Commit Graph

208 Commits

Author SHA1 Message Date
Masami Hiramatsu 53a019a951 x86: Fix insn decoder for longer instruction
Fix x86 insn decoder for hardening against invalid length
instructions. This adds length checkings for each byte-read
site and if it exceeds MAX_INSN_SIZE, returns immediately.
This can happen when decoding user-space binary.

Caller can check whether it happened by checking insn.*.got
member is set or not.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: acme@redhat.com
Cc: ming.m.lin@intel.com
Cc: robert.richter@amd.com
Cc: ravitillo@lbl.gov
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20111007133155.10933.58577.stgit@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-10 09:05:51 +02:00
Arun Sharma 60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:47 -07:00
Linus Torvalds 8e204874db Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-64, vdso: Do not allocate memory for the vDSO
  clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option
  x86, vdso: Drop now wrong comment
  Document the vDSO and add a reference parser
  ia64: Replace clocksource.fsys_mmio with generic arch data
  x86-64: Move vread_tsc and vread_hpet into the vDSO
  clocksource: Replace vread with generic arch data
  x86-64: Add --no-undefined to vDSO build
  x86-64: Allow alternative patching in the vDSO
  x86: Make alternative instruction pointers relative
  x86-64: Improve vsyscall emulation CS and RIP handling
  x86-64: Emulate legacy vsyscalls
  x86-64: Fill unused parts of the vsyscall page with 0xcc
  x86-64: Remove vsyscall number 3 (venosys)
  x86-64: Map the HPET NX
  x86-64: Remove kernel.vsyscall64 sysctl
  x86-64: Give vvars their own page
  x86-64: Document some of entry_64.S
  x86-64: Fix alignment of jiffies variable
2011-07-22 17:05:15 -07:00
Linus Torvalds eb47418dc5 Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix write lock scalability 64-bit issue
  x86: Unify rwsem assembly implementation
  x86: Unify rwlock assembly implementation
  x86, asm: Fix binutils 2.16 issue with __USER32_CS
  x86, asm: Cleanup thunk_64.S
  x86, asm: Flip RESTORE_ARGS arguments logic
  x86, asm: Flip SAVE_ARGS arguments logic
  x86, asm: Thin down SAVE/RESTORE_* asm macros
2011-07-22 17:02:24 -07:00
Robert Richter 1ac2e6ca44 x86, perf: Make copy_from_user_nmi() a library function
copy_from_user_nmi() is used in oprofile and perf. Moving it to other
library functions like copy_from_user(). As this is x86 code for 32
and 64 bits, create a new file usercopy.c for unified code.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110607172413.GJ20052@erda.amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 20:41:57 +02:00
Jan Beulich a750036f35 x86: Fix write lock scalability 64-bit issue
With the write lock path simply subtracting RW_LOCK_BIAS there
is, on large systems, the theoretical possibility of overflowing
the 32-bit value that was used so far (namely if 128 or more
CPUs manage to do the subtraction, but don't get to do the
inverse addition in the failure path quickly enough).

A first measure is to modify RW_LOCK_BIAS itself - with the new
value chosen, it is good for up to 2048 CPUs each allowed to
nest over 2048 times on the read path without causing an issue.
Quite possibly it would even be sufficient to adjust the bias a
little further, assuming that allowing for significantly less
nesting would suffice.

However, as the original value chosen allowed for even more
nesting levels, to support more than 2048 CPUs (possible
currently only for 64-bit kernels) the lock itself gets widened
to 64 bits.

Signed-off-by: Jan Beulich <jbeulich@novell.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/4E258E0D020000780004E3F0@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 09:03:36 +02:00
Jan Beulich a738669464 x86: Unify rwsem assembly implementation
Rather than having two functionally identical implementations
for 32- and 64-bit configurations, use the previously extended
assembly abstractions to fold the rwsem two implementations into
a shared one.

