Make it execute the ERMS version if support is present and we're in the
forward memmove() part and remove the unfolded alternatives section
definition.
Signed-off-by: Borislav Petkov <bp@suse.de>
Make alternatives replace single JMPs instead of whole memset functions,
thus decreasing the amount of instructions copied during patching time
at boot.
While at it, make it use the REP_GOOD version by default which means
alternatives NOP out the JMP to the other versions, as REP_GOOD is set
by default on the majority of relevant x86 processors.
Signed-off-by: Borislav Petkov <bp@suse.de>
Move clear_page() up so that we can get 2-byte forward JMPs when
patching:
apply_alternatives: feat: 3*32+16, old: (ffffffff8130adb0, len: 5), repl: (ffffffff81d0b859, len: 5)
ffffffff8130adb0: alt_insn: 90 90 90 90 90
recompute_jump: new_displ: 0x0000003e
ffffffff81d0b859: rpl_insn: eb 3e 66 66 90
even though the compiler generated 5-byte JMPs which we padded with 5
NOPs.
Also, make the REP_GOOD version be the default as the majority of
machines set REP_GOOD. This way we get to save ourselves the JMP:
old insn VA: 0xffffffff813038b0, CPU feat: X86_FEATURE_REP_GOOD, size: 5, padlen: 0
clear_page:
ffffffff813038b0 <clear_page>:
ffffffff813038b0: e9 0b 00 00 00 jmpq ffffffff813038c0
repl insn: 0xffffffff81cf0e92, size: 0
old insn VA: 0xffffffff813038b0, CPU feat: X86_FEATURE_ERMS, size: 5, padlen: 0
clear_page:
ffffffff813038b0 <clear_page>:
ffffffff813038b0: e9 0b 00 00 00 jmpq ffffffff813038c0
repl insn: 0xffffffff81cf0e92, size: 5
ffffffff81cf0e92: e9 69 2a 61 ff jmpq ffffffff81303900
ffffffff813038b0 <clear_page>:
ffffffff813038b0: e9 69 2a 61 ff jmpq ffffffff8091631e
Signed-off-by: Borislav Petkov <bp@suse.de>
... instead of the semi-version with the spelled out sections.
What is more, make the REP_GOOD version be the default copy_page()
version as the majority of the relevant x86 CPUs do set
X86_FEATURE_REP_GOOD. Thus, copy_page gets compiled to:
ffffffff8130af80 <copy_page>:
ffffffff8130af80: e9 0b 00 00 00 jmpq ffffffff8130af90 <copy_page_regs>
ffffffff8130af85: b9 00 02 00 00 mov $0x200,%ecx
ffffffff8130af8a: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi)
ffffffff8130af8d: c3 retq
ffffffff8130af8e: 66 90 xchg %ax,%ax
ffffffff8130af90 <copy_page_regs>:
...
and after the alternatives have run, the JMP to the old, unrolled
version gets NOPed out:
ffffffff8130af80 <copy_page>:
ffffffff8130af80: 66 66 90 xchg %ax,%ax
ffffffff8130af83: 66 90 xchg %ax,%ax
ffffffff8130af85: b9 00 02 00 00 mov $0x200,%ecx
ffffffff8130af8a: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi)
ffffffff8130af8d: c3 retq
On modern uarches, those NOPs are cheaper than the unconditional JMP
previously.
Signed-off-by: Borislav Petkov <bp@suse.de>
Up until now we had to pay attention to relative JMPs in alternatives
about how their relative offset gets computed so that the jump target
is still correct. Or, as it is the case for near CALLs (opcode e8), we
still have to go and readjust the offset at patching time.
What is more, the static_cpu_has_safe() facility had to forcefully
generate 5-byte JMPs since we couldn't rely on the compiler to generate
properly sized ones so we had to force the longest ones. Worse than
that, sometimes it would generate a replacement JMP which is longer than
the original one, thus overwriting the beginning of the next instruction
at patching time.
So, in order to alleviate all that and make using JMPs more
straight-forward we go and pad the original instruction in an
alternative block with NOPs at build time, should the replacement(s) be
longer. This way, alternatives users shouldn't pay special attention
so that original and replacement instruction sizes are fine but the
assembler would simply add padding where needed and not do anything
otherwise.
As a second aspect, we go and recompute JMPs at patching time so that we
can try to make 5-byte JMPs into two-byte ones if possible. If not, we
still have to recompute the offsets as the replacement JMP gets put far
away in the .altinstr_replacement section leading to a wrong offset if
copied verbatim.
