| Message ID | 20221110094951.2963479-1-ardb@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: efi: Force the use of SetVirtualAddressMap() on Altra machines | expand |
Hi, On Thu, Nov 10, 2022 at 10:49:51AM +0100, Ard Biesheuvel wrote: > Ampere Altra machines are reported to misbehave when the SetTime() EFI > runtime service is called after ExitBootServices() but before calling > SetVirtualAddressMap(). Given that the latter is horrid, pointless and > explicitly documented as optional by the EFI spec, we no longer invoke > it at boot if the configured size of the VA space guarantees that the > EFI runtime memory regions can remain mapped 1:1 like they are at boot > time. > > This means that SetTime() calls on Ampere Altra machines issued by the > rtc-efi driver now trigger a synchronous exception during boot. We can > now recover from those without bringing down the system entirely, due to > commit 23715a26c8d81291 ("arm64: efi: Recover from synchronous > exceptions occurring in firmware"). However, it would be better to avoid > this completely, given that the firmware appears to remain in a funny > state after this. > > So attempt to identify these machines based on the 'family' field in the > type #1 SMBIOS record, and call SetVirtualAddressMap() unconditionally > in that case. This works for my machine. Tested with this patch on top of the patch [1] that disables only the misbehaving services, not runtime services altogether (can test other configurations, if you feel it's necessary): Tested-by: Alexandru Elisei <alexandru.elisei@gmail.com> [1] https://lore.kernel.org/all/20221108151509.2250968-1-ardb@kernel.org/ Thanks, Alex > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> > --- > drivers/firmware/efi/libstub/Makefile | 2 +- > drivers/firmware/efi/libstub/arm64-stub.c | 17 ++++++- > drivers/firmware/efi/libstub/efistub.h | 28 ++++++++++ > drivers/firmware/efi/libstub/smbios.c | 62 +++++++++++++++++++++++ > include/linux/efi.h | 1 + > 5 files changed, 108 insertions(+), 2 deletions(-) > create mode 100644 drivers/firmware/efi/libstub/smbios.c > > diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile > index b1601aad7e1a8d66..ef5045a53ce09653 100644 > --- a/drivers/firmware/efi/libstub/Makefile > +++ b/drivers/firmware/efi/libstub/Makefile > @@ -82,7 +82,7 @@ $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE > lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o string.o intrinsics.o systable.o > > lib-$(CONFIG_ARM) += arm32-stub.o > -lib-$(CONFIG_ARM64) += arm64-stub.o > +lib-$(CONFIG_ARM64) += arm64-stub.o smbios.o > lib-$(CONFIG_X86) += x86-stub.o > lib-$(CONFIG_RISCV) += riscv-stub.o > lib-$(CONFIG_LOONGARCH) += loongarch-stub.o > diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c > index 259e4b852d63276d..f9de5217ea65ed93 100644 > --- a/drivers/firmware/efi/libstub/arm64-stub.c > +++ b/drivers/firmware/efi/libstub/arm64-stub.c > @@ -15,6 +15,21 @@ > > #include "efistub.h" > > +static bool system_needs_vamap(void) > +{ > + const u8 *type1_family = efi_get_smbios_string(1, family); > + > + /* > + * Ampere Altra machines crash in SetTime() if SetVirtualAddressMap() > + * has not been called prior. > + */ > + if (!type1_family || strcmp(type1_family, "Altra")) > + return false; > + > + efi_warn("Working around broken SetVirtualAddressMap()\n"); > + return true; > +} > + > efi_status_t check_platform_features(void) > { > u64 tg; > @@ -24,7 +39,7 @@ efi_status_t check_platform_features(void) > * UEFI runtime regions 1:1 and so calling SetVirtualAddressMap() is > * unnecessary. > */ > - if (VA_BITS_MIN >= 48) > + if (VA_BITS_MIN >= 48 && !system_needs_vamap()) > efi_novamap = true; > > /* UEFI mandates support for 4 KB granularity, no need to check */ > diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h > index a30fb5d8ef05ae9c..eb03d5a9aac88e84 100644 > --- a/drivers/firmware/efi/libstub/efistub.h > +++ b/drivers/firmware/efi/libstub/efistub.h > @@ -975,4 +975,32 @@ efi_enable_reset_attack_mitigation(void) { } > > void efi_retrieve_tpm2_eventlog(void); > > +struct efi_smbios_record { > + u8 type; > + u8 length; > + u16 