Signed-off-by: Jan Beulich <jbeulich@novell.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/4E258DF3020000780004E3ED@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 09:03:32 +02:00
Jan Beulich 4625cd6379 x86: Unify rwlock assembly implementation
Rather than having two functionally identical implementations
for 32- and 64-bit configurations, extend the existing assembly
abstractions enough to fold the two rwlock implementations into
a shared one.

Signed-off-by: Jan Beulich <jbeulich@novell.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/4E258DD7020000780004E3EA@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 09:03:31 +02:00
Andy Lutomirski 59e97e4d6f x86: Make alternative instruction pointers relative
This save a few bytes on x86-64 and means that future patches can
apply alternatives to unrelocated code.

Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/ff64a6b9a1a3860ca4a7b8b6dc7b4754f9491cd7.1310563276.git.luto@mit.edu
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-07-13 11:22:56 -07:00
Borislav Petkov 38e6b75d3b x86, asm: Cleanup thunk_64.S
Drop thunk_ra macro in favor of an additional argument to the thunk
macro since their bodies are almost identical. Do a whitespace scrubbing
and use CFI-aware macros for full annotation.

Signed-off-by: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/1306873314-32523-5-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-06-03 14:38:55 -07:00
Linus Torvalds 17b141803c Merge branches 'x86-apic-for-linus', 'x86-asm-for-linus' and 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, apic: Print verbose error interrupt reason on apic=debug

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Demacro CONFIG_PARAVIRT cpu accessors

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix mrst sparse complaints
  x86: Fix spelling error in the memcpy() source code comment
  x86, mpparse: Remove unnecessary variable
2011-05-19 17:49:35 -07:00
Jiri Olsa 26afb7c661 x86, 64-bit: Fix copy_[to/from]_user() checks for the userspace address limit
As reported in BZ #30352:

  https://bugzilla.kernel.org/show_bug.cgi?id=30352

there's a kernel bug related to reading the last allowed page on x86_64.

The _copy_to_user() and _copy_from_user() functions use the following
check for address limit:

  if (buf + size >= limit)
	fail();

while it should be more permissive:

  if (buf + size > limit)
	fail();

That's because the size represents the number of bytes being
read/write from/to buf address AND including the buf address.
So the copy function will actually never touch the limit
address even if "buf + size == limit".

Following program fails to use the last page as buffer
due to the wrong limit check:

 #include <sys/mman.h>
 #include <sys/socket.h>
 #include <assert.h>

 #define PAGE_SIZE       (4096)
 #define LAST_PAGE       ((void*)(0x7fffffffe000))

 int main()
 {
        int fds[2], err;
        void * ptr = mmap(LAST_PAGE, PAGE_SIZE, PROT_READ | PROT_WRITE,
                          MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
        assert(ptr == LAST_PAGE);
        err = socketpair(AF_LOCAL, SOCK_STREAM, 0, fds);
        assert(err == 0);
        err = send(fds[0], ptr, PAGE_SIZE, 0);
        perror("send");
        assert(err == PAGE_SIZE);
        err = recv(fds[1], ptr, PAGE_SIZE, MSG_WAITALL);
        perror("recv");
        assert(err == PAGE_SIZE);
        return 0;
 }

The other place checking the addr limit is the access_ok() function,
which is working properly. There's just a misleading comment
for the __range_not_ok() macro - which this patch fixes as well.

The last page of the user-space address range is a guard page and
Brian Gerst observed that the guard page itself due to an erratum on K8 cpus
(#121 Sequential Execution Across Non-Canonical Boundary Causes Processor
Hang).

However, the test code is using the last valid page before the guard page.
The bug is that the last byte before the guard page can't be read
because of the off-by-one error. The guard page is left in place.

This bug would normally not show up because the last page is
part of the process stack and never accessed via syscalls.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/1305210630-7136-1-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-18 12:49:00 +02:00
Fenghua Yu 2f19e06ac3 x86, mem: memset_64.S: Optimize memset by enhanced REP MOVSB/STOSB
Support memset() with enhanced rep stosb. On processors supporting enhanced
REP MOVSB/STOSB, the alternative memset_c_e function using enhanced rep stosb
overrides the fast string alternative memset_c and the original function.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1305671358-14478-10-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-17 15:40:31 -07:00
Fenghua Yu 057e05c1d6 x86, mem: memmove_64.S: Optimize memmove by enhanced REP MOVSB/STOSB
Support memmove() by enhanced rep movsb. On processors supporting enhanced
REP MOVSB/STOSB, the alternative memmove() function using enhanced rep movsb
overrides the original function.

