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2023-09-19parisc: led: Fix LAN receive and transmit LEDsHelge Deller
commit 4db89524b084f712a887256391fc19d9f66c8e55 upstream. Fix the LAN receive and LAN transmit LEDs, which where swapped up to now. Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-13parisc: Fix /proc/cpuinfo output for lscpuHelge Deller
commit 9f5ba4b3e1b3c123eeca5d2d09161e8720048b5c upstream. The lscpu command is broken since commit cab56b51ec0e ("parisc: Fix device names in /proc/iomem") added the PA pathname to all PA devices, includig the CPUs. lscpu parses /proc/cpuinfo and now believes it found different CPU types since every CPU is listed with an unique identifier (PA pathname). Fix this problem by simply dropping the PA pathname when listing the CPUs in /proc/cpuinfo. There is no need to show the pathname in this procfs file. Fixes: cab56b51ec0e ("parisc: Fix device names in /proc/iomem") Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # v4.9+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-02parisc: sys_parisc: parisc_personality() is called from asm codeHelge Deller
commit b5d89408b9fb21258f7c371d6d48a674f60f7181 upstream. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-02parisc: Cleanup mmap implementation regarding color alignmentJohn David Anglin
commit 567b35159e76997e95b643b9a8a5d9d2198f2522 upstream. This change simplifies the randomization of file mapping regions. It reworks the code to remove duplication. The flow is now similar to that for mips. Finally, we consistently use the do_color_align variable to determine when color alignment is needed. Tested on rp3440. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-08init: Remove check_bugs() leftoversThomas Gleixner
commit 61235b24b9cb37c13fcad5b9596d59a1afdcec30 upstream Everything is converted over to arch_cpu_finalize_init(). Remove the check_bugs() leftovers including the empty stubs in asm-generic, alpha, parisc, powerpc and xtensa. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Link: https://lore.kernel.org/r/20230613224545.553215951@linutronix.de Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-01parisc: fix expand_stack() conversionLinus Torvalds
commit ea3f8272876f2958463992f6736ab690fde7fa9c upstream. In commit 8d7071af8907 ("mm: always expand the stack with the mmap write lock held") I tried to deal with the remaining odd page fault handling cases. The oddest one is ia64, which has stacks that grow both up and down. And because ia64 was _so_ odd, I asked people to verify the end result. But a close second oddity is parisc, which is the only one that has a main stack growing up (our "CONFIG_STACK_GROWSUP" config option). But it looked obvious enough that I didn't worry about it. I should have worried a bit more. Not because it was particularly complex, but because I just used the wrong variable name. The previous vma isn't called "prev", it's called "prev_vma". Blush. Fixes: 8d7071af8907 ("mm: always expand the stack with the mmap write lock held") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-01mm: always expand the stack with the mmap write lock heldLinus Torvalds
commit 8d7071af890768438c14db6172cc8f9f4d04e184 upstream This finishes the job of always holding the mmap write lock when extending the user stack vma, and removes the 'write_locked' argument from the vm helper functions again. For some cases, we just avoid expanding the stack at all: drivers and page pinning really shouldn't be extending any stacks. Let's see if any strange users really wanted that. It's worth noting that architectures that weren't converted to the new lock_mm_and_find_vma() helper function are left using the legacy "expand_stack()" function, but it has been changed to drop the mmap_lock and take it for writing while expanding the vma. This makes it fairly straightforward to convert the remaining architectures. As a result of dropping and re-taking the lock, the calling conventions for this function have also changed, since the old vma may no longer be valid. So it will now return the new vma if successful, and NULL - and the lock dropped - if the area could not be extended. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [6.1: Patch drivers/iommu/io-pgfault.c instead] Signed-off-by: Samuel Mendoza-Jonas <samjonas@amazon.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-21parisc: Delete redundant register definitions in <asm/assembly.h>Ben Hutchings
commit b5b2a02bcaac7c287694aa0db4837a07bf178626 upstream. We define sp and ipsw in <asm/asmregs.h> using ".reg", and when using current binutils (snapshot 2.40.50.20230611) the definitions in <asm/assembly.h> using "=" conflict with those: arch/parisc/include/asm/assembly.h: Assembler messages: arch/parisc/include/asm/assembly.h:93: Error: symbol `sp' is already defined arch/parisc/include/asm/assembly.h:95: Error: symbol `ipsw' is already defined Delete the duplicate definitions in <asm/assembly.h>. Also delete the definition of gp, which isn't used anywhere. Signed-off-by: Ben Hutchings <benh@debian.org> Cc: stable@vger.kernel.org # v6.0+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-21parisc: Improve cache flushing for PCXL in arch_sync_dma_for_cpu()Helge Deller
[ Upstream commit 59fa12646d9f56c842b4d5b6418ed77af625c588 ] Add comment in arch_sync_dma_for_device() and handle the direction flag in arch_sync_dma_for_cpu(). When receiving data from the device (DMA_FROM_DEVICE) unconditionally purge the data cache in arch_sync_dma_for_cpu(). Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30parisc: Handle kprobes breakpoints only in kernel contextHelge Deller
commit df419492e428b6a2bce98d0f613c58a13da6666c upstream. The kernel kprobes break instructions should only be handled when running in kernel context. Cc: <stable@vger.kernel.org> # v5.18+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30parisc: Enable LOCKDEP supportHelge Deller
commit adf8e96a7ea670d45b5de7594acc67e8f4787ae6 upstream. Cc: <stable@vger.kernel.org> # v6.0+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30parisc: Allow to reboot machine after system haltHelge Deller
commit 2028315cf59bb899a5ac7e87dc48ecb8fac7ac24 upstream. In case a machine can't power-off itself on system shutdown, allow the user to reboot it by pressing the RETURN key. Cc: <stable@vger.kernel.org> # v4.14+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30parisc: Fix flush_dcache_page() for usage from irq contextHelge Deller
commit 61e150fb310729c98227a5edf6e4a3619edc3702 upstream. Since at least kernel 6.1, flush_dcache_page() is called with IRQs disabled, e.g. from aio_complete(). But the current implementation for flush_dcache_page() on parisc unintentionally re-enables IRQs, which may lead to deadlocks. Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore() for the flush_dcache_mmap_*lock() macros instead. Cc: linux-parisc@vger.kernel.org Cc: stable@kernel.org # 5.18+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30parisc: Handle kgdb breakpoints only in kernel contextHelge Deller
commit 6888ff04e37d01295620a73f3f7efbc79f6ef152 upstream. The kernel kgdb break instructions should only be handled when running in kernel context. Cc: <stable@vger.kernel.org> # v5.4+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30parisc: Use num_present_cpus() in alternative patching codeHelge Deller
commit b6405f0829d7b1dd926ba3ca5f691cab835abfaa upstream. When patching the kernel code some alternatives depend on SMP vs. !SMP. Use the value of num_present_cpus() instead of num_online_cpus() to decide, otherwise we may run into issues if and additional CPU is enabled after having loaded a module while only one CPU was enabled. Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # v6.1+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-24parisc: Replace regular spinlock with spin_trylock on panic pathGuilherme G. Piccoli
[ Upstream commit 829632dae8321787525ee37dc4828bbe6edafdae ] The panic notifiers' callbacks execute in an atomic context, with interrupts/preemption disabled, and all CPUs not running the panic function are off, so it's very dangerous to wait on a regular spinlock, there's a risk of deadlock. Refactor the panic notifier of parisc/power driver to make use of spin_trylock - for that, we've added a second version of the soft-power function. Also, some comments were reorganized and trailing white spaces, useless header inclusion and blank lines were removed. Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Jeroen Roovers <jer@xs4all.nl> Acked-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-11parisc: Ensure page alignment in flush functionsHelge Deller
commit d755bd2caeb47fd806e12399fe8b56798fa5d2cc upstream. Matthew Wilcox noticed, that if ARCH_HAS_FLUSH_ON_KUNMAP is defined (which is the case for PA-RISC), __kunmap_local() calls kunmap_flush_on_unmap(), which may call the parisc flush functions with a non-page-aligned address and thus the page might not be fully flushed. This patch ensures that flush_kernel_dcache_page_asm() and flush_kernel_dcache_page_asm() will always operate on page-aligned addresses. Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # v6.0+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-11parisc: Fix argument pointer in real64_call_asm()Helge Deller
commit 6e3220ba3323a2c24be834aebf5d6e9f89d0993f upstream. Fix the argument pointer (ap) to point to real-mode memory instead of virtual memory. It's interesting that this issue hasn't shown up earlier, as this could have happened with any 64-bit PDC ROM code. I just noticed it because I suddenly faced a HPMC while trying to execute the 64-bit STI ROM code of an Visualize-FXe graphics card for the STI text console. Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-09parisc: Wire up PTRACE_GETREGS/PTRACE_SETREGS for compat caseHelge Deller
commit 316f1f42b5cc1d95124c1f0387c867c1ba7b6d0e upstream. Wire up the missing ptrace requests PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS and PTRACE_SETFPREGS when running 32-bit applications on 64-bit kernels. Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # 4.7+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-09parisc: Replace hardcoded value with PRIV_USER constant in ptrace.cHelge Deller
commit 3f0c17809a098d3f0c1ec83f1fb3ca61638d3dcd upstream. Prefer usage of the PRIV_USER constant over the hard-coded value to set the lowest 2 bits for the userspace privilege. Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # 5.16+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-09parisc: Fix return code of pdc_iodc_print()Helge Deller
commit 5d1335dabb3c493a3d6d5b233953b6ac7b6c1ff2 upstream. There is an off-by-one if the printed string includes a new-line char. Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14parisc: Align parisc MADV_XXX constants with all other architecturesHelge Deller
commit 71bdea6f798b425bc0003780b13e3fdecb16a010 upstream. Adjust some MADV_XXX constants to be in sync what their values are on all other platforms. There is currently no reason to have an own numbering on parisc, but it requires workarounds in many userspace sources (e.g. glibc, qemu, ...) - which are often forgotten and thus introduce bugs and different behaviour on parisc. A wrapper avoids an ABI breakage for existing userspace applications by translating any old values to the new ones, so this change allows us to move over all programs to the new ABI over time. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07parisc: Drop PMD_SHIFT from calculation in pgtable.hHelge Deller
commit fe94cb1a614d2df2764d49ac959d8b7e4cb98e15 upstream. PMD_SHIFT isn't defined if CONFIG_PGTABLE_LEVELS == 3, and as such the kernel test robot found this warning: In file included from include/linux/pgtable.h:6, from arch/parisc/kernel/head.S:23: arch/parisc/include/asm/pgtable.h:169:32: warning: "PMD_SHIFT" is not defined, evaluates to 0 [-Wundef] 169 | #if (KERNEL_INITIAL_ORDER) >= (PMD_SHIFT) Avoid the warning by using PLD_SHIFT and BITS_PER_PTE. Signed-off-by: Helge Deller <deller@gmx.de> Reported-by: kernel test robot <lkp@intel.com> Cc: <stable@vger.kernel.org> # 6.0+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07parisc: Drop duplicate kgdb_pdc consoleHelge Deller
commit 7e6652c79ecd74e1112500668d956367dc3772a5 upstream. The kgdb console is already implemented and registered in pdc_cons.c, so the duplicate code can be dropped. Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # 6.1+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07parisc: Add missing FORCE prerequisites in MakefileHelge Deller
commit 9086e6017957c5cd6ea28d94b70e0d513d6b7800 upstream. Fix those make warnings: arch/parisc/kernel/vdso32/Makefile:30: FORCE prerequisite is missing arch/parisc/kernel/vdso64/Makefile:30: FORCE prerequisite is missing Add the missing FORCE prerequisites for all build targets identified by "make help". Fixes: e1f86d7b4b2a5213 ("kbuild: warn if FORCE is missing for if_changed(_dep,_rule) and filechk") Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # 5.18+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07parisc: Fix locking in pdc_iodc_print() firmware callHelge Deller
commit 7236aae5f81f3efbd93d0601e74fc05994bc2580 upstream. Utilize pdc_lock spinlock to protect parallel modifications of the iodc_dbuf[] buffer, check length to prevent buffer overflow of iodc_dbuf[], drop the iodc_retbuf[] buffer and fix some wrong indentings. Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # 6.0+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07parisc: Drop locking in pdc console codeHelge Deller
commit 7dc4dbfe750e1f18c511e73c8ed114da8de9ff85 upstream. No need to have specific locking for console I/O since the PDC functions provide an own locking. Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # 6.1+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-31parisc: Avoid printing the hardware path twiceHelge Deller
Avoid that the hardware path is shown twice in the kernel log, and clean up the output of the version numbers to show up in the same order as they are listed in the hardware database in the hardware.c file. Additionally, optimize the memory footprint of the hardware database and mark some code as init code. Fixes: cab56b51ec0e ("parisc: Fix device names in /proc/iomem") Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # v4.9+
2022-10-21parisc: Use signed char for hardware path in pdc.hHelge Deller
Clean up the struct for hardware_path and drop the struct device_path with a proper assignment of bc[] and mod members as signed chars. This patch prepares for the kbuild change from Jason A. Donenfeld to treat char as always unsigned. Signed-off-by: Helge Deller <deller@gmx.de> Cc: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-16Merge tag 'random-6.1-rc1-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/crng/random Pull more random number generator updates from Jason Donenfeld: "This time with some large scale treewide cleanups. The intent of this pull is to clean up the way callers fetch random integers. The current rules for doing this right are: - If you want a secure or an insecure random u64, use get_random_u64() - If you want a secure or an insecure random u32, use get_random_u32() The old function prandom_u32() has been deprecated for a while now and is just a wrapper around get_random_u32(). Same for get_random_int(). - If you want a secure or an insecure random u16, use get_random_u16() - If you want a secure or an insecure random u8, use get_random_u8() - If you want secure or insecure random bytes, use get_random_bytes(). The old function prandom_bytes() has been deprecated for a while now and has long been a wrapper around get_random_bytes() - If you want a non-uniform random u32, u16, or u8 bounded by a certain open interval maximum, use prandom_u32_max() I say "non-uniform", because it doesn't do any