handle; > +}; > + > +struct efi_smbios_type1_record { > + struct efi_smbios_record header; > + > + u8 manufacturer; > + u8 product_name; > + u8 version; > + u8 serial_number; > + efi_guid_t uuid; > + u8 wakeup_type; > + u8 sku_number; > + u8 family; > +}; > + > +#define efi_get_smbios_string(__type, __name) ({ \ > + int size = sizeof(struct efi_smbios_type ## __type ## _record); \ > + int off = offsetof(struct efi_smbios_type ## __type ## _record, \ > + __name); \ > + __efi_get_smbios_string(__type, off, size); \ > +}) > + > +const u8 *__efi_get_smbios_string(u8 type, int offset, int recsize); > + > #endif > diff --git a/drivers/firmware/efi/libstub/smbios.c b/drivers/firmware/efi/libstub/smbios.c > new file mode 100644 > index 0000000000000000..0b7fbd85cc2f6b4b > --- /dev/null > +++ b/drivers/firmware/efi/libstub/smbios.c > @@ -0,0 +1,62 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +// Copyright 2022 Google LLC > +// Author: Ard Biesheuvel <ardb@google.com> > + > +#include <linux/efi.h> > + > +#include "efistub.h" > + > +typedef union efi_smbios_protocol efi_smbios_protocol_t; > + > +union efi_smbios_protocol { > + struct { > + efi_status_t (__efiapi *add)(efi_smbios_protocol_t *, > + efi_handle_t, u16 *, > + struct efi_smbios_record *); > + efi_status_t (__efiapi *update_string)(efi_smbios_protocol_t *, > + u16 *, unsigned long *, > + u8 *); > + efi_status_t (__efiapi *remove)(efi_smbios_protocol_t *, u16); > + efi_status_t (__efiapi *get_next)(efi_smbios_protocol_t *, > + u16 *, u8 *, > + struct efi_smbios_record **, > + efi_handle_t *); > + > + u8 major_version; > + u8 minor_version; > + }; > + struct { > + u32 add; > + u32 update_string; > + u32 remove; > + u32 get_next; > + > + u8 major_version; > + u8 minor_version; > + } mixed_mode; > +}; > + > +const u8 *__efi_get_smbios_string(u8 type, int offset, int recsize) > +{ > + struct efi_smbios_record *record; > + efi_smbios_protocol_t *smbios; > + efi_status_t status; > + u16 handle = 0xfffe; > + const u8 *strtable; > + > + status = efi_bs_call(locate_protocol, &EFI_SMBIOS_PROTOCOL_GUID, NULL, > + (void **)&smbios) ?: > + efi_call_proto(smbios, get_next, &handle, &type, &record, NULL); > + if (status != EFI_SUCCESS) > + return NULL; > + > + strtable = (u8 *)record + recsize; > + for (int i = 1; i < ((u8 *)record)[offset]; i++) { > + int len = strlen(strtable); > + > + if (!len) > + return NULL; > + strtable += len + 1; > + } > + return strtable; > +} > diff --git a/include/linux/efi.h b/include/linux/efi.h > index 61b252386d61cc4d..cf88dda630649f87 100644 > --- a/include/linux/efi.h > +++ b/include/linux/efi.h > @@ -389,6 +389,7 @@ void efi_native_runtime_setup(void); > #define EFI_LOAD_FILE2_PROTOCOL_GUID EFI_GUID(0x4006c0c1, 0xfcb3, 0x403e, 0x99, 0x6d, 0x4a, 0x6c, 0x87, 0x24, 0xe0, 0x6d) > #define EFI_RT_PROPERTIES_TABLE_GUID EFI_GUID(0xeb66918a, 0x7eef, 0x402a, 0x84, 0x2e, 0x93, 0x1d, 0x21, 0xc3, 0x8a, 0xe9) > #define EFI_DXE_SERVICES_TABLE_GUID EFI_GUID(0x05ad34ba, 0x6f02, 0x4214, 0x95, 0x2e, 0x4d, 0xa0, 0x39, 0x8e, 0x2b, 0xb9) > +#define EFI_SMBIOS_PROTOCOL_GUID EFI_GUID(0x03583ff6, 0xcb36, 0x4940, 0x94, 0x7e, 0xb9, 0xb3, 0x9f, 0x4a, 0xfa, 0xf7) > > #define EFI_IMAGE_SECURITY_DATABASE_GUID EFI_GUID(0xd719b2cb, 0x3d3a, 0x4596, 0xa3, 0xbc, 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f) > #define EFI_SHIM_LOCK_GUID EFI_GUID(0x605dab50, 0xe046, 0x4300, 0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23) > -- > 2.35.1 >
On Thu, 10 Nov 2022 at 15:37, Alexandru Elisei <alexandru.elisei@arm.com> wrote: > > Hi, > > On Thu, Nov 10, 2022 at 10:49:51AM +0100, Ard Biesheuvel wrote: > > Ampere Altra machines are reported to misbehave when the SetTime() EFI > > runtime service is called after ExitBootServices() but before calling > > SetVirtualAddressMap(). Given that the latter is horrid, pointless and > > explicitly documented as optional by the EFI spec, we no longer invoke > > it at boot if the configured size of the VA space guarantees that the > > EFI runtime memory regions can remain mapped 1:1 like they are at boot > > time. > > > > This means that SetTime() calls on Ampere Altra