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2019-06-21x86/vdso: Prevent segfaults due to hoisted vclock readsAndy Lutomirski
GCC 5.5.0 sometimes cleverly hoists reads of the pvclock and/or hvclock pages before the vclock mode checks. This creates a path through vclock_gettime() in which no vclock is enabled at all (due to disabled TSC on old CPUs, for example) but the pvclock or hvclock page nevertheless read. This will segfault on bare metal. This fixes commit 459e3a21535a ("gcc-9: properly declare the {pv,hv}clock_page storage") in the sense that, before that commit, GCC didn't seem to generate the offending code. There was nothing wrong with that commit per se, and -stable maintainers should backport this to all supported kernels regardless of whether the offending commit was present, since the same crash could just as easily be triggered by the phase of the moon. On GCC 9.1.1, this doesn't seem to affect the generated code at all, so I'm not too concerned about performance regressions from this fix. Cc: stable@vger.kernel.org Cc: x86@kernel.org Cc: Borislav Petkov <bp@alien8.de> Reported-by: Duncan Roe <duncan_roe@optusnet.com.au> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 223Thomas Gleixner
Based on 1 normalized pattern(s): subject to the gnu public license v 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 9 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171440.130801526@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 214Thomas Gleixner
Based on 1 normalized pattern(s): subject to the gpl v 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 2 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171439.372657724@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-08x86/vdso: Remove hpet_page from vDSOJia Zhang
This trivial cleanup finalizes the removal of vDSO HPET support. Fixes: 1ed95e52d902 ("x86/vdso: Remove direct HPET access through the vDSO") Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: luto@kernel.org Cc: bp@alien8.de Link: https://lkml.kernel.org/r/20190401114045.7280-1-zhang.jia@linux.alibaba.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-06Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "This includes the following changes: - cpu_has() cleanups - sync_bitops.h modernization to the rmwcc.h facility, similarly to bitops.h - continued LTO annotations/fixes - misc cleanups and smaller cleanups" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/um/vdso: Drop unnecessary cc-ldoption x86/vdso: Rename variable to fix -Wshadow warning x86/cpu/amd: Exclude 32bit only assembler from 64bit build x86/asm: Mark all top level asm statements as .text x86/build/vdso: Add FORCE to the build rule of %.so x86/asm: Modernize sync_bitops.h x86/mm: Convert some slow-path static_cpu_has() callers to boot_cpu_has() x86: Convert some slow-path static_cpu_has() callers to boot_cpu_has() x86/asm: Clarify static_cpu_has()'s intended use x86/uaccess: Fix implicit cast of __user pointer x86/cpufeature: Remove __pure attribute to _static_cpu_has()
2019-05-01gcc-9: properly declare the {pv,hv}clock_page storageLinus Torvalds
The pvlock_page and hvclock_page variables are (as the name implies) addresses to pages, created by the linker script. But we declared them as just "extern u8" variables, which _works_, but now that gcc does some more bounds checking, it causes warnings like warning: array subscript 1 is outside array bounds of ‘u8[1]’ when we then access more than one byte from those variables. Fix this by simply making the declaration of the variables match reality, which makes the compiler happy too. Signed-off-by: Linus Torvalds <torvalds@-linux-foundation.org>
2019-04-19x86/vdso: Rename variable to fix -Wshadow warningLeonardo Brás
The go32() and go64() functions has an argument and a local variable called ‘name’. Rename both to clarify the code and to fix a warning with -Wshadow. Signed-off-by: Leonardo Brás <leobras.c@gmail.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: David.Laight@aculab.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: helen@koikeco.de Cc: linux-kbuild@vger.kernel.org Cc: lkcamp@lists.libreplanetbr.org Link: http://lkml.kernel.org/r/20181023011022.GA6574@WindFlash Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-18x86/build/vdso: Add FORCE to the build rule of %.soMasahiro Yamada
$(call if_changed,...) must have FORCE as a prerequisite. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1554280212-10578-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-26Merge 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/kprobes: Remove trampoline_handler() prototype x86/kernel: Fix more -Wmissing-prototypes warnings x86: Fix various typos in comments x86/headers: Fix -Wmissing-prototypes warning x86/process: Avoid unnecessary NULL check in get_wchan() x86/traps: Complete prototype declarations x86/mce: Fix -Wmissing-prototypes warnings x86/gart: Rewrite early_gart_iommu_check() comment
