From 6bf212c89c48458d8deef1c973678c62528dab04 Mon Sep 17 00:00:00 2001 From: Kalesh Singh Date: Tue, 26 Jul 2022 00:37:34 -0700 Subject: [PATCH] arm64: stacktrace: Add shared header for common stack unwinding code In order to reuse the arm64 stack unwinding logic for the nVHE hypervisor stack, move the common code to a shared header (arch/arm64/include/asm/stacktrace/common.h). The nVHE hypervisor cannot safely link against kernel code, so we make use of the shared header to avoid duplicated logic later in this series. Signed-off-by: Kalesh Singh Reviewed-by: Mark Brown Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220726073750.3219117-2-kaleshsingh@google.com --- arch/arm64/include/asm/stacktrace.h | 35 +--------- arch/arm64/include/asm/stacktrace/common.h | 105 +++++++++++++++++++++++++++++ arch/arm64/kernel/stacktrace.c | 57 ---------------- 3 files changed, 106 insertions(+), 91 deletions(-) create mode 100644 arch/arm64/include/asm/stacktrace/common.h diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h index aec9315..79f455b 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h @@ -8,52 +8,19 @@ #include #include #include -#include #include #include #include #include -enum stack_type { - STACK_TYPE_UNKNOWN, - STACK_TYPE_TASK, - STACK_TYPE_IRQ, - STACK_TYPE_OVERFLOW, - STACK_TYPE_SDEI_NORMAL, - STACK_TYPE_SDEI_CRITICAL, - __NR_STACK_TYPES -}; - -struct stack_info { - unsigned long low; - unsigned long high; - enum stack_type type; -}; +#include extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk, const char *loglvl); DECLARE_PER_CPU(unsigned long *, irq_stack_ptr); -static inline bool on_stack(unsigned long sp, unsigned long size, - unsigned long low, unsigned long high, - enum stack_type type, struct stack_info *info) -{ - if (!low) - return false; - - if (sp < low || sp + size < sp || sp + size > high) - return false; - - if (info) { - info->low = low; - info->high = high; - info->type = type; - } - return true; -} - static inline bool on_irq_stack(unsigned long sp, unsigned long size, struct stack_info *info) { diff --git a/arch/arm64/include/asm/stacktrace/common.h b/arch/arm64/include/asm/stacktrace/common.h new file mode 100644 index 0000000..64ae4f6 --- /dev/null +++ b/arch/arm64/include/asm/stacktrace/common.h @@ -0,0 +1,105 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Common arm64 stack unwinder code. + * + * Copyright (C) 2012 ARM Ltd. + */ +#ifndef __ASM_STACKTRACE_COMMON_H +#define __ASM_STACKTRACE_COMMON_H + +#include +#include +#include + +enum stack_type { + STACK_TYPE_UNKNOWN, + STACK_TYPE_TASK, + STACK_TYPE_IRQ, + STACK_TYPE_OVERFLOW, + STACK_TYPE_SDEI_NORMAL, + STACK_TYPE_SDEI_CRITICAL, + __NR_STACK_TYPES +}; + +struct stack_info { + unsigned long low; + unsigned long high; + enum stack_type type; +}; + +/* + * A snapshot of a frame record or fp/lr register values, along with some + * accounting information necessary for robust unwinding. + * + * @fp: The fp value in the frame record (or the real fp) + * @pc: The lr value in the frame record (or the real lr) + * + * @stacks_done: Stacks which have been entirely unwound, for which it is no + * longer valid to unwind to. + * + * @prev_fp: The fp that pointed to this frame record, or a synthetic value + * of 0. This is used to ensure that within a stack, each + * subsequent frame record is at an increasing address. + * @prev_type: The type of stack this frame record was on, or a synthetic + * value of STACK_TYPE_UNKNOWN. This is used to detect a + * transition from one stack to another. + * + * @kr_cur: When KRETPROBES is selected, holds the kretprobe instance + * associated with the most recently encountered replacement lr + * value. + * + * @task: The task being unwound. + */ +struct unwind_state { + unsigned long fp; + unsigned long pc; + DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES); + unsigned long prev_fp; + enum stack_type prev_type; +#ifdef CONFIG_KRETPROBES + struct llist_node *kr_cur; +#endif + struct task_struct *task; +}; + +static inline bool on_stack(unsigned long sp, unsigned long size, + unsigned long low, unsigned long high, + enum stack_type type, struct stack_info *info) +{ + if (!low) + return false; + + if (sp < low || sp + size < sp || sp + size > high) + return false; + + if (info) { + info->low = low; + info->high = high; + info->type = type; + } + return true; +} + +static inline void unwind_init_common(struct unwind_state *state, + struct task_struct *task) +{ + state->task = task; +#ifdef CONFIG_KRETPROBES + state->kr_cur = NULL; +#endif + + /* + * Prime the first unwind. + * + * In unwind_next() we'll check that the FP points to a valid stack, + * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be + * treated as a transition to whichever stack that happens to be. The + * prev_fp value won't be used, but we set it to 0 such that it is + * definitely not an accessible stack address. + */ + bitmap_zero(state->stacks_done, __NR_STACK_TYPES); + state->prev_fp = 0; + state->prev_type = STACK_TYPE_UNKNOWN; +} + +#endif /* __ASM_STACKTRACE_COMMON_H */ diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index fcaa151..94a5dd2 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -19,63 +19,6 @@ #include /* - * A snapshot of a frame record or fp/lr register values, along with some - * accounting information necessary for robust unwinding. - * - * @fp: The fp value in the frame record (or the real fp) - * @pc: The lr value in the frame record (or the real lr) - * - * @stacks_done: Stacks which have been entirely unwound, for which it is no - * longer valid to unwind to. - * - * @prev_fp: The fp that pointed to this frame record, or a synthetic value - * of 0. This is used to ensure that within a stack, each - * subsequent frame record is at an increasing address. - * @prev_type: The type of stack this frame record was on, or a synthetic - * value of STACK_TYPE_UNKNOWN. This is used to detect a - * transition from one stack to another. - * - * @kr_cur: When KRETPROBES is selected, holds the kretprobe instance - * associated with the most recently encountered replacement lr - * value. - * - * @task: The task being unwound. - */ -struct unwind_state { - unsigned long fp; - unsigned long pc; - DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES); - unsigned long prev_fp; - enum stack_type prev_type; -#ifdef CONFIG_KRETPROBES - struct llist_node *kr_cur; -#endif - struct task_struct *task; -}; - -static void unwind_init_common(struct unwind_state *state, - struct task_struct *task) -{ - state->task = task; -#ifdef CONFIG_KRETPROBES - state->kr_cur = NULL; -#endif - - /* - * Prime the first unwind. - * - * In unwind_next() we'll check that the FP points to a valid stack, - * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be - * treated as a transition to whichever stack that happens to be. The - * prev_fp value won't be used, but we set it to 0 such that it is - * definitely not an accessible stack address. - */ - bitmap_zero(state->stacks_done, __NR_STACK_TYPES); - state->prev_fp = 0; - state->prev_type = STACK_TYPE_UNKNOWN; -} - -/* * Start an unwind from a pt_regs. * * The unwind will begin at the PC within the regs. -- 2.7.4