machines issued by the > > rtc-efi driver now trigger a synchronous exception during boot. We can > > now recover from those without bringing down the system entirely, due to > > commit 23715a26c8d81291 ("arm64: efi: Recover from synchronous > > exceptions occurring in firmware"). However, it would be better to avoid > > this completely, given that the firmware appears to remain in a funny > > state after this. > > > > So attempt to identify these machines based on the 'family' field in the > > type #1 SMBIOS record, and call SetVirtualAddressMap() unconditionally > > in that case. > > This works for my machine. Tested with this patch on top of the patch [1] that > disables only the misbehaving services, not runtime services altogether (can > test other configurations, if you feel it's necessary): > > Tested-by: Alexandru Elisei <alexandru.elisei@gmail.com> > Thanks. I take it this means that efibootmgr now works as it should? > [1] https://lore.kernel.org/all/20221108151509.2250968-1-ardb@kernel.org/ > I probably won't merge both of these as fixes, but if this patch on top of [1] improves the situation and makes EFI variables work again, this patch by itself should be sufficient in the short term. > > > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> > > --- > > drivers/firmware/efi/libstub/Makefile | 2 +- > > drivers/firmware/efi/libstub/arm64-stub.c | 17 ++++++- > > drivers/firmware/efi/libstub/efistub.h | 28 ++++++++++ > > drivers/firmware/efi/libstub/smbios.c | 62 +++++++++++++++++++++++ > > include/linux/efi.h | 1 + > > 5 files changed, 108 insertions(+), 2 deletions(-) > > create mode 100644 drivers/firmware/efi/libstub/smbios.c > > > > diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile > > index b1601aad7e1a8d66..ef5045a53ce09653 100644 > > --- a/drivers/firmware/efi/libstub/Makefile > > +++ b/drivers/firmware/efi/libstub/Makefile > > @@ -82,7 +82,7 @@ $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE > > lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o string.o intrinsics.o systable.o > > > > lib-$(CONFIG_ARM) += arm32-stub.o > > -lib-$(CONFIG_ARM64) += arm64-stub.o > > +lib-$(CONFIG_ARM64) += arm64-stub.o smbios.o > > lib-$(CONFIG_X86) += x86-stub.o > > lib-$(CONFIG_RISCV) += riscv-stub.o > > lib-$(CONFIG_LOONGARCH) += loongarch-stub.o > > diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c > > index 259e4b852d63276d..f9de5217ea65ed93 100644 > > --- a/drivers/firmware/efi/libstub/arm64-stub.c > > +++ b/drivers/firmware/efi/libstub/arm64-stub.c > > @@ -15,6 +15,21 @@ > > > > #include "efistub.h" > > > > +static bool system_needs_vamap(void) > > +{ > > + const u8 *type1_family = efi_get_smbios_string(1, family); > > + > > + /* > > + * Ampere Altra machines crash in SetTime() if SetVirtualAddressMap() > > + * has not been called prior. > > + */ > > + if (!type1_family || strcmp(type1_family, "Altra")) > > + return false; > > + > > + efi_warn("Working around broken SetVirtualAddressMap()\n"); > > + return true; > > +} > > + > > efi_status_t check_platform_features(void) > > { > > u64 tg; > > @@ -24,7 +39,7 @@ efi_status_t check_platform_features(void) > > * UEFI runtime regions 1:1 and so calling SetVirtualAddressMap() is > > * unnecessary. > > */ > > - if (VA_BITS_MIN >= 48) > > + if (VA_BITS_MIN >= 48 && !system_needs_vamap()) > > efi_novamap = true; > > > > /* UEFI mandates support for 4 KB granularity, no need to check */ > > diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h > > index a30fb5d8ef05ae9c..eb03d5a9aac88e84 100644 > > --- a/drivers/firmware/efi/libstub/efistub.h > > +++ b/drivers/firmware/efi/libstub/efistub.h > > @@ -975,4 +975,32 @@ efi_enable_reset_attack_mitigation(void) { } > > > > void efi_retrieve_tpm2_eventlog(void); > > > > +struct efi_smbios_record { > > + u8 type; > > + u8 length; > > + u16 handle; > > +}; > > + > > +struct efi_smbios_type1_record { > > + struct efi_smbios_record header; > > + > > + u8 manufacturer; > > + u8 product_name; > > + u8 version; > > + u8 serial_number; > > + efi_guid_t uuid; > > + u8 wakeup_type; > > + u8 sku_number; > > + u8 family; > > +}; > > + > > +#define