For example, on a locally generated kernel image
old insn VA: 0xffffffff810014bd, CPU feat: X86_FEATURE_ALWAYS, size: 2
__switch_to:
ffffffff810014bd: eb 21 jmp ffffffff810014e0
repl insn: size: 5
ffffffff81d0b23c: e9 b1 62 2f ff jmpq ffffffff810014f2
gets corrected to a 2-byte JMP:
apply_alternatives: feat: 3*32+21, old: (ffffffff810014bd, len: 2), repl: (ffffffff81d0b23c, len: 5)
alt_insn: e9 b1 62 2f ff
recompute_jumps: next_rip: ffffffff81d0b241, tgt_rip: ffffffff810014f2, new_displ: 0x00000033, ret len: 2
converted to: eb 33 90 90 90
and a 5-byte JMP:
old insn VA: 0xffffffff81001516, CPU feat: X86_FEATURE_ALWAYS, size: 2
__switch_to:
ffffffff81001516: eb 30 jmp ffffffff81001548
repl insn: size: 5
ffffffff81d0b241: e9 10 63 2f ff jmpq ffffffff81001556
gets shortened into a two-byte one:
apply_alternatives: feat: 3*32+21, old: (ffffffff81001516, len: 2), repl: (ffffffff81d0b241, len: 5)
alt_insn: e9 10 63 2f ff
recompute_jumps: next_rip: ffffffff81d0b246, tgt_rip: ffffffff81001556, new_displ: 0x0000003e, ret len: 2
converted to: eb 3e 90 90 90
... and so on.
This leads to a net win of around
40ish replacements * 3 bytes savings =~ 120 bytes of I$
on an AMD guest which means some savings of precious instruction cache
bandwidth. The padding to the shorter 2-byte JMPs are single-byte NOPs
which on smart microarchitectures means discarding NOPs at decode time
and thus freeing up execution bandwidth.
Signed-off-by: Borislav Petkov <bp@suse.de>
Up until now we have always paid attention to make sure the length of
the new instruction replacing the old one is at least less or equal to
the length of the old instruction. If the new instruction is longer, at
the time it replaces the old instruction it will overwrite the beginning
of the next instruction in the kernel image and cause your pants to
catch fire.
So instead of having to pay attention, teach the alternatives framework
to pad shorter old instructions with NOPs at buildtime - but only in the
case when
len(old instruction(s)) < len(new instruction(s))
and add nothing in the >= case. (In that case we do add_nops() when
patching).
This way the alternatives user shouldn't have to care about instruction
sizes and simply use the macros.
Add asm ALTERNATIVE* flavor macros too, while at it.
Also, we need to save the pad length in a separate struct alt_instr
member for NOP optimization and the way to do that reliably is to carry
the pad length instead of trying to detect whether we're looking at
single-byte NOPs or at pathological instruction offsets like e9 90 90 90
90, for example, which is a valid instruction.
Thanks to Michael Matz for the great help with toolchain questions.
Signed-off-by: Borislav Petkov <bp@suse.de>
Recently instrumentation of builtin functions calls was removed from GCC
5.0. To check the memory accessed by such functions, userspace asan
always uses interceptors for them.
So now we should do this as well. This patch declares
memset/memmove/memcpy as weak symbols. In mm/kasan/kasan.c we have our
own implementation of those functions which checks memory before accessing
it.
Default memset/memmove/memcpy now now always have aliases with '__'
prefix. For files that built without kasan instrumentation (e.g.
mm/slub.c) original mem* replaced (via #define) with prefixed variants,
cause we don't want to check memory accesses there.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stephane reported that the PEBS fixup was broken by the recent commit to
the instruction decoder. The thing had an off-by-one which resulted in
not being able to decode the last instruction and always bail.
Reported-by: Stephane Eranian <eranian@google.com>
Fixes: 6ba48ff46f ("x86: Remove arbitrary instruction size limit in instruction decoder")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # 3.18
Cc: <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Liang Kan <kan.liang@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/20141216104614.GV3337@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull networking updates from David Miller:
1) New offloading infrastructure and example 'rocker' driver for
offloading of switching and routing to hardware.
This work was done by a large group of dedicated individuals, not
limited to: Scott Feldman, Jiri Pirko, Thomas Graf, John Fastabend,
Jamal Hadi Salim, Andy Gospodarek, Florian Fainelli, Roopa Prabhu
2) Start making the networking operate on IOV iterators instead of
modifying iov objects in-situ during transfers. Thanks to Al Viro
and Herbert Xu.
3) A set of new netlink interfaces for the TIPC stack, from Richard
Alpe.
4) Remove unnecessary looping during ipv6 routing lookups, from Martin
KaFai Lau.
5) Add PAUSE frame generation support to gianfar driver, from Matei
Pavaluca.
6) Allow for larger reordering levels in TCP, which are easily
achievable in the real world right now, from Eric Dumazet.
7) Add a variable of napi_schedule that doesn't need to disable cpu
interrupts, from Eric Dumazet.
8) Use a doubly linked list to optimize neigh_parms_release(), from
Nicolas Dichtel.
9) Various enhancements to the kernel BPF verifier, and allow eBPF
programs to actually be attached to sockets. From Alexei
Starovoitov.
10) Support TSO/LSO in sunvnet driver, from David L Stevens.
11) Allow controlling ECN usage via routing metrics, from Florian
Westphal.
12) Remote checksum offload, from Tom Herbert.
13) Add split-header receive, BQL, and xmit_more support to amd-xgbe
driver, from Thomas Lendacky.
14) Add MPLS support to openvswitch, from Simon Horman.
15) Support wildcard tunnel endpoints in ipv6 tunnels, from Steffen
Klassert.
16) Do gro flushes on a per-device basis using a timer, from Eric
Dumazet. This tries to resolve the conflicting goals between the
desired handling of bulk vs. RPC-like traffic.
17) Allow userspace to ask for the CPU upon what a packet was
received/steered, via SO_INCOMING_CPU. From Eric Dumazet.
