Observing that per-CPU data (in the SMP case) is reachable by
exploiting 64-bit address wraparound (building on the default kernel
load address being at 16Mb), the one byte shorter RIP-relative
addressing form can be used for most per-CPU accesses. The one
exception are the "stable" reads, where the use of the "P" operand
modifier prevents the compiler from using RIP-relative addressing, but
is unavoidable due to the use of the "p" constraint (side note: with
gcc 4.9.x the intended effect of this isn't being achieved anymore,
see gcc bug 63637).
With the dependency on the minimum kernel load address, arbitrarily
low values for CONFIG_PHYSICAL_START are now no longer possible. A
link time assertion is being added, directing to the need to increase
that value when it triggers.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/5458A1780200007800044A9D@mail.emea.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
By coincidence, the VVAR page is at the end of an ELF segment. As a
result, if it ends up being a partial page, the kernel loader will
leave garbage behind at the end of the vvar page. Zero-pad it to a
full page to fix this issue.
This has probably been broken since the VVAR page was introduced.
On QEMU, if you dump the run-time contents of the VVAR page, you can
find entertaining strings from seabios left behind.
It's remotely possible that this is a security bug -- conceivably
there's some BIOS out there that leaves something sensitive in the
few K of memory that is exposed to userspace.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-12-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch move the vsyscall_gtod_data handling out of vsyscall_64.c
into an additonal file vsyscall_gtod.c to make the functionality
available for x86 32 bit kernel.
It also adds a new vsyscall_32.c which setup the VVAR page.
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-2-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
When Intel mid uses SFI table to enumerate devices, it requires an extra
device table with further information about how to probe such devices.
This patch creates a section where the device table will stay if
CONFIG_X86_INTEL_MID is selected.
Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>
Link: http://lkml.kernel.org/r/1382049336-21316-12-git-send-email-david.a.cohen@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Commit e44b7b7 ("x86: move suspend wakeup code to C") didn't
care to also eliminate the side effects that the earlier 4c49156
("x86: make arch/x86/kernel/acpi/wakeup_32.S use a separate")
had, thus leaving a now pointless, almost page size gap at the
beginning of .text.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pavel Machek <pavel@ucw.cz>
Link: http://lkml.kernel.org/r/513DBAA402000078000C4896@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Migrated ACPI wakeup code to the real-mode blob.
Code existing in .x86_trampoline can be completely
removed. Static descriptor table in wakeup_asm.S is
courtesy of H. Peter Anvin.
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-7-git-send-email-jarkko.sakkinen@intel.com
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
There are three choices:
vsyscall=native: Vsyscalls are native code that issues the
corresponding syscalls.
vsyscall=emulate (default): Vsyscalls are emulated by instruction
fault traps, tested in the bad_area path. The actual contents of
the vsyscall page is the same as the vsyscall=native case except
that it's marked NX. This way programs that make assumptions about
what the code in the page does will not be confused when they read
that code.
vsyscall=none: Trying to execute a vsyscall will segfault.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/8449fb3abf89851fd6b2260972666a6f82542284.1312988155.git.luto@mit.edu
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Gold has trouble assigning numbers to the location counter inside of
an output section description. The bug was triggered by
9fd67b4ed0, which consolidated all of
the vsyscall sections into a single section. The workaround is IMO
still nicer than the old way of doing it.