efi_get_smbios_string(__type, __name) ({ \ > > + int size = sizeof(struct efi_smbios_type ## __type ## _record); \ > > + int off = offsetof(struct efi_smbios_type ## __type ## _record, \ > > + __name); \ > > + __efi_get_smbios_string(__type, off, size); \ > > +}) > > + > > +const u8 *__efi_get_smbios_string(u8 type, int offset, int recsize); > > + > > #endif > > diff --git a/drivers/firmware/efi/libstub/smbios.c b/drivers/firmware/efi/libstub/smbios.c > > new file mode 100644 > > index 0000000000000000..0b7fbd85cc2f6b4b > > --- /dev/null > > +++ b/drivers/firmware/efi/libstub/smbios.c > > @@ -0,0 +1,62 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +// Copyright 2022 Google LLC > > +// Author: Ard Biesheuvel <ardb@google.com> > > + > > +#include <linux/efi.h> > > + > > +#include "efistub.h" > > + > > +typedef union efi_smbios_protocol efi_smbios_protocol_t; > > + > > +union efi_smbios_protocol { > > + struct { > > + efi_status_t (__efiapi *add)(efi_smbios_protocol_t *, > > + efi_handle_t, u16 *, > > + struct efi_smbios_record *); > > + efi_status_t (__efiapi *update_string)(efi_smbios_protocol_t *, > > + u16 *, unsigned long *, > > + u8 *); > > + efi_status_t (__efiapi *remove)(efi_smbios_protocol_t *, u16); > > + efi_status_t (__efiapi *get_next)(efi_smbios_protocol_t *, > > + u16 *, u8 *, > > + struct efi_smbios_record **, > > + efi_handle_t *); > > + > > + u8 major_version; > > + u8 minor_version; > > + }; > > + struct { > > + u32 add; > > + u32 update_string; > > + u32 remove; > > + u32 get_next; > > + > > + u8 major_version; > > + u8 minor_version; > > + } mixed_mode; > > +}; > > + > > +const u8 *__efi_get_smbios_string(u8 type, int offset, int recsize) > > +{ > > + struct efi_smbios_record *record; > > + efi_smbios_protocol_t *smbios; > > + efi_status_t status; > > + u16 handle = 0xfffe; > > + const u8 *strtable; > > + > > + status = efi_bs_call(locate_protocol, &EFI_SMBIOS_PROTOCOL_GUID, NULL, > > + (void **)&smbios) ?: > > + efi_call_proto(smbios, get_next, &handle, &type, &record, NULL); > > + if (status != EFI_SUCCESS) > > + return NULL; > > + > > + strtable = (u8 *)record + recsize; > > + for (int i = 1; i < ((u8 *)record)[offset]; i++) { > > + int len = strlen(strtable); > > + > > + if (!len) > > + return NULL; > > + strtable += len + 1; > > + } > > + return strtable; > > +} > > diff --git a/include/linux/efi.h b/include/linux/efi.h > > index 61b252386d61cc4d..cf88dda630649f87 100644 > > --- a/include/linux/efi.h > > +++ b/include/linux/efi.h > > @@ -389,6 +389,7 @@ void efi_native_runtime_setup(void); > > #define EFI_LOAD_FILE2_PROTOCOL_GUID EFI_GUID(0x4006c0c1, 0xfcb3, 0x403e, 0x99, 0x6d, 0x4a, 0x6c, 0x87, 0x24, 0xe0, 0x6d) > > #define EFI_RT_PROPERTIES_TABLE_GUID EFI_GUID(0xeb66918a, 0x7eef, 0x402a, 0x84, 0x2e, 0x93, 0x1d, 0x21, 0xc3, 0x8a, 0xe9) > > #define EFI_DXE_SERVICES_TABLE_GUID EFI_GUID(0x05ad34ba, 0x6f02, 0x4214, 0x95, 0x2e, 0x4d, 0xa0, 0x39, 0x8e, 0x2b, 0xb9) > > +#define EFI_SMBIOS_PROTOCOL_GUID EFI_GUID(0x03583ff6, 0xcb36, 0x4940, 0x94, 0x7e, 0xb9, 0xb3, 0x9f, 0x4a, 0xfa, 0xf7) > > > > #define EFI_IMAGE_SECURITY_DATABASE_GUID EFI_GUID(0xd719b2cb, 0x3d3a, 0x4596, 0xa3, 0xbc, 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f) > > #define EFI_SHIM_LOCK_GUID EFI_GUID(0x605dab50, 0xe046, 0x4300, 0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23) > > -- > > 2.35.1 > >
Hi, On Thu, Nov 10, 2022 at 03:45:03PM +0100, Ard Biesheuvel wrote: > On Thu, 10 Nov 2022 at 15:37, Alexandru Elisei <alexandru.elisei@arm.com> wrote: > > > > Hi, > > > > On Thu, Nov 10, 2022 at 10:49:51AM +0100, Ard Biesheuvel wrote: > > > Ampere Altra machines are reported to misbehave when the SetTime() EFI > > > runtime service is called after ExitBootServices() but before calling > > > SetVirtualAddressMap(). Given that the latter is horrid, pointless and > > > explicitly documented as optional by the EFI spec, we no longer invoke > > > it at boot if the configured size of the VA space guarantees that the > > > EFI runtime memory regions can remain mapped 1:1 like they are at boot > > > time. > > > > > > This means that SetTime() calls on