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| author | Jan Beulich <jbeulich@novell.com> | 2007-05-02 19:27:10 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2007-05-02 19:27:10 +0200 |
| commit | 6fb14755a676282a4e6caa05a08c92db8e45cfff (patch) | |
| tree | 71a862edf87cafe61986c0aff90db72045cf14c3 /arch/x86_64/kernel/vmlinux.lds.S | |
| parent | d01ad8dd56527be72947b4b9997bb2c05783c3ed (diff) | |
| download | op-kernel-dev-6fb14755a676282a4e6caa05a08c92db8e45cfff.zip op-kernel-dev-6fb14755a676282a4e6caa05a08c92db8e45cfff.tar.gz | |
[PATCH] x86: tighten kernel image page access rights
On x86-64, kernel memory freed after init can be entirely unmapped instead
of just getting 'poisoned' by overwriting with a debug pattern.
On i386 and x86-64 (under CONFIG_DEBUG_RODATA), kernel text and bug table
can also be write-protected.
Compared to the first version, this one prevents re-creating deleted
mappings in the kernel image range on x86-64, if those got removed
previously. This, together with the original changes, prevents temporarily
having inconsistent mappings when cacheability attributes are being
changed on such pages (e.g. from AGP code). While on i386 such duplicate
mappings don't exist, the same change is done there, too, both for
consistency and because checking pte_present() before using various other
pte_XXX functions is a requirement anyway. At once, i386 code gets
adjusted to use pte_huge() instead of open coding this.
AK: split out cpa() changes
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/x86_64/kernel/vmlinux.lds.S')
| -rw-r--r-- | arch/x86_64/kernel/vmlinux.lds.S | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86_64/kernel/vmlinux.lds.S b/arch/x86_64/kernel/vmlinux.lds.S index 5176ecf..3bdeb88 100644 --- a/arch/x86_64/kernel/vmlinux.lds.S +++ b/arch/x86_64/kernel/vmlinux.lds.S @@ -29,6 +29,7 @@ SECTIONS .text : AT(ADDR(.text) - LOAD_OFFSET) { /* First the code that has to be first for bootstrapping */ *(.bootstrap.text) + _stext = .; /* Then all the functions that are "hot" in profiles, to group them onto the same hugetlb entry */ #include "functionlist" @@ -50,10 +51,10 @@ SECTIONS __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { *(__ex_table) } __stop___ex_table = .; - RODATA - BUG_TABLE + RODATA + . = ALIGN(PAGE_SIZE); /* Align data segment to page size boundary */ /* Data */ .data : AT(ADDR(.data) - LOAD_OFFSET) { |
