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-rw-r--r--arch/x86/include/asm/setup.h38
-rw-r--r--arch/x86/kernel/vmlinux.lds.S4
2 files changed, 23 insertions, 19 deletions
diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
index e1110e2ebc9e..c5ed79159975 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -91,19 +91,16 @@ 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.
+ * Reserve space in the .brk section, which is a block of memory from which the
+ * caller is allowed to allocate very early (before even memblock is available)
+ * by calling extend_brk(). All allocated memory will be eventually converted
+ * to memblock. Any leftover unallocated memory will be freed.
*
- * The allocation is done using inline asm (rather than using a section
- * attribute on a normal variable) in order to allow the use of @nobits, so
- * that it doesn't take up any space in the vmlinux file.
+ * The size is in bytes.
*/
-#define RESERVE_BRK(name, size) \
- asm(".pushsection .brk_reservation,\"aw\",@nobits\n\t" \
- ".brk." #name ":\n\t" \
- ".skip " __stringify(size) "\n\t" \
- ".size .brk." #name ", " __stringify(size) "\n\t" \
- ".popsection\n\t")
+#define RESERVE_BRK(name, size) \
+ __section(.bss..brk) __aligned(1) __used \
+ static char __brk_##name[size]
/* Helper for reserving space for arrays of things */
#define RESERVE_BRK_ARRAY(type, name, entries) \
@@ -121,12 +118,19 @@ asmlinkage 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.name: \
-1: .skip sz; \
- .size .brk.name,.-1b; \
+
+#else /* __ASSEMBLY */
+
+.macro __RESERVE_BRK name, size
+ .pushsection .bss..brk, "aw"
+GLOBAL(__brk_\name)
+ .skip \size
+END(__brk_\name)
.popsection
+.endm
+
+#define RESERVE_BRK(name, size) __RESERVE_BRK name, size
+
#endif /* __ASSEMBLY__ */
+
#endif /* _ASM_X86_SETUP_H */
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 34c0652ca8b4..7e12b7d93b72 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -380,10 +380,10 @@ SECTIONS
}
. = ALIGN(PAGE_SIZE);
- .brk : AT(ADDR(.brk) - LOAD_OFFSET) {
+ .brk (NOLOAD) : AT(ADDR(.brk) - LOAD_OFFSET) {
__brk_base = .;
. += 64 * 1024; /* 64k alignment slop space */
- *(.brk_reservation) /* areas brk users have reserved */
+ *(.bss..brk) /* areas brk users have reserved */
__brk_limit = .;
}