While dubug kdump, found current kernel will have problem with crashkernel=512M.
It turns out that initial mapping is to 512M, and later initial mapping to 4G
(acutally is 2040M in my platform), will put page table near 512M.
then initial mapping to 128g will be near 2g.
before this patch:
[ 0.000000] initial memory mapped : 0 - 20000000
[ 0.000000] init_memory_mapping: [0x00000000000000-0x0000007f74ffff]
[ 0.000000] 0000000000 - 007f600000 page 2M
[ 0.000000] 007f600000 - 007f750000 page 4k
[ 0.000000] kernel direct mapping tables up to 7f750000 @ [0x1fffc000-0x1fffffff]
[ 0.000000] memblock_x86_reserve_range: [0x1fffc000-0x1fffdfff] PGTABLE
[ 0.000000] init_memory_mapping: [0x00000100000000-0x0000207fffffff]
[ 0.000000] 0100000000 - 2080000000 page 2M
[ 0.000000] kernel direct mapping tables up to 2080000000 @ [0x7bc01000-0x7bc83fff]
[ 0.000000] memblock_x86_reserve_range: [0x7bc01000-0x7bc7efff] PGTABLE
[ 0.000000] RAMDISK: 7bc84000 - 7f745000
[ 0.000000] crashkernel reservation failed - No suitable area found.
after patch:
[ 0.000000] initial memory mapped : 0 - 20000000
[ 0.000000] init_memory_mapping: [0x00000000000000-0x0000007f74ffff]
[ 0.000000] 0000000000 - 007f600000 page 2M
[ 0.000000] 007f600000 - 007f750000 page 4k
[ 0.000000] kernel direct mapping tables up to 7f750000 @ [0x7f74c000-0x7f74ffff]
[ 0.000000] memblock_x86_reserve_range: [0x7f74c000-0x7f74dfff] PGTABLE
[ 0.000000] init_memory_mapping: [0x00000100000000-0x0000207fffffff]
[ 0.000000] 0100000000 - 2080000000 page 2M
[ 0.000000] kernel direct mapping tables up to 2080000000 @ [0x207ff7d000-0x207fffffff]
[ 0.000000] memblock_x86_reserve_range: [0x207ff7d000-0x207fffafff] PGTABLE
[ 0.000000] RAMDISK: 7bc84000 - 7f745000
[ 0.000000] memblock_x86_reserve_range: [0x17000000-0x36ffffff] CRASH KERNEL
[ 0.000000] Reserving 512MB of memory at 368MB for crashkernel (System RAM: 133120MB)
It means with the patch, page table for [0, 2g) will need 2g, instead of under 512M,
page table for [4g, 128g) will be near 128g, instead of under 2g.
That would good, if we have lots of memory above 4g, like 1024g, or 2048g or 16T, will not put
related page table under 2g. that would be have chance to fill the under 2g if 1G or 2M page is
not used.
the code change will use add map_low_page() and update unmap_low_page() for 64bit, and use them
to get access the corresponding high memory for page table setting.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4D0C0734.7060900@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch expands functionality of CONFIG_DEBUG_RODATA to set main
(static) kernel data area as NX.
The following steps are taken to achieve this:
1. Linker script is adjusted so .text always starts and ends on a page bound
2. Linker script is adjusted so .rodata always start and end on a page boundary
3. NX is set for all pages from _etext through _end in mark_rodata_ro.
4. free_init_pages() sets released memory NX in arch/x86/mm/init.c
5. bios rom is set to x when pcibios is used.
The results of patch application may be observed in the diff of kernel page
table dumps:
pcibios:
-- data_nx_pt_before.txt 2009-10-13 07:48:59.000000000 -0400
++ data_nx_pt_after.txt 2009-10-13 07:26:46.000000000 -0400
0x00000000-0xc0000000 3G pmd
---[ Kernel Mapping ]---
-0xc0000000-0xc0100000 1M RW GLB x pte
+0xc0000000-0xc00a0000 640K RW GLB NX pte
+0xc00a0000-0xc0100000 384K RW GLB x pte
-0xc0100000-0xc03d7000 2908K ro GLB x pte
+0xc0100000-0xc0318000 2144K ro GLB x pte
+0xc0318000-0xc03d7000 764K ro GLB NX pte
-0xc03d7000-0xc0600000 2212K RW GLB x pte
+0xc03d7000-0xc0600000 2212K RW GLB NX pte
0xc0600000-0xf7a00000 884M RW PSE GLB NX pmd
0xf7a00000-0xf7bfe000 2040K RW GLB NX pte
0xf7bfe000-0xf7c00000 8K pte
No pcibios:
-- data_nx_pt_before.txt 2009-10-13 07:48:59.000000000 -0400
++ data_nx_pt_after.txt 2009-10-13 07:26:46.000000000 -0400
0x00000000-0xc0000000 3G pmd
---[ Kernel Mapping ]---
-0xc0000000-0xc0100000 1M RW GLB x pte
+0xc0000000-0xc0100000 1M RW GLB NX pte
-0xc0100000-0xc03d7000 2908K ro GLB x pte
+0xc0100000-0xc0318000 2144K ro GLB x pte
+0xc0318000-0xc03d7000 764K ro GLB NX pte
-0xc03d7000-0xc0600000 2212K RW GLB x pte
+0xc03d7000-0xc0600000 2212K RW GLB NX pte
0xc0600000-0xf7a00000 884M RW PSE GLB NX pmd
0xf7a00000-0xf7bfe000 2040K RW GLB NX pte
0xf7bfe000-0xf7c00000 8K pte
The patch has been originally developed for Linux 2.6.34-rc2 x86 by
Siarhei Liakh <sliakh.lkml@gmail.com> and Xuxian Jiang <jiang@cs.ncsu.edu>.