The patch doesn't change the backward memmove case to use enhanced rep
movsb.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1305671358-14478-9-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-17 15:40:30 -07:00
Fenghua Yu 101068c1f4 x86, mem: memcpy_64.S: Optimize memcpy by enhanced REP MOVSB/STOSB
Support memcpy() with enhanced rep movsb. On processors supporting enhanced
rep movsb, the alternative memcpy() function using enhanced rep movsb overrides the original function and the fast string
function.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1305671358-14478-8-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-17 15:40:29 -07:00
Fenghua Yu 4307bec934 x86, mem: copy_user_64.S: Support copy_to/from_user by enhanced REP MOVSB/STOSB
Support copy_to_user/copy_from_user() by enhanced REP MOVSB/STOSB.
On processors supporting enhanced REP MOVSB/STOSB, the alternative
copy_user_enhanced_fast_string function using enhanced rep movsb overrides the
original function and the fast string function.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1305671358-14478-7-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-17 15:40:28 -07:00
Fenghua Yu e365c9df2f x86, mem: clear_page_64.S: Support clear_page() with enhanced REP MOVSB/STOSB
Intel processors are adding enhancements to REP MOVSB/STOSB and the use of
REP MOVSB/STOSB for optimal memcpy/memset or similar functions is recommended.
Enhancement availability is indicated by CPUID.7.0.EBX[9] (Enhanced REP MOVSB/
STOSB).

Support clear_page() with rep stosb for processor supporting enhanced REP MOVSB
/STOSB. On processors supporting enhanced REP MOVSB/STOSB, the alternative
clear_page_c_e function using enhanced REP STOSB overrides the original function
and the fast string function.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1305671358-14478-6-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-17 15:40:27 -07:00
Ingo Molnar 4cb1f43ce8 Merge commit 'v2.6.39-rc6' into x86/cleanups
Merge reason: move to a (much) newer upstream base.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-07 10:51:48 +02:00
Bart Van Assche 9de4966a4d x86: Fix spelling error in the memcpy() source code comment
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: http://lkml.kernel.org/r/201105011409.21629.bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-01 19:16:18 +02:00
Christoph Lameter d7c3f8cee8 percpu: Omit segment prefix in the UP case for cmpxchg_double
Omit the segment prefix in the UP case. GS is not used then
and we will generate segfaults if cmpxchg16b is used otherwise.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-27 19:25:36 -07:00
Linus Torvalds f2e1fbb5f2 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Flush TLB if PGD entry is changed in i386 PAE mode
  x86, dumpstack: Correct stack dump info when frame pointer is available
  x86: Clean up csum-copy_64.S a bit
  x86: Fix common misspellings
  x86: Fix misspelling and align params
  x86: Use PentiumPro-optimized partial_csum() on VIA C7
2011-03-18 10:45:21 -07:00
Ingo Molnar 2c76397bdd x86: Clean up csum-copy_64.S a bit
The many stray whitespaces and other uncleanlinesses made this code
almost unreadable to me - so fix those.

No changes to the code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18 10:44:26 +01:00
Lucas De Marchi 0d2eb44f63 x86: Fix common misspellings
They were generated by 'codespell' and then manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: trivial@kernel.org
LKML-Reference: <1300389856-1099-3-git-send-email-lucas.demarchi@profusion.mobi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18 10:39:30 +01:00
Linus Torvalds 79d8a8f736 Merge branch 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* '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")
2011-03-16 08:22:41 -07:00
Linus Torvalds d5d42399bd Merge branch 'x86-mem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-mem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-64, mem: Convert memmove() to assembly file and fix return value bug
2011-03-15 19:41:42 -07:00
Jan Beulich e938c287ea x86: Fix a bogus unwind annotation in lib/semaphore_32.S
'simple' would have required specifying current frame address
and return address location manually, but that's obviously not
the case (and not necessary) here.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4D6D1082020000780003454C@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-02 08:16:44 +01:00
Jan Beulich 039e13890b x86: Remove unused bits from lib/thunk_*.S
Some of the items removed were apparently never used, others
simply didn't get removed with their last user.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4D6BD3A002000078000341F1@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-28 18:06:22 +01:00
Jan Beulich 60cf637a13 x86: Use {push,pop}_cfi in more places
Cleaning up and shortening code...

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Alexander van Heukelum <heukelum@fastmail.fm>
LKML-Reference: <4D6BD35002000078000341DA@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-28 18:06:22 +01:00
Jan Beulich 39f2205e1a x86-64: Add CFI annotations to lib/rwsem_64.S
These weren't part of the initial commit of this code.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Alexander van Heukelum <heukelum@fastmail.fm>
LKML-Reference: <4D6BCDFF02000078000341B0@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-28 18:06:21 +01:00
Christoph Lameter b9ec40af0e percpu, x86: Add arch-specific this_cpu_cmpxchg_double() support
Support this_cpu_cmpxchg_double() using the cmpxchg16b and cmpxchg8b
instructions.

-tj: s/percpu_cmpxchg16b/percpu_cmpxchg16b_double/ for consistency and
     other cosmetic changes.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2011-02-28 11:20:49 +01:00
Fenghua Yu 9599ec0471 x86-64, mem: Convert memmove() to assembly file and fix return value bug
memmove_64.c only implements memmove() function which is completely written in
inline assembly code. Therefore it doesn't make sense to keep the assembly code
in .c file.

Currently memmove() doesn't store return value to rax. This may cause issue if
caller uses the return value. The patch fixes this issue.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
LKML-Reference: <1295314755-6625-1-git-send-email-fenghua.yu@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-01-25 16:58:39 -08:00
Christoph Lameter 357089fca9 x86: udelay: Use this_cpu_read to avoid address calculation
The code will use a segment prefix instead of doing the lookup and
calculation.

Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2011-01-04 06:08:55 +01:00
Ma Ling 3b4b682bec x86, mem: Optimize memmove for small size and unaligned cases
movs instruction will combine data to accelerate moving data,
however we need to concern two cases about it.

1. movs instruction need long lantency to startup,
   so here we use general mov instruction to copy data.
2. movs instruction is not good for unaligned case,
   even if src offset is 0x10, dest offset is 0x0,
   we avoid and handle the case by general mov instruction.

Signed-off-by: Ma Ling <ling.ma@intel.com>
LKML-Reference: <1284664360-6138-1-git-send-email-ling.ma@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-09-24 18:57:11 -07:00
Ma Ling 59daa706fb x86, mem: Optimize memcpy by avoiding memory false dependece
All read operations after allocation stage can run speculatively,
all write operation will run in program order, and if addresses are
different read may run before older write operation, otherwise wait
until write commit. However CPU don't check each address bit,
so read could fail to recognize different address even they
are in different page.For example if rsi is 0xf004, rdi is 0xe008,
in following operation there will generate big performance latency.
1. movq (%rsi),	%rax
2. movq %rax,	(%rdi)
3. movq 8(%rsi), %rax
4. movq %rax,	8(%rdi)

If %rsi and rdi were in really the same meory page, there are TRUE
read-after-write dependence because instruction 2 write 0x008 and
instruction 3 read 0x00c, the two address are overlap partially.
Actually there are in different page and no any issues,
but without checking each address bit CPU could think they are
in the same page, and instruction 3 have to wait for instruction 2
to write data into cache from write buffer, then load data from cache,
the cost time read spent is equal to mfence instruction. We may avoid it by
tuning operation sequence as follow.