18) Limit GSO packets to half the current congestion window, from Eric
Dumazet.
19) Add a generic helper so that all drivers set their RSS keys in a
consistent way, from Eric Dumazet.
20) Add xmit_more support to enic driver, from Govindarajulu
Varadarajan.
21) Add VLAN packet scheduler action, from Jiri Pirko.
22) Support configurable RSS hash functions via ethtool, from Eyal
Perry.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1820 commits)
Fix race condition between vxlan_sock_add and vxlan_sock_release
net/macb: fix compilation warning for print_hex_dump() called with skb->mac_header
net/mlx4: Add support for A0 steering
net/mlx4: Refactor QUERY_PORT
net/mlx4_core: Add explicit error message when rule doesn't meet configuration
net/mlx4: Add A0 hybrid steering
net/mlx4: Add mlx4_bitmap zone allocator
net/mlx4: Add a check if there are too many reserved QPs
net/mlx4: Change QP allocation scheme
net/mlx4_core: Use tasklet for user-space CQ completion events
net/mlx4_core: Mask out host side virtualization features for guests
net/mlx4_en: Set csum level for encapsulated packets
be2net: Export tunnel offloads only when a VxLAN tunnel is created
gianfar: Fix dma check map error when DMA_API_DEBUG is enabled
cxgb4/csiostor: Don't use MASTER_MUST for fw_hello call
net: fec: only enable mdio interrupt before phy device link up
net: fec: clear all interrupt events to support i.MX6SX
net: fec: reset fep link status in suspend function
net: sock: fix access via invalid file descriptor
net: introduce helper macro for_each_cmsghdr
...
As there are now no remaining users of arch_fast_hash(), lets kill
it entirely.
This basically reverts commit 71ae8aac3e ("lib: introduce arch
optimized hash library") and follow-up work, that is f.e., commit
237217546d ("lib: hash: follow-up fixups for arch hash"),
commit e3fec2f74f ("lib: Add missing arch generic-y entries for
asm-generic/hash.h") and last but not least commit 6a02652df5
("perf tools: Fix include for non x86 architectures").
Cc: Francesco Fusco <fusco@ntop.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull x86 MPX support from Thomas Gleixner:
"This enables support for x86 MPX.
MPX is a new debug feature for bound checking in user space. It
requires kernel support to handle the bound tables and decode the
bound violating instruction in the trap handler"
* 'x86-mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
asm-generic: Remove asm-generic arch_bprm_mm_init()
mm: Make arch_unmap()/bprm_mm_init() available to all architectures
x86: Cleanly separate use of asm-generic/mm_hooks.h
x86 mpx: Change return type of get_reg_offset()
fs: Do not include mpx.h in exec.c
x86, mpx: Add documentation on Intel MPX
x86, mpx: Cleanup unused bound tables
x86, mpx: On-demand kernel allocation of bounds tables
x86, mpx: Decode MPX instruction to get bound violation information
x86, mpx: Add MPX-specific mmap interface
x86, mpx: Introduce VM_MPX to indicate that a VMA is MPX specific
x86, mpx: Add MPX to disabled features
ia64: Sync struct siginfo with general version
mips: Sync struct siginfo with general version
mpx: Extend siginfo structure to include bound violation information
x86, mpx: Rename cfg_reg_u and status_reg
x86: mpx: Give bndX registers actual names
x86: Remove arbitrary instruction size limit in instruction decoder
The current x86 instruction decoder steps along through the
instruction stream but always ensures that it never steps farther
than the largest possible instruction size (MAX_INSN_SIZE).
The MPX code is now going to be doing some decoding of userspace
instructions. We copy those from userspace in to the kernel and
they're obviously completely untrusted coming from userspace. In
addition to the constraint that instructions can only be so long,
we also have to be aware of how long the buffer is that came in
from userspace. This _looks_ to be similar to what the perf and
kprobes is doing, but it's unclear to me whether they are
affected.
The whole reason we need this is that it is perfectly valid to be
executing an instruction within MAX_INSN_SIZE bytes of an
unreadable page. We should be able to gracefully handle short
reads in those cases.
This adds support to the decoder to record how long the buffer
being decoded is and to refuse to "validate" the instruction if
we would have gone over the end of the buffer to decode it.
The kprobes code probably needs to be looked at here a bit more
carefully. This patch still respects the MAX_INSN_SIZE limit
there but the kprobes code does look like it might be able to
be a bit more strict than it currently is.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: x86@kernel.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20141114153957.E6B01535@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Al Viro pointed out that the x86-64 csum_partial_copy_from_user() is
somewhat confused about what it should do on errors, notably it mostly
clears the uncopied end result buffer, but misses that for the initial
alignment case.
All users should check for errors, so it's dubious whether the clearing
is even necessary, and Al also points out that we should probably clean
up the calling conventions, but regardless of any future changes to this
function, the fact that it is inconsistent is just annoying.
