kernel/linux.git/drivers/acpi/apei, branch v6.12.91

ACPI: APEI: GHES: Disable KASAN instrumentation when compile testing with clang < 18

2026-03-13T16:20:37+00:00

[ Upstream commit b584bfbd7ec417f257f651cc00a90c66e31dfbf1 ] After a recent innocuous change to drivers/acpi/apei/ghes.c, building ARCH=arm64 allmodconfig with clang-17 or older (which has both CONFIG_KASAN=y and CONFIG_WERROR=y) fails with: drivers/acpi/apei/ghes.c:902:13: error: stack frame size (2768) exceeds limit (2048) in 'ghes_do_proc' [-Werror,-Wframe-larger-than] 902 | static void ghes_do_proc(struct ghes *ghes, | ^ A KASAN pass that removes unneeded stack instrumentation, enabled by default in clang-18 [1], drastically improves stack usage in this case. To avoid the warning in the common allmodconfig case when it can break the build, disable KASAN for ghes.o when compile testing with clang-17 and older. Disabling KASAN outright may hide legitimate runtime issues, so live with the warning in that case; the user can either increase the frame warning limit or disable -Werror, which they should probably do when debugging with KASAN anyways. Closes: https://github.com/ClangBuiltLinux/linux/issues/2148 Link: https://github.com/llvm/llvm-project/commit/51fbab134560ece663517bf1e8c2a30300d08f1a [1] Signed-off-by: Nathan Chancellor Cc: All applicable Link: https://patch.msgid.link/20260114-ghes-avoid-wflt-clang-older-than-18-v1-1-9c8248bfe4f4@kernel.org Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

APEI/GHES: ARM processor Error: don't go past allocated memory

2026-03-04T12:20:54+00:00

[ Upstream commit 87880af2d24e62a84ed19943dbdd524f097172f2 ] If the BIOS generates a very small ARM Processor Error, or an incomplete one, the current logic will fail to deferrence err->section_length and ctx_info->size Add checks to avoid that. With such changes, such GHESv2 records won't cause OOPSes like this: [ 1.492129] Internal error: Oops: 0000000096000005 [#1] SMP [ 1.495449] Modules linked in: [ 1.495820] CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.18.0-rc1-00017-gabadcc3553dd-dirty #18 PREEMPT [ 1.496125] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 02/02/2022 [ 1.496433] Workqueue: kacpi_notify acpi_os_execute_deferred [ 1.496967] pstate: 814000c5 (Nzcv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 1.497199] pc : log_arm_hw_error+0x5c/0x200 [ 1.497380] lr : ghes_handle_arm_hw_error+0x94/0x220 0xffff8000811c5324 is in log_arm_hw_error (../drivers/ras/ras.c:75). 70 err_info = (struct cper_arm_err_info *)(err + 1); 71 ctx_info = (struct cper_arm_ctx_info *)(err_info + err->err_info_num); 72 ctx_err = (u8 *)ctx_info; 73 74 for (n = 0; n < err->context_info_num; n++) { 75 sz = sizeof(struct cper_arm_ctx_info) + ctx_info->size; 76 ctx_info = (struct cper_arm_ctx_info *)((long)ctx_info + sz); 77 ctx_len += sz; 78 } 79 and similar ones while trying to access section_length on an error dump with too small size. Signed-off-by: Mauro Carvalho Chehab Reviewed-by: Jonathan Cameron Acked-by: Ard Biesheuvel Reviewed-by: Hanjun Guo [ rjw: Subject tweaks ] Link: https://patch.msgid.link/7fd9f38413be05ee2d7cfdb0dc31ea2274cf1a54.1767871950.git.mchehab+huawei@kernel.org Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

