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2023-01-18mm/khugepaged: fix GUP-fast interaction by sending IPIJann Horn1-0/+6
commit 2ba99c5e08812494bc57f319fb562f527d9bacd8 upstream. Since commit 70cbc3cc78a99 ("mm: gup: fix the fast GUP race against THP collapse"), the lockless_pages_from_mm() fastpath rechecks the pmd_t to ensure that the page table was not removed by khugepaged in between. However, lockless_pages_from_mm() still requires that the page table is not concurrently freed. Fix it by sending IPIs (if the architecture uses semi-RCU-style page table freeing) before freeing/reusing page tables. Link: https://lkml.kernel.org/r/20221129154730.2274278-2-jannh@google.com Link: https://lkml.kernel.org/r/20221128180252.1684965-2-jannh@google.com Link: https://lkml.kernel.org/r/20221125213714.4115729-2-jannh@google.com Fixes: ba76149f47d8 ("thp: khugepaged") Signed-off-by: Jann Horn <jannh@google.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Peter Xu <peterx@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [manual backport: two of the three places in khugepaged that can free ptes were refactored into a common helper between 5.15 and 6.0; TLB flushing was refactored between 5.4 and 5.10; TLB flushing was refactored between 4.19 and 5.4; pmd collapse for PTE-mapped THP was only added in 5.4; ugly hack needed in <=4.19 for s390 and arm] Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25vmlinux.lds.h: Fix placement of '.data..decrypted' sectionNathan Chancellor1-1/+1
commit 000f8870a47bdc36730357883b6aef42bced91ee upstream. Commit d4c639990036 ("vmlinux.lds.h: Avoid orphan section with !SMP") fixed an orphan section warning by adding the '.data..decrypted' section to the linker script under the PERCPU_DECRYPTED_SECTION define but that placement introduced a panic with !SMP, as the percpu sections are not instantiated with that configuration so attempting to access variables defined with DEFINE_PER_CPU_DECRYPTED() will result in a page fault. Move the '.data..decrypted' section to the DATA_MAIN define so that the variables in it are properly instantiated at boot time with CONFIG_SMP=n. Cc: stable@vger.kernel.org Fixes: d4c639990036 ("vmlinux.lds.h: Avoid orphan section with !SMP") Link: https://lore.kernel.org/cbbd3548-880c-d2ca-1b67-5bb93b291d5f@huawei.com/ Debugged-by: Ard Biesheuvel <ardb@kernel.org> Reported-by: Zhao Wenhui <zhaowenhui8@huawei.com> Tested-by: xiafukun <xiafukun@huawei.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221108174934.3384275-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05asm-generic: sections: refactor memory_intersectsQuanyang Wang1-2/+5
commit 0c7d7cc2b4fe2e74ef8728f030f0f1674f9f6aee upstream. There are two problems with the current code of memory_intersects: First, it doesn't check whether the region (begin, end) falls inside the region (virt, vend), that is (virt < begin && vend > end). The second problem is if vend is equal to begin, it will return true but this is wrong since vend (virt + size) is not the last address of the memory region but (virt + size -1) is. The wrong determination will trigger the misreporting when the function check_for_illegal_area calls memory_intersects to check if the dma region intersects with stext region. The misreporting is as below (stext is at 0x80100000): WARNING: CPU: 0 PID: 77 at kernel/dma/debug.c:1073 check_for_illegal_area+0x130/0x168 DMA-API: chipidea-usb2 e0002000.usb: device driver maps memory from kernel text or rodata [addr=800f0000] [len=65536] Modules linked in: CPU: 1 PID: 77 Comm: usb-storage Not tainted 5.19.0-yocto-standard #5 Hardware name: Xilinx Zynq Platform unwind_backtrace from show_stack+0x18/0x1c show_stack from dump_stack_lvl+0x58/0x70 dump_stack_lvl from __warn+0xb0/0x198 __warn from warn_slowpath_fmt+0x80/0xb4 warn_slowpath_fmt from check_for_illegal_area+0x130/0x168 check_for_illegal_area from debug_dma_map_sg+0x94/0x368 debug_dma_map_sg from __dma_map_sg_attrs+0x114/0x128 __dma_map_sg_attrs from dma_map_sg_attrs+0x18/0x24 dma_map_sg_attrs from usb_hcd_map_urb_for_dma+0x250/0x3b4 usb_hcd_map_urb_for_dma from usb_hcd_submit_urb+0x194/0x214 usb_hcd_submit_urb from usb_sg_wait+0xa4/0x118 usb_sg_wait from usb_stor_bulk_transfer_sglist+0xa0/0xec usb_stor_bulk_transfer_sglist from usb_stor_bulk_srb+0x38/0x70 usb_stor_bulk_srb from usb_stor_Bulk_transport+0x150/0x360 usb_stor_Bulk_transport from usb_stor_invoke_transport+0x38/0x440 usb_stor_invoke_transport from usb_stor_control_thread+0x1e0/0x238 usb_stor_control_thread from kthread+0xf8/0x104 kthread from ret_from_fork+0x14/0x2c Refactor memory_intersects to fix the two problems above. Before the 1d7db834a027e ("dma-debug: use memory_intersects() directly"), memory_intersects is called only by printk_late_init: printk_late_init -> init_section_intersects ->memory_intersects. There were few places where memory_intersects was called. When commit 1d7db834a027e ("dma-debug: use memory_intersects() directly") was merged and CONFIG_DMA_API_DEBUG is enabled, the DMA subsystem uses it to check for an illegal area and the calltrace above is triggered. [akpm@linux-foundation.org: fix nearby comment typo] Link: https://lkml.kernel.org/r/20220819081145.948016-1-quanyang.wang@windriver.com Fixes: 979559362516 ("asm/sections: add helpers to check for section data") Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Thierry Reding <treding@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25locking/atomic: Make test_and_*_bit() ordered on failureHector Martin1-6/+0
commit 415d832497098030241605c52ea83d4e2cfa7879 upstream. These operations are documented as always ordered in include/asm-generic/bitops/instrumented-atomic.h, and producer-consumer type use cases where one side needs to ensure a flag is left pending after some shared data was updated rely on this ordering, even in the failure case. This is the case with the workqueue code, which currently suffers from a reproducible ordering violation on Apple M1 platforms (which are notoriously out-of-order) that ends up causing the TTY layer to fail to deliver data to userspace properly under the right conditions. This change fixes that bug. Change the documentation to restrict the "no order on failure" story to the _lock() variant (for which it makes sense), and remove the early-exit from the generic implementation, which is what causes the missing barrier semantics in that case. Without this, the remaining atomic op is fully ordered (including on ARM64 LSE, as of recent versions of the architecture spec). Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org Fixes: e986a0d6cb36 ("locking/atomics, asm-generic/bitops/atomic.h: Rewrite using atomic_*() APIs") Fixes: 61e02392d3c7 ("locking/atomic/bitops: Document and clarify ordering semantics for failed test_and_{}_bit()") Signed-off-by: Hector Martin <marcan@marcan.st> Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-01hugetlbfs: flush TLBs correctly after huge_pmd_unshareNadav Amit1-0/+2
