From: Paolo 'Blaisorblade' Giarrusso <[EMAIL PROTECTED]>, Jeff Dike <[EMAIL
PROTECTED]>
The previous ifdef to check whether to use the host's vsyscall page
was buggy. This bug can cause crashes.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <[EMAIL PROTECTED]>
---
linux-2.6.11-paolo/arch/um/Kconfig_i386 | 4 ++++
linux-2.6.11-paolo/arch/um/Kconfig_x86_64 | 4 ++++
linux-2.6.11-paolo/arch/um/kernel/mem.c | 12 ++++++++----
3 files changed, 16 insertions(+), 4 deletions(-)
diff -puN arch/um/Kconfig_i386~uml-vsyscall arch/um/Kconfig_i386
--- linux-2.6.11/arch/um/Kconfig_i386~uml-vsyscall 2005-02-04
06:22:14.731673232 +0100
+++ linux-2.6.11-paolo/arch/um/Kconfig_i386 2005-02-04 06:22:14.738672168
+0100
@@ -18,3 +18,7 @@ config 3_LEVEL_PGTABLES
config ARCH_HAS_SC_SIGNALS
bool
default y
+
+config ARCH_REUSE_HOST_VSYSCALL_AREA
+ bool
+ default y
diff -puN arch/um/Kconfig_x86_64~uml-vsyscall arch/um/Kconfig_x86_64
--- linux-2.6.11/arch/um/Kconfig_x86_64~uml-vsyscall 2005-02-04
06:22:14.733672928 +0100
+++ linux-2.6.11-paolo/arch/um/Kconfig_x86_64 2005-02-04 06:22:14.739672016
+0100
@@ -9,3 +9,7 @@ config 3_LEVEL_PGTABLES
config ARCH_HAS_SC_SIGNALS
bool
default n
+
+config ARCH_REUSE_HOST_VSYSCALL_AREA
+ bool
+ default n
diff -puN arch/um/kernel/mem.c~uml-vsyscall arch/um/kernel/mem.c
--- linux-2.6.11/arch/um/kernel/mem.c~uml-vsyscall 2005-02-04
06:22:14.735672624 +0100
+++ linux-2.6.11-paolo/arch/um/kernel/mem.c 2005-02-04 06:22:14.739672016
+0100
@@ -152,6 +152,7 @@ void __init kmap_init(void)
static void init_highmem(void)
{
pgd_t *pgd;
+ pud_t *pud;
pmd_t *pmd;
pte_t *pte;
unsigned long vaddr;
@@ -163,7 +164,8 @@ static void init_highmem(void)
fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir);
pgd = swapper_pg_dir + pgd_index(vaddr);
- pmd = pmd_offset(pgd, vaddr);
+ pud = pud_offset(pgd, vaddr);
+ pmd = pmd_offset(pud, vaddr);
pte = pte_offset_kernel(pmd, vaddr);
pkmap_page_table = pte;
@@ -173,9 +175,10 @@ static void init_highmem(void)
static void __init fixaddr_user_init( void)
{
-#if FIXADDR_USER_START != 0
+#if CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
long size = FIXADDR_USER_END - FIXADDR_USER_START;
pgd_t *pgd;
+ pud_t *pud;
pmd_t *pmd;
pte_t *pte;
unsigned long paddr, vaddr = FIXADDR_USER_START;
@@ -187,9 +190,10 @@ static void __init fixaddr_user_init( vo
paddr = (unsigned long)alloc_bootmem_low_pages( size);
memcpy( (void *)paddr, (void *)FIXADDR_USER_START, size);
paddr = __pa(paddr);
- for ( ; size > 0; size-=PAGE_SIZE, vaddr+=PAGE_SIZE, paddr+=PAGE_SIZE) {
+ for ( ; size > 0; size-=PAGE_SIZE, vaddr+=PAGE_SIZE, paddr+=PAGE_SIZE){
pgd = swapper_pg_dir + pgd_index(vaddr);
- pmd = pmd_offset(pgd, vaddr);
+ pud = pud_offset(pgd, vaddr);
+ pmd = pmd_offset(pud, vaddr);
pte = pte_offset_kernel(pmd, vaddr);
pte_set_val( (*pte), paddr, PAGE_READONLY);
}
_
-
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