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2014-05-31x86/vdso, build: Make LE access macros clearer, host-safeH. Peter Anvin
Make it a little clearer what the littleendian access macros in vdso2c.[ch] actually do. This way they can probably also be moved to a central location (e.g. tools/include) for the benefit of other host tools. We should avoid implementation namespace symbols when writing code that is compiling for the compiler host, so avoid names starting with double underscore or underscore-capital. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/2cf258df123cb24bad63c274c8563c050547d99d.1401464755.git.luto@amacapital.net
2014-05-30x86/vdso, build: Fix cross-compilation from big-endian architecturesAndy Lutomirski
This adds a macro GET(x) to convert x from big-endian to little-endian. Hopefully I put it everywhere it needs to go and got all the cases needed for everyone's linux/elf.h. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/2cf258df123cb24bad63c274c8563c050547d99d.1401464755.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-30x86/vdso, build: When vdso2c fails, unlink the outputAndy Lutomirski
This avoids bizarre failures if make is run again. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/1764385fe9931e8940b9d001132515448ea89523.1401464755.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-20x86, mm: Improve _install_special_mapping and fix x86 vdso namingAndy Lutomirski
Using arch_vma_name to give special mappings a name is awkward. x86 currently implements it by comparing the start address of the vma to the expected address of the vdso. This requires tracking the start address of special mappings and is probably buggy if a special vma is split or moved. Improve _install_special_mapping to just name the vma directly. Use it to give the x86 vvar area a name, which should make CRIU's life easier. As a side effect, the vvar area will show up in core dumps. This could be considered weird and is fixable. [hpa: I say we accept this as-is but be prepared to deal with knocking out the vvars from core dumps if this becomes a problem.] Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/276b39b6b645fb11e345457b503f17b83c2c6fd0.1400538962.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-20x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPETAndy Lutomirski
The oops can be triggered in qemu using -no-hpet (but not nohpet) by reading a couple of pages past the end of the vdso text. This should send SIGBUS instead of OOPSing. The bug was introduced by: commit 7a59ed415f5b57469e22e41fc4188d5399e0b194 Author: Stefani Seibold <stefani@seibold.net> Date: Mon Mar 17 23:22:09 2014 +0100 x86, vdso: Add 32 bit VDSO time support for 32 bit kernel which is new in 3.15. This will be fixed separately in 3.15, but that patch will not apply to tip/x86/vdso. This is the equivalent fix for tip/x86/vdso and, presumably, 3.16. Cc: Stefani Seibold <stefani@seibold.net> Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/c8b0a9a0b8d011a8b273cbb2de88d37190ed2751.1400538962.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05x86, vdso: Remove vestiges of VDSO_PRELINK and some outdated commentsAndy Lutomirski
These definitions had no effect. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/946c104e40c47319f8ab406e54118799cb55bd99.1399317206.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05x86, vdso: Move the vvar and hpet mappings next to the 64-bit vDSOAndy Lutomirski
This makes the 64-bit and x32 vdsos use the same mechanism as the 32-bit vdso. Most of the churn is deleting all the old fixmap code. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/8af87023f57f6bb96ec8d17fce3f88018195b49b.1399317206.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05x86, vdso: Move the 32-bit vdso special pages after the textAndy Lutomirski
This unifies the vdso mapping code and teaches it how to map special pages at addresses corresponding to symbols in the vdso image. The new code is used for all vdso variants, but so far only the 32-bit variants use the new vvar page position. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/b6d7858ad7b5ac3fd3c29cab6d6d769bc45d195e.1399317206.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05x86, vdso: Reimplement vdso.so preparation in build-time CAndy Lutomirski
Currently, vdso.so files are prepared and analyzed by a combination of objcopy, nm, some linker script tricks, and some simple ELF parsers in the kernel. Replace all of that with plain C code that runs at build time. All five vdso images now generate .c files that are compiled and linked in to the kernel image. This should cause only one userspace-visible change: the loaded vDSO images are stripped more heavily than they used to be. Everything outside the loadable segment is dropped. In particular, this causes the section table and section name strings to be missing. This should be fine: real dynamic loaders don't load or inspect these tables anyway. The result is roughly equivalent to eu-strip's --strip-sections option. The purpose of this change is to enable the vvar and hpet mappings to be moved to the page following the vDSO load segment. Currently, it is possible for the section table to extend into the page after the load segment, so, if we