-v1: initial patch for 2.6.30
-v2: patch for 2.6.31-rc7
-v3: moved all code into arch/x86, adjusted credits
-v4: fixed ifdef, removed credits from CREDITS
-v5: fixed an address calculation bug in mark_nxdata_nx()
-v6: added acked-by and PT dump diff to commit log
-v7: minor adjustments for -tip
-v8: rework with the merge of "Set first MB as RW+NX"
Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com>
Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu>
Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: James Morris <jmorris@namei.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dave Jones <davej@redhat.com>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4CE2F82E.60601@free.fr>
[ minor cleanliness edits ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1.include linux/memblock.h directly. so later could reduce e820.h reference.
2 this patch is done by sed scripts mainly
-v2: use MEMBLOCK_ERROR instead of -1ULL or -1UL
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or
in a more compact fashion.
Example:
Allocated new RAMDISK: 00ec2000 - 0248ce57
Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56
The new RAMDISK's end is not page aligned.
Last page could be shared with other users.
When free_init_pages are called for initrd or .init, the page
could be freed and we could corrupt other data.
code segment in free_init_pages():
| for (; addr < end; addr += PAGE_SIZE) {
| ClearPageReserved(virt_to_page(addr));
| init_page_count(virt_to_page(addr));
| memset((void *)(addr & ~(PAGE_SIZE-1)),
| POISON_FREE_INITMEM, PAGE_SIZE);
| free_page(addr);
| totalram_pages++;
| }
last half page could be used as one whole free page.
So page align the boundaries.
-v2: make the original initramdisk to be aligned, according to
Johannes, otherwise we have the chance to lose one page.
we still need to keep initrd_end not aligned, otherwise it could
confuse decompressor.
-v3: change to WARN_ON instead, suggested by Johannes.
-v4: use PAGE_ALIGN, suggested by Johannes.
We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN
Add comments about assuming ramdisk start is aligned
in relocate_initrd(), change to re get ramdisk_image instead of save it
to make diff smaller. Add warning for wrong range, suggested by Johannes.
-v6: remove one WARN()
We need to align beginning in free_init_pages()
do not copy more than ramdisk_size, noticed by Johannes
Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Tested-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch changes the 32-bit version of kernel_physical_mapping_init() to
return the last mapped address like the 64-bit one so that we can unify the
call-site in init_memory_mapping().
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <alpine.DEB.2.00.1002241703570.1180@melkki.cs.helsinki.fi>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
It is possible for x86_64 systems to lack the NX bit either due to the
hardware lacking support or the BIOS having turned off the CPU capability,
so NX status should be reported. Additionally, anyone booting NX-capable
CPUs in 32bit mode without PAE will lack NX functionality, so this change
provides feedback for that case as well.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <1258154897-6770-6-git-send-email-hpa@zytor.com>
The 32- and 64-bit code used very different mechanisms for enabling
NX, but even the 32-bit code was enabling NX in head_32.S if it is
available. Furthermore, we had a bewildering collection of tests for
the available of NX.
This patch:
a) merges the 32-bit set_nx() and the 64-bit check_efer() function
into a single x86_configure_nx() function. EFER control is left
to the head code.
b) eliminates the nx_enabled variable entirely. Things that need to
test for NX enablement can verify __supported_pte_mask directly,
and cpu_has_nx gives the supported status of NX.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Chris Wright <chrisw@sous-sol.org>
LKML-Reference: <1258154897-6770-5-git-send-email-hpa@zytor.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
Move the NX setup into a separate file so that it can be compiled
without stack-protection while leaving the rest of the mm/init code
protected.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
This sparse warning:
arch/x86/mm/init.c:83:16: warning: symbol 'check_efer' was not declared. Should it be static?
triggers because check_efer() is not decalared before using it.
asm/proto.h includes the declaration of check_efer(), so
including asm/proto.h to fix that - this also addresses the
sparse warning.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1246458263.6940.22.camel@hpdv5.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The init_gbpages() function is conditionally called from
init_memory_mapping() function. There are two call-sites where
this 'after_bootmem' condition can be true: setup_arch() and
mem_init() via pci_iommu_alloc().
Therefore, it's safe to move the call to init_gbpages() to
setup_arch() as it's always called before mem_init().
This removes an after_bootmem use - paving the way to remove
all uses of that state variable.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <Pine.LNX.4.64.0906221731210.19474@melkki.cs.Helsinki.FI>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The hooks that we modify are:
- Page fault handler (to handle kmemcheck faults)
- Debug exception handler (to hide pages after single-stepping
the instruction that caused the page fault)
Also redefine memset() to use the optimized version if kmemcheck is
enabled.
(Thanks to Pekka Enberg for minimizing the impact on the page fault
handler.)
As kmemcheck doesn't handle MMX/SSE instructions (yet), we also disable
the optimized xor code, and rely instead on the generic C implementation
in order to avoid false-positive warnings.
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
[whitespace fixlet]
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits)
x86: fix system without memory on node0
x86, mm: Fix node_possible_map logic
mm, x86: remove MEMORY_HOTPLUG_RESERVE related code
x86: make sparse mem work in non-NUMA mode
x86: process.c, remove useless headers
x86: merge process.c a bit
x86: use sparse_memory_present_with_active_regions() on UMA
x86: unify 64-bit UMA and NUMA paging_init()
x86: Allow 1MB of slack between the e820 map and SRAT, not 4GB
x86: Sanity check the e820 against the SRAT table using e820 map only
x86: clean up and and print out initial max_pfn_mapped
x86/pci: remove rounding quirk from e820_setup_gap()
x86, e820, pci: reserve extra free space near end of RAM
x86: fix typo in address space documentation
x86: 46 bit physical address support on 64 bits
x86, mm: fault.c, use printk_once() in is_errata93()
x86: move per-cpu mmu_gathers to mm/init.c
x86: move max_pfn_mapped and max_low_pfn_mapped to setup.c
x86: unify noexec handling
x86: remove (null) in /sys kernel_page_tables
...
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, nmi: Use predefined numbers instead of hardcoded one
x86: asm/processor.h: remove double declaration
x86, mtrr: replace MTRRdefType_MSR with msr-index's MSR_MTRRdefType
x86, mtrr: replace MTRRfix4K_C0000_MSR with msr-index's MSR_MTRRfix4K_C0000
x86, mtrr: remove mtrr MSRs double declaration
x86, mtrr: replace MTRRfix16K_80000_MSR with msr-index's MSR_MTRRfix16K_80000
x86, mtrr: replace MTRRfix64K_00000_MSR with msr-index's MSR_MTRRfix64K_00000
x86, mtrr: replace MTRRcap_MSR with msr-index's MSR_MTRRcap
x86: mce: remove duplicated #include
x86: msr-index.h remove duplicate MSR C001_0015 declaration
x86: clean up arch/x86/kernel/tsc_sync.c a bit
x86: use symbolic name for VM86_SIGNAL when used as vm86 default return
x86: added 'ifndef _ASM_X86_IOMAP_H' to iomap.h
x86: avoid multiple declaration of kstack_depth_to_print
x86: vdso/vma.c declare vdso_enabled and arch_setup_additional_pages before they get used
x86: clean up declarations and variables
x86: apic/x2apic_cluster.c x86_cpu_to_logical_apicid should be static
x86 early quirks: eliminate unused function
Do this so we can check the range that is mapped before
init_memory_mapping().
To be able to print out meaningful info, we first have to fix
64-bit to have max_pfn_mapped assigned before that call. This
also unifies the code-path a bit.
[ Impact: print more debug info, cleanup ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49BF0978.40605@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
With the introduction of the .brk section, special care must be taken
that no unused page table entries remain if _brk_end and _end are
separated by a 2M page boundary. cleanup_highmap() runs very early and
hence cannot take care of that, hence potential entries needing to be
removed past _brk_end must be cleared once the brk allocator has done
its job.
[ Impact: avoids undesirable TLB aliases ]
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: cleanup, no code changed
- syscalls.h update declarations due to unifications
- irq.c declare smp_generic_interrupt() before it gets used
- process.c declare sys_fork() and sys_vfork() before they get used
- tsc.c rename tsc_khz shadowed variable
- apic/probe_32.c declare apic_default before it gets used
- apic/nmi.c prev_nmi_count should be unsigned
- apic/io_apic.c declare smp_irq_move_cleanup_interrupt() before it gets used
- mm/init.c declare direct_gbpages and free_initrd_mem before they get used
Signed-off-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, save memory
The function is only being called from boot or memory hotplug paths.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <49B910B6.76E4.0078.0@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
In preparation for moving the function declaration to a header file,
unify 32-bit and 64-bit signatures.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1236257708-27269-16-git-send-email-penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
The table_start, table_end, and table_top are too generic for global
namespace so rename them to be more specific.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1236257708-27269-15-git-send-email-penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
This patch moves the init_memory_mapping() function to common mm/init.c.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1236257708-27269-14-git-send-email-penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
The function is identical on 32-bit and 64-bit configurations so move it to the
common mm/init.c file.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236158020.29024.28.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
The function is identical on 32-bit and 64-bit configurations so move
it to the common mm/init.c file.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236160001.29024.29.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: unification
This patch introduces a common arch/x86/mm/init.c and moves the identical
free_init_pages() and free_initmem() functions to the file.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236078906.2675.18.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