commit a4a118f2eead1d6c49e00765de89878288d4b890 upstream. When __unmap_hugepage_range() calls to huge_pmd_unshare() succeed, a TLB flush is missing. This TLB flush must be performed before releasing the i_mmap_rwsem, in order to prevent an unshared PMDs page from being released and reused before the TLB flush took place. Arguably, a comprehensive solution would use mmu_gather interface to batch the TLB flushes and the PMDs page release, however it is not an easy solution: (1) try_to_unmap_one() and try_to_migrate_one() also call huge_pmd_unshare() and they cannot use the mmu_gather interface; and (2) deferring the release of the page reference for the PMDs page until after i_mmap_rwsem is dropeed can confuse huge_pmd_unshare() into thinking PMDs are shared when they are not. Fix __unmap_hugepage_range() by adding the missing TLB flush, and forcing a flush when unshare is successful. Fixes: 24669e58477e ("hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages)" # 3.6 Signed-off-by: Nadav Amit <namit@vmware.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-06arch: pgtable: define MAX_POSSIBLE_PHYSMEM_BITS where neededArnd Bergmann1-0/+13
commit cef397038167ac15d085914493d6c86385773709 upstream. Stefan Agner reported a bug when using zsram on 32-bit Arm machines with RAM above the 4GB address boundary: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = a27bd01c [00000000] *pgd=236a0003, *pmd=1ffa64003 Internal error: Oops: 207 [#1] SMP ARM Modules linked in: mdio_bcm_unimac(+) brcmfmac cfg80211 brcmutil raspberrypi_hwmon hci_uart crc32_arm_ce bcm2711_thermal phy_generic genet CPU: 0 PID: 123 Comm: mkfs.ext4 Not tainted 5.9.6 #1 Hardware name: BCM2711 PC is at zs_map_object+0x94/0x338 LR is at zram_bvec_rw.constprop.0+0x330/0xa64 pc : [<c0602b38>] lr : [<c0bda6a0>] psr: 60000013 sp : e376bbe0 ip : 00000000 fp : c1e2921c r10: 00000002 r9 : c1dda730 r8 : 00000000 r7 : e8ff7a00 r6 : 00000000 r5 : 02f9ffa0 r4 : e3710000 r3 : 000fdffe r2 : c1e0ce80 r1 : ebf979a0 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5383d Table: 235c2a80 DAC: fffffffd Process mkfs.ext4 (pid: 123, stack limit = 0x495a22e6) Stack: (0xe376bbe0 to 0xe376c000) As it turns out, zsram needs to know the maximum memory size, which is defined in MAX_PHYSMEM_BITS when CONFIG_SPARSEMEM is set, or in MAX_POSSIBLE_PHYSMEM_BITS on the x86 architecture. The same problem will be hit on all 32-bit architectures that have a physical address space larger than 4GB and happen to not enable sparsemem and include asm/sparsemem.h from asm/pgtable.h. After the initial discussion, I suggested just always defining MAX_POSSIBLE_PHYSMEM_BITS whenever CONFIG_PHYS_ADDR_T_64BIT is set, or provoking a build error otherwise. This addresses all configurations that can currently have this runtime bug, but leaves all other configurations unchanged. I looked up the possible number of bits in source code and datasheets, here is what I found: - on ARC, CONFIG_ARC_HAS_PAE40 controls whether 32 or 40 bits are used - on ARM, CONFIG_LPAE enables 40 bit addressing, without it we never support more than 32 bits, even though supersections in theory allow up to 40 bits as well. - on MIPS, some MIPS32r1 or later chips support 36 bits, and MIPS32r5 XPA supports up to 60 bits in theory, but 40 bits are more than anyone will ever ship - On PowerPC, there are three different implementations of 36 bit addressing, but 32-bit is used without CONFIG_PTE_64BIT - On RISC-V, the normal page table format can support 34 bit addressing. There is no highmem support on RISC-V, so anything above 2GB is unused, but it might be useful to eventually support CONFIG_ZRAM for high pages. Fixes: 61989a80fb3a ("staging: zsmalloc: zsmalloc memory allocation library") Fixes: 02390b87a945 ("mm/zsmalloc: Prepare to variable MAX_PHYSMEM_BITS") Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Reviewed-by: Stefan Agner <stefan@agner.ch> Tested-by: Stefan Agner <stefan@agner.ch> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Link: https://lore.kernel.org/linux-mm/bdfa44bf1c570b05d6c70898e2bbb0acf234ecdf.1604762181.git.stefan@agner.ch/ Signed-off-by: Arnd Bergmann <arnd@arndb.de> [florian: patch arch/powerpc/include/asm/pte-common.h for 4.19.y] Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-26vmlinux.lds.h: Handle clang's module.{c,d}tor sectionsNathan Chancellor1-0/+1
commit 848378812e40152abe9b9baf58ce2004f76fb988 upstream. A recent change in LLVM causes module_{c,d}tor sections to appear when CONFIG_K{A,C}SAN are enabled, which results in orphan section warnings because these are not handled anywhere: ld.lld: warning: arch/x86/pci/built-in.a(legacy.o):(.text.asan.module_ctor) is being placed in '.text.asan.module_ctor' ld.lld: warning: arch/x86/pci/built-in.a(legacy.o):(.text.asan.module_dtor) is being placed in '.text.asan.module_dtor' ld.lld: warning: arch/x86/pci/built-in.a(legacy.o):(.text.tsan.module_ctor) is being placed in '.text.tsan.module_ctor' Fangrui explains: "the function asan.module_ctor has the SHF_GNU_RETAIN flag, so it is in a separate section even with -fno-function-sections (default)". Place them in the TEXT_TEXT section so that these technologies continue to work with the newer compiler versions. All of the KASAN and KCSAN KUnit tests continue to pass after this change. Cc: stable@vger.kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/1432 Link: https://github.com/llvm/llvm-project/commit/7b789562244ee941b7bf2cefeb3fc08a59a01865 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Fangrui Song <maskray@google.com> Acked-by: Marco Elver <elver@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210731023107.1932981-1-nathan@kernel.org [nc: Resolve conflict due to lack of cf68fffb66d60] Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-16vmlinux.lds.h: Avoid orphan section with !SMPNathan Chancellor1-0/+1
commit d4c6399900364facd84c9e35ce1540b6046c345f upstream. With x86_64_defconfig and the following configs, there is an orphan section warning: CONFIG_SMP=n CONFIG_AMD_MEM_ENCRYPT=y CONFIG_HYPERVISOR_GUEST=y CONFIG_KVM=y CONFIG_PARAVIRT=y ld: warning: orphan section `.data..decrypted' from `arch/x86/kernel/cpu/vmware.o' being placed in section `.data..decrypted' ld: warning: orphan section `.data..decrypted' from `arch/x86/kernel/kvm.o' being placed in section `.data..decrypted' These sections are created with DEFINE_PER_CPU_DECRYPTED, which ultimately turns into __PCPU_ATTRS, which in turn has a section attribute with a value of PER_CPU_BASE_SECTION + the section name. When CONFIG_SMP is not set, the base section is .data and that is not currently handled in any linker script. Add .data..decrypted to PERCPU_DECRYPTED_SECTION, which is included in PERCPU_INPUT -> PERCPU_SECTION, which is include in the x86 linker script when either CONFIG_X86_64 or CONFIG_SMP is unset, taking care of the warning. Fixes: ac26963a1175 ("percpu: Introduce DEFINE_PER_CPU_DECRYPTED") Link: https://github.com/ClangBuiltLinux/linux/issues/1360 Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> # build Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210506001410.1026691-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-24vmlinux.lds.h: Create section for protection against instrumentationNicolas Boichat2-0/+13
