diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 9df3feeee890..7a094aafec20 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -329,13 +329,13 @@ long get_tagged_addr_ctrl(struct task_struct *task); * of header definitions for the use of task_stack_page. */ -#define current_top_of_stack() \ -({ \ - struct stack_info _info; \ - BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info)); \ - _info.high; \ +#define current_top_of_stack() \ +({ \ + struct stack_info _info; \ + BUG_ON(!on_accessible_stack(current, current_stack_pointer, 1, &_info)); \ + _info.high; \ }) -#define on_thread_stack() (on_task_stack(current, current_stack_pointer, NULL)) +#define on_thread_stack() (on_task_stack(current, current_stack_pointer, 1, NULL)) #endif /* __ASSEMBLY__ */ #endif /* __ASM_PROCESSOR_H */ diff --git a/arch/arm64/include/asm/sdei.h b/arch/arm64/include/asm/sdei.h index 63e0b92a5fbb..8bc30a5c4569 100644 --- a/arch/arm64/include/asm/sdei.h +++ b/arch/arm64/include/asm/sdei.h @@ -42,8 +42,9 @@ unsigned long sdei_arch_get_entry_point(int conduit); struct stack_info; -bool _on_sdei_stack(unsigned long sp, struct stack_info *info); -static inline bool on_sdei_stack(unsigned long sp, +bool _on_sdei_stack(unsigned long sp, unsigned long size, + struct stack_info *info); +static inline bool on_sdei_stack(unsigned long sp, unsigned long size, struct stack_info *info) { if (!IS_ENABLED(CONFIG_VMAP_STACK)) @@ -51,7 +52,7 @@ static inline bool on_sdei_stack(unsigned long sp, if (!IS_ENABLED(CONFIG_ARM_SDE_INTERFACE)) return false; if (in_nmi()) - return _on_sdei_stack(sp, info); + return _on_sdei_stack(sp, size, info); return false; } diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h index 4b33ca620679..1801399204d7 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h @@ -69,14 +69,14 @@ extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk, DECLARE_PER_CPU(unsigned long *, irq_stack_ptr); -static inline bool on_stack(unsigned long sp, unsigned long low, - unsigned long high, enum stack_type type, - struct stack_info *info) +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 >= high) + if (sp < low || sp + size < sp || sp + size > high) return false; if (info) { @@ -87,38 +87,38 @@ static inline bool on_stack(unsigned long sp, unsigned long low, return true; } -static inline bool on_irq_stack(unsigned long sp, +static inline bool on_irq_stack(unsigned long sp, unsigned long size, struct stack_info *info) { unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr); unsigned long high = low + IRQ_STACK_SIZE; - return on_stack(sp, low, high, STACK_TYPE_IRQ, info); + return on_stack(sp, size, low, high, STACK_TYPE_IRQ, info); } static inline bool on_task_stack(const struct task_struct *tsk, - unsigned long sp, + unsigned long sp, unsigned long size, struct stack_info *info) { unsigned long low = (unsigned long)task_stack_page(tsk); unsigned long high = low + THREAD_SIZE; - return on_stack(sp, low, high, STACK_TYPE_TASK, info); + return on_stack(sp, size, low, high, STACK_TYPE_TASK, info); } #ifdef CONFIG_VMAP_STACK DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack); -static inline bool on_overflow_stack(unsigned long sp, +static inline bool on_overflow_stack(unsigned long sp, unsigned long size, struct stack_info *info) { unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack); unsigned long high = low + OVERFLOW_STACK_SIZE; - return on_stack(sp, low, high, STACK_TYPE_OVERFLOW, info); + return on_stack(sp, size, low, high, STACK_TYPE_OVERFLOW, info); } #else -static inline bool on_overflow_stack(unsigned long sp, +static inline bool on_overflow_stack(unsigned long sp, unsigned long size, struct stack_info *info) { return false; } #endif @@ -128,21 +128,21 @@ static inline bool on_overflow_stack(unsigned long sp, * context. */ static inline bool on_accessible_stack(const struct task_struct *tsk, - unsigned long sp, + unsigned long sp, unsigned long size, struct stack_info *info) { if (info) info->type = STACK_TYPE_UNKNOWN; - if (on_task_stack(tsk, sp, info)) + if (on_task_stack(tsk, sp, size, info)) return true; if (tsk != current || preemptible()) return false; - if (on_irq_stack(sp, info)) + if (on_irq_stack(sp, size, info)) return true; - if (on_overflow_stack(sp, info)) + if (on_overflow_stack(sp, size, info)) return true; - if (on_sdei_stack(sp, info)) + if (on_sdei_stack(sp, size, info)) return true; return false; diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 3513984a88bd..294f24e16fee 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -285,7 +285,7 @@ alternative_else_nop_endif stp lr, x21, [sp, #S_LR] /* - * For exceptions from EL0, create a terminal frame record. + * For exceptions from EL0, create a final frame record. * For exceptions from EL1, create a synthetic frame record so the * interrupted code shows up in the backtrace. */ diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 96873dfa67fd..cc2d45d54838 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -393,6 +394,18 @@ SYM_FUNC_START_LOCAL(__create_page_tables) ret