2004-11-11 16:16:35

by Kirill Korotaev

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Subject: [PATCH] 4/4GB: remove FIXADDR_TOP changing

---

--- ./include/asm-i386/kmap_types.h.4gb-fix 2004-10-08 16:05:35.000000000 +0400
+++ ./include/asm-i386/kmap_types.h 2004-10-11 16:16:28.462098360 +0400
@@ -10,7 +10,8 @@ enum km_type {
* the 4G/4G virtual stack must be THREAD_SIZE aligned on each cpu.
*/
KM_BOUNCE_READ,
- KM_VSTACK_BASE,
+ __KM_VSTACK_BASE,
+ KM_VSTACK_BASE = __KM_VSTACK_BASE + (__KM_VSTACK_BASE % 2),
KM_VSTACK_TOP = KM_VSTACK_BASE + STACK_PAGE_COUNT-1,

KM_LDT_PAGE15,
@@ -29,7 +30,8 @@ enum km_type {
KM_IRQ1,
KM_SOFTIRQ0,
KM_SOFTIRQ1,
- KM_TYPE_NR
+ __KM_TYPE_NR,
+ KM_TYPE_NR=__KM_TYPE_NR + (__KM_TYPE_NR % 2)
};

#endif
--- ./include/asm-i386/fixmap.h.4gb-fix 2004-10-11 15:55:38.000000000 +0400
+++ ./include/asm-i386/fixmap.h 2004-10-11 16:25:58.279472952 +0400
@@ -21,6 +21,8 @@
#include <linux/threads.h>
#include <asm/kmap_types.h>

+#define __FIXADDR_TOP (0xfffff000UL)
+
/*
* Here we define all the compile-time 'special' virtual
* addresses. The point is to have a constant address at
@@ -77,7 +79,10 @@ enum fixed_addresses {
FIX_CYCLONE_TIMER, /*cyclone timer register*/
FIX_VSTACK_HOLE_2,
#endif
- FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
+ /* reserved pte's for temporary kernel mappings */
+ __FIX_KMAP_BEGIN,
+ FIX_KMAP_BEGIN = __FIX_KMAP_BEGIN + (__FIX_KMAP_BEGIN & 1) +
+ ((__FIXADDR_TOP >> PAGE_SHIFT) & 1),
FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
#ifdef CONFIG_ACPI_BOOT
FIX_ACPI_BEGIN,
@@ -118,7 +123,7 @@ extern void __set_fixmap (enum fixed_add
* IMPORTANT: we have to align FIXADDR_TOP so that the virtual stack
* is THREAD_SIZE aligned.
*/
-#define FIXADDR_TOP (0xffffe000UL & ~(THREAD_SIZE-1))
+#define FIXADDR_TOP __FIXADDR_TOP
#define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)

---

Attachments:

diff-arch-4gb-fixaddr (1.80 kB)

2004-11-11 20:44:57

by Ingo Molnar

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Subject: Re: [PATCH] 4/4GB: remove FIXADDR_TOP changing

---

* Kirill Korotaev <[email protected]> wrote:

> This patch fixes VSYSCALL_BASE/FIXADDR_TOP relations problems
> in 4gb split kernels (under some combinations of options/patches):
> - if FIXADDR_TOP is changed, VSYSCALL_BASE in vsyscall.lds should be
> changed as well
> - original 4gb split changes FIXADDR_TOP to be sure that stack
> is 2 pages aligned, but vsyscall.lds uses hardcoded constants inside.
> So we had /sbin/init loading problems due to ld-linux.so trying to
> access wrong addresses in VSYSCALL page.
>
> The fix is the aligment of 4gb pages instead of alignment of
> FIXADDR_TOP

indeed - thanks!

Ingo