5 files changed, 63 insertions, 57 deletions

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index aa6b9b1b30b5..53e21f36a802 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -430,22 +430,10 @@
         *(.initcall7.init)                                              \
         *(.initcall7s.init)
 
-#define PERCPU_PROLOG(vaddr)                                            \
-        VMLINUX_SYMBOL(__per_cpu_load) = .;                             \
-        .data.percpu vaddr : AT(VMLINUX_SYMBOL(__per_cpu_load)          \
-                                - LOAD_OFFSET) {                        \
-                VMLINUX_SYMBOL(__per_cpu_start) = .;
-
-#define PERCPU_EPILOG(phdr)                                             \
-                VMLINUX_SYMBOL(__per_cpu_end) = .;                      \
-        } phdr                                                          \
-        . = VMLINUX_SYMBOL(__per_cpu_load) + SIZEOF(.data.percpu);
-
 /**
- * PERCPU_VADDR_PREALLOC - define output section for percpu area with prealloc
+ * PERCPU_VADDR - define output section for percpu area
  * @vaddr: explicit base address (optional)
  * @phdr: destination PHDR (optional)
- * @prealloc: the size of prealloc area
  *
  * Macro which expands to output section for percpu area.  If @vaddr
  * is not blank, it specifies explicit base address and all percpu
@@ -457,39 +445,23 @@
  * section in the linker script will go there too.  @phdr should have
  * a leading colon.
  *
- * If @prealloc is non-zero, the specified number of bytes will be
- * reserved at the start of percpu area.  As the prealloc area is
- * likely to break alignment, this macro puts areas in increasing
- * alignment order.
- *
  * This macro defines three symbols, __per_cpu_load, __per_cpu_start
  * and __per_cpu_end.  The first one is the vaddr of loaded percpu
  * init data.  __per_cpu_start equals @vaddr and __per_cpu_end is the
  * end offset.
  */
-#define PERCPU_VADDR_PREALLOC(vaddr, segment, prealloc)                 \
-        PERCPU_PROLOG(vaddr)                                            \
-                . += prealloc;                                          \
-                *(.data.percpu)                                         \
-                *(.data.percpu.shared_aligned)                          \
-                *(.data.percpu.page_aligned)                            \
-        PERCPU_EPILOG(segment)
-
-/**
- * PERCPU_VADDR - define output section for percpu area
- * @vaddr: explicit base address (optional)
- * @phdr: destination PHDR (optional)
- *
- * Macro which expands to output section for percpu area.  Mostly
- * identical to PERCPU_VADDR_PREALLOC(@vaddr, @phdr, 0) other than
- * using slighly different layout.
- */
 #define PERCPU_VADDR(vaddr, phdr)                                       \
-        PERCPU_PROLOG(vaddr)                                            \
+        VMLINUX_SYMBOL(__per_cpu_load) = .;                             \
+        .data.percpu vaddr : AT(VMLINUX_SYMBOL(__per_cpu_load)          \
+                                - LOAD_OFFSET) {                        \
+                VMLINUX_SYMBOL(__per_cpu_start) = .;                    \
+                *(.data.percpu.first)                                   \
                 *(.data.percpu.page_aligned)                            \
                 *(.data.percpu)                                         \
                 *(.data.percpu.shared_aligned)                          \
-        PERCPU_EPILOG(phdr)
+                VMLINUX_SYMBOL(__per_cpu_end) = .;                      \
+        } phdr                                                          \
+        . = VMLINUX_SYMBOL(__per_cpu_load) + SIZEOF(.data.percpu);
 
 /**
  * PERCPU - define output section for percpu area, simple version
diff --git a/include/linux/magic.h b/include/linux/magic.h
index 0b4df7eba852..5b4e28bcb788 100644
--- a/include/linux/magic.h
+++ b/include/linux/magic.h
@@ -49,4 +49,5 @@
 #define FUTEXFS_SUPER_MAGIC     0xBAD1DEA
 #define INOTIFYFS_SUPER_MAGIC   0x2BAD1DEA
 