This produces an apparently valid kernel image and passes my vdso
tests on both GNU ld version 2.21.51.0.6-2.fc15 20110118 and GNU
gold (version 2.21.51.0.6-2.fc15 20110118) 1.10 as distributed by
Fedora 15.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/0b260cb806f1f9a25c00ce8377a5f035d57f557a.1312378163.git.luto@mit.edu
Reported-by: Arkadiusz Miskiewicz <a.miskiewicz@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Jumping to 0x00 might do something depending on the following
bytes. Jumping to 0xcc is a trap. So fill the unused parts of
the vsyscall page with 0xcc to make it useless for exploits to
jump there.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: Mikael Pettersson <mikpe@it.uu.se>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: Valdis.Kletnieks@vt.edu
Cc: pageexec@freemail.hu
Link: http://lkml.kernel.org/r/ed54bfcfbe50a9070d20ec1edbe0d149e22a4568.1307292171.git.luto@mit.edu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It just segfaults since April 2008 (a4928cff), so I'm pretty
sure that nothing uses it. And having an empty section makes
the linker script a bit fragile.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: Mikael Pettersson <mikpe@it.uu.se>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: Valdis.Kletnieks@vt.edu
Cc: pageexec@freemail.hu
Link: http://lkml.kernel.org/r/4a4abcf47ecadc269f2391a313576fe6d06acef7.1307292171.git.luto@mit.edu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move vvars out of the vsyscall page into their own page and mark
it NX.
Without this patch, an attacker who can force a daemon to call
some fixed address could wait until the time contains, say,
0xCD80, and then execute the current time.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: Mikael Pettersson <mikpe@it.uu.se>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: Valdis.Kletnieks@vt.edu
Cc: pageexec@freemail.hu
Link: http://lkml.kernel.org/r/b1460f81dc4463d66ea3f2b5ce240f58d48effec.1307292171.git.luto@mit.edu
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: vdso: Remove unused variable
x86-64: Optimize vDSO time()
x86-64: Add time to vDSO
x86-64: Turn off -pg and turn on -foptimize-sibling-calls for vDSO
x86-64: Move vread_tsc into a new file with sensible options
x86-64: Vclock_gettime(CLOCK_MONOTONIC) can't ever see nsec < 0
x86-64: Don't generate cmov in vread_tsc
x86-64: Remove unnecessary barrier in vread_tsc
x86-64: Clean up vdso/kernel shared variables
* 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu: Unify input section names
percpu: Avoid extra NOP in percpu_cmpxchg16b_double
percpu: Cast away printk format warning
percpu: Always align percpu output section to PAGE_SIZE
Fix up fairly trivial conflict in arch/x86/include/asm/percpu.h as per Tejun
Variables that are shared between the vdso and the kernel are
currently a bit of a mess. They are each defined with their own
magic, they are accessed differently in the kernel, the vsyscall page,
and the vdso, and one of them (vsyscall_clock) doesn't even really
exist.
This changes them all to use a common mechanism. All of them are
delcared in vvar.h with a fixed address (validated by the linker
script). In the kernel (as before), they look like ordinary
read-write variables. In the vsyscall page and the vdso, they are
accessed through a new macro VVAR, which gives read-only access.
The vdso is now loaded verbatim into memory without any fixups. As a
side bonus, access from the vdso is faster because a level of
indirection is removed.
While we're at it, pack jiffies and vgetcpu_mode into the same
cacheline.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Borislav Petkov <bp@amd64.org>
Link: http://lkml.kernel.org/r/%3C7357882fbb51fa30491636a7b6528747301b7ee9.1306156808.git.luto%40mit.edu%3E
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This will pave the way for each apic driver to be self-contained
and eliminate the need for apic_probe[].
Order in which apic drivers are listed in the .apicdrivers
section is important, as this determines the apic probe order.
And this is enforced by the ordering of apic driver files in the
Makefile and the macros apic_driver()/apic_drivers().
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: steiner@sgi.com
Cc: gorcunov@openvz.org
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/20110521005526.068775085@sbsiddha-MOBL3.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Percpu allocator honors alignment request upto PAGE_SIZE and both the
percpu addresses in the percpu address space and the translated kernel
addresses should be aligned accordingly. The calculation of the
former depends on the alignment of percpu output section in the kernel
image.
The linker script macros PERCPU_VADDR() and PERCPU() are used to
define this output section and the latter takes @align parameter.
Several architectures are using @align smaller than PAGE_SIZE breaking
percpu memory alignment.