x28 SYM_FUNC_END(__create_page_tables) + /* + * Create a final frame record at task_pt_regs(current)->stackframe, so + * that the unwinder can identify the final frame record of any task by + * its location in the task stack. We reserve the entire pt_regs space + * for consistency with user tasks and kthreads. + */ + .macro setup_final_frame + sub sp, sp, #PT_REGS_SIZE + stp xzr, xzr, [sp, #S_STACKFRAME] + add x29, sp, #S_STACKFRAME + .endm + /* * The following fragment of code is executed with the MMU enabled. * @@ -447,9 +460,9 @@ SYM_FUNC_START_LOCAL(__primary_switched) #endif bl switch_to_vhe // Prefer VHE if possible add sp, sp, #16 - mov x29, #0 - mov x30, #0 - b start_kernel + setup_final_frame + bl start_kernel + ASM_BUG() SYM_FUNC_END(__primary_switched) .pushsection ".rodata", "a" @@ -639,14 +652,14 @@ SYM_FUNC_START_LOCAL(__secondary_switched) cbz x2, __secondary_too_slow msr sp_el0, x2 scs_load x2, x3 - mov x29, #0 - mov x30, #0 + setup_final_frame #ifdef CONFIG_ARM64_PTR_AUTH ptrauth_keys_init_cpu x2, x3, x4, x5 #endif - b secondary_start_kernel + bl secondary_start_kernel + ASM_BUG() SYM_FUNC_END(__secondary_switched) SYM_FUNC_START_LOCAL(__secondary_too_slow) diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c index 88ff471b0bce..4a72c2727309 100644 --- a/arch/arm64/kernel/perf_callchain.c +++ b/arch/arm64/kernel/perf_callchain.c @@ -116,7 +116,7 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry, tail = (struct frame_tail __user *)regs->regs[29]; while (entry->nr < entry->max_stack && - tail && !((unsigned long)tail & 0xf)) + tail && !((unsigned long)tail & 0x7)) tail = user_backtrace(tail, entry); } else { #ifdef CONFIG_COMPAT diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index b4bb67f17a2c..8928fba54e4b 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -435,6 +435,11 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, } p->thread.cpu_context.pc = (unsigned long)ret_from_fork; p->thread.cpu_context.sp = (unsigned long)childregs; + /* + * For the benefit of the unwinder, set up childregs->stackframe + * as the final frame for the new task. + */ + p->thread.cpu_context.fp = (unsigned long)childregs->stackframe; ptrace_hw_copy_thread(p); diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index eb2f73939b7b..499b6b2f9757 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -122,7 +122,7 @@ static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) { return ((addr & ~(THREAD_SIZE - 1)) == (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))) || - on_irq_stack(addr, NULL); + on_irq_stack(addr, sizeof(unsigned long), NULL); } /** diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c index 2c7ca449dd51..c524f96f97c4 100644 --- a/arch/arm64/kernel/sdei.c +++ b/arch/arm64/kernel/sdei.c @@ -162,31 +162,33 @@ static int init_sdei_scs(void) return err; } -static bool on_sdei_normal_stack(unsigned long sp, struct stack_info *info) +static bool on_sdei_normal_stack(unsigned long sp, unsigned long size, + struct stack_info *info) { unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_normal_ptr); unsigned long high = low + SDEI_STACK_SIZE; - return on_stack(sp, low, high, STACK_TYPE_SDEI_NORMAL, info); + return on_stack(sp, size, low, high, STACK_TYPE_SDEI_NORMAL, info); } -static bool on_sdei_critical_stack(unsigned long sp, struct stack_info *info) +static bool on_sdei_critical_stack(unsigned long sp, unsigned long size, + struct stack_info *info) { unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr); unsigned long high = low + SDEI_STACK_SIZE; - return on_stack(sp, low, high, STACK_TYPE_SDEI_CRITICAL, info); + return on_stack(sp, size, low, high, STACK_TYPE_SDEI_CRITICAL, info); } -bool _on_sdei_stack(unsigned long sp, struct stack_info *info) +bool _on_sdei_stack(unsigned long sp, unsigned long size, struct stack_info *info) { if (!IS_ENABLED(CONFIG_VMAP_STACK)) return false; - if (on_sdei_critical_stack(sp, info)) + if (on_sdei_critical_stack(sp, size, info)) return true; - if (on_sdei_normal_stack(sp, info)) + if (on_sdei_normal_stack(sp, size, info)) return true; return false; diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index de07147a7926..b189de5ca6cb 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -68,13 +68,17 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) unsigned long fp = frame->fp; struct stack_info info; - if (fp & 0xf) - return -EINVAL; - if (!tsk) tsk = current; - if (!on_accessible_stack(tsk, fp, &info)) + /* Final frame; nothing to unwind */ + if (fp == (unsigned long)task_pt_regs(tsk)->stackframe) + return -ENOENT; + + if (fp & 0x7) + return -EINVAL; + + if (!on_accessible_stack(tsk, fp, 16, &info)) return -EINVAL; if (test_bit(info.type, frame->stacks_done)) @@ -128,12 +132,6 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) frame->pc = ptrauth_strip_insn_pac(frame->pc); - /* - * This is a terminal record, so we have finished unwinding. - */ - if (!frame->fp && !frame->pc) - return -ENOENT; - return 0; } NOKPROBE_SYMBOL(unwind_frame);