So make the __get_user() failure path use the same error exit as all the
other errors do.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Miller <davem@davemloft.net>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 asm updates from Ingo Molnar:
"The changes in this cycle were:
- Speed up the x86 __preempt_schedule() implementation
- Fix/improve low level asm code debug info annotations"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Unwind-annotate thunk_32.S
x86: Improve cmpxchg8b_emu.S
x86: Improve cmpxchg16b_emu.S
x86/lib/Makefile: Remove the unnecessary "+= thunk_64.o"
x86: Speed up ___preempt_schedule*() by using THUNK helpers
- don't include unneeded headers
- drop redundant entry point label
- complete unwind annotations
- use .L prefix on local labels to not clutter the symbol table
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/5422917E0200007800038081@mail.emea.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
- don't include unneeded headers
- don't open-code PER_CPU_VAR()
- drop redundant entry point label
- complete unwind annotations
- use .L prefix on local label to not clutter the symbol table
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/542290BC020000780003807D@mail.emea.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Trivial. We have "lib-y += thunk_$(BITS).o" at the start, no
need to add thunk_64.o if !CONFIG_X86_32.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140921184232.GB23727@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
___preempt_schedule() does SAVE_ALL/RESTORE_ALL but this is
suboptimal, we do not need to save/restore the callee-saved
register. And we already have arch/x86/lib/thunk_*.S which
implements the similar asm wrappers, so it makes sense to
redefine ___preempt_schedule() as "THUNK ..." and remove
preempt.S altogether.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140921184153.GA23727@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch removes the unused asm/rwlock.h and rwlock.S files.
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1408037251-45918-3-git-send-email-Waiman.Long@hp.com
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Francesco Fusco <ffusco@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Graf <tgraf@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull more perf updates from Ingo Molnar:
"A second round of perf updates:
- wide reaching kprobes sanitization and robustization, with the hope
of fixing all 'probe this function crashes the kernel' bugs, by
Masami Hiramatsu.
- uprobes updates from Oleg Nesterov: tmpfs support, corner case
fixes and robustization work.
- perf tooling updates and fixes from Jiri Olsa, Namhyung Ki, Arnaldo
et al:
* Add support to accumulate hist periods (Namhyung Kim)
* various fixes, refactorings and enhancements"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits)
perf: Differentiate exec() and non-exec() comm events
perf: Fix perf_event_comm() vs. exec() assumption
uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates
perf/documentation: Add description for conditional branch filter
perf/x86: Add conditional branch filtering support
perf/tool: Add conditional branch filter 'cond' to perf record
perf: Add new conditional branch filter 'PERF_SAMPLE_BRANCH_COND'
uprobes: Teach copy_insn() to support tmpfs
uprobes: Shift ->readpage check from __copy_insn() to uprobe_register()
perf/x86: Use common PMU interrupt disabled code
perf/ARM: Use common PMU interrupt disabled code
perf: Disable sampled events if no PMU interrupt
perf: Fix use after free in perf_remove_from_context()
perf tools: Fix 'make help' message error
perf record: Fix poll return value propagation
perf tools: Move elide bool into perf_hpp_fmt struct
perf tools: Remove elide setup for SORT_MODE__MEMORY mode
perf tools: Fix "==" into "=" in ui_browser__warning assignment
perf tools: Allow overriding sysfs and proc finding with env var
perf tools: Consider header files outside perf directory in tags target
...
Carve out early cmdline parsing function into .../lib/cmdline.c so it
can be used by early code in the kernel proper as well.
Adapted from arch/x86/boot/cmdline.c.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1400525957-11525-2-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Due to a typo the msr accessor function introduced in
22085a66c2 didn't have any lasting
effects because they accidentally wrote the old value back.
After c0a639ad0b this at the very least
this causes cpuid limits not to be lifted on some cpus leading to
missing capabilities for those.
Signed-off-by: Andres Freund <andres@anarazel.de>
Link: http://lkml.kernel.org/r/1399598957-7011-2-git-send-email-andres@anarazel.de
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
thunk/restore functions are also used for tracing irqoff etc.
and those are involved in kprobe's exception handling.
Prohibit probing on them to avoid kernel crash.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20140417081726.26341.3872.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 LTO changes from Peter Anvin:
"More infrastructure work in preparation for link-time optimization
(LTO). Most of these changes is to make sure symbols accessed from
assembly code are properly marked as visible so the linker doesn't
remove them.
My understanding is that the changes to support LTO are still not
upstream in binutils, but are on the way there. This patchset should
conclude the x86-specific changes, and remaining patches to actually
enable LTO will be fed through the Kbuild tree (other than keeping up
with changes to the x86 code base, of course), although not
necessarily in this merge window"
* 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
Kbuild, lto: Handle basic LTO in modpost
Kbuild, lto: Disable LTO for asm-offsets.c
Kbuild, lto: Add a gcc-ld script to let run gcc as ld
Kbuild, lto: add ld-version and ld-ifversion macros
Kbuild, lto: Drop .number postfixes in modpost
Kbuild, lto, workaround: Don't warn for initcall_reference in modpost
lto: Disable LTO for sys_ni
lto: Handle LTO common symbols in module loader
lto, workaround: Add workaround for initcall reordering
lto: Make asmlinkage __visible
x86, lto: Disable LTO for the x86 VDSO
initconst, x86: Fix initconst mistake in ts5500 code
initconst: Fix initconst mistake in dcdbas
asmlinkage: Make trace_hardirqs_on/off_caller visible
asmlinkage, x86: Fix 32bit memcpy for LTO
asmlinkage Make __stack_chk_failed and memcmp visible
asmlinkage: Mark rwsem functions that can be called from assembler asmlinkage
asmlinkage: Make main_extable_sort_needed visible
asmlinkage, mutex: Mark __visible
asmlinkage: Make trace_hardirq visible
...
Pull x86 hashing changes from Ingo Molnar:
"Small fixes and cleanups to the librarized arch_fast_hash() methods,
used by the net/openvswitch code"
* 'x86-hash-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, hash: Simplify switch, add __init annotation
x86, hash: Swap arguments passed to crc32_u32()
x86, hash: Fix build failure with older binutils
Minor cleanups:
- simplify switch statement
- add __init annotation to setup_arch_fast_hash()
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/530F09CE020000780011FBEF@nat28.tlf.novell.com
Cc: Francesco Fusco <ffusco@redhat.com>
Cc: Thomas Graf <tgraf@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
... to match the function's parameters. While reportedly commutative,
using the proper order allows for leveraging the instruction permitting
the source operand to be in memory.
[ hpa: This code originated in the dpdk toolkit. This was a bug in dpdk
which has recently been fixed in part due to an earlier version of
this patch. ]
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/530F09B6020000780011FBEB@nat28.tlf.novell.com
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Francesco Fusco <ffusco@redhat.com>
Cc: Thomas Graf <tgraf@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Just like for other ISA extension instruction uses we should check
whether the assembler actually supports them. The fallback here simply
is to encode an instruction with fixed operands (%eax and %ecx).
[ hpa: tagging for -stable as a build fix ]
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/530F0996020000780011FBE7@nat28.tlf.novell.com
Cc: Francesco Fusco <ffusco@redhat.com>
Cc: Thomas Graf <tgraf@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.14
We very often need to set or clear a bit in an MSR as a result of doing
some sort of a hardware configuration. Add generic versions of that
repeated functionality in order to save us a bunch of duplicated code in
the early CPU vendor detection/config code.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1394384725-10796-2-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull networking updates from David Miller:
1) BPF debugger and asm tool by Daniel Borkmann.
2) Speed up create/bind in AF_PACKET, also from Daniel Borkmann.
3) Correct reciprocal_divide and update users, from Hannes Frederic
Sowa and Daniel Borkmann.
4) Currently we only have a "set" operation for the hw timestamp socket
ioctl, add a "get" operation to match. From Ben Hutchings.
5) Add better trace events for debugging driver datapath problems, also
from Ben Hutchings.
6) Implement auto corking in TCP, from Eric Dumazet. Basically, if we
have a small send and a previous packet is already in the qdisc or
device queue, defer until TX completion or we get more data.
7) Allow userspace to manage ipv6 temporary addresses, from Jiri Pirko.
8) Add a qdisc bypass option for AF_PACKET sockets, from Daniel
Borkmann.
9) Share IP header compression code between Bluetooth and IEEE802154
layers, from Jukka Rissanen.
10) Fix ipv6 router reachability probing, from Jiri Benc.
11) Allow packets to be captured on macvtap devices, from Vlad Yasevich.
12) Support tunneling in GRO layer, from Jerry Chu.
13) Allow bonding to be configured fully using netlink, from Scott
Feldman.
14) Allow AF_PACKET users to obtain the VLAN TPID, just like they can
already get the TCI. From Atzm Watanabe.
15) New "Heavy Hitter" qdisc, from Terry Lam.
16) Significantly improve the IPSEC support in pktgen, from Fan Du.
17) Allow ipv4 tunnels to cache routes, just like sockets. From Tom
Herbert.
18) Add Proportional Integral Enhanced packet scheduler, from Vijay
Subramanian.
19) Allow openvswitch to mmap'd netlink, from Thomas Graf.
20) Key TCP metrics blobs also by source address, not just destination
address. From Christoph Paasch.
21) Support 10G in generic phylib. From Andy Fleming.
22) Try to short-circuit GRO flow compares using device provided RX
hash, if provided. From Tom Herbert.
The wireless and netfilter folks have been busy little bees too.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2064 commits)
net/cxgb4: Fix referencing freed adapter
ipv6: reallocate addrconf router for ipv6 address when lo device up
fib_frontend: fix possible NULL pointer dereference
rtnetlink: remove IFLA_BOND_SLAVE definition
rtnetlink: remove check for fill_slave_info in rtnl_have_link_slave_info
qlcnic: update version to 5.3.55
qlcnic: Enhance logic to calculate msix vectors.
qlcnic: Refactor interrupt coalescing code for all adapters.
qlcnic: Update poll controller code path
qlcnic: Interrupt code cleanup
qlcnic: Enhance Tx timeout debugging.
qlcnic: Use bool for rx_mac_learn.
bonding: fix u64 division
rtnetlink: add missing IFLA_BOND_AD_INFO_UNSPEC
sfc: Use the correct maximum TX DMA ring size for SFC9100
Add Shradha Shah as the sfc driver maintainer.
net/vxlan: Share RX skb de-marking and checksum checks with ovs
tulip: cleanup by using ARRAY_SIZE()
ip_tunnel: clear IPCB in ip_tunnel_xmit() in case dst_link_failure() is called
net/cxgb4: Don't retrieve stats during recovery
...
Pull x86 cpufeature and mpx updates from Peter Anvin:
"This includes the basic infrastructure for MPX (Memory Protection
Extensions) support, but does not include MPX support itself. It is,
however, a prerequisite for KVM support for MPX, which I believe will
be pushed later this merge window by the KVM team.