This patch removes @align parameter from PERCPU(), renames it to
PERCPU_SECTION() and makes it always align to PAGE_SIZE. While at it,
add PCPU_SETUP_BUG_ON() checks such that alignment problems are
reliably detected and remove percpu alignment comment recently added
in workqueue.c as the condition would trigger BUG way before reaching
there.
For um, this patch raises the alignment of percpu area. As the area
is in .init, there shouldn't be any noticeable difference.
This problem was discovered by David Howells while debugging boot
failure on mn10300.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: user-mode-linux-devel@lists.sourceforge.net
* 'x86-trampoline-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Fix binutils-2.21 symbol related build failures
x86-64, trampoline: Remove unused variable
x86, reboot: Fix the use of passed arguments in 32-bit BIOS reboot
x86, reboot: Move the real-mode reboot code to an assembly file
x86: Make the GDT_ENTRY() macro in <asm/segment.h> safe for assembly
x86, trampoline: Use the unified trampoline setup for ACPI wakeup
x86, trampoline: Common infrastructure for low memory trampolines
Fix up trivial conflicts in arch/x86/kernel/Makefile
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu, x86: Add arch-specific this_cpu_cmpxchg_double() support
percpu: Generic support for this_cpu_cmpxchg_double()
alpha: use L1_CACHE_BYTES for cacheline size in the linker script
percpu: align percpu readmostly subsection to cacheline
Fix up trivial conflict in arch/x86/kernel/vmlinux.lds.S due to the
percpu alignment having changed ("x86: Reduce back the alignment of the
per-CPU data section")
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, binutils, xen: Fix another wrong size directive
x86: Remove dead config option X86_CPU
x86: Really print supported CPUs if PROCESSOR_SELECT=y
x86: Fix a bogus unwind annotation in lib/semaphore_32.S
um, x86-64: Fix UML build after adding CFI annotations to lib/rwsem_64.S
x86: Remove unused bits from lib/thunk_*.S
x86: Use {push,pop}_cfi in more places
x86-64: Add CFI annotations to lib/rwsem_64.S
x86, asm: Cleanup unnecssary macros in asm-offsets.c
x86, system.h: Drop unused __SAVE/__RESTORE macros
x86: Use bitmap library functions
x86: Partly unify asm-offsets_{32,64}.c
x86: Reduce back the alignment of the per-CPU data section
Put x86 entry code into a separate link section: .entry.text.
Separating the entry text section seems to have performance
benefits - caused by more efficient instruction cache usage.
Running hackbench with perf stat --repeat showed that the change
compresses the icache footprint. The icache load miss rate went
down by about 15%:
before patch:
19417627 L1-icache-load-misses ( +- 0.147% )
after patch:
16490788 L1-icache-load-misses ( +- 0.180% )
The motivation of the patch was to fix a particular kprobes
bug that relates to the entry text section, the performance
advantage was discovered accidentally.
Whole perf output follows:
- results for current tip tree:
Performance counter stats for './hackbench/hackbench 10' (500 runs):
19417627 L1-icache-load-misses ( +- 0.147% )
2676914223 instructions # 0.497 IPC ( +- 0.079% )
5389516026 cycles ( +- 0.144% )
0.206267711 seconds time elapsed ( +- 0.138% )
- results for current tip tree with the patch applied:
Performance counter stats for './hackbench/hackbench 10' (500 runs):
16490788 L1-icache-load-misses ( +- 0.180% )
2717734941 instructions # 0.502 IPC ( +- 0.079% )
5414756975 cycles ( +- 0.148% )
0.206747566 seconds time elapsed ( +- 0.137% )
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: masami.hiramatsu.pt@hitachi.com
Cc: ananth@in.ibm.com
Cc: davem@davemloft.net
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20110307181039.GB15197@jolsa.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Common infrastructure for low memory trampolines. This code installs
the trampolines permanently in low memory very early. It also permits
multiple pieces of code to be used for this purpose.
This code also introduces a standard infrastructure for computing
symbol addresses in the trampoline code.
