commit 45a94d7cd4 upstream.
xsave_cntxt_init() does something like:
cpuid(0xd, ..); // find out what features FP/SSE/.. etc are supported
xsetbv(); // enable the features known to OS
cpuid(0xd, ..); // find out the size of the context for features enabled
Depending on what features get enabled in xsetbv(), value of the
cpuid.eax=0xd.ecx=0.ebx changes correspondingly (representing the
size of the context that is enabled).
As we don't have volatile keyword for native_cpuid(), gcc 4.1.2
optimizes away the second cpuid and the kernel continues to use
the cpuid information obtained before xsetbv(), ultimately leading to kernel
crash on processors supporting more state than the legacy FP/SSE.
Add "volatile" for native_cpuid().
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1261009542.2745.55.camel@sbs-t61.sc.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes two issues in the procfs stack information on
x86-64 linux.
The 32 bit loader compat_do_execve did not store stack
start. (this was figured out by Alexey Dobriyan).
The stack information on a x64_64 kernel always shows 0 kbyte
stack usage, because of a missing implementation of the KSTK_ESP
macro which always returned -1.
The new implementation now returns the right value.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1257240160.4889.24.camel@wall-e>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (37 commits)
sched: Fix SD_POWERSAVING_BALANCE|SD_PREFER_LOCAL vs SD_WAKE_AFFINE
sched: Stop buddies from hogging the system
sched: Add new wakeup preemption mode: WAKEUP_RUNNING
sched: Fix TASK_WAKING & loadaverage breakage
sched: Disable wakeup balancing
sched: Rename flags to wake_flags
sched: Clean up the load_idx selection in select_task_rq_fair
sched: Optimize cgroup vs wakeup a bit
sched: x86: Name old_perf in a unique way
sched: Implement a gentler fair-sleepers feature
sched: Add SD_PREFER_LOCAL
sched: Add a few SYNC hint knobs to play with
sched: Fix sync wakeups again
sched: Add WF_FORK
sched: Rename sync arguments
sched: Rename select_task_rq() argument
sched: Feature to disable APERF/MPERF cpu_power
x86: sched: Provide arch implementations using aperf/mperf
x86: Add generic aperf/mperf code
x86: Move APERF/MPERF into a X86_FEATURE
...
Fix up trivial conflict in arch/x86/include/asm/processor.h due to
nearby addition of amd_get_nb_id() declaration from the EDAC merge.
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits)
x86: Fix code patching for paravirt-alternatives on 486
x86, msr: change msr-reg.o to obj-y, and export its symbols
x86: Use hard_smp_processor_id() to get apic id for AMD K8 cpus
x86, sched: Workaround broken sched domain creation for AMD Magny-Cours
x86, mcheck: Use correct cpumask for shared bank4
x86, cacheinfo: Fixup L3 cache information for AMD multi-node processors
x86: Fix CPU llc_shared_map information for AMD Magny-Cours
x86, msr: Fix msr-reg.S compilation with gas 2.16.1, on 32-bit too
x86: Move kernel_fpu_using to irq_fpu_usable in asm/i387.h
x86, msr: fix msr-reg.S compilation with gas 2.16.1
x86, msr: Export the register-setting MSR functions via /dev/*/msr
x86, msr: Create _on_cpu helpers for {rw,wr}msr_safe_regs()
x86, msr: Have the _safe MSR functions return -EIO, not -EFAULT
x86, msr: CFI annotations, cleanups for msr-reg.S
x86, asm: Make _ASM_EXTABLE() usable from assembly code
x86, asm: Add 32-bit versions of the combined CFI macros
x86, AMD: Disable wrongly set X86_FEATURE_LAHF_LM CPUID bit
x86, msr: Rewrite AMD rd/wrmsr variants
x86, msr: Add rd/wrmsr interfaces with preset registers
x86: add specific support for Intel Atom architecture
...
As reported in <http://bugs.debian.org/511703> and
<http://bugs.debian.org/515982>, kernels with paravirt-alternatives
enabled crash in text_poke_early() on at least some 486-class
processors.
The problem is that text_poke_early() itself uses inline functions
affected by paravirt-alternatives and so will modify instructions that
have already been prefetched. Pentium and later processors will
invalidate the prefetched instructions in this case, but 486-class
processors do not.
Change sync_core() to limit prefetching on 486-class (and 386-class)
processors, and move the call to sync_core() above the call to the
modifiable local_irq_restore().
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
LKML-Reference: <1252547631.3423.134.camel@localhost>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Pack aligned things together into a special section to minimize
padding holes.
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <4AA035C0.9070202@goop.org>
[ queued up in tip:x86/asm because it depends on this commit:
x86/i386: Make sure stack-protector segment base is cache aligned ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The Intel Optimization Reference Guide says:
In Intel Atom microarchitecture, the address generation unit
assumes that the segment base will be 0 by default. Non-zero
segment base will cause load and store operations to experience
a delay.
- If the segment base isn't aligned to a cache line
boundary, the max throughput of memory operations is
reduced to one [e]very 9 cycles.
[...]
Assembly/Compiler Coding Rule 15. (H impact, ML generality)
For Intel Atom processors, use segments with base set to 0
whenever possible; avoid non-zero segment base address that is
not aligned to cache line boundary at all cost.
We can't avoid having a non-zero base for the stack-protector
segment, but we can make it cache-aligned.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: <stable@kernel.org>
LKML-Reference: <4AA01893.6000507@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits)
Revert "x86, bts: reenable ptrace branch trace support"
tracing: do not translate event helper macros in print format
ftrace/documentation: fix typo in function grapher name
tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK
tracing: add protection around module events unload
tracing: add trace_seq_vprint interface
tracing: fix the block trace points print size
tracing/events: convert block trace points to TRACE_EVENT()
ring-buffer: fix ret in rb_add_time_stamp
ring-buffer: pass in lockdep class key for reader_lock
tracing: add annotation to what type of stack trace is recorded
tracing: fix multiple use of __print_flags and __print_symbolic
tracing/events: fix output format of user stack
tracing/events: fix output format of kernel stack
tracing/trace_stack: fix the number of entries in the header
ring-buffer: discard timestamps that are at the start of the buffer
ring-buffer: try to discard unneeded timestamps
ring-buffer: fix bug in ring_buffer_discard_commit
ftrace: do not profile functions when disabled
tracing: make trace pipe recognize latency format flag
...
* '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
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, 64-bit: ifdef out struct thread_struct::ip
x86, 32-bit: ifdef out struct thread_struct::fs
x86: clean up alternative.h
* 'x86-kbuild-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (46 commits)
x86, boot: add new generated files to the appropriate .gitignore files
x86, boot: correct the calculation of ZO_INIT_SIZE
x86-64: align __PHYSICAL_START, remove __KERNEL_ALIGN
x86, boot: correct sanity checks in boot/compressed/misc.c
x86: add extension fields for bootloader type and version
x86, defconfig: update kernel position parameters
x86, defconfig: update to current, no material changes
x86: make CONFIG_RELOCATABLE the default
x86: default CONFIG_PHYSICAL_START and CONFIG_PHYSICAL_ALIGN to 16 MB
x86: document new bzImage fields
x86, boot: make kernel_alignment adjustable; new bzImage fields
x86, boot: remove dead code from boot/compressed/head_*.S
x86, boot: use LOAD_PHYSICAL_ADDR on 64 bits
x86, boot: make symbols from the main vmlinux available
x86, boot: determine compressed code offset at compile time
x86, boot: use appropriate rep string for move and clear
x86, boot: zero EFLAGS on 32 bits
x86, boot: set up the decompression stack as early as possible
x86, boot: straighten out ranges to copy/zero in compressed/head*.S
x86, boot: stylistic cleanups for boot/compressed/head_64.S
...
Fixed trivial conflict in arch/x86/configs/x86_64_defconfig manually
A long ago, in days of yore, it all began with a god named Thor.
There were vikings and boats and some plans for a Linux kernel
header. Unfortunately, a single 8-bit field was used for bootloader
type and version. This has generally worked without *too* much pain,
but we're getting close to flat running out of ID fields.
Add extension fields for both type and version. The type will be
extended if it the old field is 0xE; the version is a simple MSB
extension.
Keep /proc/sys/kernel/bootloader_type containing
(type << 4) + (ver & 0xf) for backwards compatiblity, but also add
/proc/sys/kernel/bootloader_version which contains the full version
number.
[ Impact: new feature to support more bootloaders ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
setup_force_cpu_cap() only have one user (Xen guest code),
but it should not reuse cleared_cpu_cpus, otherwise it
will have problems on SMP.
Need to have a separate cpu_cpus_set array too, for forced-on
flags, beyond the forced-off flags.
Also need to setup handling before all cpus caps are combined.
[ Impact: fix the forced-set CPU feature flag logic ]
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Yinghai Lu <yinghai.lu@kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts:
arch/x86/kernel/ptrace.c
Merge reason: fix the conflict above, and also pick up the CONFIG_BROKEN
dependency change from upstream so that we can remove it
here.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In non-SMP mode, the variable section attribute specified by DECLARE_PER_CPU()
does not agree with that specified by DEFINE_PER_CPU(). This means that
architectures that have a small data section references relative to a base
register may throw up linkage errors due to too great a displacement between
where the base register points and the per-CPU variable.
On FRV, the .h declaration says that the variable is in the .sdata section, but
the .c definition says it's actually in the .data section. The linker throws
up the following errors:
kernel/built-in.o: In function `release_task':
kernel/exit.c:78: relocation truncated to fit: R_FRV_GPREL12 against symbol `per_cpu__process_counts' defined in .data section in kernel/built-in.o
kernel/exit.c:78: relocation truncated to fit: R_FRV_GPREL12 against symbol `per_cpu__process_counts' defined in .data section in kernel/built-in.o
To fix this, DECLARE_PER_CPU() should simply apply the same section attribute
as does DEFINE_PER_CPU(). However, this is made slightly more complex by
virtue of the fact that there are several variants on DEFINE, so these need to
be matched by variants on DECLARE.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