+#define STACK_END_MAGIC         0x57AC6E9D
 #endif /* __LINUX_MAGIC_H__ */
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 9f2a3751873a..0e24202b5a4e 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -9,34 +9,39 @@
 #include <asm/percpu.h>
 
 #ifdef CONFIG_SMP
-#define DEFINE_PER_CPU(type, name)                                      \
-        __attribute__((__section__(".data.percpu")))                    \
-        PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
+#define PER_CPU_BASE_SECTION ".data.percpu"
 
 #ifdef MODULE
-#define SHARED_ALIGNED_SECTION ".data.percpu"
+#define PER_CPU_SHARED_ALIGNED_SECTION ""
 #else
-#define SHARED_ALIGNED_SECTION ".data.percpu.shared_aligned"
+#define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned"
 #endif
+#define PER_CPU_FIRST_SECTION ".first"
 
-#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)                       \
-        __attribute__((__section__(SHARED_ALIGNED_SECTION)))            \
-        PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name             \
-        ____cacheline_aligned_in_smp
+#else
+
+#define PER_CPU_BASE_SECTION ".data"
+#define PER_CPU_SHARED_ALIGNED_SECTION ""
+#define PER_CPU_FIRST_SECTION ""
+
+#endif
 
-#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name)                 \
-        __attribute__((__section__(".data.percpu.page_aligned")))       \
+#define DEFINE_PER_CPU_SECTION(type, name, section)                     \
+        __attribute__((__section__(PER_CPU_BASE_SECTION section)))      \
         PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
-#else
+
 #define DEFINE_PER_CPU(type, name)                                      \
-        PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
+        DEFINE_PER_CPU_SECTION(type, name, "")
 
-#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)                     \
-        DEFINE_PER_CPU(type, name)
+#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)                       \
+        DEFINE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \
+        ____cacheline_aligned_in_smp
 
-#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name)               \
-        DEFINE_PER_CPU(type, name)
-#endif
+#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name)                         \
+        DEFINE_PER_CPU_SECTION(type, name, ".page_aligned")
+
+#define DEFINE_PER_CPU_FIRST(type, name)                                \
+        DEFINE_PER_CPU_SECTION(type, name, PER_CPU_FIRST_SECTION)
 
 #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
 #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f134a0f7080a..b85b10abf770 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1159,10 +1159,9 @@ struct task_struct {
         pid_t pid;
         pid_t tgid;
 
-#ifdef CONFIG_CC_STACKPROTECTOR
         /* Canary value for the -fstack-protector gcc feature */
         unsigned long stack_canary;
-#endif
+
         /* 
          * pointers to (original) parent process, youngest child, younger sibling,
          * older sibling, respectively.  (p->father can be replaced with 
@@ -2069,6 +2068,19 @@ static inline int object_is_on_stack(void *obj)
 
 extern void thread_info_cache_init(void);
 
+#ifdef CONFIG_DEBUG_STACK_USAGE
+static inline unsigned long stack_not_used(struct task_struct *p)
+{
+        unsigned long *n = end_of_stack(p);
+
+        do {    /* Skip over canary */
+                n++;
+        } while (!*n);
+
+        return (unsigned long)n - (unsigned long)end_of_stack(p);
+}
+#endif
+
 /* set thread flags in other task's structures
  * - see asm/thread_info.h for TIF_xxxx flags available
  */
diff --git a/include/linux/stackprotector.h b/include/linux/stackprotector.h
new file mode 100644
index 000000000000..6f3e54c704c0
--- /dev/null
+++ b/include/linux/stackprotector.h
@@ -0,0 +1,16 @@
+#ifndef _LINUX_STACKPROTECTOR_H
+#define _LINUX_STACKPROTECTOR_H 1
+
+#include <linux/compiler.h>
+#include <linux/sched.h>
+#include <linux/random.h>
+
+#ifdef CONFIG_CC_STACKPROTECTOR
+# include <asm/stackprotector.h>
+#else
+static inline void boot_init_stack_canary(void)
+{
+}
+#endif
+
+#endif