The only change to the actual SMP trampolines themselves is that the
64-bit trampoline has been made reusable -- the previous version would
overwrite the code with a status variable; this moves the status
variable to a separate location.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <4D5DFBE4.7090104@intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Matthieu Castet <castet.matthieu@free.fr>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
This complements commit:
47f19a0814e8: percpu: Remove the multi-page alignment facility
reverting one leftover of:
fe8e0c25cad2: x86, 32-bit: Align percpu area and irq stacks to THREAD_SIZE
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4D525CE60200007800030EE5@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Alexander van Heukelum <heukelum@fastmail.fm>
Currently percpu readmostly subsection may share cachelines with other
percpu subsections which may result in unnecessary cacheline bounce
and performance degradation.
This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR()
linker macros, makes each arch linker scripts specify its cacheline
size and use it to align percpu subsections.
This is based on Shaohua's x86 only patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Shaohua Li <shaohua.li@intel.com>
This reverts commit 86b1e8dd83 ("x86: Make relocatable kernel work with
new binutils").
Markus Trippelsdorf reported a boot failure caused by this patch.
The real solution to the original patch will likely involve an
arch-generic solution to define an overlaid jiffies_64 and jiffies
variables.
Until that's done and tested on all architectures revert this commit to
solve the regression.
Reported-and-bisected-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: "Lu, Hongjiu" <hongjiu.lu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Cc: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <4D36A759.60704@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The CONFIG_RELOCATABLE=y option is broken with new binutils, which will make
boot panic.
According to Lu Hongjiu, the affected binutils are from 2.20.51.0.12 to
2.21.51.0.3, which are release since Oct 22 this year. At least ubuntu 10.10 is
using such binutils. See:
http://sourceware.org/bugzilla/show_bug.cgi?id=12327
The reason of the boot panic is that we have 'jiffies = jiffies_64;' in
vmlinux.lds.S. The jiffies isn't in any section. In kernel build, there is
warning saying jiffies is an absolute address and can't be relocatable. At
runtime, jiffies will have virtual address 0.
Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Cc: Lu Hongjiu<hongjiu.lu@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <1295312269.1949.725.camel@sli10-conroe>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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>
The irq stacks, located in the percpu-area, need to be
THREAD_SIZE aligned. Add the infrastucture to align percpu
variables to larger-than-pagesize amounts within the percpu
area, and use it to specify the alignment for the irq stacks.
Also align the percpu area itself to THREAD_SIZE.
This should make irq stacks work with 8K THREAD_SIZE.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Cc: Tejun Heo <tj@kernel.org>
Cc: hch@lst.de
LKML-Reference: <1283799222.15941.1393621887@webmail.messagingengine.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This boot crash was observed:
DMA-API: preallocated 32768 debug entries
DMA-API: debugging enabled by kernel config
BUG: unable to handle kernel paging request at 19da8955
IP: [<f4ffffff>] 0xf4ffffff
*pde = 00000000
The crux of the failure was that even if we did not use any
of the .iommu_table section, the linker would still insert it
in the vmlinux file. This patch fixes that and also fixes the
runtime crash where we would try to access the array.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
LKML-Reference: <1283191802-25086-1-git-send-email-konrad.wilk@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Updating the linker section with comments about .iommu_table and
some other ones that I know of.
CC: Sam Ravnborg <sam@ravnborg.org>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Fujita Tomonori <fujita.tomonori@lab.ntt.co.jp>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
LKML-Reference: <1282933173-19960-1-git-send-email-konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This patch set adds a mechanism to "modularize" the IOMMUs we have
on X86. Currently the count of IOMMUs is up to six and they have a complex
relationship that requires careful execution order. 'pci_iommu_alloc'
does that today, but most folks are unhappy with how it does it.