2018-12-26Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "Two changes: - Remove (some) remnants of the vDSO's fake section table mechanism that were left behind when the vDSO build process reverted to using "objdump -S" to strip the userspace image. - Remove hardcoded POPCNT mnemonics now that the minimum binutils version supports the symbolic form" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Remove a stale/misleading comment from the linker script x86/vdso: Remove obsolete "fake section table" reservation x86: Use POPCNT mnemonics in arch_hweight.h
2018-12-15x86/vdso: Pass --eh-frame-hdr to the linkerAlistair Strachan
Commit 379d98ddf413 ("x86: vdso: Use $LD instead of $CC to link") accidentally broke unwinding from userspace, because ld would strip the .eh_frame sections when linking. Originally, the compiler would implicitly add --eh-frame-hdr when invoking the linker, but when this Makefile was converted from invoking ld via the compiler, to invoking it directly (like vmlinux does), the flag was missed. (The EH_FRAME section is important for the VDSO shared libraries, but not for vmlinux.) Fix the problem by explicitly specifying --eh-frame-hdr, which restores parity with the old method. See relevant bug reports for additional info: https://bugzilla.kernel.org/show_bug.cgi?id=201741 https://bugzilla.redhat.com/show_bug.cgi?id=1659295 Fixes: 379d98ddf413 ("x86: vdso: Use $LD instead of $CC to link") Reported-by: Florian Weimer <fweimer@redhat.com> Reported-by: Carlos O'Donell <carlos@redhat.com> Reported-by: "H. J. Lu" <hjl.tools@gmail.com> Signed-off-by: Alistair Strachan <astrachan@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Laura Abbott <labbott@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Carlos O'Donell <carlos@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: kernel-team@android.com Cc: Laura Abbott <labbott@redhat.com> Cc: stable <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: X86 ML <x86@kernel.org> Link: https://lkml.kernel.org/r/20181214223637.35954-1-astrachan@google.com
2018-12-07x86/vdso: Drop implicit common-page-size linker flagNick Desaulniers
GNU linker's -z common-page-size's default value is based on the target architecture. arch/x86/entry/vdso/Makefile sets it to the architecture default, which is implicit and redundant. Drop it. Fixes: 2aae950b21e4 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Reported-by: Dmitry Golovin <dima@golovin.in> Reported-by: Bill Wendling <morbo@google.com> Suggested-by: Dmitry Golovin <dima@golovin.in> Suggested-by: Rui Ueyama <ruiu@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Fangrui Song <maskray@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20181206191231.192355-1-ndesaulniers@google.com Link: https://bugs.llvm.org/show_bug.cgi?id=38774 Link: https://github.com/ClangBuiltLinux/linux/issues/31
2018-12-05x86/vdso: Remove a stale/misleading comment from the linker scriptSean Christopherson
Once upon a time, vdso2c aggressively stripped data from the vDSO image when generating the final userspace image. This included stripping the .altinstructions and .altinstr_replacement sections. Eventually, the stripping process reverted to "objdump -S" and no longer removed the aforementioned sections, but the comment remained. Keeping the .alt* sections at the end of the PT_LOAD segment is no longer necessary, but there's no harm in doing so and it's a helpful reminder that they don't need to be included in the final vDSO image, i.e. someone may want to take another stab at zapping/stripping the unneeded sections. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: da861e18eccc ("x86, vdso: Get rid of the fake section mechanism") Link: http://lkml.kernel.org/r/20181204212600.28090-3-sean.j.christopherson@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-05x86/vdso: Remove obsolete "fake section table" reservationSean Christopherson
At one point the vDSO image was manually stripped down by vdso2c in an attempt to minimize the size of the image mapped into userspace. Part of that stripping process involved building a fake section table so as not to break userspace processes that parse the section table. Memory for the fake section table was reserved in the .rodata section so that vdso2c could simply copy the entire PT_LOAD segment into the userspace image after building the fake table. Eventually, the entire fake section table approach was dropped in favor of stripping the vdso "the old fashioned way", i.e. via objdump -S. But, the reservation in .rodata for the fake table was left behind. Remove the reserveration along with a few other related defines and section entries. Removing the fake section table placeholder zaps a whopping 0x340 bytes from the 64-bit vDSO image, which drops the current image's size to under 4k, i.e. reduces the effective size of the userspace vDSO mapping by a full page. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: da861e18eccc ("x86, vdso: Get rid of the fake section mechanism") Link: http://lkml.kernel.org/r/20181204212600.28090-2-sean.j.christopherson@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-03x86: Fix various typos in commentsIngo Molnar