Ampere Altra machines issued by the > > > rtc-efi driver now trigger a synchronous exception during boot. We can > > > now recover from those without bringing down the system entirely, due to > > > commit 23715a26c8d81291 ("arm64: efi: Recover from synchronous > > > exceptions occurring in firmware"). However, it would be better to avoid > > > this completely, given that the firmware appears to remain in a funny > > > state after this. > > > > > > So attempt to identify these machines based on the 'family' field in the > > > type #1 SMBIOS record, and call SetVirtualAddressMap() unconditionally > > > in that case. > > > > This works for my machine. Tested with this patch on top of the patch [1] that > > disables only the misbehaving services, not runtime services altogether (can > > test other configurations, if you feel it's necessary): > > > > Tested-by: Alexandru Elisei <alexandru.elisei@gmail.com> > > > > Thanks. > > I take it this means that efibootmgr now works as it should? Yes, tested GetVariable() (# efibootmgr) and SetVariable() (# efibootmgr -t 30). Also tested this patch on top of v6.1-rc4, same results. Thanks, Alex > > > [1] https://lore.kernel.org/all/20221108151509.2250968-1-ardb@kernel.org/ > > > > I probably won't merge both of these as fixes, but if this patch on > top of [1] improves the situation and makes EFI variables work again, > this patch by itself should be sufficient in the short term. > > > > > > > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> > > > --- > > > drivers/firmware/efi/libstub/Makefile | 2 +- > > > drivers/firmware/efi/libstub/arm64-stub.c | 17 ++++++- > > > drivers/firmware/efi/libstub/efistub.h | 28 ++++++++++ > > > drivers/firmware/efi/libstub/smbios.c | 62 +++++++++++++++++++++++ > > > include/linux/efi.h | 1 + > > > 5 files changed, 108 insertions(+), 2 deletions(-) > > > create mode 100644 drivers/firmware/efi/libstub/smbios.c > > > > > > diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile > > > index b1601aad7e1a8d66..ef5045a53ce09653 100644 > > > --- a/drivers/firmware/efi/libstub/Makefile > > > +++ b/drivers/firmware/efi/libstub/Makefile > > > @@ -82,7 +82,7 @@ $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE > > > lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o string.o intrinsics.o systable.o > > > > > > lib-$(CONFIG_ARM) += arm32-stub.o > > > -lib-$(CONFIG_ARM64) += arm64-stub.o > > > +lib-$(CONFIG_ARM64) += arm64-stub.o smbios.o > > > lib-$(CONFIG_X86) += x86-stub.o > > > lib-$(CONFIG_RISCV) += riscv-stub.o > > > lib-$(CONFIG_LOONGARCH) += loongarch-stub.o > > > diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c > > > index 259e4b852d63276d..f9de5217ea65ed93 100644 > > > --- a/drivers/firmware/efi/libstub/arm64-stub.c > > > +++ b/drivers/firmware/efi/libstub/arm64-stub.c > > > @@ -15,6 +15,21 @@ > > > > > > #include "efistub.h" > > > > > > +static bool system_needs_vamap(void) > > > +{ > > > + const u8 *type1_family = efi_get_smbios_string(1, family); > > > + > > > + /* > > > + * Ampere Altra machines crash in SetTime() if SetVirtualAddressMap() > > > + * has not been called prior. > > > + */ > > > + if (!type1_family || strcmp(type1_family, "Altra")) > > > + return false; > > > + > > > + efi_warn("Working around broken SetVirtualAddressMap()\n"); > > > + return true; > > > +} > > > + > > > efi_status_t check_platform_features(void) > > > { > > > u64 tg; > > > @@ -24,7 +39,7 @@ efi_status_t check_platform_features(void) > > > * UEFI runtime regions 1:1 and so calling SetVirtualAddressMap() is > > > * unnecessary. > > > */ > > > - if (VA_BITS_MIN >= 48) > > > + if (VA_BITS_MIN >= 48 && !system_needs_vamap()) > > > efi_novamap = true; > > > > > > /* UEFI mandates support for 4 KB granularity, no need to check */ > > > diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h > > > index a30fb5d8ef05ae9c..eb03d5a9aac88e84 100644 > > > --- a/drivers/firmware/efi/libstub/efistub.h > > > +++ b/drivers/firmware/efi/libstub/efistub.h > > > @@ -975,4 +975,32 @@ efi_enable_reset_attack_mitigation(void) { } > > > > > > void efi_retrieve_tpm2_eventlog(void); > > > > > > +struct