rejection sampling or divisions. Hence, it stays within the prandom_*() namespace, not the get_random_*() namespace. I'm currently investigating a "uniform" function for 6.2. We'll see what comes of that. By applying these rules uniformly, we get several benefits: - By using prandom_u32_max() with an upper-bound that the compiler can prove at compile-time is ≤65536 or ≤256, internally get_random_u16() or get_random_u8() is used, which wastes fewer batched random bytes, and hence has higher throughput. - By using prandom_u32_max() instead of %, when the upper-bound is not a constant, division is still avoided, because prandom_u32_max() uses a faster multiplication-based trick instead. - By using get_random_u16() or get_random_u8() in cases where the return value is intended to indeed be a u16 or a u8, we waste fewer batched random bytes, and hence have higher throughput. This series was originally done by hand while I was on an airplane without Internet. Later, Kees and I worked on retroactively figuring out what could be done with Coccinelle and what had to be done manually, and then we split things up based on that. So while this touches a lot of files, the actual amount of code that's hand fiddled is comfortably small" * tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: prandom: remove unused functions treewide: use get_random_bytes() when possible treewide: use get_random_u32() when possible treewide: use get_random_{u8,u16}() when possible, part 2 treewide: use get_random_{u8,u16}() when possible, part 1 treewide: use prandom_u32_max() when possible, part 2 treewide: use prandom_u32_max() when possible, part 1
2022-10-14Merge tag 'parisc-for-6.1-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux Pull parisc updates from Helge Deller: "Fixes: - When we added basic vDSO support in kernel 5.18 we introduced a bug which prevented a mmap() of graphic card memory. This is because we used the DMB (data memory break trap bit) page flag as special-bit, but missed to clear that bit when loading the TLB. - Graphics card memory size was not correctly aligned - Spelling fixes (from Colin Ian King) Enhancements: - PDC console (which uses firmware calls) now rewritten as early console - Reduced size of alternative tables" * tag 'parisc-for-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Fix spelling mistake "mis-match" -> "mismatch" in eisa driver parisc: Fix userspace graphics card breakage due to pgtable special bit parisc: fbdev/stifb: Align graphics memory size to 4MB parisc: Convert PDC console to an early console parisc: Reduce kernel size by packing alternative tables
2022-10-14parisc: Fix userspace graphics card breakage due to pgtable special bitHelge Deller
Commit df24e1783e6e ("parisc: Add vDSO support") introduced the vDSO support, for which a _PAGE_SPECIAL page table flag was needed. Since we wanted to keep every page table entry in 32-bits, this patch re-used the existing - but yet unused - _PAGE_DMB flag (which triggers a hardware break if a page is accessed) to store the special bit. But when graphics card memory is mmapped into userspace, the kernel uses vm_iomap_memory() which sets the the special flag. So, with the DMB bit set, every access to the graphics memory now triggered a hardware exception and segfaulted the userspace program. Fix this breakage by dropping the DMB bit when writing the page protection bits to the CPU TLB. In addition this patch adds a small optimization: if huge pages aren't configured (which is at least the case for 32-bit kernels), then the special bit is stored in the hpage (HUGE PAGE) bit instead. That way we can skip to reset the DMB bit. Fixes: df24e1783e6e ("parisc: Add vDSO support") Cc: <stable@vger.kernel.org> # 5.18+ Signed-off-by: Helge Deller <deller@gmx.de>
2022-10-12Merge tag 'mm-nonmm-stable-2022-10-11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - hfs and hfsplus kmap API modernization (Fabio Francesco) - make crash-kexec work properly when invoked from an NMI-time panic (Valentin Schneider) - ntfs bugfixes (Hawkins Jiawei) - improve IPC msg scalability by replacing atomic_t's with percpu counters (Jiebin Sun) - nilfs2 cleanups (Minghao Chi) - lots of other single patches all over the tree! * tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits) include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype proc: test how it holds up with mapping'less process mailmap: update Frank Rowand email address ia64: mca: use strscpy() is more robust and safer init/Kconfig: fix unmet direct dependencies ia64: update config files nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure fork: remove duplicate included header files init/main.c: remove unnecessary (void*) conversions proc: mark more files as permanent nilfs2: remove the unneeded result variable nilfs2: delete unnecessary checks before brelse() checkpatch: warn for non-standard fixes tag style usr/gen_init_cpio.c: remove unnecessary -1 values from int file ipc/msg: mitigate the lock contention with percpu counter percpu: add percpu_counter_add_local and percpu_counter_sub_local fs/ocfs2: fix repeated words in comments relay: use kvcalloc to alloc page array in relay_alloc_page_array proc: make config PROC_CHILDREN depend on PROC_FS fs: uninline inode_maybe_inc_iversion() ...
