, &psd->clock_list, node) { | |
| 404 | + if (ce->status < PCE_STATUS_ERROR) { | |
| 405 | + ret = __pm_clk_enable(dev, ce->clk); | |
| 406 | + if (!ret) | |
| 407 | + ce->status = PCE_STATUS_ENABLED; | |
| 408 | + } | |
| 409 | + } | |
| 399 | 410 | |
| 400 | 411 | spin_unlock_irqrestore(&psd->lock, flags); |
| 401 | 412 |