APEI/GHES: ensure that won't go past CPER allocated record

2026-03-04T12:20:54+00:00

[ Upstream commit fa2408a24f8f0db14d9cfc613ef162dc267d7ad4 ] The logic at ghes_new() prevents allocating too large records, by checking if they're bigger than GHES_ESTATUS_MAX_SIZE (currently, 64KB). Yet, the allocation is done with the actual number of pages from the CPER bios table location, which can be smaller. Yet, a bad firmware could send data with a different size, which might be bigger than the allocated memory, causing an OOPS: Unable to handle kernel paging request at virtual address fff00000f9b40000 Mem abort info: ESR = 0x0000000096000007 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x07: level 3 translation fault Data abort info: ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 swapper pgtable: 4k pages, 52-bit VAs, pgdp=000000008ba16000 [fff00000f9b40000] pgd=180000013ffff403, p4d=180000013fffe403, pud=180000013f85b403, pmd=180000013f68d403, pte=0000000000000000 Internal error: Oops: 0000000096000007 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 303 Comm: kworker/0:1 Not tainted 6.19.0-rc1-00002-gda407d200220 #34 PREEMPT Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 02/02/2022 Workqueue: kacpi_notify acpi_os_execute_deferred pstate: 214020c5 (nzCv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : hex_dump_to_buffer+0x30c/0x4a0 lr : hex_dump_to_buffer+0x328/0x4a0 sp : ffff800080e13880 x29: ffff800080e13880 x28: ffffac9aba86f6a8 x27: 0000000000000083 x26: fff00000f9b3fffc x25: 0000000000000004 x24: 0000000000000004 x23: ffff800080e13905 x22: 0000000000000010 x21: 0000000000000083 x20: 0000000000000001 x19: 0000000000000008 x18: 0000000000000010 x17: 0000000000000001 x16: 00000007c7f20fec x15: 0000000000000020 x14: 0000000000000008 x13: 0000000000081020 x12: 0000000000000008 x11: ffff800080e13905 x10: ffff800080e13988 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000001 x6 : 0000000000000020 x5 : 0000000000000030 x4 : 00000000fffffffe x3 : 0000000000000000 x2 : ffffac9aba78c1c8 x1 : ffffac9aba76d0a8 x0 : 0000000000000008 Call trace: hex_dump_to_buffer+0x30c/0x4a0 (P) print_hex_dump+0xac/0x170 cper_estatus_print_section+0x90c/0x968 cper_estatus_print+0xf0/0x158 __ghes_print_estatus+0xa0/0x148 ghes_proc+0x1bc/0x220 ghes_notify_hed+0x5c/0xb8 notifier_call_chain+0x78/0x148 blocking_notifier_call_chain+0x4c/0x80 acpi_hed_notify+0x28/0x40 acpi_ev_notify_dispatch+0x50/0x80 acpi_os_execute_deferred+0x24/0x48 process_one_work+0x15c/0x3b0 worker_thread+0x2d0/0x400 kthread+0x148/0x228 ret_from_fork+0x10/0x20 Code: 6b14033f 540001ad a94707e2 f100029f (b8747b44) ---[ end trace 0000000000000000 ]--- Prevent that by taking the actual allocated are into account when checking for CPER length. Signed-off-by: Mauro Carvalho Chehab Reviewed-by: Jonathan Cameron Acked-by: Ard Biesheuvel Reviewed-by: Hanjun Guo [ rjw: Subject tweaks ] Link: https://patch.msgid.link/4e70310a816577fabf37d94ed36cde4ad62b1e0a.1767871950.git.mchehab+huawei@kernel.org Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

efi/cper: align ARM CPER type with UEFI 2.9A/2.10 specs

2025-12-18T12:55:21+00:00

[ Upstream commit 96b010536ee020e716d28d9b359a4bcd18800aeb ] Up to UEFI spec 2.9, the type byte of CPER struct for ARM processor was defined simply as: Type at byte offset 4: - Cache error - TLB Error - Bus Error - Micro-architectural Error All other values are reserved Yet, there was no information about how this would be encoded. Spec 2.9A errata corrected it by defining: - Bit 1 - Cache Error - Bit 2 - TLB Error - Bit 3 - Bus Error - Bit 4 - Micro-architectural Error All other values are reserved That actually aligns with the values already defined on older versions at N.2.4.1. Generic Processor Error Section. Spec 2.10 also preserve the same encoding as 2.9A. Adjust CPER and GHES handling code for both generic and ARM processors to properly handle UEFI 2.9A and 2.10 encoding. Link: https://uefi.org/specs/UEFI/2.10/Apx_N_Common_Platform_Error_Record.html#arm-processor-error-information Signed-off-by: Mauro Carvalho Chehab Reviewed-by: Jonathan Cameron Acked-by: Borislav Petkov (AMD) Signed-off-by: Ard Biesheuvel Signed-off-by: Sasha Levin

