| Message ID | 20230920180337.809-1-shiju.jose@huawei.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | [v3,1/1] ACPI / APEI: Fix for overwriting AER info when error status data has multiple sections | expand |
On Wed, Sep 20, 2023 at 8:03 PM <shiju.jose@huawei.com> wrote: > > From: Shiju Jose <shiju.jose@huawei.com> > > 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> > --- > Changes from v2 to v3: > 1. Add stub code for ghes_estatus_pool_region_free() to fix following > build error, reported by kernel test robot, if CONFIG_ACPI_APEI_GHES > is not enabled. > ld: drivers/pci/pcie/aer.o: in function `aer_recover_work_func': > aer.c:(.text+0xec5): undefined reference to `ghes_estatus_pool_region_free' > > Changes from v1 to v2: > 1. Updated patch description with the description Bjorn has suggested. > 2. Add Acked-by: Bjorn Helgaas <bhelgaas@google.com>. > --- > 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 ef59d6ea16da..63ad0541db38 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 e85ff946e8c8..ba1ce820c141 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" > @@ -996,6 +997,15 @@ 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 3c8bba9f1114..be1dd4c1a917 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); > -- Applied as 6.7 material, thanks!
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index ef59d6ea16da..63ad0541db38 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 e85ff946e8c8..ba1ce820c141 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" @@ -996,6 +997,15 @@ 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 3c8bba9f1114..be1dd4c1a917 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);