Use C instead of asm for accessing the stack pointer. And define some
macros to make the code easier to understand.
Signed-off-by: Chuck Ebbert <cebbert.l...@gmail.com>
diff --git a/arch/x86/include/asm/page_32_types.h
b/arch/x86/include/asm/page_32_types.h
index f48b17d..a8ca0cb 100644
--- a/arch/x86/include/asm/page_32_types.h
+++ b/arch/x86/include/asm/page_32_types.h
@@ -19,6 +19,8 @@
#define THREAD_SIZE_ORDER 1
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
+#define THREAD_SIZE_MASK (THREAD_SIZE - 1)
+#define CURRENT_MASK (~THREAD_SIZE_MASK)
#define STACKFAULT_STACK 0
#define DOUBLEFAULT_STACK 1
diff --git a/arch/x86/include/asm/page_64_types.h
b/arch/x86/include/asm/page_64_types.h
index 6782051..ded89b0 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -2,8 +2,9 @@
#define _ASM_X86_PAGE_64_DEFS_H
#define THREAD_SIZE_ORDER 2
-#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
-#define CURRENT_MASK (~(THREAD_SIZE - 1))
+#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
+#define THREAD_SIZE_MASK (THREAD_SIZE - 1)
+#define CURRENT_MASK (~THREAD_SIZE_MASK)
#define EXCEPTION_STACK_ORDER 0
#define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index 63ce838..bef90fc 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -27,6 +27,12 @@ EXPORT_PER_CPU_SYMBOL(irq_stat);
DEFINE_PER_CPU(struct pt_regs *, irq_regs);
EXPORT_PER_CPU_SYMBOL(irq_regs);
+/* how to get the current stack pointer from C */
+#define current_stack_pointer ({ \
+ register unsigned long sp asm("esp"); \
+ sp; \
+})
+
#ifdef CONFIG_DEBUG_STACKOVERFLOW
int sysctl_panic_on_stackoverflow __read_mostly;
@@ -34,12 +40,8 @@ int sysctl_panic_on_stackoverflow __read_mostly;
/* Debugging check for stack overflow: is there less than 1KB free? */
static int check_stack_overflow(void)
{
- long sp;
-
- __asm__ __volatile__("andl %%esp,%0" :
- "=r" (sp) : "0" (THREAD_SIZE - 1));
-
- return sp < (sizeof(struct thread_info) + STACK_WARN);
+ return (current_stack_pointer & THREAD_SIZE_MASK)
+ < sizeof(struct thread_info) + STACK_WARN;
}
static void print_stack_overflow(void)
@@ -69,16 +71,9 @@ static void call_on_stack(void *func, void *stack)
: "memory", "cc", "edx", "ecx", "eax");
}
-/* how to get the current stack pointer from C */
-#define current_stack_pointer ({ \
- unsigned long sp; \
- asm("mov %%esp,%0" : "=g" (sp)); \
- sp; \
-})
-
static inline void *current_stack(void)
{
- return (void *)(current_stack_pointer & ~(THREAD_SIZE - 1));
+ return (void *)(current_stack_pointer & CURRENT_MASK);
}
static inline int
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
