kernel/linux.git/include/asm-generic, branch v5.10.141

asm-generic: sections: refactor memory_intersects

2022-08-31T15:15:22+00:00

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 Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: Thierry Reding Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

locking/atomic: Make test_and_*_bit() ordered on failure

2022-08-25T09:38:10+00:00

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 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 Acked-by: Will Deacon Reviewed-by: Arnd Bergmann Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry

2022-04-20T07:23:22+00:00

[ Upstream commit 697a1d44af8ba0477ee729e632f4ade37999249a ] tlb_remove_huge_tlb_entry only considers PMD_SIZE and PUD_SIZE when updating the mmu_gather structure. Unfortunately on arm64 there are two additional huge page sizes that need to be covered: CONT_PTE_SIZE and CONT_PMD_SIZE. Where an end-user attempts to employ contiguous huge pages, a VM_BUG_ON can be experienced due to the fact that the tlb structure hasn't been correctly updated by the relevant tlb_flush_p.._range() call from tlb_remove_huge_tlb_entry. This patch adds inequality logic to the generic implementation of tlb_remove_huge_tlb_entry s.t. CONT_PTE_SIZE and CONT_PMD_SIZE are effectively covered on arm64. Also, as well as ptes, pmds and puds; p4ds are now considered too. Reported-by: David Hildenbrand Suggested-by: Peter Zijlstra (Intel) Cc: Anshuman Khandual Cc: Catalin Marinas Cc: Will Deacon Link: https://lore.kernel.org/linux-mm/811c5c8e-b3a2-85d2-049c-717f17c3a03a@redhat.com/ Signed-off-by: Steve Capper Acked-by: David Hildenbrand Reviewed-by: Anshuman Khandual Reviewed-by: Catalin Marinas Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220330112543.863-1-steve.capper@arm.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

vmlinux.lds.h: Handle clang's module.{c,d}tor sections

2021-08-18T06:59:18+00:00

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 Reviewed-by: Nick Desaulniers Reviewed-by: Fangrui Song Acked-by: Marco Elver Signed-off-by: Kees Cook 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 Signed-off-by: Greg Kroah-Hartman

sched/core: Initialize the idle task with preemption disabled

2021-07-14T14:55:50+00:00

[ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ] As pointed out by commit de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread") init_idle() can and will be invoked more than once on the same idle task. At boot time, it is invoked for the boot CPU thread by sched_init(). Then smp_init() creates the threads for all the secondary CPUs and invokes init_idle() on them. As the hotplug machinery brings the secondaries to life, it will issue calls to idle_thread_get(), which itself invokes init_idle() yet again. In this case it's invoked twice more per secondary: at _cpu_up(), and at bringup_cpu(). Given smp_init() already initializes the idle tasks for all *possible* CPUs, no further initialization should be required. Now, removing init_idle() from idle_thread_get() exposes some interesting expectations with regards to the idle task's preempt_count: the secondary startup always issues a preempt_disable(), requiring some reset of the preempt count to 0 between hot-unplug and hotplug, which is currently served by idle_thread_get() -> idle_init(). Given the idle task is supposed to have preemption disabled once and never see it re-enabled, it seems that what we actually want is to initialize its preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove init_idle() from idle_thread_get(). Secondary startups were patched via coccinelle: @begone@ @@ -preempt_disable(); ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); Signed-off-by: Valentin Schneider Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com Signed-off-by: Sasha Levin

vmlinux.lds.h: Avoid orphan section with !SMP

2021-06-16T10:01:45+00:00

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 Signed-off-by: Nathan Chancellor Tested-by: Nick Desaulniers # build Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20210506001410.1026691-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman

static_call: Allow module use without exposing static_call_key

2021-03-30T12:31:53+00:00

[ Upstream commit 73f44fe19d359635a607e8e8daa0da4001c1cfc2 ] When exporting static_call_key; with EXPORT_STATIC_CALL*(), the module can use static_call_update() to change the function called. This is not desirable in general. Not exporting static_call_key however also disallows usage of static_call(), since objtool needs the key to construct the static_call_site. Solve this by allowing objtool to create the static_call_site using the trampoline address when it builds a module and cannot find the static_call_key symbol. The module loader will then try and map the trampole back to a key before it constructs the normal sites list. Doing this requires a trampoline -> key associsation, so add another magic section that keeps those. Originally-by: Peter Zijlstra (Intel) Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lkml.kernel.org/r/20210127231837.ifddpn7rhwdaepiu@treble Signed-off-by: Sasha Levin

vmlinux.lds.h: Define SANTIZER_DISCARDS with CONFIG_GCOV_KERNEL=y

2021-03-04T10:37:19+00:00

commit f5b6a74d9c08b19740ca056876bf6584acdba582 upstream. clang produces .eh_frame sections when CONFIG_GCOV_KERNEL is enabled, even when -fno-asynchronous-unwind-tables is in KBUILD_CFLAGS: $ make CC=clang vmlinux ... ld: warning: orphan section `.eh_frame' from `init/main.o' being placed in section `.eh_frame' ld: warning: orphan section `.eh_frame' from `init/version.o' being placed in section `.eh_frame' ld: warning: orphan section `.eh_frame' from `init/do_mounts.o' being placed in section `.eh_frame' ld: warning: orphan section `.eh_frame' from `init/do_mounts_initrd.o' being placed in section `.eh_frame' ld: warning: orphan section `.eh_frame' from `init/initramfs.o' being placed in section `.eh_frame' ld: warning: orphan section `.eh_frame' from `init/calibrate.o' being placed in section `.eh_frame' ld: warning: orphan section `.eh_frame' from `init/init_task.o' being placed in section `.eh_frame' ... $ rg "GCOV_KERNEL|GCOV_PROFILE_ALL" .config CONFIG_GCOV_KERNEL=y CONFIG_ARCH_HAS_GCOV_PROFILE_ALL=y CONFIG_GCOV_PROFILE_ALL=y This was already handled for a couple of other options in commit d812db78288d ("vmlinux.lds.h: Avoid KASAN and KCSAN's unwanted sections") and there is an open LLVM bug for this issue. Take advantage of that section for this config as well so that there are no more orphan warnings. Link: https://bugs.llvm.org/show_bug.cgi?id=46478 Link: https://github.com/ClangBuiltLinux/linux/issues/1069 Reported-by: kernel test robot Reviewed-by: Fangrui Song Reviewed-by: Nick Desaulniers Signed-off-by: Nathan Chancellor Fixes: d812db78288d ("vmlinux.lds.h: Avoid KASAN and KCSAN's unwanted sections") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20210130004650.2682422-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman

vmlinux.lds.h: add DWARF v5 sections

2021-03-04T10:37:17+00:00

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 Suggested-by: Fangrui Song Reviewed-by: Nathan Chancellor Reviewed-by: Mark Wielaard Tested-by: Sedat Dilek Signed-off-by: Nick Desaulniers Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

firmware_loader: align .builtin_fw to 8

2021-02-17T10:02:27+00:00

[ 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 Reported-by: kernel test robot Acked-by: Arnd Bergmann Reviewed-by: Nick Desaulniers Tested-by: Nick Desaulniers Tested-by: Douglas Anderson Acked-by: Nathan Chancellor Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin