Failure after v6.2-rc2-5-ga7334dc70496: arm64: efi: Account for the EFI runtime stack in stack unwinder:

Results changed to -10 # build_abe binutils: -9 # build_abe stage1: -5 # build_abe qemu: -2 # linux_n_obj: 8685 # linux build successful: all # First few build errors in logs:

from -10 # build_abe binutils: -9 # build_abe stage1: -5 # build_abe qemu: -2 # linux_n_obj: 8685 # linux build successful: all # linux boot successful: boot

THIS IS THE END OF INTERESTING STUFF. BELOW ARE LINKS TO BUILDS, REPRODUCTION INSTRUCTIONS, AND THE RAW COMMIT.

For latest status see comments in https://linaro.atlassian.net/browse/GNU-681 . Status of v6.2-rc2-5-ga7334dc70496 commit for tcwg_kernel: commit a7334dc70496bb0cec7f1d3b1f148855951f41c5 Author: Ard Biesheuvel ardb@kernel.org Date: Fri Dec 9 12:10:13 2022 +0100

arm64: efi: Account for the EFI runtime stack in stack unwinder

The EFI runtime services run from a dedicated stack now, and so the stack unwinder needs to be informed about this.

Cc: stable@vger.kernel.org # v6.1+ Acked-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Ard Biesheuvel ardb@kernel.org * gnu-master-aarch64-next-defconfig ** Failure after v6.2-rc2-5-ga7334dc70496: arm64: efi: Account for the EFI runtime stack in stack unwinder: ** https://ci.linaro.org/job/tcwg_kernel-gnu-build-gnu-master-aarch64-next-defc...

Bad build: https://ci.linaro.org/job/tcwg_kernel-gnu-build-gnu-master-aarch64-next-defc... Good build: https://ci.linaro.org/job/tcwg_kernel-gnu-build-gnu-master-aarch64-next-defc...

Reproduce current build: <cut> mkdir -p investigate-linux-a7334dc70496bb0cec7f1d3b1f148855951f41c5 cd investigate-linux-a7334dc70496bb0cec7f1d3b1f148855951f41c5

# Fetch scripts git clone https://git.linaro.org/toolchain/jenkins-scripts

# Fetch manifests for bad and good builds mkdir -p bad/artifacts good/artifacts curl -o bad/artifacts/manifest.sh https://ci.linaro.org/job/tcwg_kernel-gnu-build-gnu-master-aarch64-next-defc... --fail curl -o good/artifacts/manifest.sh https://ci.linaro.org/job/tcwg_kernel-gnu-build-gnu-master-aarch64-next-defc... --fail

# Reproduce bad build (cd bad; ../jenkins-scripts/tcwg_kernel-build.sh ^^ true %%rr[top_artifacts] artifacts) # Reproduce good build (cd good; ../jenkins-scripts/tcwg_kernel-build.sh ^^ true %%rr[top_artifacts] artifacts) </cut>

Full commit (up to 1000 lines): <cut> commit a7334dc70496bb0cec7f1d3b1f148855951f41c5 Author: Ard Biesheuvel ardb@kernel.org Date: Fri Dec 9 12:10:13 2022 +0100

arm64: efi: Account for the EFI runtime stack in stack unwinder

The EFI runtime services run from a dedicated stack now, and so the stack unwinder needs to be informed about this.

Cc: stable@vger.kernel.org # v6.1+ Acked-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Ard Biesheuvel ardb@kernel.org --- arch/arm64/include/asm/stacktrace.h | 15 +++++++++++++++ arch/arm64/kernel/stacktrace.c | 12 ++++++++++++ 2 files changed, 27 insertions(+)

diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h index 4e5354beafb0..66ec8caa6ac0 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h @@ -106,4 +106,19 @@ static inline struct stack_info stackinfo_get_sdei_critical(void) #define stackinfo_get_sdei_critical() stackinfo_get_unknown() #endif

+#ifdef CONFIG_EFI +extern u64 *efi_rt_stack_top; + +static inline struct stack_info stackinfo_get_efi(void) +{ + unsigned long high = (u64)efi_rt_stack_top; + unsigned long low = high - THREAD_SIZE; + + return (struct stack_info) { + .low = low, + .high = high, + }; +} +#endif + #endif /* __ASM_STACKTRACE_H */ diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index 117e2c180f3c..83154303e682 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -5,6 +5,7 @@ * Copyright (C) 2012 ARM Ltd. */ #include <linux/kernel.h> +#include <linux/efi.h> #include <linux/export.h> #include <linux/ftrace.h> #include <linux/sched.h> @@ -12,6 +13,7 @@ #include <linux/sched/task_stack.h> #include <linux/stacktrace.h>

+#include <asm/efi.h> #include <asm/irq.h> #include <asm/stack_pointer.h> #include <asm/stacktrace.h> @@ -186,6 +188,13 @@ void show_stack(struct task_struct *tsk, unsigned long *sp, const char *loglvl) : stackinfo_get_unknown(); \ })

+#define STACKINFO_EFI \ + ({ \ + ((task == current) && current_in_efi()) \ + ? stackinfo_get_efi() \ + : stackinfo_get_unknown(); \ + }) + noinline noinstr void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, struct task_struct *task, struct pt_regs *regs) @@ -199,6 +208,9 @@ noinline noinstr void arch_stack_walk(stack_trace_consume_fn consume_entry, #if defined(CONFIG_VMAP_STACK) && defined(CONFIG_ARM_SDE_INTERFACE) STACKINFO_SDEI(normal), STACKINFO_SDEI(critical), +#endif +#ifdef CONFIG_EFI + STACKINFO_EFI, #endif }; struct unwind_state state = { </cut>