From: Thomas Gleixner <tglx@linutronix.de> commit 6553896666433e7efec589838b400a2a652b3ffa upstream. Some code pathes, especially the low level entry code, must be protected against instrumentation for various reasons: - Low level entry code can be a fragile beast, especially on x86. - With NO_HZ_FULL RCU state needs to be established before using it. Having a dedicated section for such code allows to validate with tooling that no unsafe functions are invoked. Add the .noinstr.text section and the noinstr attribute to mark functions. noinstr implies notrace. Kprobes will gain a section check later. Provide also a set of markers: instrumentation_begin()/end() These are used to mark code inside a noinstr function which calls into regular instrumentable text section as safe. The instrumentation markers are only active when CONFIG_DEBUG_ENTRY is enabled as the end marker emits a NOP to prevent the compiler from merging the annotation points. This means the objtool verification requires a kernel compiled with this option. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134100.075416272@linutronix.de [Nicolas: Guard noinstr macro in include/linux/compiler_types.h in __KERNEL__ && !__ASSEMBLY__, otherwise noinstr is expanded in the linker script construct. Upstream does not have this problem as many macros were moved by commit 71391bdd2e9a ("include/linux/compiler_types.h: don't pollute userspace with macro definitions"). We take the minimal approach here and just guard the new macro. Minor context conflicts in: arch/powerpc/kernel/vmlinux.lds.S include/asm-generic/vmlinux.lds.h include/linux/compiler.h] Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04vmlinux.lds.h: add DWARF v5 sectionsNick Desaulniers1-1/+6
commit 3c4fa46b30c551b1df2fb1574a684f68bc22067c upstream. We expect toolchains to produce these new debug info sections as part of DWARF v5. Add explicit placements to prevent the linker warnings from --orphan-section=warn. Compilers may produce such sections with explicit -gdwarf-5, or based on the implicit default version of DWARF when -g is used via DEBUG_INFO. This implicit default changes over time, and has changed to DWARF v5 with GCC 11. .debug_sup was mentioned in review, but without compilers producing it today, let's wait to add it until it becomes necessary. Cc: stable@vger.kernel.org Link: https://bugzilla.redhat.com/show_bug.cgi?id=1922707 Reported-by: Chris Murphy <lists@colorremedies.com> Suggested-by: Fangrui Song <maskray@google.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Mark Wielaard <mark@klomp.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-23firmware_loader: align .builtin_fw to 8Fangrui Song1-1/+1
[ Upstream commit 793f49a87aae24e5bcf92ad98d764153fc936570 ] arm64 references the start address of .builtin_fw (__start_builtin_fw) with a pair of R_AARCH64_ADR_PREL_PG_HI21/R_AARCH64_LDST64_ABS_LO12_NC relocations. The compiler is allowed to emit the R_AARCH64_LDST64_ABS_LO12_NC relocation because struct builtin_fw in include/linux/firmware.h is 8-byte aligned. The R_AARCH64_LDST64_ABS_LO12_NC relocation requires the address to be a multiple of 8, which may not be the case if .builtin_fw is empty. Unconditionally align .builtin_fw to fix the linker error. 32-bit architectures could use ALIGN(4) but that would add unnecessary complexity, so just use ALIGN(8). Link: https://lkml.kernel.org/r/20201208054646.2913063-1-maskray@google.com Link: https://github.com/ClangBuiltLinux/linux/issues/1204 Fixes: 5658c76 ("firmware: allow firmware files to be built into kernel image") Signed-off-by: Fangrui Song <maskray@google.com> Reported-by: kernel test robot <lkp@intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Douglas Anderson <dianders@chromium.org> Acked-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-17vmlinux.lds.h: Add PGO and AutoFDO input sectionsNick Desaulniers1-1/+4
commit eff8728fe69880d3f7983bec3fb6cea4c306261f upstream. Basically, consider .text.{hot|unlikely|unknown}.* part of .text, too. When compiling with profiling information (collected via PGO instrumentations or AutoFDO sampling), Clang will separate code into .text.hot, .text.unlikely, or .text.unknown sections based on profiling information. After D79600 (clang-11), these sections will have a trailing `.` suffix, ie. .text.hot., .text.unlikely., .text.unknown.. When using -ffunction-sections together with profiling infomation, either explicitly (FGKASLR) or implicitly (LTO), code may be placed in sections following the convention: .text.hot.<foo>, .text.unlikely.<bar>, .text.unknown.<baz> where <foo>, <bar>, and <baz> are functions. (This produces one section per function; we generally try to merge these all back via linker script so that we don't have 50k sections). For the above cases, we need to teach our linker scripts that such sections might exist and that we'd explicitly like them grouped together, otherwise we can wind up with code outside of the _stext/_etext boundaries that might not be mapped properly for some architectures, resulting in boot failures. If the linker script is not told about possible input sections, then where the section is placed as output is a heuristic-laiden mess that's non-portable between linkers (ie. BFD and LLD), and has resulted in many hard to debug bugs. Kees Cook is working on cleaning this up by adding --orphan-handling=warn linker flag used in ARCH=powerpc to additional architectures. In the case of linker scripts, borrowing from the Zen of Python: explicit is better than implicit. Also, ld.bfd's internal linker script considers .text.hot AND .text.hot.* to be part of .text, as well as .text.unlikely and .text.unlikely.*. I didn't see support for .text.unknown.*, and didn't see Clang producing such code in our kernel builds, but I see code in LLVM that can produce such section names if profiling information is missing. That may point to a larger issue with generating or collecting profiles, but I would much rather be safe and explicit than have to debug yet another issue related to orphan section placement. Reported-by: Jian Cai <jiancai@google.com> Suggested-by: Fāng-ruì Sòng <maskray@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Luis Lozano <llozano@google.com> Tested-by: Manoj Gupta <manojgupta@google.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: linux-arch@vger.kernel.org Cc: stable@vger.kernel.org Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=add44f8d5c5c05e08b11e033127a744d61c26aee Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=1de778ed23ce7492c523d5850c6c6dbb34152655 Link: https://reviews.llvm.org/D79600 Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1084760 Link: https://lore.kernel.org/r/20200821194310.3089815-7-keescook@chromium.org Debugged-by: Luis Lozano <llozano@google.com> [nc: Resolve small conflict due to lack of NOINSTR_TEXT] Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10mm: always have io_remap_pfn_range() set pgprot_decrypted()Jason Gunthorpe1-4/+0