2022-10-11treewide: use get_random_u32() when possibleJason A. Donenfeld
The prandom_u32() function has been a deprecated inline wrapper around get_random_u32() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. The same also applies to get_random_int(), which is just a wrapper around get_random_u32(). This was done as a basic find and replace. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Acked-by: Helge Deller <deller@gmx.de> # for parisc Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11treewide: use prandom_u32_max() when possible, part 1Jason A. Donenfeld
Rather than incurring a division or requesting too many random bytes for the given range, use the prandom_u32_max() function, which only takes the minimum required bytes from the RNG and avoids divisions. This was done mechanically with this coccinelle script: @basic@ expression E; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u64; @@ ( - ((T)get_random_u32() % (E)) + prandom_u32_max(E) | - ((T)get_random_u32() & ((E) - 1)) + prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2) | - ((u64)(E) * get_random_u32() >> 32) + prandom_u32_max(E) | - ((T)get_random_u32() & ~PAGE_MASK) + prandom_u32_max(PAGE_SIZE) ) @multi_line@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; identifier RAND; expression E; @@ - RAND = get_random_u32(); ... when != RAND - RAND %= (E); + RAND = prandom_u32_max(E); // Find a potential literal @literal_mask@ expression LITERAL; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; position p; @@ ((T)get_random_u32()@p & (LITERAL)) // Add one to the literal. @script:python add_one@ literal << literal_mask.LITERAL; RESULT; @@ value = None if literal.startswith('0x'): value = int(literal, 16) elif literal[0] in '123456789': value = int(literal, 10) if value is None: print("I don't know how to handle %s" % (literal)) cocci.include_match(False) elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1: print("Skipping 0x%x for cleanup elsewhere" % (value)) cocci.include_match(False) elif value & (value + 1) != 0: print("Skipping 0x%x because it's not a power of two minus one" % (value)) cocci.include_match(False) elif literal.startswith('0x'): coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1)) else: coccinelle.RESULT = cocci.make_expr("%d" % (value + 1)) // Replace the literal mask with the calculated result. @plus_one@ expression literal_mask.LITERAL; position literal_mask.p; expression add_one.RESULT; identifier FUNC; @@ - (FUNC()@p & (LITERAL)) + prandom_u32_max(RESULT) @collapse_ret@ type T; identifier VAR; expression E; @@ { - T VAR; - VAR = (E); - return VAR; + return E; } @drop_var@ type T; identifier VAR; @@ { - T VAR; ... when != VAR } Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: KP Singh <kpsingh@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11parisc: Convert PDC console to an early consoleHelge Deller
Rewrite the PDC console to become an early console. Beside the fact that now boot information is visible until another (text- or graphics) console takes over, this benefits as well machines with a yet-unsupported STI console and kgdb. Signed-off-by: Helge Deller <deller@gmx.de>
2022-10-11parisc: Reduce kernel size by packing alternative tablesHelge Deller
The values stored in the length and condition fields of the alternative tables fit into 16 bits, so we can save 4 bytes per alternative table entry. Since a typical 32-bit kernel has more than 3000 entries this saves > 12k of storage on disc. bloat-o-meter shows a reduction of -0.01% by this change: Total: Before=10196505, After=10195529, chg -0.01% $ ls -la vmlinux vmlinux.before -rwxr-xr-x 14437324 vmlinux -rwxr-xr-x 14449512 vmlinux.before Signed-off-by: Helge Deller <deller@gmx.de>
2022-10-10Merge tag 'mm-stable-2022-10-08' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
2022-10-10Merge tag 'kbuild-v6.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Remove potentially incomplete targets when Kbuid is interrupted by SIGINT etc in case GNU Make may miss to do that when stderr is piped to another program. - Rewrite the single target build so it works more correctly. - Fix rpm-pkg builds with V=1. - List top-level subdirectories in ./Kbuild. - Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in kallsyms. - Avoid two different modules in lib/zstd/ having shared code, which potentially causes building the common code as build-in and modular back-and-forth. - Unify two modpost invocations to optimize the build process. - Remove head-y syntax in favor of linker scripts for placing particular sections in the head of vmlinux. - Bump the minimal GNU Make version to 3.82. - Clean up misc Makefiles and scripts. * tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits) docs: bump minimal GNU Make version to 3.82 ia64: simplify esi object addition in Makefile Revert "kbuild: Check if linker supports the -X option" kbuild: rebuild .vmlinux.export.o when its prerequisite is updated kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o zstd: Fixing mixed module-builtin objects kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols kallsyms: take the input file instead of reading stdin kallsyms: drop duplicated ignore patterns from kallsyms.c kbuild: reuse mksysmap output for kallsyms mksysmap: update comment about __crc_* kbuild: remove head-y syntax kbuild: use obj-y instead extra-y for objects placed at the head kbuild: hide error checker logs for V=1 builds kbuild: re-run modpost when it is updated kbuild: unify two modpost invocations kbuild: move vmlinux.o rule to the top Makefile kbuild: move .vmlinux.objs rule to Makefile.modpost kbuild: list sub-directories in ./Kbuild Makefile.compiler: replace cc-ifversion with compiler-specific macros ...
2022-10-07Merge tag 'tty-6.1-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here is the big set of TTY and Serial driver updates for 6.1-rc1. Lots of cleanups in here, no real new functionality this time around, with the diffstat being that we removed more lines than we added! Included in here are: - termios unification cleanups from Al Viro, it's nice to finally get this work done - tty serial transmit cleanups in various drivers in preparation for more cleanup and unification in future releases (that work was not ready for this release) - n_gsm fixes and updates - ktermios cleanups and code reductions - dt bindings json conversions and updates for new devices - some serial driver updates for new devices - lots of other tiny cleanups and janitorial stuff. Full details in the shortlog. All of these have been in linux-next for a while with no reported issues" * tag 'tty-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (102 commits) serial: cpm_uart: Don't request IRQ too early for console port tty: serial: do unlock on a common path in altera_jtaguart_console_putc() tty: serial: unify TX space reads under altera_jtaguart_tx_space() tty: serial: use FIELD_GET() in lqasc_tx_ready() tty: serial: extend lqasc_tx_ready() to lqasc_console_putchar() tty: serial: allow pxa.c to be COMPILE_TESTed serial: stm32: Fix unused-variable warning tty: serial: atmel: Add COMMON_CLK dependency to SERIAL_ATMEL serial: 8250: Fix restoring termios speed after suspend serial: Deassert Transmit Enable on probe in driver-specific way serial: 8250_dma: Convert to use uart_xmit_advance() serial: 8250_omap: Convert to use uart_xmit_advance() MAINTAINERS: Solve warning regarding inexistent atmel-usart binding serial: stm32: Deassert Transmit Enable on ->rs485_config() serial: ar933x: Deassert Transmit Enable on ->rs485_config() tty: serial: atmel: Use FIELD_PREP/FIELD_GET tty: serial: atmel: Make the driver aware of the existence of GCLK tty: serial: atmel: Only divide Clock Divisor if the IP is USART tty: serial: atmel: Separate mode clearing between UART and USART dt-bindings: serial: atmel,at91-usart: Add gclk as a possible USART clock ...
2022-10-06Merge tag 'asm-generic-6.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull asm-generic updates from Arnd Bergmann: "This contains a series from Linus Walleij to unify the linux/io.h interface by making the ia64, alpha, parisc and sparc include asm-generic/io.h. All functions provided by the generic header are now available to all drivers, but the architectures can still override this. For the moment, mips and sh still don't include asm-generic/io.h but provide a full set of functions themselves. There are also a few minor cleanups unrelated to this" * tag 'asm-generic-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: alpha: add full ioread64/iowrite64 implementation parisc: Drop homebrewn io[read|write]64_[lo_hi|hi_lo] parisc: hide ioread64 declaration on 32-bit ia64: export memory_add_physaddr_to_nid to fix cxl build error asm-generic: Remove empty #ifdef SA_RESTORER parisc: Use the generic IO helpers parisc: Remove 64bit access on 32bit machines sparc: Fix the generic IO helpers alpha: Use generic <asm-generic/io.h>
2022-10-02kbuild: remove head-y syntaxMasahiro Yamada
Kbuild puts the objects listed in head-y at the head of vmlinux. Conventionally, we do this for head*.S, which contains the kernel entry point. A counter approach is to control the section order by the linker script. Actually, the code marked as __HEAD goes into the ".head.text" section, which is placed before the normal ".text" section. I do not know if both of them are needed. From the build system perspective, head-y is not mandatory. If you can achieve the proper code placement by the linker script only, it would be cleaner. I collected the current head-y objects into head-object-list.txt. It is a whitelist. My hope is it will be reduced in the long run. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-10-02kbuild: use obj-y instead extra-y for objects placed at the headMasahiro Yamada
The objects placed at the head of vmlinux need special treatments: - arch/$(SRCARCH)/Makefile adds them to head-y in order to place them before other archives in the linker command line. - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of obj-y to avoid them going into built-in.a. This commit gets rid of the latter. Create vmlinux.a to collect all the objects that are unconditionally linked to vmlinux. The objects listed in head-y are moved to the head of vmlinux.a by using 'ar m'. With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y for builtin objects. There is no *.o that is directly linked to vmlinux. Drop unneeded code in scripts/clang-tools/gen_compile_commands.py. $(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested by Nathan Chancellor [1]. [1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-09-26parisc: remove mmap linked list from cache handlingMatthew Wilcox (Oracle)