1. movq 8(%rsi), %rax
2. movq %rax,	8(%rdi)
3. movq (%rsi),	%rax
4. movq %rax,	(%rdi)

Instruction 3 read 0x004, instruction 2 write address 0x010, no any
dependence.  At last on Core2 we gain 1.83x speedup compared with
original instruction sequence.  In this patch we first handle small
size(less 20bytes), then jump to different copy mode. Based on our
micro-benchmark small bytes from 1 to 127 bytes, we got up to 2X
improvement, and up to 1.5X improvement for 1024 bytes on Corei7.  (We
use our micro-benchmark, and will do further test according to your
requirment)

Signed-off-by: Ma Ling <ling.ma@intel.com>
LKML-Reference: <1277753065-18610-1-git-send-email-ling.ma@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-08-23 14:56:41 -07:00
Ma, Ling fdf4289679 x86, mem: Don't implement forward memmove() as memcpy()
memmove() allow source and destination address to be overlap, but
there is no such limitation for memcpy().  Therefore, explicitly
implement memmove() in both the forwards and backward directions, to
give us the ability to optimize memcpy().

Signed-off-by: Ma Ling <ling.ma@intel.com>
LKML-Reference: <C10D3FB0CD45994C8A51FEC1227CE22F0E483AD86A@shsmsx502.ccr.corp.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-08-23 14:14:27 -07:00
Linus Torvalds c029b55af7 Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, asm: Use a lower case name for the end macro in atomic64_386_32.S
  x86, asm: Refactor atomic64_386_32.S to support old binutils and be cleaner
  x86: Document __phys_reloc_hide() usage in __pa_symbol()
  x86, apic: Map the local apic when parsing the MP table.
2010-08-13 10:35:48 -07:00
Luca Barbieri 417484d47e x86, asm: Use a lower case name for the end macro in atomic64_386_32.S
Use a lowercase name for the end macro, which somehow fixes a binutils 2.16
problem.

Signed-off-by: Luca Barbieri <luca@luca-barbieri.com>
LKML-Reference: <tip-30246557a06bb20618bed906a06d1e1e0faa8bb4@git.kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-08-12 07:04:16 -07:00
Luca Barbieri 30246557a0 x86, asm: Refactor atomic64_386_32.S to support old binutils and be cleaner
The old code didn't work on binutils 2.12 because setting a symbol to
a register apparently requires a fairly recent version.

This commit refactors the code to use the C preprocessor instead, and
in the process makes the whole code a bit easier to understand.

The object code produced is unchanged as expected.

This fixes kernel bugzilla 16506.

Reported-by: Dieter Stussy <kd6lvw+software@kd6lvw.ampr.org>
Signed-off-by: Luca Barbieri <luca@luca-barbieri.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@kernel.org> 2.6.35
LKML-Reference: <tip-*@git.kernel.org>
2010-08-11 21:03:28 -07:00
Linus Torvalds 66cd55d2b9 Merge branch 'x86-alternatives-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-alternatives-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, alternatives: BUG on encountering an invalid CPU feature number
  x86, alternatives: Fix one more open-coded 8-bit alternative number
  x86, alternatives: Use 16-bit numbers for cpufeature index
2010-08-06 16:24:17 -07:00
H. Peter Anvin a378d9338e x86, asm: Merge cmpxchg_486_u64() and cmpxchg8b_emu()
We have two functions for doing exactly the same thing -- emulating
cmpxchg8b on 486 and older hardware -- with different calling
conventions, and yet doing the same thing.  Drop the C version and use
the assembly version, via alternatives, for both the local and
non-local versions of cmpxchg8b.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <AANLkTikAmaDPji-TVDarmG1yD=fwbffcsmEU=YEuP+8r@mail.gmail.com>
2010-07-28 17:05:11 -07:00
H. Peter Anvin 90c8f92f5c x86, asm: Move cmpxchg emulation code to arch/x86/lib
Move cmpxchg emulation code from arch/x86/kernel/cpu (which is
otherwise CPU identification) to arch/x86/lib, where other emulation
code lives already.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <AANLkTikAmaDPji-TVDarmG1yD=fwbffcsmEU=YEuP+8r@mail.gmail.com>
2010-07-28 16:53:49 -07:00
H. Peter Anvin df378ccfc4 x86, alternatives: Fix one more open-coded 8-bit alternative number
Fix a missing case of an 8-bit alternative number, buried inside an
assembly macro.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Reported-by: Yinghai Lu <yinhai@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <4C3BDDA3.2060900@kernel.org>
2010-07-13 14:56:16 -07:00
H. Peter Anvin 83a7a2ad2a x86, alternatives: Use 16-bit numbers for cpufeature index
We already have cpufeature indicies above 255, so use a 16-bit number
for the alternatives index.  This consumes a padding field and so
doesn't add any size, but it means that abusing the padding field to
create assembly errors on overflow no longer works.  We can retain the
test simply by redirecting it to the .discard section, however.

