user/sven/linux.git/include/asm-generic, branch v6.6.93

mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()

2025-03-13T11:58:38Z

commit 02410ac72ac3707936c07ede66e94360d0d65319 upstream. In order to fix a bug, arm64 needs to be told the size of the huge page for which the huge_pte is being cleared in huge_ptep_get_and_clear(). Provide for this by adding an `unsigned long sz` parameter to the function. This follows the same pattern as huge_pte_clear() and set_huge_pte_at(). This commit makes the required interface modifications to the core mm as well as all arches that implement this function (arm64, loongarch, mips, parisc, powerpc, riscv, s390, sparc). The actual arm64 bug will be fixed in a separate commit. Cc: stable@vger.kernel.org Fixes: 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit") Acked-by: David Hildenbrand Reviewed-by: Alexandre Ghiti # riscv Reviewed-by: Christophe Leroy Reviewed-by: Catalin Marinas Reviewed-by: Anshuman Khandual Signed-off-by: Ryan Roberts Acked-by: Alexander Gordeev # s390 Link: https://lore.kernel.org/r/20250226120656.2400136-2-ryan.roberts@arm.com Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

vmlinux.lds: Ensure that const vars with relocations are mapped R/O

2025-03-07T15:45:47Z

commit 68f3ea7ee199ef77551e090dfef5a49046ea8443 upstream. In the kernel, there are architectures (x86, arm64) that perform boot-time relocation (for KASLR) without relying on PIE codegen. In this case, all const global objects are emitted into .rodata, including const objects with fields that will be fixed up by the boot-time relocation code. This implies that .rodata (and .text in some cases) need to be writable at boot, but they will usually be mapped read-only as soon as the boot completes. When using PIE codegen, the compiler will emit const global objects into .data.rel.ro rather than .rodata if the object contains fields that need such fixups at boot-time. This permits the linker to annotate such regions as requiring read-write access only at load time, but not at execution time (in user space), while keeping .rodata truly const (in user space, this is important for reducing the CoW footprint of dynamic executables). This distinction does not matter for the kernel, but it does imply that const data will end up in writable memory if the .data.rel.ro sections are not treated in a special way, as they will end up in the writable .data segment by default. So emit .data.rel.ro into the .rodata segment. Cc: stable@vger.kernel.org Signed-off-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250221135704.431269-5-ardb+git@google.com Signed-off-by: Josh Poimboeuf Signed-off-by: Greg Kroah-Hartman

Rename .data.once to .data..once to fix resetting WARN*_ONCE

2024-12-09T09:32:59Z

[ Upstream commit dbefa1f31a91670c9e7dac9b559625336206466f ] Commit b1fca27d384e ("kernel debug: support resetting WARN*_ONCE") added support for clearing the state of once warnings. However, it is not functional when CONFIG_LD_DEAD_CODE_DATA_ELIMINATION or CONFIG_LTO_CLANG is enabled, because .data.once matches the .data.[0-9a-zA-Z_]* pattern in the DATA_MAIN macro. Commit cb87481ee89d ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured") was introduced to suppress the issue for the default CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=n case, providing a minimal fix for stable backporting. We were aware this did not address the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y. The plan was to apply correct fixes and then revert cb87481ee89d. [1] Seven years have passed since then, yet the #ifdef workaround remains in place. Meanwhile, commit b1fca27d384e introduced the .data.once section, and commit dc5723b02e52 ("kbuild: add support for Clang LTO") extended the #ifdef. Using a ".." separator in the section name fixes the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION and CONFIG_LTO_CLANG. [1]: https://lore.kernel.org/linux-kbuild/CAK7LNASck6BfdLnESxXUeECYL26yUDm0cwRZuM4gmaWUkxjL5g@mail.gmail.com/ Fixes: b1fca27d384e ("kernel debug: support resetting WARN*_ONCE") Fixes: dc5723b02e52 ("kbuild: add support for Clang LTO") Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