Use the VMA iterator instead. Link: https://lkml.kernel.org/r/20220906194824.2110408-33-Liam.Howlett@oracle.com Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: SeongJae Park <sj@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-25Merge 7e2cd21e02b3 ("Merge tag 'tty-6.0-rc7' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty") into tty-next We need the tty fixes and api additions in this branch. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-23parisc: Drop homebrewn io[read|write]64_[lo_hi|hi_lo]Linus Walleij
The parisc implements ioread64_lo_hi(), ioread64_hi_lo() iowrite64_lo_hi() and iowrite64_hi_lo() while we already have a perfectly working generic version in the generic portable assembly in <linux/io-64-nonatomic-hi-lo.h>. Drop the custom versions in favor for the defaults. Fixes: 77bfc8bdb5a1 ("parisc: Remove 64bit access on 32bit machines") Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Helge Deller <deller@gmx.de> Reported-by: Helge Deller <deller@gmx.de> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-09-15parisc: Allow CONFIG_64BIT with ARCH=pariscHelge Deller
The previous patch triggered a build failure for the debian kernel, which has CONFIG_64BIT enabled, uses the CROSS_COMPILER environment variable and uses ARCH=parisc to configure the kernel for 64-bit support. This patch weakens the previous patch while keeping the recommended way to configure the kernel with: ARCH=parisc -> build 32-bit kernel ARCH=parisc64 -> build 64-bit kernel while adding the possibility for debian to configure a 64-bit kernel even if ARCH=parisc is set (PA8X00 CPU has to be selected and CONFIG_64BIT needs to be enabled). The downside of this patch is, that we now have a small window open again where people may get it wrong: if they enable CONFIG_64BIT and try to compile with a 32-bit compiler. Fixes: 3dcfb729b5f4 ("parisc: Make CONFIG_64BIT available for ARCH=parisc64 only") Signed-off-by: Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org> # 5.15+
2022-09-12parisc: hide ioread64 declaration on 32-bitArnd Bergmann
The definition of ioread64 etc is hidden on 32-bit, but the declaration remained by accident, which led to the generic definition getting left out: ERROR: modpost: "ioread64" [drivers/pci/switch/switchtec.ko] undefined! Hide the declaration and #define under the same #ifdef. Reported-by: kernel test robot <lkp@intel.com> Fixes: 77bfc8bdb5a1 ("parisc: Remove 64bit access on 32bit machines") Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-09-11kernel: exit: cleanup release_thread()Kefeng Wang
Only x86 has own release_thread(), introduce a new weak release_thread() function to clean empty definitions in other ARCHs. Link: https://lkml.kernel.org/r/20220819014406.32266-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Guo Ren <guoren@kernel.org> [csky] Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Brian Cain <bcain@quicinc.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Acked-by: Stafford Horne <shorne@gmail.com> [openrisc] Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Acked-by: Huacai Chen <chenhuacai@kernel.org> [LoongArch] Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Chris Zankel <chris@zankel.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Guo Ren <guoren@kernel.org> [csky] Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Jonas Bonn <jonas@southpole.se> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Xuerui Wang <kernel@xen0n.name> Cc: Yoshinori Sato <ysato@users.osdn.me> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm/madvise: introduce MADV_COLLAPSE sync hugepage collapseZach O'Keefe
This idea was introduced by David Rientjes[1]. Introduce a new madvise mode, MADV_COLLAPSE, that allows users to request a synchronous collapse of memory at their own expense. The benefits of this approach are: * CPU is charged to the process that wants to spend the cycles for the THP * Avoid unpredictable timing of khugepaged collapse Semantics This call is independent of the system-wide THP sysfs settings, but will fail for memory marked VM_NOHUGEPAGE. If the ranges provided span multiple VMAs, the semantics of the collapse over each VMA is independent from the others. This implies a hugepage cannot cross a VMA boundary. If collapse of a given hugepage-aligned/sized region fails, the operation may continue to attempt collapsing the remainder of memory