map it, it risks overlapping the vvar or hpet page. This happens whenever the load segment is just under a multiple of PAGE_SIZE. The only real subtlety here is that the old code had a C file with inline assembler that did 'call VDSO32_vsyscall' and a linker script that defined 'VDSO32_vsyscall = __kernel_vsyscall'. This most likely worked by accident: the linker script entry defines a symbol associated with an address as opposed to an alias for the real dynamic symbol __kernel_vsyscall. That caused ld to relocate the reference at link time instead of leaving an interposable dynamic relocation. Since the VDSO32_vsyscall hack is no longer needed, I now use 'call __kernel_vsyscall', and I added -Bsymbolic to make it work. vdso2c will generate an error and abort the build if the resulting image contains any dynamic relocations, so we won't silently generate bad vdso images. (Dynamic relocations are a problem because nothing will even attempt to relocate the vdso.) Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/2c4fcf45524162a34d87fdda1eb046b2a5cecee7.1399317206.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05x86, vdso: Move syscall and sysenter setup into kernel/cpu/common.cAndy Lutomirski
This code is used during CPU setup, and it isn't strictly speaking related to the 32-bit vdso. It's easier to understand how this works when the code is closer to its callers. This also lets syscall32_cpu_init be static, which might save some trivial amount of kernel text. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/4e466987204e232d7b55a53ff6b9739f12237461.1399317206.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05x86, vdso: Clean up 32-bit vs 64-bit vdso paramsAndy Lutomirski
Rather than using 'vdso_enabled' and an awful #define, just call the parameters vdso32_enabled and vdso64_enabled. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/87913de56bdcbae3d93917938302fc369b05caee.1399317206.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-04-22Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vdso fix from Peter Anvin: "This is a single build fix for building with gold as opposed to GNU ld. It got queued up separately and was expected to be pushed during the merge window, but it got left behind" * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, vdso: Make the vdso linker script compatible with Gold
2014-04-03x86, vdso: Make the vdso linker script compatible with GoldAndy Lutomirski
Gold can't parse the script due to: https://sourceware.org/bugzilla/show_bug.cgi?id=16804 With a workaround in place for that issue, Gold 2.23 crashes due to: https://sourceware.org/bugzilla/show_bug.cgi?id=15355 This works around the former bug and avoids the second by removing the unnecessary vvar and hpet sections and segments. The vdso and hpet symbols are still there, and nothing needed the sections or segments. Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/243fa205098d112ec759c9b1b26785c09f399833.1396547532.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-04-02Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vdso changes from Peter Anvin: "This is the revamp of the 32-bit vdso and the associated cleanups. This adds timekeeping support to the 32-bit vdso that we already have in the 64-bit vdso. Although 32-bit x86 is legacy, it is likely to remain in the embedded space for a very long time to come. This removes the traditional COMPAT_VDSO support; the configuration variable is reused for simply removing the 32-bit vdso, which will produce correct results but obviously suffer a performance penalty. Only one beta version of glibc was affected, but that version was unfortunately included in one OpenSUSE release. This is not the end of the vdso cleanups. Stefani and Andy have agreed to continue work for the next kernel cycle; in fact Andy has already produced another set of cleanups that came too late for this cycle. An incidental, but arguably important, change is that this ensures that unused space in the VVAR page is properly zeroed. It wasn't before, and would contain whatever garbage was left in memory by BIOS or the bootloader. Since the VVAR page is accessible to user space this had the potential of information leaks" * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86, vdso: Fix the symbol versions on the 32-bit vDSO x86, vdso, build: Don't rebuild 32-bit vdsos on every make x86, vdso: Actually discard the .discard sections x86, vdso: Fix size of get_unmapped_area() x86, vdso: Finish removing VDSO32_PRELINK x86, vdso: Move more vdso definitions into vdso.h x86: Load the 32-bit vdso in place, just like the 64-bit vdsos x86, vdso32: handle 32 bit vDSO larger one page x86, vdso32: Disable stack protector, adjust optimizations x86, vdso: Zero-pad the VVAR page x86, vdso: Add 32 bit VDSO time support for 64 bit kernel x86, vdso: Add 32 bit VDSO time support for 32 bit kernel x86, vdso: Patch alternatives in the 32-bit VDSO x86, vdso: Introduce VVAR marco for vdso32 x86, vdso: Cleanup __vdso_gettimeofday() x86, vdso: Replace VVAR(vsyscall_gtod_data) by gtod macro x86, vdso: __vdso_clock_gettime() cleanup x86, vdso: Revamp vclock_gettime.c mm: Add new func _install_special_mapping() to mmap.c x86, vdso: Make vsyscall_gtod_data handling x86 generic ...
