Robert Allan JamesandClaude Sonnet 5
9142dda2d6
Root-caused a heap-corruption bug that reliably failed WIREBIND identity attach on the third attach/detach cycle in one boot. sk_console_readline() and sk_console_getkey() captured `active_vm` once from their caller and kept passing that same (possibly long-stale) pointer to sk_repl_idle() on every idle tick serviced while blocked waiting for input. If the VM it pointed at was killed (WIREBIND detach) mid-block, the existing bailout only checked a generic "is anyone attached" boolean -- masked as soon as a different identity attached next -- so blk_vm_flush_all() kept writing into a freed VM struct sitting on kmalloc's own free list, corrupting the free list's linked-list metadata itself. Both idle branches now re-resolve the live active VM fresh from g_repl_active_vm on every tick, matching the dispatch-side fix already made for the sibling bug in §XII.3. Verified: rebuilt amd64, reran the exact three-cycle repro that reliably corrupted the heap before the fix -- free-list census stayed stable through the same idle window that previously collapsed to zero. All three architectures (amd64/aarch64/riscv64) boot clean to the zuse)ok> prompt. kmalloc_debug_census()/kmalloc_debug_census_bytes() kept as permanent diagnostic infrastructure; every other temporary probe added during the investigation was reverted. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01EXieurDfDSsDFdnSyusuWo
87 lines
3.1 KiB
C
87 lines
3.1 KiB
C
/*
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StarForth — Steady-State Virtual Machine Runtime
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Copyright (c) 2023–2025 Robert A. James
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All rights reserved.
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This file is part of the StarForth project.
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Licensed under the StarForth License, Version 1.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at:
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https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
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This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
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express or implied, including but not limited to the warranties of
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merchantability, fitness for a particular purpose, and noninfringement.
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See the License for the specific language governing permissions and
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limitations under the License.
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StarForth — Steady-State Virtual Machine Runtime
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Copyright (c) 2023–2025 Robert A. James
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All rights reserved.
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This file is part of the StarForth project.
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Licensed under the StarForth License, Version 1.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at:
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https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
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This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
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express or implied, including but not limited to the warranties of
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merchantability, fitness for a particular purpose, and noninfringement.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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/**
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* kmalloc.h - Kernel heap allocator interface
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*/
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#ifndef STARKERNEL_KMALLOC_H
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#define STARKERNEL_KMALLOC_H
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#include <stddef.h>
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#include <stdint.h>
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typedef struct {
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uint64_t total_bytes;
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uint64_t used_bytes;
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uint64_t peak_bytes;
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uint64_t free_bytes;
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} kmalloc_stats_t;
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int kmalloc_init(uint64_t heap_size_bytes);
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int kmalloc_is_initialized(void);
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void *kmalloc(size_t size);
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void *kmalloc_aligned(size_t size, size_t align);
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void kfree(void *ptr);
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kmalloc_stats_t kmalloc_get_stats(void);
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uintptr_t kmalloc_heap_base_addr(void);
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uintptr_t kmalloc_heap_end_addr(void);
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/* Debug/diagnostic probe -- free-list census (largest free block, count of
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free blocks, count of allocated blocks, total blocks). Kept as permanent
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infrastructure (FABRIC-3.md SXIII, 2026-09-10): a cheap O(n) walk over
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the free list, useful for any future heap-shape investigation, not just
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the one that introduced it. Not called anywhere in the normal boot path
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today -- callers add their own log_message() call sites when debugging. */
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void kmalloc_debug_census(size_t *out_largest_free, size_t *out_free_count,
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size_t *out_used_count, size_t *out_total_blocks);
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/* Same precedent as kmalloc_debug_census() above -- sum of free-block bytes
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and used-block bytes across the whole free list. The pairing of the two
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(block-count census + byte-sum census) is what let FABRIC-3.md SXIII tell
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real heap corruption apart from ordinary fragmentation: fragmentation
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grows free_count while total_free_bytes stays flat; corruption drops
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both together. */
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void kmalloc_debug_census_bytes(size_t *out_total_free_bytes, size_t *out_total_used_bytes);
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#endif /* STARKERNEL_KMALLOC_H */
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