specified. The memory ranges provided must be page-aligned, but are not required to be hugepage-aligned. If the memory ranges are not hugepage-aligned, the start/end of the range will be clamped to the first/last hugepage-aligned address covered by said range. The memory ranges must span at least one hugepage-sized region. All non-resident pages covered by the range will first be swapped/faulted-in, before being internally copied onto a freshly allocated hugepage. Unmapped pages will have their data directly initialized to 0 in the new hugepage. However, for every eligible hugepage aligned/sized region to-be collapsed, at least one page must currently be backed by memory (a PMD covering the address range must already exist). Allocation for the new hugepage may enter direct reclaim and/or compaction, regardless of VMA flags. When the system has multiple NUMA nodes, the hugepage will be allocated from the node providing the most native pages. This operation operates on the current state of the specified process and makes no persistent changes or guarantees on how pages will be mapped, constructed, or faulted in the future Return Value If all hugepage-sized/aligned regions covered by the provided range were either successfully collapsed, or were already PMD-mapped THPs, this operation will be deemed successful. On success, process_madvise(2) returns the number of bytes advised, and madvise(2) returns 0. Else, -1 is returned and errno is set to indicate the error for the most-recently attempted hugepage collapse. Note that many failures might have occurred, since the operation may continue to collapse in the event a single hugepage-sized/aligned region fails. ENOMEM Memory allocation failed or VMA not found EBUSY Memcg charging failed EAGAIN Required resource temporarily unavailable. Try again might succeed. EINVAL Other error: No PMD found, subpage doesn't have Present bit set, "Special" page no backed by struct page, VMA incorrectly sized, address not page-aligned, ... Most notable here is ENOMEM and EBUSY (new to madvise) which are intended to provide the caller with actionable feedback so they may take an appropriate fallback measure. Use Cases An immediate user of this new functionality are malloc() implementations that manage memory in hugepage-sized chunks, but sometimes subrelease memory back to the system in native-sized chunks via MADV_DONTNEED; zapping the pmd. Later, when the memory is hot, the implementation could madvise(MADV_COLLAPSE) to re-back the memory by THPs to regain hugepage coverage and dTLB performance. TCMalloc is such an implementation that could benefit from this[2]. Only privately-mapped anon memory is supported for now, but additional support for file, shmem, and HugeTLB high-granularity mappings[2] is expected. File and tmpfs/shmem support would permit: * Backing executable text by THPs. Current support provided by CONFIG_READ_ONLY_THP_FOR_FS may take a long time on a large system which might impair services from serving at their full rated load after (re)starting. Tricks like mremap(2)'ing text onto anonymous memory to immediately realize iTLB performance prevents page sharing and demand paging, both of which increase steady state memory footprint. With MADV_COLLAPSE, we get the best of both worlds: Peak upfront performance and lower RAM footprints. * Backing guest memory by hugapages after the memory contents have been migrated in native-page-sized chunks to a new host, in a userfaultfd-based live-migration stack. [1] https://lore.kernel.org/linux-mm/d098c392-273a-36a4-1a29-59731cdf5d3d@google.com/ [2] https://github.com/google/tcmalloc/tree/master/tcmalloc [jrdr.linux@gmail.com: avoid possible memory leak in failure path] Link: https://lkml.kernel.org/r/20220713024109.62810-1-jrdr.linux@gmail.com [zokeefe@google.com add missing kfree() to madvise_collapse()] Link: https://lore.kernel.org/linux-mm/20220713024109.62810-1-jrdr.linux@gmail.com/ Link: https://lkml.kernel.org/r/20220713161851.1879439-1-zokeefe@google.com [zokeefe@google.com: delay computation of hpage boundaries until use]] Link: https://lkml.kernel.org/r/20220720140603.1958773-4-zokeefe@google.com Link: https://lkml.kernel.org/r/20220706235936.2197195-10-zokeefe@google.com Signed-off-by: Zach O'Keefe <zokeefe@google.com> Signed-off-by: "Souptick Joarder (HPE)" <jrdr.linux@gmail.com> Suggested-by: David Rientjes <rientjes@google.com> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Chris Kennelly <ckennelly@google.com> Cc: Chris Zankel <chris@zankel.net> Cc: David Hildenbrand <david@redhat.com> Cc: Helge Deller <deller@gmx.de> Cc: Hugh Dickins <hughd@google.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>