[ v3: updated to include open-coded locations ]

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <tip-f88731e3068f9d1392ba71cc9f50f035d26a0d4f@git.kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-07-07 10:36:28 -07:00
Linus Torvalds 93c9d7f60c Merge branch 'x86-atomic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-atomic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix LOCK_PREFIX_HERE for uniprocessor build
  x86, atomic64: In selftest, distinguish x86-64 from 586+
  x86-32: Fix atomic64_inc_not_zero return value convention
  lib: Fix atomic64_inc_not_zero test
  lib: Fix atomic64_add_unless return value convention
  x86-32: Fix atomic64_add_unless return value convention
  lib: Fix atomic64_add_unless test
  x86: Implement atomic[64]_dec_if_positive()
  lib: Only test atomic64_dec_if_positive on archs having it
  x86-32: Rewrite 32-bit atomic64 functions in assembly
  lib: Add self-test for atomic64_t
  x86-32: Allow UP/SMP lock replacement in cmpxchg64
  x86: Add support for lock prefix in alternatives
2010-05-18 08:40:05 -07:00
Ingo Molnar cce9131781 Merge branch 'perf/urgent' into perf/core
Merge reason: Resolve patch dependency

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-07 11:30:30 +02:00
David Howells a66f6375bd Fix the x86_64 implementation of call_rwsem_wait()
The x86_64 call_rwsem_wait() treats the active state counter part of the
R/W semaphore state as being 16-bit when it's actually 32-bit (it's half
of the 64-bit state).  It should do "decl %edx" not "decw %dx".

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-04 15:24:14 -07:00
H. Peter Anvin d9c5841e22 Merge branch 'x86/asm' into x86/atomic
Merge reason:
	Conflict between LOCK_PREFIX_HERE and relative alternatives
	pointers

Resolved Conflicts:
	arch/x86/include/asm/alternative.h
	arch/x86/kernel/alternative.c

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-04-29 16:53:17 -07:00
Ingo Molnar ba7e4d13fc perf, x86: Add INSTRUCTION_DECODER config flag
The PEBS+LBR decoding magic needs the insn_get_length() infrastructure
to be able to decode x86 instruction length.

So split it out of KPROBES dependency and make it enabled when either
KPROBES or PERF_EVENTS is enabled.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-10 13:34:12 +01:00
Luca Barbieri f3e8313146 x86-32: Fix atomic64_inc_not_zero return value convention
atomic64_inc_not_zero must return 1 if it perfomed the add and 0 otherwise.
It was doing the opposite thing.

Signed-off-by: Luca Barbieri <luca@luca-barbieri.com>
LKML-Reference: <1267469749-11878-6-git-send-email-luca@luca-barbieri.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-03-01 11:39:03 -08:00
Luca Barbieri 6e6104fe08 x86-32: Fix atomic64_add_unless return value convention
atomic64_add_unless must return 1 if it perfomed the add and 0 otherwise.
The implementation did the opposite thing.

Reported-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Luca Barbieri <luca@luca-barbieri.com>
LKML-Reference: <1267469749-11878-3-git-send-email-luca@luca-barbieri.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-03-01 11:38:46 -08:00