efi_smbios_record { > > > + u8 type; > > > + u8 length; > > > + u16 handle; > > > +}; > > > + > > > +struct efi_smbios_type1_record { > > > + struct efi_smbios_record header; > > > + > > > + u8 manufacturer; > > > + u8 product_name; > > > + u8 version; > > > + u8 serial_number; > > > + efi_guid_t uuid; > > > + u8 wakeup_type; > > > + u8 sku_number; > > > + u8 family; > > > +}; > > > + > > > +#define efi_get_smbios_string(__type, __name) ({ \ > > > + int size = sizeof(struct efi_smbios_type ## __type ## _record); \ > > > + int off = offsetof(struct efi_smbios_type ## __type ## _record, \ > > > + __name); \ > > > + __efi_get_smbios_string(__type, off, size); \ > > > +}) > > > + > > > +const u8 *__efi_get_smbios_string(u8 type, int offset, int recsize); > > > + > > > #endif > > > diff --git a/drivers/firmware/efi/libstub/smbios.c b/drivers/firmware/efi/libstub/smbios.c > > > new file mode 100644 > > > index 0000000000000000..0b7fbd85cc2f6b4b > > > --- /dev/null > > > +++ b/drivers/firmware/efi/libstub/smbios.c > > > @@ -0,0 +1,62 @@ > > > +// SPDX-License-Identifier: GPL-2.0-only > > > +// Copyright 2022 Google LLC > > > +// Author: Ard Biesheuvel <ardb@google.com> > > > + > > > +#include <linux/efi.h> > > > + > > > +#include "efistub.h" > > > + > > > +typedef union efi_smbios_protocol efi_smbios_protocol_t; > > > + > > > +union efi_smbios_protocol { > > > + struct { > > > + efi_status_t (__efiapi *add)(efi_smbios_protocol_t *, > > > + efi_handle_t, u16 *, > > > + struct efi_smbios_record *); > > > + efi_status_t (__efiapi *update_string)(efi_smbios_protocol_t *, > > > + u16 *, unsigned long *, > > > + u8 *); > > > + efi_status_t (__efiapi *remove)(efi_smbios_protocol_t *, u16); > > > + efi_status_t (__efiapi *get_next)(efi_smbios_protocol_t *, > > > + u16 *, u8 *, > > > + struct efi_smbios_record **, > > > + efi_handle_t *); > > > + > > > + u8 major_version; > > > + u8 minor_version; > > > + }; > > > + struct { > > > + u32 add; > > > + u32 update_string; > > > + u32 remove; > > > + u32 get_next; > > > + > > > + u8 major_version; > > > + u8 minor_version; > > > + } mixed_mode; > > > +}; > > > + > > > +const u8 *__efi_get_smbios_string(u8 type, int offset, int recsize) > > > +{ > > > + struct efi_smbios_record *record; > > > + efi_smbios_protocol_t *smbios; > > > + efi_status_t status; > > > + u16 handle = 0xfffe; > > > + const u8 *strtable; > > > + > > > + status = efi_bs_call(locate_protocol, &EFI_SMBIOS_PROTOCOL_GUID, NULL, > > > + (void **)&smbios) ?: > > > + efi_call_proto(smbios, get_next, &handle, &type, &record, NULL); > > > + if (status != EFI_SUCCESS) > > > + return NULL; > > > + > > > + strtable = (u8 *)record + recsize; > > > + for (int i = 1; i < ((u8 *)record)[offset]; i++) { > > > + int len = strlen(strtable); > > > + > > > + if (!len) > > > + return NULL; > > > + strtable += len + 1; > > > + } > > > + return strtable; > > > +} > > > diff --git a/include/linux/efi.h b/include/linux/efi.h > > > index 61b252386d61cc4d..cf88dda630649f87 100644 > > > --- a/include/linux/efi.h > > > +++ b/include/linux/efi.h > > > @@ -389,6 +389,7 @@ void efi_native_runtime_setup(void); > > > #define EFI_LOAD_FILE2_PROTOCOL_GUID EFI_GUID(0x4006c0c1, 0xfcb3, 0x403e, 0x99, 0x6d, 0x4a, 0x6c, 0x87, 0x24, 0xe0, 0x6d) > > > #define EFI_RT_PROPERTIES_TABLE_GUID EFI_GUID(0xeb66918a, 0x7eef, 0x402a, 0x84, 0x2e, 0x93, 0x1d, 0x21, 0xc3, 0x8a, 0xe9) > > > #define EFI_DXE_SERVICES_TABLE_GUID EFI_GUID(0x05ad34ba, 0x6f02, 0x4214, 0x95, 0x2e, 0x4d, 0xa0, 0x39, 0x8e, 0x2b, 0xb9) > > > +#define EFI_SMBIOS_PROTOCOL_GUID EFI_GUID(0x03583ff6, 0xcb36, 0x4940, 0x94, 0x7e, 0xb9, 0xb3, 0x9f, 0x4a, 0xfa, 0xf7) > > > > > > #define EFI_IMAGE_SECURITY_DATABASE_GUID EFI_GUID(0xd719b2cb, 0x3d3a, 0x4596, 0xa3, 0xbc, 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f) > > > #define EFI_SHIM_LOCK_GUID EFI_GUID(0x605dab50, 0xe046, 0x4300, 0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23) > > > -- > > > 2.35.1 > > >