Rename .data.unlikely to .data..unlikely

2024-12-09T09:32:59Z

[ Upstream commit bb43a59944f45e89aa158740b8a16ba8f0b0fa2b ] Commit 7ccaba5314ca ("consolidate WARN_...ONCE() static variables") was intended to collect all .data.unlikely sections into one chunk. However, this has not worked when CONFIG_LD_DEAD_CODE_DATA_ELIMINATION or CONFIG_LTO_CLANG is enabled, because .data.unlikely matches the .data.[0-9a-zA-Z_]* pattern in the DATA_MAIN macro. Commit cb87481ee89d ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured") was introduced to suppress the issue for the default CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=n case, providing a minimal fix for stable backporting. We were aware this did not address the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y. The plan was to apply correct fixes and then revert cb87481ee89d. [1] Seven years have passed since then, yet the #ifdef workaround remains in place. Using a ".." separator in the section name fixes the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION and CONFIG_LTO_CLANG. [1]: https://lore.kernel.org/linux-kbuild/CAK7LNASck6BfdLnESxXUeECYL26yUDm0cwRZuM4gmaWUkxjL5g@mail.gmail.com/ Fixes: cb87481ee89d ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured") Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

init/modpost: conditionally check section mismatch to __meminit*

2024-12-09T09:32:59Z

[ Upstream commit 73db3abdca58c8a014ec4c88cf5ef925cbf63669 ] This reverts commit eb8f689046b8 ("Use separate sections for __dev/ _cpu/__mem code/data"). Check section mismatch to __meminit* only when CONFIG_MEMORY_HOTPLUG=n. With this change, the linker script and modpost become simpler, and we can get rid of the __ref annotations from the memory hotplug code. [sfr@canb.auug.org.au: remove MEM_KEEP from arch/powerpc/kernel/vmlinux.lds.S] Link: https://lkml.kernel.org/r/20240710093213.2aefb25f@canb.auug.org.au Link: https://lkml.kernel.org/r/20240706160511.2331061-2-masahiroy@kernel.org Signed-off-by: Masahiro Yamada Signed-off-by: Stephen Rothwell Reviewed-by: Wei Yang Cc: Stephen Rothwell Signed-off-by: Andrew Morton Stable-dep-of: bb43a59944f4 ("Rename .data.unlikely to .data..unlikely") Signed-off-by: Sasha Levin

vmlinux.lds.h: catch .bss..L* sections into BSS")

2024-08-03T06:53:35Z

[ Upstream commit 1a7b7326d587c9a5e8ff067e70d6aaf0333f4bb3 ] Commit 9a427556fb8e ("vmlinux.lds.h: catch compound literals into data and BSS") added catches for .data..L* and .rodata..L* but missed .bss..L* Since commit 5431fdd2c181 ("ptrace: Convert ptrace_attach() to use lock guards") the following appears at build: LD .tmp_vmlinux.kallsyms1 powerpc64-linux-ld: warning: orphan section `.bss..Lubsan_data33' from `kernel/ptrace.o' being placed in section `.bss..Lubsan_data33' NM .tmp_vmlinux.kallsyms1.syms KSYMS .tmp_vmlinux.kallsyms1.S AS .tmp_vmlinux.kallsyms1.S LD .tmp_vmlinux.kallsyms2 powerpc64-linux-ld: warning: orphan section `.bss..Lubsan_data33' from `kernel/ptrace.o' being placed in section `.bss..Lubsan_data33' NM .tmp_vmlinux.kallsyms2.syms KSYMS .tmp_vmlinux.kallsyms2.S AS .tmp_vmlinux.kallsyms2.S LD vmlinux powerpc64-linux-ld: warning: orphan section `.bss..Lubsan_data33' from `kernel/ptrace.o' being placed in section `.bss..Lubsan_data33' Lets add .bss..L* to BSS_MAIN macro to catch those sections into BSS. Fixes: 9a427556fb8e ("vmlinux.lds.h: catch compound literals into data and BSS") Signed-off-by: Christophe Leroy Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202404031349.nmKhyuUG-lkp@intel.com/ Signed-off-by: Arnd Bergmann Signed-off-by: Sasha Levin