This patch set addresses this and also paves a mechanism to jettison
unused IOMMUs during run-time. For details that sparked this, please
refer to: http://lkml.org/lkml/2010/8/2/282
The first solution that comes to mind is to convert wholesale
the IOMMU detection routines to be called during initcall
time frame. Unfortunately that misses the dependency relationship
that some of the IOMMUs have (for example: for AMD-Vi IOMMU to work,
GART detection MUST run first, and before all of that SWIOTLB MUST run).
The second solution would be to introduce a registration call wherein
the IOMMU would provide its detection/init routines and as well on what
MUST run before it. That would work, except that the 'pci_iommu_alloc'
which would run through this list, is called during mem_init. This means we
don't have any memory allocator, and it is so early that we haven't yet
started running through the initcall_t list.
This solution borrows concepts from the 2nd idea and from how
MODULE_INIT works. A macro is provided that each IOMMU uses to define
it's detect function and early_init (before the memory allocate is
active), and as well what other IOMMU MUST run before us. Since most IOMMUs
depend on having SWIOTLB run first ("pci_swiotlb_detect") a convenience macro
to depends on that is also provided.
This macro is similar in design to MODULE_PARAM macro wherein
we setup a .iommu_table section in which we populate it with the values
that match a struct iommu_table_entry. During bootup we will sort
through the array so that the IOMMUs that MUST run before us are first
elements in the array. And then we just iterate through them calling the
detection routine and if appropiate, the init routines.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
LKML-Reference: <1282845485-8991-2-git-send-email-konrad.wilk@oracle.com>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Fujita Tomonori <fujita.tomonori@lab.ntt.co.jp>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* 'for-35' of git://repo.or.cz/linux-kbuild: (81 commits)
kbuild: Revert part of e8d400a to resolve a conflict
kbuild: Fix checking of scm-identifier variable
gconfig: add support to show hidden options that have prompts
menuconfig: add support to show hidden options which have prompts
gconfig: remove show_debug option
gconfig: remove dbg_print_ptype() and dbg_print_stype()
kconfig: fix zconfdump()
kconfig: some small fixes
add random binaries to .gitignore
kbuild: Include gen_initramfs_list.sh and the file list in the .d file
kconfig: recalc symbol value before showing search results
.gitignore: ignore *.lzo files
headerdep: perlcritic warning
scripts/Makefile.lib: Align the output of LZO
kbuild: Generate modules.builtin in make modules_install
Revert "kbuild: specify absolute paths for cscope"
kbuild: Do not unnecessarily regenerate modules.builtin
headers_install: use local file handles
headers_check: fix perl warnings
export_report: fix perl warnings
...
Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
This adds a new category of symbols to the relocs program: symbols
which are known to be relative, even though the linker emits them as
absolute; this is the case for symbols that live in the linker script,
which currently applies to _end.
Unfortunately the previous workaround of putting _end in its own empty
section was defeated by newer binutils, which remove empty sections
completely.
This patch also changes the symbol matching to use regular expressions
instead of hardcoded C for specific patterns.
This is a decidedly non-minimal patch: a modified version of the
relocs program is used as part of the Syslinux build, and this is
basically a backport to Linux of some of those changes; they have
thus been well tested.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <4AF86211.3070103@zytor.com>
Acked-by: Michal Marek <mmarek@suse.cz>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (36 commits)
x86, mm: Correct the implementation of is_untracked_pat_range()
x86/pat: Trivial: don't create debugfs for memtype if pat is disabled
x86, mtrr: Fix sorting of mtrr after subtracting
x86: Move find_smp_config() earlier and avoid bootmem usage
x86, platform: Change is_untracked_pat_range() to bool; cleanup init
x86: Change is_ISA_range() into an inline function
x86, mm: is_untracked_pat_range() takes a normal semiclosed range
x86, mm: Call is_untracked_pat_range() rather than is_ISA_range()
x86: UV SGI: Don't track GRU space in PAT
x86: SGI UV: Fix BAU initialization
x86, numa: Use near(er) online node instead of roundrobin for NUMA
x86, numa, bootmem: Only free bootmem on NUMA failure path
x86: Change crash kernel to reserve via reserve_early()
x86: Eliminate redundant/contradicting cache line size config options
x86: When cleaning MTRRs, do not fold WP into UC
x86: remove "extern" from function prototypes in <asm/proto.h>
x86, mm: Report state of NX protections during boot
x86, mm: Clean up and simplify NX enablement
x86, pageattr: Make set_memory_(x|nx) aware of NX support
x86, sleep: Always save the value of EFER
...