This includes moving the functionality in
futex_atomic_cmpxchg_inatomic() into a new function in uaccess.h so it
can be reused - this will be used by the final MPX patches.
The actual MPX functionality (map management and so on) will be pushed
in a future merge window, when ready"
* 'x86/mpx' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/intel/mpx: Remove unused LWP structure
x86, mpx: Add MPX related opcodes to the x86 opcode map
x86: replace futex_atomic_cmpxchg_inatomic() with user_atomic_cmpxchg_inatomic
x86: add user_atomic_cmpxchg_inatomic at uaccess.h
x86, xsave: Support eager-only xsave features, add MPX support
x86, cpufeature: Define the Intel MPX feature flag
Pull x86 cleanups from Ingo Molnar:
"Misc cleanups"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, cpu, amd: Fix a shadowed variable situation
um, x86: Fix vDSO build
x86: Delete non-required instances of include <linux/init.h>
x86, realmode: Pointer walk cleanups, pull out invariant use of __pa()
x86/traps: Clean up error exception handler definitions
This patch adds all the MPX instructions to x86 opcode map, so the x86
instruction decoder can decode MPX instructions.
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Link: http://lkml.kernel.org/r/1389518403-7715-4-git-send-email-qiaowei.ren@intel.com
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
[ hpa: undid incorrect removal from arch/x86/kernel/head_32.S ]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Link: http://lkml.kernel.org/r/1389054026-12947-1-git-send-email-paul.gortmaker@windriver.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
We introduce a new hashing library that is meant to be used in
the contexts where speed is more important than uniformity of the
hashed values. The hash library leverages architecture specific
implementation to achieve high performance and fall backs to
jhash() for the generic case.
On Intel-based x86 architectures, the library can exploit the crc32l
instruction, part of the Intel SSE4.2 instruction set, if the
instruction is supported by the processor. This implementation
is twice as fast as the jhash() implementation on an i7 processor.
Additional architectures, such as Arm64 provide instructions for
accelerating the computation of CRC, so they could be added as well
in follow-up work.
Signed-off-by: Francesco Fusco <ffusco@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Thomas Graf <tgraf@redhat.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
When we are using lea to produce a 32-bit result, we can use the leal
form, rather than using leaq and worry about truncation elsewhere.
Make the leal explicit, both to be more obvious and since that is what
gcc generates and thus is less likely to trigger obscure gas bugs.
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1384634221-6006-1-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Operation of rep movsb instruction handles zero byte copy. As pointed out by
Linus, there is no need to check zero size in kernel. Removing this redundant
check saves a few cycles in copy user functions.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1384634221-6006-1-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
- New power capping framework and the the Intel Running Average Power
Limit (RAPL) driver using it from Srinivas Pandruvada and Jacob Pan.
- Addition of the in-kernel switching feature to the arm_big_little
cpufreq driver from Viresh Kumar and Nicolas Pitre.
- cpufreq support for iMac G5 from Aaro Koskinen.
- Baytrail processors support for intel_pstate from Dirk Brandewie.
- cpufreq support for Midway/ECX-2000 from Mark Langsdorf.
- ARM vexpress/TC2 cpufreq support from Sudeep KarkadaNagesha.
- ACPI power management support for the I2C and SPI bus types from
Mika Westerberg and Lv Zheng.
- cpufreq core fixes and cleanups from Viresh Kumar, Srivatsa S Bhat,
Stratos Karafotis, Xiaoguang Chen, Lan Tianyu.
- cpufreq drivers updates (mostly fixes and cleanups) from Viresh Kumar,
Aaro Koskinen, Jungseok Lee, Sudeep KarkadaNagesha, Lukasz Majewski,
Manish Badarkhe, Hans-Christian Egtvedt, Evgeny Kapaev.
- intel_pstate updates from Dirk Brandewie and Adrian Huang.
- ACPICA update to version 20130927 includig fixes and cleanups and
some reduction of divergences between the ACPICA code in the kernel
and ACPICA upstream in order to improve the automatic ACPICA patch
generation process. From Bob Moore, Lv Zheng, Tomasz Nowicki,
Naresh Bhat, Bjorn Helgaas, David E Box.
- ACPI IPMI driver fixes and cleanups from Lv Zheng.
- ACPI hotplug fixes and cleanups from Bjorn Helgaas, Toshi Kani,
Zhang Yanfei, Rafael J Wysocki.
- Conversion of the ACPI AC driver to the platform bus type and
multiple driver fixes and cleanups related to ACPI from Zhang Rui.
- ACPI processor driver fixes and cleanups from Hanjun Guo, Jiang Liu,
Bartlomiej Zolnierkiewicz, Mathieu Rhéaume, Rafael J Wysocki.
- Fixes and cleanups and new blacklist entries related to the ACPI
video support from Aaron Lu, Felipe Contreras, Lennart Poettering,
Kirill Tkhai.
- cpuidle core cleanups from Viresh Kumar and Lorenzo Pieralisi.
- cpuidle drivers fixes and cleanups from Daniel Lezcano, Jingoo Han,
Bartlomiej Zolnierkiewicz, Prarit Bhargava.
