4KB stack + irq stack for x86

diff -Nru a/arch/i386/boot/compressed/misc.c b/arch/i386/boot/compressed/misc.c
@@ -377,3 +377,7 @@
 	if (high_loaded) close_output_buffer_if_we_run_high(mv);
 	return high_loaded;
 }
+
+/* We don't actually check for stack overflows this early. */
+__asm__(".globl mcount ; mcount: ret\n");
+

diff -Nru a/arch/i386/kernel/i386_ksyms.c b/arch/i386/kernel/i386_ksyms.c
@@ -172,3 +172,8 @@
 EXPORT_SYMBOL(is_sony_vaio_laptop);
 
 EXPORT_SYMBOL(__PAGE_KERNEL);
+
+#ifdef CONFIG_X86_STACK_CHECK
+extern void mcount(void);
+EXPORT_SYMBOL(mcount);
+#endif

diff -Nru a/arch/i386/kernel/init_task.c b/arch/i386/kernel/init_task.c
@@ -13,6 +13,14 @@
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 struct mm_struct init_mm = INIT_MM(init_mm);
 
+union thread_union init_irq_union
+	__attribute__((__section__(".data.init_task")));
+
+#ifdef CONFIG_X86_STACK_CHECK
+union thread_union stack_overflow_stack
+	__attribute__((__section__(".data.init_task")));
+#endif
+
 /*
  * Initial thread structure.
  *

@@ -22,7 +30,15 @@
  */
 union thread_union init_thread_union 
 	__attribute__((__section__(".data.init_task"))) =
-		{ INIT_THREAD_INFO(init_task) };
+		{ { 
+			task:		&init_task,
+			exec_domain:	&default_exec_domain,
+			flags:		0,
+			cpu:		0,
+			addr_limit:	KERNEL_DS,
+			irq_stack:	&init_irq_union,
+		} };
+
 
 /*
  * Initial task structure.

diff -Nru a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c
@@ -311,7 +311,8 @@
  * SMP cross-CPU interrupts have their own specific
  * handlers).
  */
-asmlinkage unsigned int do_IRQ(struct pt_regs regs)
+struct pt_regs *do_IRQ(struct pt_regs *regs) __attribute__((regparm(1)));
+struct pt_regs *do_IRQ(struct pt_regs *regs)
 {	
 	/* 
 	 * We ack quickly, we don't want the irq controller

@@ -323,7 +324,7 @@
 	 * 0 return value means that this irq is already being
 	 * handled by some other CPU. (or is disabled)
 	 */
-	int irq = regs.orig_eax & 0xff; /* high bits used in ret_from_ code  */
+	int irq = regs->orig_eax & 0xff; /* high bits used in ret_from_ code  */
 	int cpu = smp_processor_id();
 	irq_desc_t *desc = irq_desc + irq;
 	struct irqaction * action;

@@ -373,7 +374,7 @@
 	 */
 	for (;;) {
 		spin_unlock(&desc->lock);
-		handle_IRQ_event(irq, &regs, action);
+		handle_IRQ_event(irq, regs, action);
 		spin_lock(&desc->lock);
 		
 		if (likely(!(desc->status & IRQ_PENDING)))

@@ -392,7 +393,7 @@
 
 	irq_exit();
 
-	return 1;
+	return regs;
 }
 
 /**

diff -Nru a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
@@ -438,6 +438,16 @@
 
 extern void show_trace(unsigned long* esp);
 
+#ifdef CONFIG_X86_STACK_CHECK
+void stack_overflow_panic(void *esp, void *eip)
+{
+	printk("stack overflow from %p.  esp: %p\n", eip, esp);
+	show_trace(esp);
+	panic("stack overflow\n");
+}
+
+#endif
+
 void show_regs(struct pt_regs * regs)
 {
 	unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;

@@ -693,6 +703,7 @@
 
 	/* never put a printk in __switch_to... printk() calls wake_up*() indirectly */
 
+	next_p->thread_info->irq_stack = prev_p->thread_info->irq_stack;
 	unlazy_fpu(prev_p);
 
 	/*

diff -Nru a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
@@ -67,6 +67,10 @@
 /* Per CPU bogomips and other parameters */
 struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
 
+extern union thread_union init_irq_union;
+union thread_union *irq_stacks[NR_CPUS] __cacheline_aligned =
+	{ &init_irq_union, };
+
 /* Set when the idlers are all forked */
 int smp_threads_ready;
 

@@ -762,6 +766,27 @@
 	return (send_status | accept_status);
 }
 
+static void __init setup_irq_stack(struct task_struct *p, int cpu)
+{
+	unsigned long stk;
+
+	stk = __get_free_pages(GFP_KERNEL, THREAD_ORDER);
+	if (!stk)
+		panic("I can't seem to allocate my irq stack.  Oh well, giving up.");
+
+	irq_stacks[cpu] = (void *)stk;
+	memset(irq_stacks[cpu], 0, THREAD_SIZE);
+	irq_stacks[cpu]->thread_info.cpu = cpu;
+	irq_stacks[cpu]->thread_info.preempt_count = 1;
+					/* interrupts are not preemptable */
+	p->thread_info->irq_stack = irq_stacks[cpu];
+
+	/* If we want to make the irq stack more than one unit
+	 * deep, we can chain then off of the irq_stack pointer
+	 * here.
+	 */
+}
+
 extern unsigned long cpu_initialized;
 
 static void __init do_boot_cpu (int apicid) 

@@ -785,6 +810,8 @@
 	if (IS_ERR(idle))
 		panic("failed fork for CPU %d", cpu);
 
+	setup_irq_stack(idle, cpu);
+
 	/*
 	 * We remove it from the pidhash and the runqueue
 	 * once we got the process:

@@ -802,7 +829,13 @@
 
 	/* So we see what's up   */
 	printk("Booting processor %d/%d eip %lx\n", cpu, apicid, start_eip);
-	stack_start.esp = (void *) (1024 + PAGE_SIZE + (char *)idle->thread_info);
+
+	/* The -4 is to correct for the fact that the stack pointer
+	 * is used to find the location of the thread_info structure
+	 * by masking off several of the LSBs.  Without the -4, esp
+	 * is pointing to the page after the one the stack is on.
+	 */
+	stack_start.esp = (void *)(THREAD_SIZE - 4 + (char *)idle->thread_info);
 
 	/*
 	 * This grunge runs the startup process for

diff -Nru a/include/asm-i386/page.h b/include/asm-i386/page.h
@@ -3,7 +3,11 @@
 
 /* PAGE_SHIFT determines the page size */
 #define PAGE_SHIFT	12
+#ifndef __ASSEMBLY__
 #define PAGE_SIZE	(1UL << PAGE_SHIFT)
+#else
+#define PAGE_SIZE	(1 << PAGE_SHIFT)
+#endif
 #define PAGE_MASK	(~(PAGE_SIZE-1))
 
 #define LARGE_PAGE_MASK (~(LARGE_PAGE_SIZE-1))

86 lines not on this page · raw message