commit f8f6ae5d077a9bdaf5cbf2ac960a5d1a04b47482 upstream. The purpose of io_remap_pfn_range() is to map IO memory, such as a memory mapped IO exposed through a PCI BAR. IO devices do not understand encryption, so this memory must always be decrypted. Automatically call pgprot_decrypted() as part of the generic implementation. This fixes a bug where enabling AMD SME causes subsystems, such as RDMA, using io_remap_pfn_range() to expose BAR pages to user space to fail. The CPU will encrypt access to those BAR pages instead of passing unencrypted IO directly to the device. Places not mapping IO should use remap_pfn_range(). Fixes: aca20d546214 ("x86/mm: Add support to make use of Secure Memory Encryption") Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "Dave Young" <dyoung@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ingo Molnar <mingo@kernel.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Toshimitsu Kani <toshi.kani@hpe.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/0-v1-025d64bdf6c4+e-amd_sme_fix_jgg@nvidia.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-19include/asm-generic/vmlinux.lds.h: align ro_after_initRomain Naour1-0/+1
commit 7f897acbe5d57995438c831670b7c400e9c0dc00 upstream. Since the patch [1], building the kernel using a toolchain built with binutils 2.33.1 prevents booting a sh4 system under Qemu. Apply the patch provided by Alan Modra [2] that fix alignment of rodata. [1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ebd2263ba9a9124d93bbc0ece63d7e0fae89b40e [2] https://www.sourceware.org/ml/binutils/2019-12/msg00112.html Signed-off-by: Romain Naour <romain.naour@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alan Modra <amodra@gmail.com> Cc: Bin Meng <bin.meng@windriver.com> Cc: Chen Zhou <chenzhou10@huawei.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Cc: Rich Felker <dalias@libc.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Arnd Bergmann <arnd@arndb.de> Cc: <stable@vger.kernel.org> Link: https://marc.info/?l=linux-sh&m=158429470221261 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29x86, vmlinux.lds: Page-align end of ..page_aligned sectionsJoerg Roedel1-1/+4
commit de2b41be8fcccb2f5b6c480d35df590476344201 upstream. On x86-32 the idt_table with 256 entries needs only 2048 bytes. It is page-aligned, but the end of the .bss..page_aligned section is not guaranteed to be page-aligned. As a result, objects from other .bss sections may end up on the same 4k page as the idt_table, and will accidentially get mapped read-only during boot, causing unexpected page-faults when the kernel writes to them. This could be worked around by making the objects in the page aligned sections page sized, but that's wrong. Explicit sections which store only page aligned objects have an implicit guarantee that the object is alone in the page in which it is placed. That works for all objects except the last one. That's inconsistent. Enforcing page sized objects for these sections would wreckage memory sanitizers, because the object becomes artificially larger than it should be and out of bound access becomes legit. Align the end of the .bss..page_aligned and .data..page_aligned section on page-size so all objects places in these sections are guaranteed to have their own page. [ tglx: Amended changelog ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20200721093448.10417-1-joro@8bytes.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03include/asm-generic/topology.h: guard cpumask_of_node() macro argumentArnd Bergmann1-1/+1
[ Upstream commit 4377748c7b5187c3342a60fa2ceb60c8a57a8488 ] drivers/hwmon/amd_energy.c:195:15: error: invalid operands to binary expression ('void' and 'int') (channel - data->nr_cpus)); ~~~~~~~~~^~~~~~~~~~~~~~~~~ include/asm-generic/topology.h:51:42: note: expanded from macro 'cpumask_of_node' #define cpumask_of_node(node) ((void)node, cpu_online_mask) ^~~~ include/linux/cpumask.h:618:72: note: expanded from macro 'cpumask_first_and' #define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p)) ^~~~~ Fixes: f0b848ce6fe9 ("cpumask: Introduce cpumask_of_{node,pcibus} to replace {node,pcibus}_to_cpumask") Fixes: 8abee9566b7e ("hwmon: Add amd_energy driver to report energy counters") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Guenter Roeck <linux@roeck-us.net> Link: http://lkml.kernel.org/r/20200527134623.930247-1-arnd@arndb.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-25asm-generic: fix -Wtype-limits compiler warningsQian Cai1-30/+20
[ Upstream commit cbedfe11347fe418621bd188d58a206beb676218 ] Commit d66acc39c7ce ("bitops: Optimise get_order()") introduced a compilation warning because "rx_frag_size" is an "ushort" while PAGE_SHIFT here is 16. The commit changed the get_order() to be a multi-line macro where compilers insist to check all statements in the macro even when __builtin_constant_p(rx_frag_size) will return false as "rx_frag_size" is a module parameter. In file included from ./arch/powerpc/include/asm/page_64.h:107, from ./arch/powerpc/include/asm/page.h:242, from ./arch/powerpc/include/asm/mmu.h:132, from ./arch/powerpc/include/asm/lppaca.h:47, from ./arch/powerpc/include/asm/paca.h:17, from ./arch/powerpc/include/asm/current.h:13, from ./include/linux/thread_info.h:21, from ./arch/powerpc/include/asm/processor.h:39, from ./include/linux/prefetch.h:15, from drivers/net/ethernet/emulex/benet/be_main.c:14: drivers/net/ethernet/emulex/benet/be_main.c: In function 'be_rx_cqs_create': ./include/asm-generic/getorder.h:54:9: warning: comparison is always true due to limited range of data type [-Wtype-limits] (((n) < (1UL << PAGE_SHIFT)) ? 0 : \ ^ drivers/net/ethernet/emulex/benet/be_main.c:3138:33: note: in expansion of macro 'get_order' adapter->big_page_size = (1 << get_order(rx_frag_size)) * PAGE_SIZE; ^~~~~~~~~ Fix it by moving all of this multi-line macro into a proper function, and killing __get_order() off. [akpm@linux-foundation.org: remove __get_order() altogether] [cai@lca.pw: v2] Link: http://lkml.kernel.org/r/1564000166-31428-1-git-send-email-cai@lca.pw Link: http://lkml.kernel.org/r/1563914986-26502-1-git-send-email-cai@lca.pw Fixes: d66acc39c7ce ("bitops: Optimise get_order()") Signed-off-by: Qian Cai <cai@lca.pw> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Howells <dhowells@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Bill Wendling <morbo@google.com> Cc: James Y Knight <jyknight@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-26include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT ↵Drew Davenport1-2/+4