- devfreq updates from Sachin Kamat, Dan Carpenter, Manish Badarkhe.
- Operation Performance Points (OPP) core updates from Nishanth Menon.
- Runtime power management core fix from Rafael J Wysocki and update
from Ulf Hansson.
- Hibernation fixes from Aaron Lu and Rafael J Wysocki.
- Device suspend/resume lockup detection mechanism from Benoit Goby.
- Removal of unused proc directories created for various ACPI drivers
from Lan Tianyu.
- ACPI LPSS driver fix and new device IDs for the ACPI platform scan
handler from Heikki Krogerus and Jarkko Nikula.
- New ACPI _OSI blacklist entry for Toshiba NB100 from Levente Kurusa.
- Assorted fixes and cleanups related to ACPI from Andy Shevchenko,
Al Stone, Bartlomiej Zolnierkiewicz, Colin Ian King, Dan Carpenter,
Felipe Contreras, Jianguo Wu, Lan Tianyu, Yinghai Lu, Mathias Krause,
Liu Chuansheng.
- Assorted PM fixes and cleanups from Andy Shevchenko, Thierry Reding,
Jean-Christophe Plagniol-Villard.
/
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (GNU/Linux)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=JCxk
-----END PGP SIGNATURE-----
Merge tag 'pm+acpi-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management updates from Rafael J Wysocki:
- New power capping framework and the the Intel Running Average Power
Limit (RAPL) driver using it from Srinivas Pandruvada and Jacob Pan.
- Addition of the in-kernel switching feature to the arm_big_little
cpufreq driver from Viresh Kumar and Nicolas Pitre.
- cpufreq support for iMac G5 from Aaro Koskinen.
- Baytrail processors support for intel_pstate from Dirk Brandewie.
- cpufreq support for Midway/ECX-2000 from Mark Langsdorf.
- ARM vexpress/TC2 cpufreq support from Sudeep KarkadaNagesha.
- ACPI power management support for the I2C and SPI bus types from Mika
Westerberg and Lv Zheng.
- cpufreq core fixes and cleanups from Viresh Kumar, Srivatsa S Bhat,
Stratos Karafotis, Xiaoguang Chen, Lan Tianyu.
- cpufreq drivers updates (mostly fixes and cleanups) from Viresh
Kumar, Aaro Koskinen, Jungseok Lee, Sudeep KarkadaNagesha, Lukasz
Majewski, Manish Badarkhe, Hans-Christian Egtvedt, Evgeny Kapaev.
- intel_pstate updates from Dirk Brandewie and Adrian Huang.
- ACPICA update to version 20130927 includig fixes and cleanups and
some reduction of divergences between the ACPICA code in the kernel
and ACPICA upstream in order to improve the automatic ACPICA patch
generation process. From Bob Moore, Lv Zheng, Tomasz Nowicki, Naresh
Bhat, Bjorn Helgaas, David E Box.
- ACPI IPMI driver fixes and cleanups from Lv Zheng.
- ACPI hotplug fixes and cleanups from Bjorn Helgaas, Toshi Kani, Zhang
Yanfei, Rafael J Wysocki.
- Conversion of the ACPI AC driver to the platform bus type and
multiple driver fixes and cleanups related to ACPI from Zhang Rui.
- ACPI processor driver fixes and cleanups from Hanjun Guo, Jiang Liu,
Bartlomiej Zolnierkiewicz, Mathieu Rhéaume, Rafael J Wysocki.
- Fixes and cleanups and new blacklist entries related to the ACPI
video support from Aaron Lu, Felipe Contreras, Lennart Poettering,
Kirill Tkhai.
- cpuidle core cleanups from Viresh Kumar and Lorenzo Pieralisi.
- cpuidle drivers fixes and cleanups from Daniel Lezcano, Jingoo Han,
Bartlomiej Zolnierkiewicz, Prarit Bhargava.
- devfreq updates from Sachin Kamat, Dan Carpenter, Manish Badarkhe.
- Operation Performance Points (OPP) core updates from Nishanth Menon.
- Runtime power management core fix from Rafael J Wysocki and update
from Ulf Hansson.
- Hibernation fixes from Aaron Lu and Rafael J Wysocki.
- Device suspend/resume lockup detection mechanism from Benoit Goby.
- Removal of unused proc directories created for various ACPI drivers
from Lan Tianyu.
- ACPI LPSS driver fix and new device IDs for the ACPI platform scan
handler from Heikki Krogerus and Jarkko Nikula.
- New ACPI _OSI blacklist entry for Toshiba NB100 from Levente Kurusa.
- Assorted fixes and cleanups related to ACPI from Andy Shevchenko, Al
Stone, Bartlomiej Zolnierkiewicz, Colin Ian King, Dan Carpenter,
Felipe Contreras, Jianguo Wu, Lan Tianyu, Yinghai Lu, Mathias Krause,
Liu Chuansheng.
- Assorted PM fixes and cleanups from Andy Shevchenko, Thierry Reding,
Jean-Christophe Plagniol-Villard.