sched: Add missing memory barrier in switch_mm_cid

2024-04-27T15:11:41Z

commit fe90f3967bdb3e13f133e5f44025e15f943a99c5 upstream. Many architectures' switch_mm() (e.g. arm64) do not have an smp_mb() which the core scheduler code has depended upon since commit: commit 223baf9d17f25 ("sched: Fix performance regression introduced by mm_cid") If switch_mm() doesn't call smp_mb(), sched_mm_cid_remote_clear() can unset the actively used cid when it fails to observe active task after it sets lazy_put. There *is* a memory barrier between storing to rq->curr and _return to userspace_ (as required by membarrier), but the rseq mm_cid has stricter requirements: the barrier needs to be issued between store to rq->curr and switch_mm_cid(), which happens earlier than: - spin_unlock(), - switch_to(). So it's fine when the architecture switch_mm() happens to have that barrier already, but less so when the architecture only provides the full barrier in switch_to() or spin_unlock(). It is a bug in the rseq switch_mm_cid() implementation. All architectures that don't have memory barriers in switch_mm(), but rather have the full barrier either in finish_lock_switch() or switch_to() have them too late for the needs of switch_mm_cid(). Introduce a new smp_mb__after_switch_mm(), defined as smp_mb() in the generic barrier.h header, and use it in switch_mm_cid() for scheduler transitions where switch_mm() is expected to provide a memory barrier. Architectures can override smp_mb__after_switch_mm() if their switch_mm() implementation provides an implicit memory barrier. Override it with a no-op on x86 which implicitly provide this memory barrier by writing to CR3. Fixes: 223baf9d17f2 ("sched: Fix performance regression introduced by mm_cid") Reported-by: levi.yun Signed-off-by: Mathieu Desnoyers Signed-off-by: Ingo Molnar Reviewed-by: Catalin Marinas # for arm64 Acked-by: Dave Hansen # for x86 Cc: # 6.4.x Cc: Linus Torvalds Link: https://lore.kernel.org/r/20240415152114.59122-2-mathieu.desnoyers@efficios.com Signed-off-by: Greg Kroah-Hartman

linux/init: remove __memexit* annotations

2024-02-23T08:25:03Z

commit 6a4e59eeedc3018cb57722eecfcbb49431aeb05f upstream. We have never used __memexit, __memexitdata, or __memexitconst. These were unneeded. Signed-off-by: Masahiro Yamada Acked-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

mm: Introduce flush_cache_vmap_early()

2024-02-16T18:10:52Z

[ Upstream commit 7a92fc8b4d20680e4c20289a670d8fca2d1f2c1b ] The pcpu setup when using the page allocator sets up a new vmalloc mapping very early in the boot process, so early that it cannot use the flush_cache_vmap() function which may depend on structures not yet initialized (for example in riscv, we currently send an IPI to flush other cpus TLB). But on some architectures, we must call flush_cache_vmap(): for example, in riscv, some uarchs can cache invalid TLB entries so we need to flush the new established mapping to avoid taking an exception. So fix this by introducing a new function flush_cache_vmap_early() which is called right after setting the new page table entry and before accessing this new mapping. This new function implements a local flush tlb on riscv and is no-op for other architectures (same as today). Signed-off-by: Alexandre Ghiti Acked-by: Geert Uytterhoeven Signed-off-by: Dennis Zhou Stable-dep-of: d9807d60c145 ("riscv: mm: execute local TLB flush after populating vmemmap") Signed-off-by: Sasha Levin

arm64: irq: set the correct node for VMAP stack

2024-02-05T20:14:14Z

[ Upstream commit 75b5e0bf90bffaca4b1f19114065dc59f5cc161f ] In current code, init_irq_stacks() will call cpu_to_node(). The cpu_to_node() depends on percpu "numa_node" which is initialized in: arch_call_rest_init() --> rest_init() -- kernel_init() --> kernel_init_freeable() --> smp_prepare_cpus() But init_irq_stacks() is called in init_IRQ() which is before arch_call_rest_init(). So in init_irq_stacks(), the cpu_to_node() does not work, it always return 0. In NUMA, it makes the node 1 cpu accesses the IRQ stack which is in the node 0. This patch fixes it by: 1.) export the early_cpu_to_node(), and use it in the init_irq_stacks(). 2.) change init_irq_stacks() to __init function. Reviewed-by: Catalin Marinas Signed-off-by: Huang Shijie Link: https://lore.kernel.org/r/20231124031513.81548-1-shijie@os.amperecomputing.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin