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-rw-r--r--arch/arm64/include/asm/irq.h25
-rw-r--r--arch/arm64/include/asm/ptrace.h1
-rw-r--r--arch/arm64/include/asm/traps.h5
-rw-r--r--arch/arm64/kernel/asm-offsets.c1
-rw-r--r--arch/arm64/kernel/entry.S20
-rw-r--r--arch/arm64/kernel/head.S4
-rw-r--r--arch/arm64/kernel/stacktrace.c33
-rw-r--r--arch/arm64/kernel/traps.c32
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));
}
}