Go over arch/x86/ and fix common typos in comments, and a typo in an actual function argument name. No change in functionality intended. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-26x86: convert vdso to use vm_fault_tMatthew Wilcox
Return vm_fault_t codes directly from the appropriate mm routines instead of converting from errnos ourselves. Fixes a minor bug where we'd return SIGBUS instead of the correct OOM code if we ran out of memory allocating page tables. Link: http://lkml.kernel.org/r/20180828145728.11873-5-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-23Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vdso updates from Ingo Molnar: "Two main changes: - Cleanups, simplifications and CLOCK_TAI support (Thomas Gleixner) - Improve code generation (Andy Lutomirski)" * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Rearrange do_hres() to improve code generation x86/vdso: Document vgtod_ts better x86/vdso: Remove "memory" clobbers in the vDSO syscall fallbacks x66/vdso: Add CLOCK_TAI support x86/vdso: Move cycle_last handling into the caller x86/vdso: Simplify the invalid vclock case x86/vdso: Replace the clockid switch case x86/vdso: Collapse coarse functions x86/vdso: Collapse high resolution functions x86/vdso: Introduce and use vgtod_ts x86/vdso: Use unsigned int consistently for vsyscall_gtod_data:: Seq x86/vdso: Enforce 64bit clocksource x86/time: Implement clocksource_arch_init() clocksource: Provide clocksource_arch_init()
2018-10-08x86/fsgsbase/64: Clean up various detailsIngo Molnar
So: - use 'extern' consistently for APIs - fix weird header guard - clarify code comments - reorder APIs by type Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Markus T Metzger <markus.t.metzger@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08x86/segments: Introduce the 'CPUNODE' naming to better document the segment ↵Ingo Molnar
limit CPU/node NR trick We have a special segment descriptor entry in the GDT, whose sole purpose is to encode the CPU and node numbers in its limit (size) field. There are user-space instructions that allow the reading of the limit field, which gives us a really fast way to read the CPU and node IDs from the vDSO for example. But the naming of related functionality does not make this clear, at all: VDSO_CPU_SIZE VDSO_CPU_MASK __CPU_NUMBER_SEG GDT_ENTRY_CPU_NUMBER vdso_encode_cpu_node vdso_read_cpu_node There's a number of problems: - The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number of bits, nor does it make it clear which 'CPU' this refers to, i.e. that this is about a GDT entry whose limit encodes the CPU and node number. - Furthermore, the 'CPU_NUMBER' naming is actively misleading as well, because the segment limit encodes not just the CPU number but the node ID as well ... So use a better nomenclature all around: name everything related to this trick as 'CPUNODE', to make it clear that this is something special, and add _BITS to make it clear that these are number of bits, and propagate this to every affected name: VDSO_CPU_SIZE => VDSO_CPUNODE_BITS VDSO_CPU_MASK => VDSO_CPUNODE_MASK __CPU_NUMBER_SEG => __CPUNODE_SEG GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE vdso_encode_cpu_node => vdso_encode_cpunode vdso_read_cpu_node => vdso_read_cpunode This, beyond being less confusing, also makes it easier to grep for all related functionality: $ git grep -i cpunode arch/x86 Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode(). Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Markus T Metzger <markus.t.metzger@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08x86/vdso: Initialize the CPU/node NR segment descriptor earlierChang S. Bae
Currently the CPU/node NR segment descriptor (GDT_ENTRY_CPU_NUMBER) is initialized relatively late during CPU init, from the vCPU code, which has a number of disadvantages, such as hotplug CPU notifiers and SMP cross-calls. Instead just initialize it much earlier, directly in cpu_init(). This reduces complexity and increases robustness. [ mingo: Wrote new changelog. ] Suggested-by: H. Peter Anvin <hpa@zytor.com> Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Markus T Metzger <markus.t.metzger@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1537312139-5580-9-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08x86/vdso: Introduce helper functions for CPU and node numberChang S. Bae