RAS: Report all ARM processor CPER information to userspace

2025-12-18T12:55:04+00:00

[ Upstream commit 05954511b73e748d0370549ad9dd9cd95297d97a ] The ARM processor CPER record was added in UEFI v2.6 and remained unchanged up to v2.10. Yet, the original arm_event trace code added by e9279e83ad1f ("trace, ras: add ARM processor error trace event") is incomplete, as it only traces some fields of UAPI 2.6 table N.16, not exporting any information from tables N.17 to N.29 of the record. This is not enough for the user to be able to figure out what has exactly happened or to take appropriate action. According to the UEFI v2.9 specification chapter N2.4.4, the ARM processor error section includes: - several (ERR_INFO_NUM) ARM processor error information structures (Tables N.17 to N.20); - several (CONTEXT_INFO_NUM) ARM processor context information structures (Tables N.21 to N.29); - several vendor specific error information structures. The size is given by Section Length minus the size of the other fields. In addition, it also exports two fields that are parsed by the GHES driver when firmware reports it, e.g.: - error severity - CPU logical index Report all of these information to userspace via a the ARM tracepoint so that userspace can properly record the error and take decisions related to CPU core isolation according to error severity and other info. The updated ARM trace event now contains the following fields: ====================================== ============================= UEFI field on table N.16 ARM Processor trace fields ====================================== ============================= Validation handled when filling data for affinity MPIDR and running state. ERR_INFO_NUM pei_len CONTEXT_INFO_NUM ctx_len Section Length indirectly reported by pei_len, ctx_len and oem_len Error affinity level affinity MPIDR_EL1 mpidr MIDR_EL1 midr Running State running_state PSCI State psci_state Processor Error Information Structure pei_err - count at pei_len Processor Context ctx_err- count at ctx_len Vendor Specific Error Info oem - count at oem_len ====================================== ============================= It should be noted that decoding of tables N.17 to N.29, if needed, will be handled in userspace. That gives more flexibility, as there won't be any need to flood the kernel with micro-architecture specific error decoding. Also, decoding the other fields require a complex logic, and should be done for each of the several values inside the record field. So, let userspace daemons like rasdaemon decode them, parsing such tables and having vendor-specific micro-architecture-specific decoders. [mchehab: modified description, solved merge conflicts and fixed coding style] Signed-off-by: Jason Tian Co-developed-by: Shengwei Luo Signed-off-by: Shengwei Luo Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Daniel Ferguson # rebased Reviewed-by: Jonathan Cameron Tested-by: Shiju Jose Acked-by: Borislav Petkov (AMD) Fixes: e9279e83ad1f ("trace, ras: add ARM processor error trace event") Link: https://uefi.org/specs/UEFI/2.10/Apx_N_Common_Platform_Error_Record.html#arm-processor-error-section Signed-off-by: Ard Biesheuvel Signed-off-by: Sasha Levin

ACPI: APEI: GHES: add TAINT_MACHINE_CHECK on GHES panic path

2025-08-20T16:30:25+00:00

[ Upstream commit 4734c8b46b901cff2feda8b82abc710b65dc31c1 ] When a GHES (Generic Hardware Error Source) triggers a panic, add the TAINT_MACHINE_CHECK taint flag to the kernel. This explicitly marks the kernel as tainted due to a machine check event, improving diagnostics and post-mortem analysis. The taint is set with LOCKDEP_STILL_OK to indicate lockdep remains valid. At large scale deployment, this helps to quickly determine panics that are coming due to hardware failures. Signed-off-by: Breno Leitao Reviewed-by: Tony Luck Link: https://patch.msgid.link/20250702-add_tain-v1-1-9187b10914b9@debian.org Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: APEI: send SIGBUS to current task if synchronous memory error not recovered