2014-03-30x86, vdso: Fix the symbol versions on the 32-bit vDSOAndy Lutomirski
The new symbols provide the same API as the 64-bit variants, so they should have the same symbol version name. This can't break userspace, since these symbols are new for 32-bit Linux. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/0a869bce03d25619565b1eee7d69a4fd15fd203a.1396124118.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-03-25x86, vdso, build: Don't rebuild 32-bit vdsos on every makeAndy Lutomirski
vdso32/vclock_gettime.o was confusing kbuild. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/d741449340642213744dd659471a35bb970a0c4c.1395789923.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-25x86, vdso: Actually discard the .discard sectionsH. Peter Anvin
The .discard/.discard.* sections are used to generate intermediate results for the assembler (effectively "test assembly".) The output is waste and should not be retained. Cc: Stefani Seibold <stefani@seibold.net> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/n/tip-psizrnant8x3nrhbgvq2vekr@git.kernel.org
2014-03-24x86, vdso: Fix size of get_unmapped_area()Stefani Seibold
The size of the reserved memory for a 32 bit vdso must be the size of the 32 bit vDSO in pages + HPET page + VVAR page. One page is not enough for this. Grrrr.... silly copy and paste bug, was right in previous patch. Signed-off-by: Stefani Seibold <stefani@seibold.net> Cc: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/1395592694-20571-1-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-20x86, vdso: Move more vdso definitions into vdso.hAndy Lutomirski
This fixes the Xen build and gets rid of a silly header file. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1df77311795aff75f5742c787d277518314a38d3.1395366931.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-03-20x86: Load the 32-bit vdso in place, just like the 64-bit vdsosAndy Lutomirski
This replaces a decent amount of incomprehensible and buggy code with much more straightforward code. It also brings the 32-bit vdso more in line with the 64-bit vdsos, so maybe someday they can share even more code. This wastes a small amount of kernel .data and .text space, but it avoids a couple of allocations on startup, so it should be more or less a wash memory-wise. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/b8093933fad09ce181edb08a61dcd5d2592e9814.1395352498.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-18x86, vdso32: handle 32 bit vDSO larger one pageStefani Seibold
This patch enables 32 bit vDSO which are larger than a page. Signed-off-by: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-14-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-18x86, vdso32: Disable stack protector, adjust optimizationsH. Peter Anvin
For the 32-bit VDSO, match the 64-bit VDSO in: 1. Disable the stack protector. 2. Use -fno-omit-frame-pointer for user space debugging sanity. 3. Use -foptimize-sibling-calls like the 64-bit VDSO does. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-13-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-18x86, vdso: Add 32 bit VDSO time support for 64 bit kernelStefani Seibold
This patch add the VDSO time support for the IA32 Emulation Layer. Due the nature of the kernel headers and the LP64 compiler where the size of a long and a pointer differs against a 32 bit compiler, there is some type hacking necessary for optimal performance. The vsyscall_gtod_data struture must be a rearranged to serve 32- and 64-bit code access at the same time: - The seqcount_t was replaced by an unsigned, this makes the vsyscall_gtod_data intedepend of kernel configuration and internal functions. - All kernel internal structures are replaced by fix size elements which works for 32- and 64-bit access - The inner struct clock was removed to pack the whole struct. The "unsigned seq" would be handled by functions derivated from seqcount_t. Signed-off-by: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-11-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-18x86, vdso: Add 32 bit VDSO time support for 32 bit kernelStefani Seibold
This patch add the time support for 32 bit a VDSO to a 32 bit kernel. For 32 bit programs running on a 32 bit kernel, the same mechanism is used as for 64 bit programs running on a 64 bit kernel. Reviewed-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-10-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-18x86, vdso: Patch alternatives in the 32-bit VDSOAndy Lutomirski
We need the alternatives mechanism for rdtsc_barrier() to work. Signed-off-by: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-9-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-18x86, vdso: Cleanup __vdso_gettimeofday()Stefani Seibold