On Thu, 10 Nov 2022 at 16:34, Alexandru Elisei <alexandru.elisei@arm.com> wrote: > > Hi, > > On Thu, Nov 10, 2022 at 03:45:03PM +0100, Ard Biesheuvel wrote: > > On Thu, 10 Nov 2022 at 15:37, Alexandru Elisei <alexandru.elisei@arm.com> wrote: > > > > > > Hi, > > > > > > On Thu, Nov 10, 2022 at 10:49:51AM +0100, Ard Biesheuvel wrote: > > > > Ampere Altra machines are reported to misbehave when the SetTime() EFI > > > > runtime service is called after ExitBootServices() but before calling > > > > SetVirtualAddressMap(). Given that the latter is horrid, pointless and > > > > explicitly documented as optional by the EFI spec, we no longer invoke > > > > it at boot if the configured size of the VA space guarantees that the > > > > EFI runtime memory regions can remain mapped 1:1 like they are at boot > > > > time. > > > > > > > > This means that SetTime() calls on Ampere Altra machines issued by the > > > > rtc-efi driver now trigger a synchronous exception during boot. We can > > > > now recover from those without bringing down the system entirely, due to > > > > commit 23715a26c8d81291 ("arm64: efi: Recover from synchronous > > > > exceptions occurring in firmware"). However, it would be better to avoid > > > > this completely, given that the firmware appears to remain in a funny > > > > state after this. > > > > > > > > So attempt to identify these machines based on the 'family' field in the > > > > type #1 SMBIOS record, and call SetVirtualAddressMap() unconditionally > > > > in that case. > > > > > > This works for my machine. Tested with this patch on top of the patch [1] that > > > disables only the misbehaving services, not runtime services altogether (can > > > test other configurations, if you feel it's necessary): > > > > > > Tested-by: Alexandru Elisei <alexandru.elisei@gmail.com> > > > > > > > Thanks. > > > > I take it this means that efibootmgr now works as it should? > > Yes, tested GetVariable() (# efibootmgr) and SetVariable() (# efibootmgr -t > 30). Also tested this patch on top of v6.1-rc4, same results. > Excellent news, thank you very much.
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index b1601aad7e1a8d66..ef5045a53ce09653 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -82,7 +82,7 @@ $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o string.o intrinsics.o systable.o lib-$(CONFIG_ARM) += arm32-stub.o -lib-$(CONFIG_ARM64) += arm64-stub.o +lib-$(CONFIG_ARM64) += arm64-stub.o smbios.o lib-$(CONFIG_X86) += x86-stub.o lib-$(CONFIG_RISCV) += riscv-stub.o lib-$(CONFIG_LOONGARCH) += loongarch-stub.o diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index 259e4b852d63276d..f9de5217ea65ed93 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -15,6 +15,21 @@ #include "efistub.h" +static bool system_needs_vamap(void) +{ + const u8 *type1_family = efi_get_smbios_string(1, family); + + /* + * Ampere Altra machines crash in SetTime() if SetVirtualAddressMap() + * has not been called prior. + */ + if (!type1_family || strcmp(type1_family, "Altra")) + return false; + + efi_warn("Working around broken SetVirtualAddressMap()\n"); + return true; +} + efi_status_t check_platform_features(void) { u64 tg; @@ -24,7 +39,7 @@ efi_status_t check_platform_features(void) * UEFI runtime regions 1:1 and so calling SetVirtualAddressMap() is * unnecessary. */ - if (VA_BITS_MIN >= 48) + if (VA_BITS_MIN >= 48 && !system_needs_vamap()) efi_novamap = true; /* UEFI mandates support for 4 KB granularity, no need to check */ diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index a30fb5d8ef05ae9c..eb03d5a9aac88e84 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -975,4 +975,32 @@ efi_enable_reset_attack_mitigation(void) { } void efi_retrieve_tpm2_eventlog(void); +struct efi_smbios_record { + u8 type; + u8 length; + u16 handle; +}; + +struct efi_smbios_type1_record { + struct efi_smbios_record header; + + u8 manufacturer; + u8 product_name; + u8 version; + u8 serial_number; + efi_guid_t uuid; + u8 wakeup_type; + u8 sku_number; + u8 family; +}; + +#define efi_get_smbios_string(__type, __name) ({ \ + int size = sizeof(struct efi_smbios_type ## __type ## _record); \ + int off = offsetof(struct efi_smbios_type ## __type ## _record, \ + __name); \ + __efi_get_smbios_string(__type, off, size); \ +}) + +const u8 *__efi_get_smbios_string(u8 