architectures commit 6b15f678fb7d5ef54e089e6ace72f007fe6e9895 upstream. For architectures using __WARN_TAINT, the WARN_ON macro did not print out the "cut here" string. The other WARN_XXX macros would print "cut here" inside __warn_printk, which is not called for WARN_ON since it doesn't have a message to print. Link: http://lkml.kernel.org/r/20190624154831.163888-1-ddavenport@chromium.org Fixes: a7bed27af194 ("bug: fix "cut here" location for __WARN_TAINT architectures") Signed-off-by: Drew Davenport <ddavenport@chromium.org> Acked-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03futex: Update comments and docs about return values of arch futex codeWill Deacon1-2/+6
commit 427503519739e779c0db8afe876c1b33f3ac60ae upstream. The architecture implementations of 'arch_futex_atomic_op_inuser()' and 'futex_atomic_cmpxchg_inatomic()' are permitted to return only -EFAULT, -EAGAIN or -ENOSYS in the case of failure. Update the comments in the asm-generic/ implementation and also a stray reference in the robust futex documentation. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23x86/unwind/orc: Fix ORC unwind table alignmentJosh Poimboeuf1-1/+1
commit f76a16adc485699f95bb71fce114f97c832fe664 upstream. The .orc_unwind section is a packed array of 6-byte structs. It's currently aligned to 6 bytes, which is causing warnings in the LLD linker. Six isn't a power of two, so it's not a valid alignment value. The actual alignment doesn't matter much because it's an array of packed structs. An alignment of two is sufficient. In reality it always gets aligned to four bytes because it comes immediately after the 4-byte-aligned .orc_unwind_ip section. Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") Reported-by: Nick Desaulniers <ndesaulniers@google.com> Reported-by: Dmitry Golovin <dima@golovin.in> Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/218 Link: https://lkml.kernel.org/r/d55027ee95fe73e952dcd8be90aebd31b0095c45.1551892041.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-29mm: introduce mm_[p4d|pud|pmd]_foldedMartin Schwidefsky1-0/+16
[ Upstream commit 1071fc5779d9846fec56a4ff6089ab08cac1ab72 ] Add three architecture overrideable functions to test if the p4d, pud, or pmd layer of a page table is folded or not. Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-12-29mm: make the __PAGETABLE_PxD_FOLDED defines non-emptyMartin Schwidefsky6-6/+6
[ Upstream commit a8874e7e8a8896f2b6c641f4b8e2473eafd35204 ] Change the currently empty defines for __PAGETABLE_PMD_FOLDED, __PAGETABLE_PUD_FOLDED and __PAGETABLE_P4D_FOLDED to return 1. This makes it possible to use __is_defined() to test if the preprocessor define exists. Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-10-12vmlinux.lds.h: Fix linker warnings about orphan .LPBX sectionsPeter Oberparleiter1-1/+1
Enabling both CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y and CONFIG_GCOV_PROFILE_ALL=y results in linker warnings: warning: orphan section `.data..LPBX1' being placed in section `.data..LPBX1'. LD_DEAD_CODE_DATA_ELIMINATION adds compiler flag -fdata-sections. This option causes GCC to create separate data sections for data objects, including those generated by GCC internally for gcov profiling. The names of these objects start with a dot (.LPBX0, .LPBX1), resulting in section names starting with 'data..'. As section names starting with 'data..' are used for specific purposes in the Linux kernel, the linker script does not automatically include them in the output data section, resulting in the "orphan section" linker warnings. Fix this by specifically including sections named "data..LPBX*" in the data section. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Tested-by: Stephen Rothwell <sfr@canb.auug.org.au> Tested-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
2018-10-12vmlinux.lds.h: Fix incomplete .text.exit discardsPeter Oberparleiter1-2/+2
Enabling CONFIG_GCOV_PROFILE_ALL=y causes linker errors on ARM: `.text.exit' referenced in section `.ARM.exidx.text.exit': defined in discarded section `.text.exit' `.text.exit' referenced in section `.fini_array.00100': defined in discarded section `.text.exit' And related errors on NDS32: `.text.exit' referenced in section `.dtors.65435': defined in discarded section `.text.exit' The gcov compiler flags cause certain compiler versions to generate additional destructor-related sections that are not yet handled by the linker script, resulting in references between discarded and non-discarded sections. Since destructors are not used in the Linux kernel, fix this by discarding these additional sections. Reported-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Reported-by: Greentime Hu <green.hu@gmail.com> Tested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
2018-09-14asm-generic: io: Fix ioport_map() for !CONFIG_GENERIC_IOMAP && ↵Andrew Murray1-1/+2
CONFIG_INDIRECT_PIO The !CONFIG_GENERIC_IOMAP version of ioport_map uses MMIO_UPPER_LIMIT to prevent users from making I/O accesses outside the expected I/O range - however it erroneously treats MMIO_UPPER_LIMIT as a mask which is contradictory to its other users. The introduction of CONFIG_INDIRECT_PIO, which subtracts an arbitrary amount from IO_SPACE_LIMIT to form MMIO_UPPER_LIMIT, results in ioport_map mangling the given port rather than capping it. We address this by aligning more closely with the CONFIG_GENERIC_IOMAP implementation of ioport_map by using the comparison operator and returning NULL where the port exceeds MMIO_UPPER_LIMIT. Though note that we preserve the existing behavior of masking with IO_SPACE_LIMIT such that we don't break existing buggy drivers that somehow rely on this masking. Fixes: 5745392e0c2b ("PCI: Apply the new generic I/O management on PCI IO hosts") Reported-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-08-25Merge tag 'kbuild-v4.19-2' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - add build_{menu,n,g,x}config targets for compile-testing Kconfig - fix and improve recursive dependency detection in Kconfig - fix parallel building of menuconfig/nconfig - fix syntax error in clang-version.sh - suppress distracting log from syncconfig - remove obsolete "rpm" target - remove VMLINUX_SYMBOL(_STR) macro entirely - fix microblaze build with CONFIG_DYNAMIC_FTRACE - move compiler test for dead code/data elimination to Kconfig - rename well-known LDFLAGS variable to KBUILD_LDFLAGS - misc fixes and cleanups * tag 'kbuild-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: rename LDFLAGS to KBUILD_LDFLAGS kbuild: pass LDFLAGS to recordmcount.pl kbuild: test dead code/data elimination support in Kconfig initramfs: move gen_initramfs_list.sh from scripts/ to usr/ vmlinux.lds.h: remove stale <linux/export.h> include export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() Coccinelle: remove pci_alloc_consistent semantic to detect in zalloc-simple.cocci kbuild: make sorting initramfs contents independent of locale kbuild: remove "rpm" target, which is alias of "rpm-pkg" kbuild: Fix LOADLIBES rename in Documentation/kbuild/makefiles.txt kconfig: suppress "configuration written to .config" for syncconfig kconfig: fix "Can't open ..." in parallel build kbuild: Add a space after `!` to prevent parsing as file pattern scripts: modpost: check memory allocation results kconfig: improve the recursive dependency report kconfig: report recursive dependency involving 'imply' kconfig: error out when seeing recursive dependency kconfig: add build-only configurator targets scripts/dtc: consolidate include path options in Makefile