Clean up the CPU/node number related code a bit, to make it more apparent how we are encoding/extracting the CPU and node fields from the segment limit. No change in functionality intended. [ mingo: Wrote new changelog. ] Suggested-by: Andy Lutomirski <luto@kernel.org> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Markus T Metzger <markus.t.metzger@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/1537312139-5580-8-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08x86/segments/64: Rename the GDT PER_CPU entry to CPU_NUMBERChang S. Bae
The old 'per CPU' naming was misleading: 64-bit kernels don't use this GDT entry for per CPU data, but to store the CPU (and node) ID. [ mingo: Wrote new changelog. ] Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Markus T Metzger <markus.t.metzger@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/1537312139-5580-7-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-05x86/vdso: Rearrange do_hres() to improve code generationAndy Lutomirski
vgetcyc() is full of barriers, so fetching values out of the vvar page before vgetcyc() for use after vgetcyc() results in poor code generation. Put vgetcyc() first to avoid this problem. Also, pull the tv_sec division into the loop and put all the ts writes together. The old code wrote ts->tv_sec on each iteration before the syscall fallback check and then added in the offset afterwards, which forced the compiler to pointlessly copy base->sec to ts->tv_sec on each iteration. The new version seems to generate sensible code. Saves several cycles. With this patch applied, the result is faster than before the clock_gettime() rewrite. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/3c05644d010b72216aa286a6d20b5078d5fae5cd.1538762487.git.luto@kernel.org
2018-10-05x86/vdso: Remove "memory" clobbers in the vDSO syscall fallbacksAndy Lutomirski
When a vDSO clock function falls back to the syscall, no special barriers or ordering is needed, and the syscall fallbacks don't clobber any memory that is not explicitly listed in the asm constraints. Remove the "memory" clobber. This causes minor changes to the generated code, but otherwise has no obvious performance impact. I think it's nice to have, though, since it may help the optimizer in the future. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/3a7438f5fb2422ed881683d2ccffd7f987b2dc44.1538689401.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-04x86/vdso: Move cycle_last handling into the callerThomas Gleixner
Dereferencing gtod->cycle_last all over the place and foing the cycles < last comparison in the vclock read functions generates horrible code. Doing it at the call site is much better and gains a few cycles both for TSC and pvclock. Caveat: This adds the comparison to the hyperv vclock as well, but I have no way to test that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Rickard <matt@softrans.com.au> Cc: Stephen Boyd <sboyd@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: devel@linuxdriverproject.org Cc: virtualization@lists.linux-foundation.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Juergen Gross <jgross@suse.com> Link: https://lkml.kernel.org/r/20180917130707.741440803@linutronix.de
2018-10-04x86/vdso: Simplify the invalid vclock caseThomas Gleixner
The code flow for the vclocks is convoluted as it requires the vclocks which can be invalidated separately from the vsyscall_gtod_data sequence to store the fact in a separate variable. That's inefficient. Restructure the code so the vclock readout returns cycles and the conversion to nanoseconds is handled at the call site. If the clock gets invalidated or vclock is already VCLOCK_NONE, return U64_MAX as the cycle value, which is invalid for all clocks and leave the sequence loop immediately in that case by calling the fallback function directly. This allows to remove the gettimeofday fallback as it now uses the clock_gettime() fallback and does the nanoseconds to microseconds conversion in the same way as it does when the vclock is functional. It does not make a difference whether the division by 1000 happens in the kernel fallback or in userspace. Generates way better code and gains a few cycles back. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Rickard <matt@softrans.com.au> Cc: Stephen Boyd <sboyd@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: devel@linuxdriverproject.org Cc: virtualization@lists.linux-foundation.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Juergen Gross <jgross@suse.com> Link: https://lkml.kernel.org/r/20180917130707.657928937@linutronix.de
2018-10-04x86/vdso: Replace the clockid switch caseThomas Gleixner
Now that the time getter functions use the clockid as index into the storage array for the base time access, the switch case can be replaced. - Check for clockid >= MAX_CLOCKS and for negative clockid (CPU/FD) first and call the fallback function right away. - After establishing that clockid is < MAX_CLOCKS, convert the clockid to a bitmask - Check for the supported high resolution and coarse functions by anding the bitmask of supported clocks and check whether a bit is set. This completely avoids jump tables, reduces the number of conditionals and makes the VDSO extensible for other clock ids. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Rickard <matt@softrans.com.au> Cc: Stephen Boyd <sboyd@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: devel@linuxdriverproject.org Cc: virtualization@lists.linux-foundation.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Juergen Gross <jgross@suse.com> Link: https://lkml.kernel.org/r/20180917130707.574315796@linutronix.de
2018-10-04x86/vdso: Collapse coarse functionsThomas Gleixner
do_realtime_coarse() and do_monotonic_coarse() are now the same except for the storage array index. Hand the index in as an argument and collapse the functions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Rickard <matt@softrans.com.au> Cc: Stephen Boyd <sboyd@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: devel@linuxdriverproject.org Cc: virtualization@lists.linux-foundation.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Juergen Gross <jgross@suse.com> Link: https://lkml.kernel.org/r/20180917130707.490733779@linutronix.de
2018-10-04x86/vdso: Collapse high resolution functionsThomas Gleixner
do_realtime() and do_monotonic() are now the same except for the storage array index. Hand the index in as an argument and collapse the functions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Rickard <matt@softrans.com.au> Cc: Stephen Boyd <sboyd@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: devel@linuxdriverproject.org Cc: virtualization@lists.linux-foundation.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Juergen Gross <jgross@suse.com> Link: https://lkml.kernel.org/r/20180917130707.407955860@linutronix.de
2018-10-04x86/vdso: Introduce and use vgtod_tsThomas Gleixner
It's desired to support more clocks in the VDSO, e.g. CLOCK_TAI. This results either in indirect calls due to the larger switch case, which then requires retpolines or when the compiler is forced to avoid jump tables it results in even more conditionals. To avoid both variants which are bad for performance the high resolution functions and the coarse grained functions will be collapsed into one for each. That requires to store the clock specific base time in an array. Introcude struct vgtod_ts for storage and convert the data store, the update function and the individual clock functions over to use it. The new storage does not longer use gtod_long_t for seconds depending on 32 or 64 bit compile because this needs to be the full 64bit value even for 32bit when a Y2038 function is added. No point in keeping the distinction alive in the internal representation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Rickard <matt@softrans.com.au> Cc: Stephen Boyd <sboyd@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: devel@linuxdriverproject.org Cc: virtualization@lists.linux-foundation.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Juergen Gross <jgross@suse.com> Link: https://lkml.kernel.org/r/20180917130707.324679401@linutronix.de
2018-10-04x86/vdso: Use unsigned int consistently for vsyscall_gtod_data:: SeqThomas Gleixner
The sequence count in vgtod_data is unsigned int, but the call sites use unsigned long, which is a pointless exercise. Fix the call sites and replace 'unsigned' with unsinged 'int' while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Rickard <matt@softrans.com.au> Cc: Stephen Boyd <sboyd@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: devel@linuxdriverproject.org Cc: virtualization@lists.linux-foundation.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Juergen Gross <jgross@suse.com> Link: https://lkml.kernel.org/r/20180917130707.236250416@linutronix.de
2018-10-04x86/vdso: Enforce 64bit clocksourceThomas Gleixner
All VDSO clock sources are TSC based and use CLOCKSOURCE_MASK(64). There is no point in masking with all FF. Get rid of it and enforce the mask in the sanity checker. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Rickard <matt@softrans.com.au> Cc: Stephen Boyd <sboyd@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: devel@linuxdriverproject.org Cc: virtualization@lists.linux-foundation.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Juergen Gross <jgross@suse.com> Link: https://lkml.kernel.org/r/20180917130707.151963007@linutronix.de
2018-10-04x86/vdso: Fix vDSO syscall fallback asm constraint regressionAndy Lutomirski
When I added the missing memory outputs, I failed to update the index of the first argument (ebx) on 32-bit builds, which broke the fallbacks. Somehow I must have screwed up my testing or gotten lucky. Add another test to cover gettimeofday() as well. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: 715bd9d12f84 ("x86/vdso: Fix asm constraints on vDSO syscall fallbacks") Link: http://lkml.kernel.org/r/21bd45ab04b6d838278fa5bebfa9163eceffa13c.1538608971.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-03x86/vdso: Only enable vDSO retpolines when enabled and supportedAndy Lutomirski
When I fixed the vDSO build to use inline retpolines, I messed up the Makefile logic and made it unconditional. It should have depended on CONFIG_RETPOLINE and on the availability of compiler support. This broke the build on some older compilers. Reported-by: nikola.ciprich@linuxbox.cz Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Rickard <matt@softrans.com.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: jason.vas.dias@gmail.com Cc: stable@vger.kernel.org Fixes: 2e549b2ee0e3 ("x86/vdso: Fix vDSO build if a retpoline is emitted") Link: http://lkml.kernel.org/r/08a1f29f2c238dd1f493945e702a521f8a5aa3ae.1538540801.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-02x86/vdso: Fix asm constraints on vDSO syscall fallbacksAndy Lutomirski
The syscall fallbacks in the vDSO have incorrect asm constraints. They are not marked as writing to their outputs -- instead, they are marked as clobbering "memory", which is useless. In particular, gcc is smart enough to know that the timespec parameter hasn't escaped, so a memory clobber doesn't clobber it. And passing a pointer as an asm *input* does not tell gcc that the pointed-to value is changed. Add in the fact that the asm instructions weren't volatile, and gcc was free to omit them entirely unless their sole output (the return value) is used. Which it is (phew!), but that stops happening with some upcoming patches. As a trivial example, the following code: void test_fallback(struct timespec *ts) { vdso_fallback_gettime(CLOCK_MONOTONIC, ts); } compiles to: 00000000000000c0 <test_fallback>: c0: c3 retq To add insult to injury, the RCX and R11 clobbers on 64-bit builds were missing. The "memory" clobber is also unnecessary -- no ordering with respect to other memory operations is needed, but that's going to be fixed in a separate not-for-stable patch. Fixes: 2aae950b21e4 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/2c0231690551989d2fafa60ed0e7b5cc8b403908.1538422295.git.luto@kernel.org
2018-08-20x86/vdso: Fix vDSO build if a retpoline is emittedAndy Lutomirski
Currently, if the vDSO ends up containing an indirect branch or call, GCC will emit the "external thunk" style of retpoline, and it will fail to link. Fix it by building the vDSO with inline retpoline thunks. I haven't seen any reports of this triggering on an unpatched kernel. Fixes: commit 76b043848fd2 ("x86/retpoline: Add initial retpoline support") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Matt Rickard <matt@softrans.com.au> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Vas Dias <jason.vas.dias@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/c76538cd3afbe19c6246c2d1715bc6a60bd63985.1534448381.git.luto@kernel.org
2018-08-15Merge tag 'kbuild-v4.19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - verify depmod is installed before modules_install - support build salt in case build ids must be unique between builds - allow users to specify additional host compiler flags via HOST*FLAGS, and rename internal variables to KBUILD_HOST*FLAGS - update buildtar script to drop vax support, add arm64 support - update builddeb script for better debarch support - document the pit-fall of if_changed usage - fix parallel build of UML with O= option - make 'samples' target depend on headers_install to fix build errors - remove deprecated host-progs variable - add a new coccinelle script for refcount_t vs atomic_t check - improve double-test coccinelle script - misc cleanups and fixes * tag 'kbuild-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits) coccicheck: return proper error code on fail Coccinelle: doubletest: reduce side effect false positives kbuild: remove deprecated host-progs variable kbuild: make samples really depend on headers_install um: clean up archheaders recipe kbuild: add %asm-generic to no-dot-config-targets um: fix parallel building with O= option scripts: Add Python 3 support to tracing/draw_functrace.py builddeb: Add automatic support for sh{3,4}{,eb} architectures builddeb: Add automatic support for riscv* architectures builddeb: Add automatic support for m68k architecture builddeb: Add automatic support for or1k architecture builddeb: Add automatic support for sparc64 architecture builddeb: Add automatic support for mips{,64}r6{,el} architectures builddeb: Add automatic support for mips64el architecture builddeb: Add automatic support for ppc64 and powerpcspe architectures builddeb: Introduce functions to simplify kconfig tests in set_debarch builddeb: Drop check for 32-bit s390 builddeb: Change architecture detection fallback to use dpkg-architecture builddeb: Skip architecture detection when KBUILD_DEBARCH is set ...
2018-08-13Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 vdso update from Thomas Gleixner: "Use LD to link the VDSO libs instead of indirecting trough CC which causes build failures with Clang" * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: vdso: Use $LD instead of $CC to link
2018-08-05x86: vdso: Use $LD instead of $CC to linkAlistair Strachan
The vdso{32,64}.so can fail to link with CC=clang when clang tries to find a suitable GCC toolchain to link these libraries with. /usr/bin/ld: arch/x86/entry/vdso/vclock_gettime.o: access beyond end of merged section (782) This happens because the host environment leaked into the cross compiler environment due to the way clang searches for suitable GCC toolchains. Clang is a retargetable compiler, and each invocation of it must provide --target=<something> --gcc-toolchain=<something> to allow it to find the correct binutils for cross compilation. These flags had been added to KBUILD_CFLAGS, but the vdso code uses CC and not KBUILD_CFLAGS (for various reasons) which breaks clang's ability to find the correct linker when cross compiling. Most of the time this goes unnoticed because the host linker is new enough to work anyway, or is incompatible and skipped, but this cannot be reliably assumed. This change alters the vdso makefile to just use LD directly, which bypasses clang and thus the searching problem. The makefile will just use ${CROSS_COMPILE}ld instead, which is always what we want. This matches the method used to link vmlinux. This drops references to DISABLE_LTO; this option doesn't seem to be set anywhere, and not knowing what its possible values are, it's not clear how to convert it from CC to LD flag. Signed-off-by: Alistair Strachan <astrachan@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: kernel-team@android.com Cc: joel@joelfernandes.org Cc: Andi Kleen <andi.kleen@intel.com> Link: https://lkml.kernel.org/r/20180803173931.117515-1-astrachan@google.com
2018-07-18x86: Add build salt to the vDSOLaura Abbott
The vDSO needs to have a unique build id in a similar manner to the kernel and modules. Use the build salt macro. Acked-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-03x86/build/vdso: Simplify 'cmd_vdso2c'Masahiro Yamada
No reason to use 'define' directive here. Just use the = operator. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1530582614-5173-3-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-04Merge branch 'x86-build-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 build updates from Ingo Molnar: "A handful of build system (Makefile, linker script) cleanups by Masahiro Yamada" * 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/build/vdso: Put generated linker scripts to $(obj)/ x86/build/vdso: Remove unnecessary export in Makefile x86/build/vdso: Remove unused $(vobjs-nox32) in Makefile x86/build: Remove no-op macro VMLINUX_SYMBOL()
2018-05-15x86/build/vdso: Put generated linker scripts to $(obj)/Masahiro Yamada
Let's put generated files to $(obj)/ rather than $(src)/ although this is just a matter of taste because both are the same. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard@nod.at> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: user-mode-linux-devel@lists.sourceforge.net Cc: user-mode-linux-user@lists.sourceforge.net Link: http://lkml.kernel.org/r/1526352744-28229-4-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-15x86/build/vdso: Remove unnecessary export in MakefileMasahiro Yamada
CPPFLAGS_vdso.lds is assigned and referenced internally in each Makefile. No need to export it. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard@nod.at> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: user-mode-linux-devel@lists.sourceforge.net Cc: user-mode-linux-user@lists.sourceforge.net Link: http://lkml.kernel.org/r/1526352744-28229-3-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-15x86/build/vdso: Remove unused $(vobjs-nox32) in MakefileMasahiro Yamada
Since commit bfad381c0d1e ("x86/vdso: Improve the fake section headers"), $(vobjs-nox32) is empty. Therefore, $(vobjs64-for-x32) is the same as $(vobjs-y). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1526352744-28229-2-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-05x86/vdso: Remove unused fileJann Horn
commit da861e18eccc ("x86, vdso: Get rid of the fake section mechanism") left this file behind; nothing is using it anymore. Signed-off-by: Jann Horn <jannh@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: luto@amacapital.net Link: http://lkml.kernel.org/r/20180504175935.104085-1-jannh@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-07kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markersMasahiro Yamada
GNU Make automatically deletes intermediate files that are updated in a chain of pattern rules. Example 1) %.dtb.o <- %.dtb.S <- %.dtb <- %.dts Example 2) %.o <- %.c <- %.c_shipped A couple of makefiles mark such targets as .PRECIOUS to prevent Make from deleting them, but the correct way is to use .SECONDARY. .SECONDARY Prerequisites of this special target are treated as intermediate files but are never automatically deleted. .PRECIOUS When make is interrupted during execution, it may delete the target file it is updating if the file was modified since make started. If you mark the file as precious, make will never delete the file if interrupted. Both can avoid deletion of intermediate files, but the difference is the behavior when Make is interrupted; .SECONDARY deletes the target, but .PRECIOUS does not. The use of .PRECIOUS is relatively rare since we do not want to keep partially constructed (possibly corrupted) targets. Another difference is that .PRECIOUS works with pattern rules whereas .SECONDARY does not. .PRECIOUS: $(obj)/%.lex.c works, but .SECONDARY: $(obj)/%.lex.c has no effect. However, for the reason above, I do not want to use .PRECIOUS which could cause obscure build breakage. The targets specified as .SECONDARY must be explicit. $(targets) contains all targets that need to include .*.cmd files. So, the intermediates you want to keep are mostly in there. Therefore, mark $(targets) as .SECONDARY. It means primary targets are also marked as .SECONDARY, but I do not see any drawback for this. I replaced some .SECONDARY / .PRECIOUS markers with 'targets'. This will make Kbuild search for non-existing .*.cmd files, but this is not a noticeable performance issue. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Frank Rowand <frowand.list@gmail.com> Acked-by: Ingo Molnar <mingo@kernel.org>
2018-03-20x86/cpu: Remove the CONFIG_X86_PPRO_FENCE=y quirkChristoph Hellwig
There were only a few Pentium Pro multiprocessors systems where this errata applied. They are more than 20 years old now, and we've slowly dropped places which put the workarounds in and discouraged anyone from enabling the workaround. Get rid of it for good. Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jon Mason <jdmason@kudzu.us> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Muli Ben-Yehuda <mulix@mulix.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: iommu@lists.linux-foundation.org Link: http://lkml.kernel.org/r/20180319103826.12853-2-hch@lst.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-06Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc x86 fixes from Ingo Molnar: - make CR4 handling irq-safe, which bug vmware guests ran into - don't crash on early IRQs in Xen guests - don't crash secondary CPU bringup if #UD assisted WARN()ings are triggered - make X86_BUG_FXSAVE_LEAK optional on newer AMD CPUs that have the fix - fix AMD Fam17h microcode loading - fix broadcom_postcore_init() if ACPI is disabled - fix resume regression in __restore_processor_context() - fix Sparse warnings - fix a GCC-8 warning * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Change time() prototype to match __vdso_time() x86: Fix Sparse warnings about non-static functions x86/power: Fix some ordering bugs in __restore_processor_context() x86/PCI: Make broadcom_postcore_init() check acpi_disabled x86/microcode/AMD: Add support for fam17h microcode loading x86/cpufeatures: Make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD x86/idt: Load idt early in start_secondary x86/xen: Support early interrupts in xen pv guests x86/tlb: Disable interrupts when changing CR4 x86/tlb: Refactor CR4 setting and shadow write
2017-12-06x86/vdso: Change time() prototype to match __vdso_time()Arnd Bergmann
gcc-8 warns that time() is an alias for __vdso_time() but the two have different prototypes: arch/x86/entry/vdso/vclock_gettime.c:327:5: error: 'time' alias between functions of incompatible types 'int(time_t *)' {aka 'int(long int *)'} and 'time_t(time_t *)' {aka 'long int(long int *)'} [-Werror=attribute-alias] int time(time_t *t) ^~~~ arch/x86/entry/vdso/vclock_gettime.c:318:16: note: aliased declaration here I could not figure out whether this is intentional, but I see that changing it to return time_t avoids the warning. Returning 'int' from time() is also a bit questionable, as it causes an overflow in y2038 even on 64-bit architectures that use a 64-bit time_t type. On 32-bit architecture with 64-bit time_t, time() should always be implement by the C library by calling a (to be added) clock_gettime() variant that takes a sufficiently wide argument. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Link: http://lkml.kernel.org/r/20171204150203.852959-1-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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