This patch cleans up the __vdso_gettimeofday() function a little. It kicks out an unneeded ret local variable and makes the code faster if only the timezone is needed (an admittedly rare case.) Reviewed-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-7-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-18x86, vdso: Replace VVAR(vsyscall_gtod_data) by gtod macroStefani Seibold
There a currently more than 30 users of the gtod macro, so replace the last VVAR(vsyscall_gtod_data) by gtod macro. Reviewed-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-6-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-18x86, vdso: __vdso_clock_gettime() cleanupStefani Seibold
This patch is a small code cleanup for the __vdso_clock_gettime() function. It removes the unneeded return values from do_monotonic_coarse() and do_realtime_coarse() and add a fallback label for doing the kernel gettimeofday() system call. Reviewed-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-5-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-18x86, vdso: Revamp vclock_gettime.cStefani Seibold
This intermediate patch revamps the vclock_gettime.c by moving some functions around. It is only for spliting purpose, to make whole the 32 bit vdso timer patch easier to review. Reviewed-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Stefani Seibold <stefani@seibold.net> Link: http://lkml.kernel.org/r/1395094933-14252-4-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-13x86, vdso: Remove compat vdso supportAndy Lutomirski
The compat vDSO is a complicated hack that's needed to maintain compatibility with a small range of glibc versions. This removes it and replaces it with a much simpler hack: a config option to disable the 32-bit vDSO by default. This also changes the default value of CONFIG_COMPAT_VDSO to n -- users configuring kernels from scratch almost certainly want that choice. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/4bb4690899106eb11430b1186d5cc66ca9d1660c.1394751608.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-02-13x86, lto: Disable LTO for the x86 VDSOAndi Kleen
The VDSO does not play well with LTO, so just disable LTO for it. Also pass a 32bit linker flag for the 32bit version. [ hpa: change braces to parens to match kernel Makefile style ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1391846481-31491-1-git-send-email-ak@linux.intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-20Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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
2014-01-12seqlock: Use raw_ prefix instead of _no_lockdepJohn Stultz
Linus disliked the _no_lockdep() naming, so instead use the more-consistent raw_* prefix to the non-lockdep enabled seqcount methods. This also adds raw_ methods for the write operations as well, which will be utilized in a following patch. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Krzysztof Hałasa <khalasa@piap.pl> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Willy Tarreau <w@1wt.eu> Link: http://lkml.kernel.org/r/1388704274-5278-1-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-06x86: Delete non-required instances of include <linux/init.h>Paul Gortmaker
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>
2013-11-06seqcount: Add lockdep functionality to seqcount/seqlock structuresJohn Stultz
Currently seqlocks and seqcounts don't support lockdep. After running across a seqcount related deadlock in the timekeeping code, I used a less-refined and more focused variant of this patch to narrow down the cause of the issue. This is a first-pass attempt to properly enable lockdep functionality on seqlocks and seqcounts. Since seqcounts are used in the vdso gettimeofday code, I've provided non-lockdep accessors for those needs. I've also handled one case where there were nested seqlock writers and there may be more edge cases. Comments and feedback would be appreciated! Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/1381186321-4906-3-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-07-18remove sched notifier for cross-cpu migrationsMarcelo Tosatti
Linux as a guest on KVM hypervisor, the only user of the pvclock vsyscall interface, does not require notification on task migration because: 1. cpu ID number maps 1:1 to per-CPU pvclock time info. 2. per-CPU pvclock time info is updated if the underlying CPU changes. 3. that version is increased whenever underlying CPU changes. Which is sufficient to guarantee nanoseconds counter is calculated properly. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-19x86/vdso: Convert use of typedef ctl_table to struct ctl_tableJoe Perches
