@@ -75,6 +75,7 @@ config ARM64
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
+ select HAVE_ARCH_VMAP_STACK
select HAVE_ARM_SMCCC
select HAVE_EBPF_JIT
select HAVE_C_RECORDMCOUNT
@@ -49,7 +49,12 @@
*/
#define EFI_FDT_ALIGN SZ_2M /* used by allocate_new_fdt_and_exit_boot() */
-#define EFI_KIMG_ALIGN SEGMENT_ALIGN
+/*
+ * In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
+ * kernel need greater alignment than we require the segments to be padded to.
+ */
+#define EFI_KIMG_ALIGN \
+ (SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
/* on arm64, the FDT may be located anywhere in system RAM */
static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base)
@@ -102,7 +102,17 @@
#define KASAN_SHADOW_SIZE (0)
#endif
-#define THREAD_SHIFT 14
+#define MIN_THREAD_SHIFT 14
+
+/*
+ * VMAP'd stacks are allocated at page granularity, so we must ensure that such
+ * stacks are a multiple of page size.
+ */
+#if defined(CONFIG_VMAP_STACK) && (MIN_THREAD_SHIFT < PAGE_SHIFT)
+#define THREAD_SHIFT PAGE_SHIFT
+#else
+#define THREAD_SHIFT MIN_THREAD_SHIFT
+#endif
#if THREAD_SHIFT >= PAGE_SHIFT
#define THREAD_SIZE_ORDER (THREAD_SHIFT - PAGE_SHIFT)
@@ -110,6 +120,17 @@
#define THREAD_SIZE (UL(1) << THREAD_SHIFT)
+/*
+ * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
+ * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
+ * assembly.
+ */
+#ifdef CONFIG_VMAP_STACK
+#define THREAD_ALIGN (2 * THREAD_SIZE)
+#else
+#define THREAD_ALIGN THREAD_SIZE
+#endif
+
#define IRQ_STACK_SIZE THREAD_SIZE
/*
@@ -23,15 +23,15 @@
#include <linux/kernel_stat.h>
#include <linux/irq.h>
+#include <linux/memory.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/irqchip.h>
#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
unsigned long irq_err_count;
-/* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */
-DEFINE_PER_CPU(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack) __aligned(16);
DEFINE_PER_CPU(unsigned long *, irq_stack_ptr);
int arch_show_interrupts(struct seq_file *p, int prec)
@@ -51,6 +51,31 @@ void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
handle_arch_irq = handle_irq;
}
+#ifdef CONFIG_VMAP_STACK
+static void init_irq_stacks(void)
+{
+ int cpu;
+ unsigned long *p;
+
+ for_each_possible_cpu(cpu) {
+ /*
+ * To ensure that VMAP'd stack overflow detection works
+ * correctly, the IRQ stacks need to have the same
+ * alignment as other stacks.
+ */
+ p = __vmalloc_node_range(IRQ_STACK_SIZE, THREAD_ALIGN,
+ VMALLOC_START, VMALLOC_END,
+ THREADINFO_GFP, PAGE_KERNEL,
+ 0, cpu_to_node(cpu),
+ __builtin_return_address(0));
+
+ per_cpu(irq_stack_ptr, cpu) = p;
+ }
+}
+#else
+/* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */
+DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack);
+
static void init_irq_stacks(void)
{
int cpu;
@@ -58,6 +83,7 @@ static void init_irq_stacks(void)
for_each_possible_cpu(cpu)
per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
}
+#endif
void __init init_IRQ(void)
{
@@ -176,7 +176,7 @@ SECTIONS
_data = .;
_sdata = .;
- RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+ RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_ALIGN)
/*
* Data written with the MMU off but read with the MMU on requires