Fix up conflicts (added both iommu_shutdown and is_untracked_pat_range)
to 'struct x86_platform_ops') in
arch/x86/include/asm/x86_init.h
arch/x86/kernel/x86_init.c
Rather than having X86_L1_CACHE_BYTES and X86_L1_CACHE_SHIFT
(with inconsistent defaults), just having the latter suffices as
the former can be easily calculated from it.
To be consistent, also change X86_INTERNODE_CACHE_BYTES to
X86_INTERNODE_CACHE_SHIFT, and set it to 7 (128 bytes) for NUMA
to account for last level cache line size (which here matters
more than L1 cache line size).
Finally, make sure the default value for X86_L1_CACHE_SHIFT,
when X86_GENERIC is selected, is being seen before that for the
individual CPU model options (other than on x86-64, where
GENERIC_CPU is part of the choice construct, X86_GENERIC is a
separate option on ix86).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Ravikiran Thirumalai <kiran@scalex86.org>
Acked-by: Nick Piggin <npiggin@suse.de>
LKML-Reference: <4AFD5710020000780001F8F0@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now that the return from alloc_percpu is compatible with the address
of per-cpu vars, it makes sense to hand around the address of per-cpu
variables. To make this sane, we remove the per_cpu__ prefix we used
created to stop people accidentally using these vars directly.
Now we have sparse, we can use that (next patch).
tj: * Updated to convert stuff which were missed by or added after the
original patch.
* Kill per_cpu_var() macro.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Add a comment explaining why RODATA is aligned to 2 MB.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
CONFIG_DEBUG_RODATA chops the large pages spanning boundaries of kernel
text/rodata/data to small 4KB pages as they are mapped with different
attributes (text as RO, RODATA as RO and NX etc).
On x86_64, preserve the large page mappings for kernel text/rodata/data
boundaries when CONFIG_DEBUG_RODATA is enabled. This is done by allowing the
RODATA section to be hugepage aligned and having same RWX attributes
for the 2MB page boundaries
Extra Memory pages padding the sections will be freed during the end of the boot
and the kernel identity mappings will have different RWX permissions compared to
the kernel text mappings.
Kernel identity mappings to these physical pages will be mapped with smaller
pages but large page mappings are still retained for kernel text,rodata,data
mappings.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20091014220254.190119924@sbs-t61.sc.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Older binutils breaks if ASSERT() is used without a sink
for the output.
For example 2.14.90.0.6 is known to be broken, the link
fails with:
LD .tmp_vmlinux1
ld:arch/x86/kernel/vmlinux.lds:678: parse error
Document this quirk in all three files that use it.
See: http://marc.info/?l=linux-kbuild&m=124930110427870&w=2
See[2]: d2ba8b2 ("x86: Fix assert syntax in vmlinux.lds.S")
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <4AD6523D.5030909@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This reverts commit e9a63a4e55.
This breaks older binutils, where sink-less asserts are broken.
See this commit for further details:
d2ba8b2: x86: Fix assert syntax in vmlinux.lds.S
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <4AD6523D.5030909@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The linker scripts grew some use of weirdly wrong linker script syntax.
It happens to work, but it's not what the syntax is documented to be.
Clean it up to use the official syntax.
Signed-off-by: Roland McGrath <roland@redhat.com>
CC: Ian Lance Taylor <iant@google.com>
While these don't get actively used (afaict), it still doesn't hurt
for them to properly reflect what how respective segments will get
mapped/ accessed.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4AA0E95F0200007800013707@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jan Beulich