2018-08-23mm: mmu_notifier fix for tlb_end_vmaNicholas Piggin1-4/+13
The generic tlb_end_vma does not call invalidate_range mmu notifier, and it resets resets the mmu_gather range, which means the notifier won't be called on part of the range in case of an unmap that spans multiple vmas. ARM64 seems to be the only arch I could see that has notifiers and uses the generic tlb_end_vma. I have not actually tested it. [ Catalin and Will point out that ARM64 currently only uses the notifiers for KVM, which doesn't use the ->invalidate_range() callback right now, so it's a bug, but one that happens to not affect them. So not necessary for stable. - Linus ] Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23x86/mm/tlb: Revert the recent lazy TLB patchesPeter Zijlstra1-10/+0
Revert commits: 95b0e6357d3e x86/mm/tlb: Always use lazy TLB mode 64482aafe55f x86/mm/tlb: Only send page table free TLB flush to lazy TLB CPUs ac0315896970 x86/mm/tlb: Make lazy TLB mode lazier 61d0beb5796a x86/mm/tlb: Restructure switch_mm_irqs_off() 2ff6ddf19c0e x86/mm/tlb: Leave lazy TLB mode at page table free time In order to simplify the TLB invalidate fixes for x86 and unify the parts that need backporting. We'll try again later. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@surriel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22module: use relative references for __ksymtab entriesArd Biesheuvel1-2/+10
An ordinary arm64 defconfig build has ~64 KB worth of __ksymtab entries, each consisting of two 64-bit fields containing absolute references, to the symbol itself and to a char array containing its name, respectively. When we build the same configuration with KASLR enabled, we end up with an additional ~192 KB of relocations in the .init section, i.e., one 24 byte entry for each absolute reference, which all need to be processed at boot time. Given how the struct kernel_symbol that describes each entry is completely local to module.c (except for the references emitted by EXPORT_SYMBOL() itself), we can easily modify it to contain two 32-bit relative references instead. This reduces the size of the __ksymtab section by 50% for all 64-bit architectures, and gets rid of the runtime relocations entirely for architectures implementing KASLR, either via standard PIE linking (arm64) or using custom host tools (x86). Note that the binary search involving __ksymtab contents relies on each section being sorted by symbol name. This is implemented based on the input section names, not the names in the ksymtab entries, so this patch does not interfere with that. Given that the use of place-relative relocations requires support both in the toolchain and in the module loader, we cannot enable this feature for all architectures. So make it dependent on whether CONFIG_HAVE_ARCH_PREL32_RELOCATIONS is defined. Link: http://lkml.kernel.org/r/20180704083651.24360-4-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Jessica Yu <jeyu@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <james.morris@microsoft.com> Cc: James Morris <jmorris@namei.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22include/asm-generic/bug.h: clarify valid uses of WARN()Dmitry Vyukov1-3/+13
Explicitly state that WARN*() should be used only for recoverable kernel issues/bugs and that it should not be used for any kind of invalid external inputs or transient conditions. Motivation: it's a very useful capability to be able to understand if a particular kernel splat means a kernel bug or simply an invalid user-space program. For the former one wants to notify kernel developers, while notifying kernel developers for the latter is annoying. Even a kernel developer may not know what to do with a WARNING in an unfamiliar subsystem. This is especially critical for any automated testing systems that may use panic_on_warn and mail kernel developers. The clear separation also serves as an additional documentation: is it a condition that must never occur because of additional checks/logic elsewhere? or is it simply a check for invalid inputs or unfortunate conditions? Use of pr_err() for user messages also leads to better error messages. "Something is wrong in file foo on line X" is not particularly useful message for end user. pr_err() forces developers to write more meaningful error messages for user. As of now we are almost there. We are doing systematic kernel testing with panic_on_warn and are not seeing massive amounts of false positives. But every now and then another WARN on ENOMEM or invalid inputs pops up and leads to a lengthy argument each time. The goal of this change is to officially document the rules. Link: http://lkml.kernel.org/r/20180620103716.61636-1-dvyukov@gmail.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22vmlinux.lds.h: remove stale <linux/export.h> includeMasahiro Yamada1-2/+0
This is unneeded since commit a62143850053 ("vmlinux.lds.h: remove no-op macro VMLINUX_SYMBOL()"). Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-18Merge tag 'driver-core-4.19-rc1' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here are all of the driver core and related patches for 4.19-rc1. Nothing huge here, just a number of small cleanups and the ability to now stop the deferred probing after init happens. All of these have been in linux-next for a while with only a merge issue reported" * tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits) base: core: Remove WARN_ON from link dependencies check drivers/base: stop new probing during shutdown drivers: core: Remove glue dirs from sysfs earlier driver core: remove unnecessary function extern declare sysfs.h: fix non-kernel-doc comment PM / Domains: Stop deferring probe at the end of initcall iommu: Remove IOMMU_OF_DECLARE iommu: Stop deferring probe at end of initcalls pinctrl: Support stopping deferred probe after initcalls dt-bindings: pinctrl: add a 'pinctrl-use-default' property driver core: allow stopping deferred probe after init driver core: add a debugfs entry to show deferred devices sysfs: Fix internal_create_group() for named group updates base: fix order of OF initialization linux/device.h: fix kernel-doc notation warning Documentation: update firmware loader fallback reference kobject: Replace strncpy with memcpy drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number kernfs: Replace strncpy with memcpy device: Add #define dev_fmt similar to #define pr_fmt ...
