---

yaml
---
r: 138771
b: refs/heads/master
c: 796216a
h: refs/heads/master
i:
  138769: 57f88da
  138767: df55019
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 7543c1de84ed93c6769c9f20dced08a522af8912
+refs/heads/master: 796216a57fe45c04adc35bda1f0782efec78a713

trunk/arch/x86/include/asm/setup.h

@@ -104,6 +104,29 @@ extern struct boot_params boot_params;
 extern unsigned long _brk_end;
 void *extend_brk(size_t size, size_t align);
 
+/*
+ * Reserve space in the brk section.  The name must be unique within
+ * the file, and somewhat descriptive.  The size is in bytes.  Must be
+ * used at file scope.
+ *
+ * (This uses a temp function to wrap the asm so we can pass it the
+ * size parameter; otherwise we wouldn't be able to.  We can't use a
+ * "section" attribute on a normal variable because it always ends up
+ * being @progbits, which ends up allocating space in the vmlinux
+ * executable.)
+ */
+#define RESERVE_BRK(name,sz)						\
+	static void __section(.discard) __used			\
+	__brk_reservation_fn_##name##__(void) {				\
+		asm volatile (						\
+			".pushsection .brk_reservation,\"aw\",@nobits;" \
+			"__brk_reservation_" #name "__:"		\
+			" 1:.skip %c0;"					\
+			" .size __brk_reservation_" #name "__, . - 1b;"	\
+			" .popsection"					\
+			: : "i" (sz));					\
+	}
+
 #ifdef __i386__
 
 void __init i386_start_kernel(void);
@@ -115,6 +138,13 @@ void __init x86_64_start_reservations(char *real_mode_data);
 
 #endif /* __i386__ */
 #endif /* _SETUP */
+#else
+#define RESERVE_BRK(name,sz)				\
+	.pushsection .brk_reservation,"aw",@nobits;	\
+__brk_reservation_##name##__:				\
+1:	.skip sz;					\
+	.size __brk_reservation_##name##__,.-1b;	\
+	.popsection
 #endif /* __ASSEMBLY__ */
 #endif  /*  __KERNEL__  */
 

trunk/arch/x86/kernel/head_32.S

@@ -75,6 +75,8 @@ ALLOCATOR_SLOP = 4
 
 INIT_MAP_BEYOND_END = BOOTBITMAP_SIZE + (PAGE_TABLE_SIZE + ALLOCATOR_SLOP)*PAGE_SIZE_asm
 
+RESERVE_BRK(pagetables, PAGE_TABLE_SIZE * PAGE_SIZE)
+
 /*
  * 32-bit kernel entrypoint; only used by the boot CPU.  On entry,
  * %esi points to the real-mode code as a 32-bit pointer.

trunk/arch/x86/kernel/setup.c

@@ -112,6 +112,8 @@
 #define ARCH_SETUP
 #endif
 
+RESERVE_BRK(dmi_alloc, 65536);
+
 unsigned int boot_cpu_id __read_mostly;
 
 static __initdata unsigned long _brk_start = (unsigned long)__brk_base;

trunk/arch/x86/kernel/vmlinux_32.lds.S

@@ -192,7 +192,8 @@ SECTIONS
 
 	. = ALIGN(PAGE_SIZE);
 	__brk_base = . ;
-	. += 1024 * 1024 ;
+	. += 64 * 1024 ;	/* 64k slop space */
+	*(.brk_reservation)	/* areas brk users have reserved */
 	__brk_limit = . ;
 
   	_end = . ;
@@ -201,6 +202,7 @@ SECTIONS
   /* Sections to be discarded */
   /DISCARD/ : {
 	*(.exitcall.exit)
+	*(.discard)
 	}
 
   STABS_DEBUG

trunk/arch/x86/kernel/vmlinux_64.lds.S

@@ -250,7 +250,8 @@ SECTIONS
 
 	. = ALIGN(PAGE_SIZE);
 	__brk_base = . ;
-	. += 1024 * 1024 ;
+	. += 64 * 1024;		/* 64k slop space */
+	*(.brk_reservation)	/* areas brk users have reserved */
 	__brk_limit = . ;
   }
 
@@ -260,6 +261,7 @@ SECTIONS
   /DISCARD/ : {
 	*(.exitcall.exit)
 	*(.eh_frame)
+	*(.discard)
 	}
 
   STABS_DEBUG