2025-08-20T16:30:22+00:00

[ Upstream commit 79a5ae3c4c5eb7e38e0ebe4d6bf602d296080060 ] If a synchronous error is detected as a result of user-space process triggering a 2-bit uncorrected error, the CPU will take a synchronous error exception such as Synchronous External Abort (SEA) on Arm64. The kernel will queue a memory_failure() work which poisons the related page, unmaps the page, and then sends a SIGBUS to the process, so that a system wide panic can be avoided. However, no memory_failure() work will be queued when abnormal synchronous errors occur. These errors can include situations like invalid PA, unexpected severity, no memory failure config support, invalid GUID section, etc. In such a case, the user-space process will trigger SEA again. This loop can potentially exceed the platform firmware threshold or even trigger a kernel hard lockup, leading to a system reboot. Fix it by performing a force kill if no memory_failure() work is queued for synchronous errors. Signed-off-by: Shuai Xue Reviewed-by: Jarkko Sakkinen Reviewed-by: Jonathan Cameron Reviewed-by: Yazen Ghannam Reviewed-by: Jane Chu Reviewed-by: Hanjun Guo Link: https://patch.msgid.link/20250714114212.31660-2-xueshuai@linux.alibaba.com [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

firmware: SDEI: Allow sdei initialization without ACPI_APEI_GHES

2025-06-19T13:31:38+00:00

[ Upstream commit 59529bbe642de4eb2191a541d9b4bae7eb73862e ] SDEI usually initialize with the ACPI table, but on platforms where ACPI is not used, the SDEI feature can still be used to handle specific firmware calls or other customized purposes. Therefore, it is not necessary for ARM_SDE_INTERFACE to depend on ACPI_APEI_GHES. In commit dc4e8c07e9e2 ("ACPI: APEI: explicit init of HEST and GHES in acpi_init()"), to make APEI ready earlier, sdei_init was moved into acpi_ghes_init instead of being a standalone initcall, adding ACPI_APEI_GHES dependency to ARM_SDE_INTERFACE. This restricts the flexibility and usability of SDEI. This patch corrects the dependency in Kconfig and splits sdei_init() into two separate functions: sdei_init() and acpi_sdei_init(). sdei_init() will be called by arch_initcall and will only initialize the platform driver, while acpi_sdei_init() will initialize the device from acpi_ghes_init() when ACPI is ready. This allows the initialization of SDEI without ACPI_APEI_GHES enabled. Fixes: dc4e8c07e9e2 ("ACPI: APEI: explicit init of HEST and GHES in apci_init()") Cc: Shuai Xue Signed-off-by: Huang Yiwei Reviewed-by: Shuai Xue Reviewed-by: Gavin Shan Acked-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20250507045757.2658795-1-quic_hyiwei@quicinc.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

APEI: GHES: Have GHES honor the panic= setting

2025-02-17T09:04:52+00:00

[ Upstream commit 5c0e00a391dd0099fe95991bb2f962848d851916 ] The GHES driver overrides the panic= setting by force-rebooting the system after a fatal hw error has been reported. The intent being that such an error would be reported earlier. However, this is not optimal when a hard-to-debug issue requires long time to reproduce and when that happens, the box will get rebooted after 30 seconds and thus destroy the whole hw context of when the error happened. So rip out the default GHES panic timeout and honor the global one. In the panic disabled (panic=0) case, the error will still be logged to dmesg for later inspection and if panic after a hw error is really required, then that can be controlled the usual way - use panic= on the cmdline or set it in the kernel .config's CONFIG_PANIC_TIMEOUT. Reported-by: Feng Tang Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Feng Tang Reviewed-by: Ira Weiny Link: https://patch.msgid.link/20250113125224.GFZ4UMiNtWIJvgpveU@fat_crate.local Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

Merge tag 'cxl-fixes-6.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

2024-10-05T17:40:16+00:00

Pull cxl fix from Ira Weiny: - Fix calculation for SBDF in error injection * tag 'cxl-fixes-6.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: EINJ, CXL: Fix CXL device SBDF calculation