2018-08-18mm: provide a fallback for PAGE_KERNEL_EXEC for architecturesLuis R. Rodriguez1-0/+4
Some architectures just don't have PAGE_KERNEL_EXEC. The mm/nommu.c and mm/vmalloc.c code have been using PAGE_KERNEL as a fallback for years. Move this fallback to asm-generic. Link: http://lkml.kernel.org/r/20180510185507.2439-3-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Suggested-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-18mm: provide a fallback for PAGE_KERNEL_RO for architecturesLuis R. Rodriguez1-0/+14
Some architectures do not define certain PAGE_KERNEL_* flags, this is either because: a) The way to implement some of these flags is *not yet ported*, or b) The architecture *has no way* to describe them Over time we have accumulated a few PAGE_KERNEL_* fallback workarounds for architectures in the kernel which do not define them using *relatively safe* equivalents. Move these scattered fallback hacks into asm-generic. We start off with PAGE_KERNEL_RO using PAGE_KERNEL as a fallback. This has been in place on the firmware loader for years. Move the fallback into the respective asm-generic header. Link: http://lkml.kernel.org/r/20180510185507.2439-2-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-14Merge branch 'l1tf-final' of ↵Linus Torvalds1-0/+12
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Merge L1 Terminal Fault fixes from Thomas Gleixner: "L1TF, aka L1 Terminal Fault, is yet another speculative hardware engineering trainwreck. It's a hardware vulnerability which allows unprivileged speculative access to data which is available in the Level 1 Data Cache when the page table entry controlling the virtual address, which is used for the access, has the Present bit cleared or other reserved bits set. If an instruction accesses a virtual address for which the relevant page table entry (PTE) has the Present bit cleared or other reserved bits set, then speculative execution ignores the invalid PTE and loads the referenced data if it is present in the Level 1 Data Cache, as if the page referenced by the address bits in the PTE was still present and accessible. While this is a purely speculative mechanism and the instruction will raise a page fault when it is retired eventually, the pure act of loading the data and making it available to other speculative instructions opens up the opportunity for side channel attacks to unprivileged malicious code, similar to the Meltdown attack. While Meltdown breaks the user space to kernel space protection, L1TF allows to attack any physical memory address in the system and the attack works across all protection domains. It allows an attack of SGX and also works from inside virtual machines because the speculation bypasses the extended page table (EPT) protection mechanism. The assoicated CVEs are: CVE-2018-3615, CVE-2018-3620, CVE-2018-3646 The mitigations provided by this pull request include: - Host side protection by inverting the upper address bits of a non present page table entry so the entry points to uncacheable memory. - Hypervisor protection by flushing L1 Data Cache on VMENTER. - SMT (HyperThreading) control knobs, which allow to 'turn off' SMT by offlining the sibling CPU threads. The knobs are available on the kernel command line and at runtime via sysfs - Control knobs for the hypervisor mitigation, related to L1D flush and SMT control. The knobs are available on the kernel command line and at runtime via sysfs - Extensive documentation about L1TF including various degrees of mitigations. Thanks to all people who have contributed to this in various ways - patches, review, testing, backporting - and the fruitful, sometimes heated, but at the end constructive discussions. There is work in progress to provide other forms of mitigations, which might be less horrible performance wise for a particular kind of workloads, but this is not yet ready for consumption due to their complexity and limitations" * 'l1tf-final' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits) x86/microcode: Allow late microcode loading with SMT disabled tools headers: Synchronise x86 cpufeatures.h for L1TF additions x86/mm/kmmio: Make the tracer robust against L1TF x86/mm/pat: Make set_memory_np() L1TF safe x86/speculation/l1tf: Make pmd/pud_mknotpresent() invert x86/speculation/l1tf: Invert all not present mappings cpu/hotplug: Fix SMT supported evaluation KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry x86/speculation: Use ARCH_CAPABILITIES to skip L1D flush on vmentry x86/speculation: Simplify sysfs report of VMX L1TF vulnerability Documentation/l1tf: Remove Yonah processors from not vulnerable list x86/KVM/VMX: Don't set l1tf_flush_l1d from vmx_handle_external_intr() x86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d x86: Don't include linux/irq.h from asm/hardirq.h x86/KVM/VMX: Introduce per-host-cpu analogue of l1tf_flush_l1d x86/irq: Demote irq_cpustat_t::__softirq_pending to u16 x86/KVM/VMX: Move the l1tf_flush_l1d test to vmx_l1d_flush() x86/KVM/VMX: Replace 'vmx_l1d_flush_always' with 'vmx_l1d_flush_cond' x86/KVM/VMX: Don't set l1tf_flush_l1d to true from vmx_l1d_flush() cpu/hotplug: detect SMT disabled by BIOS ...
2018-08-14Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds2-4/+14
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Thomas Gleixner: - Make lazy TLB mode even lazier to avoid pointless switch_mm() operations, which reduces CPU load by 1-2% for memcache workloads - Small cleanups and improvements all over the place * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Remove redundant check for kmem_cache_create() arm/asm/tlb.h: Fix build error implicit func declaration x86/mm/tlb: Make clear_asid_other() static x86/mm/tlb: Skip atomic operations for 'init_mm' in switch_mm_irqs_off() x86/mm/tlb: Always use lazy TLB mode x86/mm/tlb: Only send page table free TLB flush to lazy TLB CPUs x86/mm/tlb: Make lazy TLB mode lazier x86/mm/tlb: Restructure switch_mm_irqs_off() x86/mm/tlb: Leave lazy TLB mode at page table free time mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids x86/mm: Add TLB purge to free pmd/pte page interfaces ioremap: Update pgtable free interfaces with addr x86/mm: Disable ioremap free page handling on x86-PAE
2018-08-05Merge 4.18-rc7 into master to pick up the KVM dependcyThomas Gleixner2-1/+9
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-07-30Merge 4.18-rc7 into driver-core-nextGreg Kroah-Hartman1-0/+8
We need the driver core changes in here as well for testing. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25locking/atomics: Instrument cmpxchg_double*()Mark Rutland1-13/+8
We currently don't instrument cmpxchg_double() and cmpxchg_double_local() due to compilation issues reported in the past, which are supposedly related to GCC bug 72873 [1], reported when GCC 7 was not yet released. This bug only applies to x86-64, and does not apply to other architectures. While the test case for GCC bug 72873 triggers issues with released versions of GCC, the instrumented kernel code compiles fine for all configurations I have tried, and it is unclear how the two cases are/were related. As we can't reproduce the kernel build failures, let's instrument cmpxchg_double*() again. We can revisit the issue if build failures reappear. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: andy.shevchenko@gmail.com Cc: aryabinin@virtuozzo.com Cc: catalin.marinas@arm.com Cc: glider@google.com Cc: linux-arm-kernel@lists.infradead.org Cc: parri.andrea@gmail.com Cc: peter@hurleysoftware.com Link: http://lkml.kernel.org/r/20180716113017.3909-6-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25locking/atomics: Instrument xchg()Mark Rutland1-0/+7
While we instrument all of the (non-relaxed) atomic_*() functions and cmpxchg(), we missed xchg(). Let's add instrumentation for xchg(), fixing up x86 to implement arch_xchg(). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: andy.shevchenko@gmail.com Cc: arnd@arndb.de Cc: aryabinin@virtuozzo.com Cc: catalin.marinas@arm.com Cc: glider@google.com Cc: linux-arm-kernel@lists.infradead.org Cc: parri.andrea@gmail.com Cc: peter@hurleysoftware.com Link: http://lkml.kernel.org/r/20180716113017.3909-5-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25locking/atomics: Simplify cmpxchg() instrumentationMark Rutland1-85/+15
Currently we define some fairly verbose wrappers for the cmpxchg() family so that we can pass a pointer and size into kasan_check_write(). The wrappers duplicate the size-switching logic necessary in arch code, and only work for scalar types. On some architectures, (cmp)xchg are used on non-scalar types, and thus the instrumented wrappers need to be able to handle this. We could take the type-punning logic from {READ,WRITE}_ONCE(), but this makes the wrappers even more verbose, and requires several local variables in the macros. Instead, let's simplify the wrappers into simple macros which: * snapshot the pointer into a single local variable, called __ai_ptr to avoid conflicts with variables in the scope of the caller. * call kasan_check_write() on __ai_ptr. * invoke the relevant arch_*() function, passing the original arguments, bar __ai_ptr being substituted for ptr. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: andy.shevchenko@gmail.com Cc: arnd@arndb.de Cc: aryabinin@virtuozzo.com Cc: catalin.marinas@arm.com Cc: glider@google.com Cc: linux-arm-kernel@lists.infradead.org Cc: parri.andrea@gmail.com Cc: peter@hurleysoftware.com Link: http://lkml.kernel.org/r/20180716113017.3909-4-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17x86/mm/tlb: Leave lazy TLB mode at page table free timeRik van Riel1-0/+10
Andy discovered that speculative memory accesses while in lazy TLB mode can crash a system, when a CPU tries to dereference a speculative access using memory contents that used to be valid page table memory, but have since been reused for something else and point into la-la land. The latter problem can be prevented in two ways. The first is to always send a TLB shootdown IPI to CPUs in lazy TLB mode, while the second one is to only send the TLB shootdown at page table freeing time. The second should result in fewer IPIs, since operationgs like mprotect and madvise are very common with some workloads, but do not involve page table freeing. Also, on munmap, batching of page table freeing covers much larger ranges of virtual memory than the batching of unmapped user pages. Tested-by: Song Liu <songliubraving@fb.com> Signed-off-by: Rik van Riel <riel@surriel.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: efault@gmx.de Cc: kernel-team@fb.com Cc: luto@kernel.org Link: http://lkml.kernel.org/r/20180716190337.26133-3-riel@surriel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17Merge tag 'v4.18-rc5' into x86/mm, to pick up fixesIngo Molnar1-0/+8
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17Merge tag 'v4.18-rc5' into locking/core, to pick up fixesIngo Molnar2-1/+9
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-15x86/speculation/l1tf: Unbreak !__HAVE_ARCH_PFN_MODIFY_ALLOWED architecturesJiri Kosina1-12/+12
pfn_modify_allowed() and arch_has_pfn_modify_check() are outside of the !__ASSEMBLY__ section in include/asm-generic/pgtable.h, which confuses assembler on archs that don't have __HAVE_ARCH_PFN_MODIFY_ALLOWED (e.g. ia64) and breaks build: include/asm-generic/pgtable.h: Assembler messages: include/asm-generic/pgtable.h:538: Error: Unknown opcode `static inline bool pfn_modify_allowed(unsigned long pfn,pgprot_t prot)' include/asm-generic/pgtable.h:540: Error: Unknown opcode `return true' include/asm-generic/pgtable.h:543: Error: Unknown opcode `static inline bool arch_has_pfn_modify_check(void)' include/asm-generic/pgtable.h:545: Error: Unknown opcode `return false' arch/ia64/kernel/entry.S:69: Error: `mov' does not fit into bundle Move those two static inlines into the !__ASSEMBLY__ section so that they don't confuse the asm build pass. Fixes: 42e4089c7890 ("x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings") Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-07-14mm: allow arch to supply p??_free_tlb functionsNicholas Piggin1-0/+8
The mmu_gather APIs keep track of the invalidated address range including the span covered by invalidated page table pages. Ranges covered by page tables but not ptes (and therefore no TLBs) still need to be invalidated because some architectures (x86) can cache intermediate page table entries, and invalidate those with normal TLB invalidation instructions to be almost-backward-compatible. Architectures which don't cache intermediate page table entries, or which invalidate these caches separately from TLB invalidation, do not require TLB invalidation range expanded over page tables. Allow architectures to supply their own p??_free_tlb functions, which can avoid the __tlb_adjust_range. Link: http://lkml.kernel.org/r/20180703013131.2807-1-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Aneesh Kumar K. V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-10iommu: Remove IOMMU_OF_DECLARERob Herring1-2/+0
Now that we use the driver core to stop deferred probe for missing drivers, IOMMU_OF_DECLARE can be removed. This is slightly less optimal than having a list of built-in drivers in that we'll now defer probe twice before giving up. This shouldn't have a significant impact on boot times as past discussions about deferred probe have given no evidence of deferred probe having a substantial impact. Cc: Robin Murphy <robin.murphy@arm.com> Cc: Kukjin Kim <kgene@kernel.org> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Rob Clark <robdclark@gmail.com> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Frank Rowand <frowand.list@gmail.com> Cc: linux-arm-kernel@lists.infradead.org Cc: iommu@lists.linux-foundation.org Cc: linux-samsung-soc@vger.kernel.org Cc: linux-arm-msm@vger.kernel.org Cc: linux-rockchip@lists.infradead.org Cc: devicetree@vger.kernel.org Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-04ioremap: Update pgtable free interfaces with addrChintan Pandya1-4/+4
The following kernel panic was observed on ARM64 platform due to a stale TLB entry. 1. ioremap with 4K size, a valid pte page table is set. 2. iounmap it, its pte entry is set to 0. 3. ioremap the same address with 2M size, update its pmd entry with a new value. 4. CPU may hit an exception because the old pmd entry is still in TLB, which leads to a kernel panic. Commit b6bdb7517c3d ("mm/vmalloc: add interfaces to free unmapped page table") has addressed this panic by falling to pte mappings in the above case on ARM64. To support pmd mappings in all cases, TLB purge needs to be performed in this case on ARM64. Add a new arg, 'addr', to pud_free_pmd_page() and pmd_free_pte_page() so that TLB purge can be added later in seprate patches. [toshi.kani@hpe.com: merge changes, rewrite patch description] Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces") Signed-off-by: Chintan Pandya <cpandya@codeaurora.org> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: mhocko@suse.com Cc: akpm@linux-foundation.org Cc: hpa@zytor.com Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: Will Deacon <will.deacon@arm.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20180627141348.21777-3-toshi.kani@hpe.com
2018-06-22locking/qspinlock: Fix build for anonymous union in older GCC compilersSteven Rostedt (VMware)1-1/+1
One of my tests compiles the kernel with gcc 4.5.3, and I hit the following build error: include/linux/semaphore.h: In function 'sema_init': include/linux/semaphore.h:35:17: error: unknown field 'val' specified in initializer include/linux/semaphore.h:35:17: warning: missing braces around initializer include/linux/semaphore.h:35:17: warning: (near initialization for '(anonymous).raw_lock.<anonymous>.val') I bisected it down to: 625e88be1f41 ("locking/qspinlock: Merge 'struct __qspinlock' into 'struct qspinlock'") ... which makes qspinlock have an anonymous union, which makes initializing it special for older compilers. By adding strategic brackets, it makes the build happy again. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Waiman Long <longman@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Fixes: 625e88be1f41 ("locking/qspinlock: Merge 'struct __qspinlock' into 'struct qspinlock'") Link: http://lkml.kernel.org/r/20180621203526.172ab5c4@vmware.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21atomics/treewide: Make conditional inc/dec ops optionalMark Rutland2-0/+4
The conditional inc/dec ops differ for atomic_t and atomic64_t: - atomic_inc_unless_positive() is optional for atomic_t, and doesn't exist for atomic64_t. - atomic_dec_unless_negative() is optional for atomic_t, and doesn't exist for atomic64_t. - atomic_dec_if_positive is optional for atomic_t, and is mandatory for atomic64_t. Let's make these consistently optional for both. At the same time, let's clean up the existing fallbacks to use atomic_try_cmpxchg(). The instrumented atomics are updated accordingly. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-18-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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