* tag 'pm+acpi-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (386 commits)
cpufreq: conservative: fix requested_freq reduction issue
ACPI / hotplug: Consolidate deferred execution of ACPI hotplug routines
PM / runtime: Use pm_runtime_put_sync() in __device_release_driver()
ACPI / event: remove unneeded NULL pointer check
Revert "ACPI / video: Ignore BIOS initial backlight value for HP 250 G1"
ACPI / video: Quirk initial backlight level 0
ACPI / video: Fix initial level validity test
intel_pstate: skip the driver if ACPI has power mgmt option
PM / hibernate: Avoid overflow in hibernate_preallocate_memory()
ACPI / hotplug: Do not execute "insert in progress" _OST
ACPI / hotplug: Carry out PCI root eject directly
ACPI / hotplug: Merge device hot-removal routines
ACPI / hotplug: Make acpi_bus_hot_remove_device() internal
ACPI / hotplug: Simplify device ejection routines
ACPI / hotplug: Fix handle_root_bridge_removal()
ACPI / hotplug: Refuse to hot-remove all objects with disabled hotplug
ACPI / scan: Start matching drivers after trying scan handlers
ACPI: Remove acpi_pci_slot_init() headers from internal.h
ACPI / blacklist: fix name of ThinkPad Edge E530
PowerCap: Fix build error with option -Werror=format-security
...
Conflicts:
arch/arm/mach-omap2/opp.c
drivers/Kconfig
drivers/spi/spi.c
Pull x86 user access changes from Ingo Molnar:
"This tree contains two copy_[from/to]_user() build time checking
changes/enhancements from Jan Beulich.
The desired outcome is to get better compiler warnings with
CONFIG_DEBUG_STRICT_USER_COPY_CHECKS=y, to keep people from
introducing bugs such as overflows and information leaks"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Unify copy_to_user() and add size checking to it
x86: Unify copy_from_user() size checking
The arch_perf_output_copy_user() default of
__copy_from_user_inatomic() returns bytes not copied, while all other
argument functions given DEFINE_OUTPUT_COPY() return bytes copied.
Since copy_from_user_nmi() is the odd duck out by returning bytes
copied where all other *copy_{to,from}* functions return bytes not
copied, change it over and ammend DEFINE_OUTPUT_COPY() to expect bytes
not copied.
Oddly enough DEFINE_OUTPUT_COPY() already returned bytes not copied
while expecting its worker functions to return bytes copied.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: will.deacon@arm.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20131030201622.GR16117@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that we can deal with nested NMI due to IRET re-enabling NMIs and
can deal with faults from NMI by making sure we preserve CR2 over NMIs
we can in fact simply access user-space memory from NMI context.
So rewrite copy_from_user_nmi() to use __copy_from_user_inatomic() and
rework the fault path to do the minimal required work before taking
the in_atomic() fault handler.
In particular avoid perf_sw_event() which would make perf recurse on
itself (it should be harmless as our recursion protections should be
able to deal with this -- but why tempt fate).
Also rename notify_page_fault() to kprobes_fault() as that is a much
better name; there is no notifier in it and its specific to kprobes.
Don measured that his worst case NMI path shrunk from ~300K cycles to
~150K cycles.
Cc: Stephane Eranian <eranian@google.com>
Cc: jmario@redhat.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: dave.hansen@linux.intel.com
Tested-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131024105206.GM2490@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Similarly to copy_from_user(), where the range check is to
protect against kernel memory corruption, copy_to_user() can
benefit from such checking too: Here it protects against kernel
information leaks.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/5265059502000078000FC4F6@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Commits 4a31276930 ("x86: Turn the
copy_from_user check into an (optional) compile time warning")
and 63312b6a6f ("x86: Add a
Kconfig option to turn the copy_from_user warnings into errors")
touched only the 32-bit variant of copy_from_user(), whereas the
original commit 9f0cf4adb6 ("x86:
Use __builtin_object_size() to validate the buffer size for
copy_from_user()") also added the same code to the 64-bit one.
Further the earlier conversion from an inline WARN() to the call
to copy_from_user_overflow() went a little too far: When the
number of bytes to be copied is not a constant (e.g. [looking at
3.11] in drivers/net/tun.c:__tun_chr_ioctl() or
drivers/pci/pcie/aer/aer_inject.c:aer_inject_write()), the
compiler will always have to keep the funtion call, and hence
there will always be a warning. By using __builtin_constant_p()
we can avoid this.
And then this slightly extends the effect of
CONFIG_DEBUG_STRICT_USER_COPY_CHECKS in that apart from
converting warnings to errors in the constant size case, it
retains the (possibly wrong) warnings in the non-constant size
case, such that if someone is prepared to get a few false
positives, (s)he'll be able to recover the current behavior
(except that these diagnostics now will never be converted to
errors).
Since the 32-bit variant (intentionally) didn't call
might_fault(), the unification results in this being called
twice now. Adding a suitable #ifdef would be the alternative if
that's a problem.
I'd like to point out though that with
__compiletime_object_size() being restricted to gcc before 4.6,
the whole construct is going to become more and more pointless
going forward. I would question however that commit
2fb0815c9e ("gcc4: disable
__compiletime_object_size for GCC 4.6+") was really necessary,
and instead this should have been dealt with as is done here
from the beginning.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/5265056D02000078000FC4F3@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Having 64-bit MSR access methods on given CPU can avoid shifting and
simplify MSR content manipulation. We already have other combinations
of rdmsrl_xxx and wrmsrl_xxx but missing the _on_cpu version.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