type, int offset, int recsize); + #endif diff --git a/drivers/firmware/efi/libstub/smbios.c b/drivers/firmware/efi/libstub/smbios.c new file mode 100644 index 0000000000000000..0b7fbd85cc2f6b4b --- /dev/null +++ b/drivers/firmware/efi/libstub/smbios.c @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright 2022 Google LLC +// Author: Ard Biesheuvel <ardb@google.com> + +#include <linux/efi.h> + +#include "efistub.h" + +typedef union efi_smbios_protocol efi_smbios_protocol_t; + +union efi_smbios_protocol { + struct { + efi_status_t (__efiapi *add)(efi_smbios_protocol_t *, + efi_handle_t, u16 *, + struct efi_smbios_record *); + efi_status_t (__efiapi *update_string)(efi_smbios_protocol_t *, + u16 *, unsigned long *, + u8 *); + efi_status_t (__efiapi *remove)(efi_smbios_protocol_t *, u16); + efi_status_t (__efiapi *get_next)(efi_smbios_protocol_t *, + u16 *, u8 *, + struct efi_smbios_record **, + efi_handle_t *); + + u8 major_version; + u8 minor_version; + }; + struct { + u32 add; + u32 update_string; + u32 remove; + u32 get_next; + + u8 major_version; + u8 minor_version; + } mixed_mode; +}; + +const u8 *__efi_get_smbios_string(u8 type, int offset, int recsize) +{ + struct efi_smbios_record *record; + efi_smbios_protocol_t *smbios; + efi_status_t status; + u16 handle = 0xfffe; + const u8 *strtable; + + status = efi_bs_call(locate_protocol, &EFI_SMBIOS_PROTOCOL_GUID, NULL, + (void **)&smbios) ?: + efi_call_proto(smbios, get_next, &handle, &type, &record, NULL); + if (status != EFI_SUCCESS) + return NULL; + + strtable = (u8 *)record + recsize; + for (int i = 1; i < ((u8 *)record)[offset]; i++) { + int len = strlen(strtable); + + if (!len) + return NULL; + strtable += len + 1; + } + return strtable; +} diff --git a/include/linux/efi.h b/include/linux/efi.h index 61b252386d61cc4d..cf88dda630649f87 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -389,6 +389,7 @@ void efi_native_runtime_setup(void); #define EFI_LOAD_FILE2_PROTOCOL_GUID EFI_GUID(0x4006c0c1, 0xfcb3, 0x403e, 0x99, 0x6d, 0x4a, 0x6c, 0x87, 0x24, 0xe0, 0x6d) #define EFI_RT_PROPERTIES_TABLE_GUID EFI_GUID(0xeb66918a, 0x7eef, 0x402a, 0x84, 0x2e, 0x93, 0x1d, 0x21, 0xc3, 0x8a, 0xe9) #define EFI_DXE_SERVICES_TABLE_GUID EFI_GUID(0x05ad34ba, 0x6f02, 0x4214, 0x95, 0x2e, 0x4d, 0xa0, 0x39, 0x8e, 0x2b, 0xb9) +#define EFI_SMBIOS_PROTOCOL_GUID EFI_GUID(0x03583ff6, 0xcb36, 0x4940, 0x94, 0x7e, 0xb9, 0xb3, 0x9f, 0x4a, 0xfa, 0xf7) #define EFI_IMAGE_SECURITY_DATABASE_GUID EFI_GUID(0xd719b2cb, 0x3d3a, 0x4596, 0xa3, 0xbc, 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f) #define EFI_SHIM_LOCK_GUID EFI_GUID(0x605dab50, 0xe046, 0x4300, 0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23)
Ampere Altra machines are reported to misbehave when the SetTime() EFI runtime service is called after ExitBootServices() but before calling SetVirtualAddressMap(). Given that the latter is horrid, pointless and explicitly documented as optional by the EFI spec, we no longer invoke it at boot if the configured size of the VA space guarantees that the EFI runtime memory regions can remain mapped 1:1 like they are at boot time. This means that SetTime() calls on Ampere Altra machines issued by the rtc-efi driver now trigger a synchronous exception during boot. We can now recover from those without bringing down the system entirely, due to commit 23715a26c8d81291 ("arm64: efi: Recover from synchronous exceptions occurring in firmware"). However, it would be better to avoid this completely, given that the firmware appears to remain in a funny state after this. So attempt to identify these machines based on the 'family' field in the type #1 SMBIOS record, and call SetVirtualAddressMap() unconditionally in that case. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- drivers/firmware/efi/libstub/Makefile | 2 +- drivers/firmware/efi/libstub/arm64-stub.c | 17 ++++++- drivers/firmware/efi/libstub/efistub.h | 28 ++++++++++ drivers/firmware/efi/libstub/smbios.c | 62 +++++++++++++++++++++++ include/linux/efi.h | 1 + 5 files changed, 108 insertions(+), 2 deletions(-) create mode 100644 drivers/firmware/efi/libstub/smbios.c