diff options
| -rw-r--r-- | arch/arm64/include/asm/irq.h | 25 | ||||
| -rw-r--r-- | arch/arm64/include/asm/ptrace.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/traps.h | 5 | ||||
| -rw-r--r-- | arch/arm64/kernel/asm-offsets.c | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry.S | 20 | ||||
| -rw-r--r-- | arch/arm64/kernel/head.S | 4 | ||||
| -rw-r--r-- | arch/arm64/kernel/stacktrace.c | 33 | ||||
| -rw-r--r-- | arch/arm64/kernel/traps.c | 32 |
8 files changed, 36 insertions, 85 deletions
diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h index 8155e486ce48..8ba89c4ca183 100644 --- a/arch/arm64/include/asm/irq.h +++ b/arch/arm64/include/asm/irq.h @@ -16,31 +16,6 @@ struct pt_regs; DECLARE_PER_CPU(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack); -/* - * The highest address on the stack, and the first to be used. Used to - * find the dummy-stack frame put down by el?_irq() in entry.S, which - * is structured as follows: - * - * ------------ - * | | <- irq_stack_ptr - * top ------------ - * | x19 | <- irq_stack_ptr - 0x08 - * ------------ - * | x29 | <- irq_stack_ptr - 0x10 - * ------------ - * - * where x19 holds a copy of the task stack pointer where the struct pt_regs - * from kernel_entry can be found. - * - */ -#define IRQ_STACK_PTR() ((unsigned long)raw_cpu_ptr(irq_stack) + IRQ_STACK_START_SP) - -/* - * The offset from irq_stack_ptr where entry.S will store the original - * stack pointer. Used by unwind_frame() and dump_backtrace(). - */ -#define IRQ_STACK_TO_TASK_STACK(ptr) (*((unsigned long *)((ptr) - 0x08))) - extern void set_handle_irq(void (*handle_irq)(struct pt_regs *)); static inline int nr_legacy_irqs(void) diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index 11403fdd0a50..ee72aa979078 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -119,6 +119,7 @@ struct pt_regs { u64 syscallno; u64 orig_addr_limit; u64 unused; // maintain 16 byte alignment + u64 stackframe[2]; }; #define MAX_REG_OFFSET offsetof(struct pt_regs, pstate) diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h index 02e9035b0685..41361684580d 100644 --- a/arch/arm64/include/asm/traps.h +++ b/arch/arm64/include/asm/traps.h @@ -60,4 +60,9 @@ static inline int in_exception_text(unsigned long ptr) return in ? : __in_irqentry_text(ptr); } +static inline int in_entry_text(unsigned long ptr) +{ + return ptr >= (unsigned long)&__entry_text_start && + ptr < (unsigned long)&__entry_text_end; +} #endif diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index b3bb7ef97bc8..71bf088f1e4b 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -75,6 +75,7 @@ int main(void) DEFINE(S_ORIG_X0, offsetof(struct pt_regs, orig_x0)); DEFINE(S_SYSCALLNO, offsetof(struct pt_regs, syscallno)); DEFINE(S_ORIG_ADDR_LIMIT, offsetof(struct pt_regs, orig_addr_limit)); + DEFINE(S_STACKFRAME, offsetof(struct pt_regs, stackframe)); DEFINE(S_FRAME_SIZE, sizeof(struct pt_regs)); BLANK(); DEFINE(MM_CONTEXT_ID, offsetof(struct mm_struct, context.id.counter)); diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 9e126d3d8b53..612a077ba109 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -111,6 +111,18 @@ mrs x23, spsr_el1 stp lr, x21, [sp, #S_LR] + /* + * In order to be able to dump the contents of struct pt_regs at the + * time the exception was taken (in case we attempt to walk the call + * stack later), chain it together with the stack frames. + */ + .if \el == 0 + stp xzr, xzr, [sp, #S_STACKFRAME] + .else + stp x29, x22, [sp, #S_STACKFRAME] + .endif + add x29, sp, #S_STACKFRAME + #ifdef CONFIG_ARM64_SW_TTBR0_PAN /* * Set the TTBR0 PAN bit in SPSR. When the exception is taken from @@ -265,14 +277,6 @@ alternative_else_nop_endif /* switch to the irq stack */ mov sp, x26 - - /* - * Add a dummy stack frame, this non-standard format is fixed up - * by unwind_frame() - */ - stp x29, x19, [sp, #-16]! - mov x29, sp - 9998: .endm diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 973df7de7bf8..f9e4aacf4f42 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -362,6 +362,9 @@ __primary_switched: ret // to __primary_switch() 0: #endif + add sp, sp, #16 + mov x29, #0 + mov x30, #0 b start_kernel ENDPROC(__primary_switched) @@ -617,6 +620,7 @@ __secondary_switched: ldr x2, [x0, #CPU_BOOT_TASK] msr sp_el0, x2 mov x29, #0 + mov x30, #0 b secondary_start_kernel ENDPROC(__secondary_switched) diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index beaf51fb3088..81d9262acaf0 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -76,34 +76,13 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ /* - * Check whether we are going to walk through from interrupt stack - * to task stack. - * If we reach the end of the stack - and its an interrupt stack, - * unpack the dummy frame to find the original elr. - * - * Check the frame->fp we read from the bottom of the irq_stack, - * and the original task stack pointer are both in current->stack. + * Frames created upon entry from EL0 have NULL FP and PC values, so + * don't bother reporting these. Frames created by __noreturn functions + * might have a valid FP even if PC is bogus, so only terminate where + * both are NULL. */ - if (frame->sp == IRQ_STACK_PTR()) { - struct pt_regs *irq_args; - unsigned long orig_sp = IRQ_STACK_TO_TASK_STACK(frame->sp); - - if (object_is_on_stack((void *)orig_sp) && - object_is_on_stack((void *)frame->fp)) { - frame->sp = orig_sp; - - /* orig_sp is the saved pt_regs, find the elr */ - irq_args = (struct pt_regs *)orig_sp; - frame->pc = irq_args->pc; - } else { - /* - * This frame has a non-standard format, and we - * didn't fix it, because the data looked wrong. - * Refuse to output this frame. - */ - return -EINVAL; - } - } + if (!frame->fp && !frame->pc) + return -EINVAL; return 0; } diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 5797f5037ec9..075c29a24345 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -143,7 +143,6 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) { struct stackframe frame; - unsigned long irq_stack_ptr; int skip; pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk); @@ -154,15 +153,6 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) if (!try_get_task_stack(tsk)) return; - /* - * Switching between stacks is valid when tracing current and in - * non-preemptible context. - */ - if (tsk == current && !preemptible()) - irq_stack_ptr = IRQ_STACK_PTR(); - else - irq_stack_ptr = 0; - if (tsk == current) { frame.fp = (unsigned long)__builtin_frame_address(0); frame.sp = current_stack_pointer; @@ -182,13 +172,12 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) skip = !!regs; printk("Call trace:\n"); while (1) { - unsigned long where = frame.pc; unsigned long stack; int ret; /* skip until specified stack frame */ if (!skip) { - dump_backtrace_entry(where); + dump_backtrace_entry(frame.pc); } else if (frame.fp == regs->regs[29]) { skip = 0; /* @@ -203,20 +192,13 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) ret = unwind_frame(tsk, &frame); if (ret < 0) break; - stack = frame.sp; - if (in_exception_text(where)) { - /* - * If we switched to the irq_stack before calling this - * exception handler, then the pt_regs will be on the - * task stack. The easiest way to tell is if the large - * pt_regs would overlap with the end of the irq_stack. - */ - if (stack < irq_stack_ptr && - (stack + sizeof(struct pt_regs)) > irq_stack_ptr) - stack = IRQ_STACK_TO_TASK_STACK(irq_stack_ptr); + if (in_entry_text(frame.pc)) { + stack = frame.fp - offsetof(struct pt_regs, stackframe); - dump_mem("", "Exception stack", stack, - stack + sizeof(struct pt_regs)); + if (on_task_stack(tsk, stack) || + (tsk == current && !preemptible() && on_irq_stack(stack))) + dump_mem("", "Exception stack", stack, + stack + sizeof(struct pt_regs)); } } |