diff options
| author | Li Zhijian <lizhijian@fujitsu.com> | 2023-10-25 16:54:50 +0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2023-10-27 13:04:51 -0700 |
| commit | 3531b27f1f04a6bc9c95cf00d40efe618d57aa93 (patch) | |
| tree | eb8366b6567aa9143e73a6989817200bd5af5b31 /drivers/cxl | |
| parent | 0cf36a85c1408f86a967fb1db721de1b89b9e675 (diff) | |
cxl/region: Fix cxl_region_rwsem lock held when returning to user space
Fix a missed "goto out" to unlock on error to cleanup this splat:
WARNING: lock held when returning to user space!
6.6.0-rc3-lizhijian+ #213 Not tainted
------------------------------------------------
cxl/673 is leaving the kernel with locks still held!
1 lock held by cxl/673:
#0: ffffffffa013b9d0 (cxl_region_rwsem){++++}-{3:3}, at: commit_store+0x7d/0x3e0 [cxl_core]
In terms of user visible impact of this bug for backports:
cxl_region_invalidate_memregion() on x86 invokes wbinvd which is a
problematic instruction for virtualized environments. So, on virtualized
x86, cxl_region_invalidate_memregion() returns an error. This failure
case got missed because CXL memory-expander device passthrough is not a
production use case, and emulation of CXL devices is typically limited
to kernel development builds with CONFIG_CXL_REGION_INVALIDATION_TEST=y,
that makes cxl_region_invalidate_memregion() succeed.
In other words, the expected exposure of this bug is limited to CXL
subsystem development environments using QEMU that neglected
CONFIG_CXL_REGION_INVALIDATION_TEST=y.
Fixes: d1257d098a5a ("cxl/region: Move cache invalidation before region teardown, and before setup")
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20231025085450.2514906-1-lizhijian@fujitsu.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl')
| -rw-r--r-- | drivers/cxl/core/region.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 4860ff170e71..3167b19f4081 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -288,7 +288,7 @@ static ssize_t commit_store(struct device *dev, struct device_attribute *attr, */ rc = cxl_region_invalidate_memregion(cxlr); if (rc) - return rc; + goto out; if (commit) { rc = cxl_region_decode_commit(cxlr); |