From 10ebd8556b7990499c896a550e3d416b444211e6 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 02:23:07 +0000
Subject: [PATCH] add led
---
kernel/arch/x86/kernel/dumpstack_64.c | 154 ++++++++++++++++++++++++++++++++++----------------
1 files changed, 104 insertions(+), 50 deletions(-)
diff --git a/kernel/arch/x86/kernel/dumpstack_64.c b/kernel/arch/x86/kernel/dumpstack_64.c
index 5cdb9e8..1dd8513 100644
--- a/kernel/arch/x86/kernel/dumpstack_64.c
+++ b/kernel/arch/x86/kernel/dumpstack_64.c
@@ -16,23 +16,21 @@
#include <linux/bug.h>
#include <linux/nmi.h>
+#include <asm/cpu_entry_area.h>
#include <asm/stacktrace.h>
-static char *exception_stack_names[N_EXCEPTION_STACKS] = {
- [ DOUBLEFAULT_STACK-1 ] = "#DF",
- [ NMI_STACK-1 ] = "NMI",
- [ DEBUG_STACK-1 ] = "#DB",
- [ MCE_STACK-1 ] = "#MC",
-};
-
-static unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = {
- [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,
- [DEBUG_STACK - 1] = DEBUG_STKSZ
+static const char * const exception_stack_names[] = {
+ [ ESTACK_DF ] = "#DF",
+ [ ESTACK_NMI ] = "NMI",
+ [ ESTACK_DB ] = "#DB",
+ [ ESTACK_MCE ] = "#MC",
+ [ ESTACK_VC ] = "#VC",
+ [ ESTACK_VC2 ] = "#VC2",
};
const char *stack_type_name(enum stack_type type)
{
- BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
+ BUILD_BUG_ON(N_EXCEPTION_STACKS != 6);
if (type == STACK_TYPE_IRQ)
return "IRQ";
@@ -52,43 +50,92 @@
return NULL;
}
-static bool in_exception_stack(unsigned long *stack, struct stack_info *info)
+/**
+ * struct estack_pages - Page descriptor for exception stacks
+ * @offs: Offset from the start of the exception stack area
+ * @size: Size of the exception stack
+ * @type: Type to store in the stack_info struct
+ */
+struct estack_pages {
+ u32 offs;
+ u16 size;
+ u16 type;
+};
+
+#define EPAGERANGE(st) \
+ [PFN_DOWN(CEA_ESTACK_OFFS(st)) ... \
+ PFN_DOWN(CEA_ESTACK_OFFS(st) + CEA_ESTACK_SIZE(st) - 1)] = { \
+ .offs = CEA_ESTACK_OFFS(st), \
+ .size = CEA_ESTACK_SIZE(st), \
+ .type = STACK_TYPE_EXCEPTION + ESTACK_ ##st, }
+
+/*
+ * Array of exception stack page descriptors. If the stack is larger than
+ * PAGE_SIZE, all pages covering a particular stack will have the same
+ * info. The guard pages including the not mapped DB2 stack are zeroed
+ * out.
+ */
+static const
+struct estack_pages estack_pages[CEA_ESTACK_PAGES] ____cacheline_aligned = {
+ EPAGERANGE(DF),
+ EPAGERANGE(NMI),
+ EPAGERANGE(DB),
+ EPAGERANGE(MCE),
+ EPAGERANGE(VC),
+ EPAGERANGE(VC2),
+};
+
+static __always_inline bool in_exception_stack(unsigned long *stack, struct stack_info *info)
{
- unsigned long *begin, *end;
+ unsigned long begin, end, stk = (unsigned long)stack;
+ const struct estack_pages *ep;
struct pt_regs *regs;
- unsigned k;
+ unsigned int k;
- BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
+ BUILD_BUG_ON(N_EXCEPTION_STACKS != 6);
- for (k = 0; k < N_EXCEPTION_STACKS; k++) {
- end = (unsigned long *)raw_cpu_ptr(&orig_ist)->ist[k];
- begin = end - (exception_stack_sizes[k] / sizeof(long));
- regs = (struct pt_regs *)end - 1;
+ begin = (unsigned long)__this_cpu_read(cea_exception_stacks);
+ /*
+ * Handle the case where stack trace is collected _before_
+ * cea_exception_stacks had been initialized.
+ */
+ if (!begin)
+ return false;
- if (stack <= begin || stack >= end)
- continue;
+ end = begin + sizeof(struct cea_exception_stacks);
+ /* Bail if @stack is outside the exception stack area. */
+ if (stk < begin || stk >= end)
+ return false;
- info->type = STACK_TYPE_EXCEPTION + k;
- info->begin = begin;
- info->end = end;
- info->next_sp = (unsigned long *)regs->sp;
+ /* Calc page offset from start of exception stacks */
+ k = (stk - begin) >> PAGE_SHIFT;
+ /* Lookup the page descriptor */
+ ep = &estack_pages[k];
+ /* Guard page? */
+ if (!ep->size)
+ return false;
- return true;
- }
+ begin += (unsigned long)ep->offs;
+ end = begin + (unsigned long)ep->size;
+ regs = (struct pt_regs *)end - 1;
- return false;
+ info->type = ep->type;
+ info->begin = (unsigned long *)begin;
+ info->end = (unsigned long *)end;
+ info->next_sp = (unsigned long *)regs->sp;
+ return true;
}
-static bool in_irq_stack(unsigned long *stack, struct stack_info *info)
+static __always_inline bool in_irq_stack(unsigned long *stack, struct stack_info *info)
{
- unsigned long *end = (unsigned long *)this_cpu_read(irq_stack_ptr);
+ unsigned long *end = (unsigned long *)this_cpu_read(hardirq_stack_ptr);
unsigned long *begin = end - (IRQ_STACK_SIZE / sizeof(long));
/*
* This is a software stack, so 'end' can be a valid stack pointer.
* It just means the stack is empty.
*/
- if (stack <= begin || stack > end)
+ if (stack < begin || stack >= end)
return false;
info->type = STACK_TYPE_IRQ;
@@ -104,32 +151,38 @@
return true;
}
+bool noinstr get_stack_info_noinstr(unsigned long *stack, struct task_struct *task,
+ struct stack_info *info)
+{
+ if (in_task_stack(stack, task, info))
+ return true;
+
+ if (task != current)
+ return false;
+
+ if (in_exception_stack(stack, info))
+ return true;
+
+ if (in_irq_stack(stack, info))
+ return true;
+
+ if (in_entry_stack(stack, info))
+ return true;
+
+ return false;
+}
+
int get_stack_info(unsigned long *stack, struct task_struct *task,
struct stack_info *info, unsigned long *visit_mask)
{
+ task = task ? : current;
+
if (!stack)
goto unknown;
- task = task ? : current;
-
- if (in_task_stack(stack, task, info))
- goto recursion_check;
-
- if (task != current)
+ if (!get_stack_info_noinstr(stack, task, info))
goto unknown;
- if (in_exception_stack(stack, info))
- goto recursion_check;
-
- if (in_irq_stack(stack, info))
- goto recursion_check;
-
- if (in_entry_stack(stack, info))
- goto recursion_check;
-
- goto unknown;
-
-recursion_check:
/*
* Make sure we don't iterate through any given stack more than once.
* If it comes up a second time then there's something wrong going on:
@@ -137,7 +190,8 @@
*/
if (visit_mask) {
if (*visit_mask & (1UL << info->type)) {
- printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
+ if (task == current)
+ printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
goto unknown;
}
*visit_mask |= 1UL << info->type;
--
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