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yaml
---
r: 257286
b: refs/heads/master
c: 9fd67b4
h: refs/heads/master
v: v3
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Andy Lutomirski authored and Ingo Molnar committed Jun 5, 2011
1 parent a72a351 commit 140084d
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Showing 6 changed files with 36 additions and 24 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 8b4777a4b50cb0c84c1152eac85d24415fb6ff7d
refs/heads/master: 9fd67b4ed0714ab718f1f9bd14c344af336a6df7
1 change: 1 addition & 0 deletions trunk/arch/x86/include/asm/fixmap.h
Original file line number Diff line number Diff line change
Expand Up @@ -78,6 +78,7 @@ enum fixed_addresses {
VSYSCALL_LAST_PAGE,
VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
+ ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
VVAR_PAGE,
VSYSCALL_HPET,
#endif
FIX_DBGP_BASE,
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2 changes: 2 additions & 0 deletions trunk/arch/x86/include/asm/pgtable_types.h
Original file line number Diff line number Diff line change
Expand Up @@ -108,6 +108,7 @@
#define __PAGE_KERNEL_UC_MINUS (__PAGE_KERNEL | _PAGE_PCD)
#define __PAGE_KERNEL_VSYSCALL (__PAGE_KERNEL_RX | _PAGE_USER)
#define __PAGE_KERNEL_VSYSCALL_NOCACHE (__PAGE_KERNEL_VSYSCALL | _PAGE_PCD | _PAGE_PWT)
#define __PAGE_KERNEL_VVAR (__PAGE_KERNEL_RO | _PAGE_USER)
#define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE)
#define __PAGE_KERNEL_LARGE_NOCACHE (__PAGE_KERNEL | _PAGE_CACHE_UC | _PAGE_PSE)
#define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE)
Expand All @@ -130,6 +131,7 @@
#define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC)
#define PAGE_KERNEL_VSYSCALL __pgprot(__PAGE_KERNEL_VSYSCALL)
#define PAGE_KERNEL_VSYSCALL_NOCACHE __pgprot(__PAGE_KERNEL_VSYSCALL_NOCACHE)
#define PAGE_KERNEL_VVAR __pgprot(__PAGE_KERNEL_VVAR)

#define PAGE_KERNEL_IO __pgprot(__PAGE_KERNEL_IO)
#define PAGE_KERNEL_IO_NOCACHE __pgprot(__PAGE_KERNEL_IO_NOCACHE)
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22 changes: 10 additions & 12 deletions trunk/arch/x86/include/asm/vvar.h
Original file line number Diff line number Diff line change
Expand Up @@ -10,33 +10,32 @@
* In normal kernel code, they are used like any other variable.
* In user code, they are accessed through the VVAR macro.
*
* Each of these variables lives in the vsyscall page, and each
* one needs a unique offset within the little piece of the page
* reserved for vvars. Specify that offset in DECLARE_VVAR.
* (There are 896 bytes available. If you mess up, the linker will
* catch it.)
* These variables live in a page of kernel data that has an extra RO
* mapping for userspace. Each variable needs a unique offset within
* that page; specify that offset with the DECLARE_VVAR macro. (If
* you mess up, the linker will catch it.)
*/

/* Offset of vars within vsyscall page */
#define VSYSCALL_VARS_OFFSET (3072 + 128)
/* Base address of vvars. This is not ABI. */
#define VVAR_ADDRESS (-10*1024*1024 - 4096)

#if defined(__VVAR_KERNEL_LDS)

/* The kernel linker script defines its own magic to put vvars in the
* right place.
*/
#define DECLARE_VVAR(offset, type, name) \
EMIT_VVAR(name, VSYSCALL_VARS_OFFSET + offset)
EMIT_VVAR(name, offset)

#else

#define DECLARE_VVAR(offset, type, name) \
static type const * const vvaraddr_ ## name = \
(void *)(VSYSCALL_START + VSYSCALL_VARS_OFFSET + (offset));
(void *)(VVAR_ADDRESS + (offset));

#define DEFINE_VVAR(type, name) \
type __vvar_ ## name \
__attribute__((section(".vsyscall_var_" #name), aligned(16)))
type name \
__attribute__((section(".vvar_" #name), aligned(16)))

#define VVAR(name) (*vvaraddr_ ## name)

Expand All @@ -49,4 +48,3 @@ DECLARE_VVAR(16, int, vgetcpu_mode)
DECLARE_VVAR(128, struct vsyscall_gtod_data, vsyscall_gtod_data)

#undef DECLARE_VVAR
#undef VSYSCALL_VARS_OFFSET
28 changes: 17 additions & 11 deletions trunk/arch/x86/kernel/vmlinux.lds.S
Original file line number Diff line number Diff line change
Expand Up @@ -161,12 +161,6 @@ SECTIONS

#define VVIRT_OFFSET (VSYSCALL_ADDR - __vsyscall_0)
#define VVIRT(x) (ADDR(x) - VVIRT_OFFSET)
#define EMIT_VVAR(x, offset) .vsyscall_var_ ## x \
ADDR(.vsyscall_0) + offset \
: AT(VLOAD(.vsyscall_var_ ## x)) { \
*(.vsyscall_var_ ## x) \
} \
x = VVIRT(.vsyscall_var_ ## x);

. = ALIGN(4096);
__vsyscall_0 = .;
Expand All @@ -192,19 +186,31 @@ SECTIONS
*(.vsyscall_3)
}

#define __VVAR_KERNEL_LDS
#include <asm/vvar.h>
#undef __VVAR_KERNEL_LDS

. = __vsyscall_0 + PAGE_SIZE;
. = ALIGN(__vsyscall_0 + PAGE_SIZE, PAGE_SIZE);

#undef VSYSCALL_ADDR
#undef VLOAD_OFFSET
#undef VLOAD
#undef VVIRT_OFFSET
#undef VVIRT

__vvar_page = .;

.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {

/* Place all vvars at the offsets in asm/vvar.h. */
#define EMIT_VVAR(name, offset) \
. = offset; \
*(.vvar_ ## name)
#define __VVAR_KERNEL_LDS
#include <asm/vvar.h>
#undef __VVAR_KERNEL_LDS
#undef EMIT_VVAR

} :data

. = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);

#endif /* CONFIG_X86_64 */

/* Init code and data - will be freed after init */
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5 changes: 5 additions & 0 deletions trunk/arch/x86/kernel/vsyscall_64.c
Original file line number Diff line number Diff line change
Expand Up @@ -284,9 +284,14 @@ void __init map_vsyscall(void)
{
extern char __vsyscall_0;
unsigned long physaddr_page0 = __pa_symbol(&__vsyscall_0);
extern char __vvar_page;
unsigned long physaddr_vvar_page = __pa_symbol(&__vvar_page);

/* Note that VSYSCALL_MAPPED_PAGES must agree with the code below. */
__set_fixmap(VSYSCALL_FIRST_PAGE, physaddr_page0, PAGE_KERNEL_VSYSCALL);
__set_fixmap(VVAR_PAGE, physaddr_vvar_page, PAGE_KERNEL_VVAR);
BUILD_BUG_ON((unsigned long)__fix_to_virt(VVAR_PAGE) !=
(unsigned long)VVAR_ADDRESS);
}

static int __init vsyscall_init(void)
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