Possible race accessing memdev structures after dropping the mutex. Dan Williams says this could race against another thread that is doing:
# echo "ACPI0012:00" > /sys/bus/acpi/drivers/nfit/unbind Reported-by: Jane Chu <[email protected]> Signed-off-by: Tony Luck <[email protected]> --- This time with a commit message and credit to Jane for finding it. drivers/acpi/nfit/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 011d3db19c80..22945bf803c8 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -721,6 +721,7 @@ int nfit_get_smbios_id(u32 device_handle, u16 *flags) struct acpi_nfit_memory_map *memdev; struct acpi_nfit_desc *acpi_desc; struct nfit_mem *nfit_mem; + u16 physical_id; mutex_lock(&acpi_desc_lock); list_for_each_entry(acpi_desc, &acpi_descs, list) { @@ -728,10 +729,11 @@ int nfit_get_smbios_id(u32 device_handle, u16 *flags) list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) { memdev = __to_nfit_memdev(nfit_mem); if (memdev->device_handle == device_handle) { + *flags = memdev->flags; + physical_id = memdev->physical_id; mutex_unlock(&acpi_desc->init_mutex); mutex_unlock(&acpi_desc_lock); - *flags = memdev->flags; - return memdev->physical_id; + return physical_id; } } mutex_unlock(&acpi_desc->init_mutex); -- 2.19.1 _______________________________________________ Linux-nvdimm mailing list [email protected] https://lists.01.org/mailman/listinfo/linux-nvdimm
