From: Tejun Heo <tj@kernel.org>
Date: Fri, 3 Jul 2009 22:13:18 +0000 (+0900)
Subject: Merge branch 'master' into for-next
X-Git-Tag: firefly_0821_release~12956^2^2~35
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=c43768cbb7655ea5ff782ae250f6e2ef4297cf98;p=firefly-linux-kernel-4.4.55.git
Merge branch 'master' into for-next
Pull linus#master to merge PER_CPU_DEF_ATTRIBUTES and alpha build fix
changes. As alpha in percpu tree uses 'weak' attribute instead of
inline assembly, there's no need for __used attribute.
Conflicts:
arch/alpha/include/asm/percpu.h
arch/mn10300/kernel/vmlinux.lds.S
include/linux/percpu-defs.h
---
c43768cbb7655ea5ff782ae250f6e2ef4297cf98
diff --cc arch/arm/kernel/vmlinux.lds.S
index e256c57b8981,69371028a202..5cc4812c9763
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@@ -82,9 -83,16 +83,17 @@@ SECTION
EXIT_TEXT
EXIT_DATA
*(.exitcall.exit)
+ *(.discard)
*(.ARM.exidx.exit.text)
*(.ARM.extab.exit.text)
+ #ifndef CONFIG_HOTPLUG_CPU
+ *(.ARM.exidx.cpuexit.text)
+ *(.ARM.extab.cpuexit.text)
+ #endif
+ #ifndef CONFIG_HOTPLUG
+ *(.ARM.exidx.devexit.text)
+ *(.ARM.extab.devexit.text)
+ #endif
#ifndef CONFIG_MMU
*(.fixup)
*(__ex_table)
diff --cc arch/mn10300/kernel/vmlinux.lds.S
index 5d9f2f96ad92,bcebcefb4ad7..5609d4962a55
--- a/arch/mn10300/kernel/vmlinux.lds.S
+++ b/arch/mn10300/kernel/vmlinux.lds.S
@@@ -145,8 -117,7 +117,8 @@@ SECTION
/* Sections to be discarded */
/DISCARD/ : {
- *(.exitcall.exit)
+ EXIT_CALL
+ *(.discard)
}
STABS_DEBUG
diff --cc include/asm-generic/vmlinux.lds.h
index a19120c4e109,dccdbed05848..c5c18ac878ab
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@@ -625,17 -626,9 +626,17 @@@
*(.init.ramfs) \
VMLINUX_SYMBOL(__initramfs_end) = .;
#else
- #define INITRAMFS
+ #define INIT_RAM_FS
#endif
+#define DISCARDS \
+ /DISCARD/ : { \
+ EXIT_TEXT \
+ EXIT_DATA \
+ *(.exitcall.exit) \
+ *(.discard) \
+ }
+
/**
* PERCPU_VADDR - define output section for percpu area
* @vaddr: explicit base address (optional)
diff --cc include/linux/percpu-defs.h
index 9b7a53cc16eb,68438e18fff4..aefc2f12b48c
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@@ -17,61 -17,15 +17,63 @@@
* linkage errors occur due the compiler generating the wrong code to access
* that section.
*/
-#define DECLARE_PER_CPU_SECTION(type, name, section) \
- extern \
- __attribute__((__section__(PER_CPU_BASE_SECTION section))) \
- PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
-
-#define DEFINE_PER_CPU_SECTION(type, name, section) \
- __attribute__((__section__(PER_CPU_BASE_SECTION section))) \
- PER_CPU_ATTRIBUTES PER_CPU_DEF_ATTRIBUTES \
+#define __PCPU_ATTRS(sec) \
+ __attribute__((section(PER_CPU_BASE_SECTION sec))) \
+ PER_CPU_ATTRIBUTES
+
+#define __PCPU_DUMMY_ATTRS \
+ __attribute__((section(".discard"), unused))
+
+/*
+ * s390 and alpha modules require percpu variables to be defined as
+ * weak to force the compiler to generate GOT based external
+ * references for them. This is necessary because percpu sections
+ * will be located outside of the usually addressable area.
+ *
+ * This definition puts the following two extra restrictions when
+ * defining percpu variables.
+ *
+ * 1. The symbol must be globally unique, even the static ones.
+ * 2. Static percpu variables cannot be defined inside a function.
+ *
+ * Archs which need weak percpu definitions should define
+ * ARCH_NEEDS_WEAK_PER_CPU in asm/percpu.h when necessary.
+ *
+ * To ensure that the generic code observes the above two
+ * restrictions, if CONFIG_DEBUG_FORCE_WEAK_PER_CPU is set weak
+ * definition is used for all cases.
+ */
+#if defined(ARCH_NEEDS_WEAK_PER_CPU) || defined(CONFIG_DEBUG_FORCE_WEAK_PER_CPU)
+/*
+ * __pcpu_scope_* dummy variable is used to enforce scope. It
+ * receives the static modifier when it's used in front of
+ * DEFINE_PER_CPU() and will trigger build failure if
+ * DECLARE_PER_CPU() is used for the same variable.
+ *
+ * __pcpu_unique_* dummy variable is used to enforce symbol uniqueness
+ * such that hidden weak symbol collision, which will cause unrelated
+ * variables to share the same address, can be detected during build.
+ */
+#define DECLARE_PER_CPU_SECTION(type, name, sec) \
+ extern __PCPU_DUMMY_ATTRS char __pcpu_scope_##name; \
+ extern __PCPU_ATTRS(sec) __typeof__(type) per_cpu__##name
+
+#define DEFINE_PER_CPU_SECTION(type, name, sec) \
+ __PCPU_DUMMY_ATTRS char __pcpu_scope_##name; \
+ __PCPU_DUMMY_ATTRS char __pcpu_unique_##name; \
- __PCPU_ATTRS(sec) __weak __typeof__(type) per_cpu__##name
++ __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES __weak \
++ __typeof__(type) per_cpu__##name
+#else
+/*
+ * Normal declaration and definition macros.
+ */
+#define DECLARE_PER_CPU_SECTION(type, name, sec) \
+ extern __PCPU_ATTRS(sec) __typeof__(type) per_cpu__##name
+
+#define DEFINE_PER_CPU_SECTION(type, name, sec) \
- __PCPU_ATTRS(sec) __typeof__(type) per_cpu__##name
++ __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES \
+ __typeof__(type) per_cpu__##name
+#endif
/*
* Variant on the per-CPU variable declaration/definition theme used for