This typedef is unnecessary and should just be removed. Signed-off-by: Joe Perches <joe@perches.com> Cc: Jiri Kosina <trivial@kernel.org> Link: http://lkml.kernel.org/r/a756fa0060e8eea25e8c1863c2764e86c2823617.1371177118.git.joe@perches.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-02-15timers/x86/hpet: Use HPET_COUNTER to specify the hpet counter in vread_hpet()Satoru Takeuchi
vread_hpet() uses "0xf0" as the offset of the hpet counter. To clarify the meaning of this code, it should use symbolic name, HPET_COUNTER, instead. Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-12-13Merge tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Marcelo Tosatti: "Considerable KVM/PPC work, x86 kvmclock vsyscall support, IA32_TSC_ADJUST MSR emulation, amongst others." Fix up trivial conflict in kernel/sched/core.c due to cross-cpu migration notifier added next to rq migration call-back. * tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (156 commits) KVM: emulator: fix real mode segment checks in address linearization VMX: remove unneeded enable_unrestricted_guest check KVM: VMX: fix DPL during entry to protected mode x86/kexec: crash_vmclear_local_vmcss needs __rcu kvm: Fix irqfd resampler list walk KVM: VMX: provide the vmclear function and a bitmap to support VMCLEAR in kdump x86/kexec: VMCLEAR VMCSs loaded on all cpus if necessary KVM: MMU: optimize for set_spte KVM: PPC: booke: Get/set guest EPCR register using ONE_REG interface KVM: PPC: bookehv: Add EPCR support in mtspr/mfspr emulation KVM: PPC: bookehv: Add guest computation mode for irq delivery KVM: PPC: Make EPCR a valid field for booke64 and bookehv KVM: PPC: booke: Extend MAS2 EPN mask for 64-bit KVM: PPC: e500: Mask MAS2 EPN high 32-bits in 32/64 tlbwe emulation KVM: PPC: Mask ea's high 32-bits in 32/64 instr emulation KVM: PPC: e500: Add emulation helper for getting instruction ea KVM: PPC: bookehv64: Add support for interrupt handling KVM: PPC: bookehv: Remove GET_VCPU macro from exception handler KVM: PPC: booke: Fix get_tb() compile error on 64-bit KVM: PPC: e500: Silence bogus GCC warning in tlb code ...
2012-12-11mm: use vm_unmapped_area() on x86_64 architectureMichel Lespinasse
Update the x86_64 arch_get_unmapped_area[_topdown] functions to make use of vm_unmapped_area() instead of implementing a brute force search. Signed-off-by: Michel Lespinasse <walken@google.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-27x86: vdso: pvclock gettime supportMarcelo Tosatti
Improve performance of time system calls when using Linux pvclock, by reading time info from fixmap visible copy of pvclock data. Originally from Jeremy Fitzhardinge. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-09-24time: Convert x86_64 to using new update_vsyscallJohn Stultz
Switch x86_64 to using sub-ns precise vsyscall Cc: Tony Luck <tony.luck@intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-06-07x86, cpu: Rename checking_wrmsrl() to wrmsrl_safe()H. Peter Anvin
Rename checking_wrmsrl() to wrmsrl_safe(), to match the naming convention used by all the other MSR access functions/macros. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-03-29Merge branch 'x86-x32-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x32 support for x86-64 from Ingo Molnar: "This tree introduces the X32 binary format and execution mode for x86: 32-bit data space binaries using 64-bit instructions and 64-bit kernel syscalls. This allows applications whose working set fits into a 32 bits address space to make use of 64-bit instructions while using a 32-bit address space with shorter pointers, more compressed data structures, etc." Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c} * 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) x32: Fix alignment fail in struct compat_siginfo x32: Fix stupid ia32/x32 inversion in the siginfo format x32: Add ptrace for x32 x32: Switch to a 64-bit clock_t x32: Provide separate is_ia32_task() and is_x32_task() predicates x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls x86/x32: Fix the binutils auto-detect x32: Warn and disable rather than error if binutils too old x32: Only clear TIF_X32 flag once x32: Make sure TS_COMPAT is cleared for x32 tasks fs: Remove missed ->fds_bits from cessation use of fd_set structs internally fs: Fix close_on_exec pointer in alloc_fdtable x32: Drop non-__vdso weak symbols from the x32 VDSO x32: Fix coding style violations in the x32 VDSO code x32: Add x32 VDSO support x32: Allow x32 to be configured x32: If configured, add x32 system calls to system call tables x32: Handle process creation x32: Signal-related system calls x86: Add #ifdef CONFIG_COMPAT to <asm/sys_ia32.h> ...
