6.6-stable review patch. If anyone has any objections, please let me know.
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From: Shiju Jose shiju.jose@huawei.com
[ Upstream commit e2abc47a5a1a9f641e7cacdca643fdd40729bf6e ]
ghes_handle_aer() passes AER data to the PCI core for logging and recovery by calling aer_recover_queue() with a pointer to struct aer_capability_regs.
The problem was that aer_recover_queue() queues the pointer directly without copying the aer_capability_regs data. The pointer was to the ghes->estatus buffer, which could be reused before aer_recover_work_func() reads the data.
To avoid this problem, allocate a new aer_capability_regs structure from the ghes_estatus_pool, copy the AER data from the ghes->estatus buffer into it, pass a pointer to the new struct to aer_recover_queue(), and free it after aer_recover_work_func() has processed it.
Reported-by: Bjorn Helgaas helgaas@kernel.org Acked-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Shiju Jose shiju.jose@huawei.com [ rjw: Subject edits ] Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/acpi/apei/ghes.c | 23 ++++++++++++++++++++++- drivers/pci/pcie/aer.c | 10 ++++++++++ include/acpi/ghes.h | 4 ++++ 3 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index ef59d6ea16da0..63ad0541db381 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -209,6 +209,20 @@ int ghes_estatus_pool_init(unsigned int num_ghes) return -ENOMEM; }
+/** + * ghes_estatus_pool_region_free - free previously allocated memory + * from the ghes_estatus_pool. + * @addr: address of memory to free. + * @size: size of memory to free. + * + * Returns none. + */ +void ghes_estatus_pool_region_free(unsigned long addr, u32 size) +{ + gen_pool_free(ghes_estatus_pool, addr, size); +} +EXPORT_SYMBOL_GPL(ghes_estatus_pool_region_free); + static int map_gen_v2(struct ghes *ghes) { return apei_map_generic_address(&ghes->generic_v2->read_ack_register); @@ -564,6 +578,7 @@ static void ghes_handle_aer(struct acpi_hest_generic_data *gdata) pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO) { unsigned int devfn; int aer_severity; + u8 *aer_info;
devfn = PCI_DEVFN(pcie_err->device_id.device, pcie_err->device_id.function); @@ -577,11 +592,17 @@ static void ghes_handle_aer(struct acpi_hest_generic_data *gdata) if (gdata->flags & CPER_SEC_RESET) aer_severity = AER_FATAL;
+ aer_info = (void *)gen_pool_alloc(ghes_estatus_pool, + sizeof(struct aer_capability_regs)); + if (!aer_info) + return; + memcpy(aer_info, pcie_err->aer_info, sizeof(struct aer_capability_regs)); + aer_recover_queue(pcie_err->device_id.segment, pcie_err->device_id.bus, devfn, aer_severity, (struct aer_capability_regs *) - pcie_err->aer_info); + aer_info); } #endif } diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c index 9c8fd69ae5ad8..40d84cb0c601e 100644 --- a/drivers/pci/pcie/aer.c +++ b/drivers/pci/pcie/aer.c @@ -29,6 +29,7 @@ #include <linux/kfifo.h> #include <linux/slab.h> #include <acpi/apei.h> +#include <acpi/ghes.h> #include <ras/ras_event.h>
#include "../pci.h" @@ -997,6 +998,15 @@ static void aer_recover_work_func(struct work_struct *work) continue; } cper_print_aer(pdev, entry.severity, entry.regs); + /* + * Memory for aer_capability_regs(entry.regs) is being allocated from the + * ghes_estatus_pool to protect it from overwriting when multiple sections + * are present in the error status. Thus free the same after processing + * the data. + */ + ghes_estatus_pool_region_free((unsigned long)entry.regs, + sizeof(struct aer_capability_regs)); + if (entry.severity == AER_NONFATAL) pcie_do_recovery(pdev, pci_channel_io_normal, aer_root_reset); diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h index 3c8bba9f1114a..be1dd4c1a9174 100644 --- a/include/acpi/ghes.h +++ b/include/acpi/ghes.h @@ -73,8 +73,12 @@ int ghes_register_vendor_record_notifier(struct notifier_block *nb); void ghes_unregister_vendor_record_notifier(struct notifier_block *nb);
struct list_head *ghes_get_devices(void); + +void ghes_estatus_pool_region_free(unsigned long addr, u32 size); #else static inline struct list_head *ghes_get_devices(void) { return NULL; } + +static inline void ghes_estatus_pool_region_free(unsigned long addr, u32 size) { return; } #endif
int ghes_estatus_pool_init(unsigned int num_ghes);