2012-03-29Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer core updates from Thomas Gleixner. * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: ia64: vsyscall: Add missing paranthesis alarmtimer: Don't call rtc_timer_init() when CONFIG_RTC_CLASS=n x86: vdso: Put declaration before code x86-64: Inline vdso clock_gettime helpers x86-64: Simplify and optimize vdso clock_gettime monotonic variants kernel-time: fix s/then/than/ spelling errors time: remove no_sync_cmos_clock time: Avoid scary backtraces when warning of > 11% adj alarmtimer: Make sure we initialize the rtctimer ntp: Fix leap-second hrtimer livelock x86, tsc: Skip refined tsc calibration on systems with reliable TSC rtc: Provide flag for rtc devices that don't support UIE ia64: vsyscall: Use seqcount instead of seqlock x86: vdso: Use seqcount instead of seqlock x86: vdso: Remove bogus locking in update_vsyscall_tz() time: Remove bogus comments time: Fix change_clocksource locking time: x86: Fix race switching from vsyscall to non-vsyscall clock
2012-03-23coredump: remove VM_ALWAYSDUMP flagJason Baron
The motivation for this patchset was that I was looking at a way for a qemu-kvm process, to exclude the guest memory from its core dump, which can be quite large. There are already a number of filter flags in /proc/<pid>/coredump_filter, however, these allow one to specify 'types' of kernel memory, not specific address ranges (which is needed in this case). Since there are no more vma flags available, the first patch eliminates the need for the 'VM_ALWAYSDUMP' flag. The flag is used internally by the kernel to mark vdso and vsyscall pages. However, it is simple enough to check if a vma covers a vdso or vsyscall page without the need for this flag. The second patch then replaces the 'VM_ALWAYSDUMP' flag with a new 'VM_NODUMP' flag, which can be set by userspace using new madvise flags: 'MADV_DONTDUMP', and unset via 'MADV_DODUMP'. The core dump filters continue to work the same as before unless 'MADV_DONTDUMP' is set on the region. The qemu code which implements this features is at: http://people.redhat.com/~jbaron/qemu-dump/qemu-dump.patch In my testing the qemu core dump shrunk from 383MB -> 13MB with this patch. I also believe that the 'MADV_DONTDUMP' flag might be useful for security sensitive apps, which might want to select which areas are dumped. This patch: The VM_ALWAYSDUMP flag is currently used by the coredump code to indicate that a vma is part of a vsyscall or vdso section. However, we can determine if a vma is in one these sections by checking it against the gate_vma and checking for a non-NULL return value from arch_vma_name(). Thus, freeing a valuable vma bit. Signed-off-by: Jason Baron <jbaron@redhat.com> Acked-by: Roland McGrath <roland@hack.frob.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Avi Kivity <avi@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23x86-64: Inline vdso clock_gettime helpersAndy Lutomirski
This is about a 3% speedup on Sandy Bridge. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-03-23x86-64: Simplify and optimize vdso clock_gettime monotonic variantsAndy Lutomirski
We used to store the wall-to-monotonic offset and the realtime base. It's faster to precompute the monotonic base. This is about a 3% speedup on Sandy Bridge for CLOCK_MONOTONIC. It's much more impressive for CLOCK_MONOTONIC_COARSE. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-03-15x86: vdso: Use seqcount instead of seqlockThomas Gleixner
The update of the vdso data happens under xtime_lock, so adding a nested lock is pointless. Just use a seqcount to sync the readers. Reviewed-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-03-15time: x86: Fix race switching from vsyscall to non-vsyscall clockJohn Stultz
When switching from a vsyscall capable to a non-vsyscall capable clocksource, there was a small race, where the last vsyscall gettimeofday before the switch might return a invalid time value using the new non-vsyscall enabled clocksource values after the switch is complete. This is due to the vsyscall code checking the vclock_mode once outside of the seqcount protected section. After it reads the vclock mode, it doesn't re-check that the sampled clock data that is obtained in the seqcount critical section still matches. The fix is to sample vclock_mode inside the protected section, and as long as it isn't VCLOCK_NONE, return the calculated value. If it has changed and is now VCLOCK_NONE, fall back to the syscall gettime calculation. v2: * Cleanup checks as suggested by tglx * Also fix same issue present in gettimeofday path CC: Andy Lutomirski <luto@amacapital.net> CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>