From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f202.google.com (mail-dy1-f202.google.com [74.125.82.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E19A83AFD0E for ; Sat, 6 Jun 2026 15:15:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780758903; cv=none; b=TFbjwNGQfUoeaUwnBWOXdztUR/ZVFhhKM2RcSb16bPjPq8YEJNCp5Mrawt9Qk/JFJhgiKrP3e/+tohUENEJdv06yo1ymx4IgBOjGtEKxrnIKpiIjUm1Kz4/iX32kC1UsuF7t/rPaOdLSqipejXZRenyCq+T+wcjWN/DGgiU/XeA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780758903; c=relaxed/simple; bh=YhgoGHMNpnW9JpeUF9+TMv+j9gScTgFvntxsb+ynrl0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=XpwymfZ/XaGLA+8okQKxCLcWXHuT99FuPaeH4P15K5lhrw/1l5qtP1exZRB4TngqLtbNTEw6RSkKgm5JsPI9/Hqu4L6xGNLUEZ6Mt2oAOutvhAcYzNEP4cICZJoMxoWubOJzscqazSvGtmAHaGaP+PLJf/hv/yezxkJne/Mnc5E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=NI/Ebm/M; arc=none smtp.client-ip=74.125.82.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="NI/Ebm/M" Received: by mail-dy1-f202.google.com with SMTP id 5a478bee46e88-304d0d0b28eso976228eec.0 for ; Sat, 06 Jun 2026 08:15:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1780758901; x=1781363701; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=8WVncgs0Wj4cr28/YhDTFkSQ+e6UITgAvcbWCWhc7EI=; b=NI/Ebm/MTZ3qKhw7s+rWEpFIFYg5f2UyVFf2JV8kwopBQkFPNe5jZr2uw2C30R/lfV 6BO1vlK3rtL/BVKIu+qFuRVjfqeZK0+lDr6bZM76KZGLies5LuOeXLVuq6cqfjljyG78 bL4oGMzHnOZwtCCDkB0zVpOeDvfwakxlS0QuTdmdFUtVubMH72isNb587v7TRRve1hXX T4A+3FzZHuHiiLRBNvMnbPYPG8eqvtN3IdLdoCbiC5mVYgY6XrJv3w9YHUlo7uDx+lXW ly5RIwdqW4MoMsy1Eda0K+FW9J6DB8DLgRUnQmShEGGporkROFXqzGgdsGKGnmfKwyH6 nAIA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780758901; x=1781363701; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=8WVncgs0Wj4cr28/YhDTFkSQ+e6UITgAvcbWCWhc7EI=; b=HsTMIwSErjiGFWqGZ5lBmwDkR6wr0JWoffqNg06YQP/FQE+AEpd02+kKgFqvkk6gkr LH4fJia3ZXWQ9lX0+NREMuPatAu8bbtMNhoTdb/btL5aThFhbf80Bg5izqbccZHzGJ7i AKv3ZdjM7mljBnbmb6vKXrQC+H6aE5owcwNSKpQFgjUq5M0ZtPCdeFFRSor4b/VZOCtU JUZX0sMWZdSAkL8JM7oe19PsbmrNYrdCrDnhGRVoP9lT4K5NYxAqFO+zyKN9ndBT34Dn rUv1dDKphXfKaQZDUWXA2q+g+4ubXZhmJ844kpVTeAJlT7kVEmmoiMq4S/Uc2y1JNXy0 Nj9A== X-Forwarded-Encrypted: i=1; AFNElJ89eEg/floAOJH5VShr9duqBhlNQ/fPnir0eWVzwrIBQauyLUgu+Ai1hFFfPpcV21BiKrLhcBepK3HGfLA=@vger.kernel.org X-Gm-Message-State: AOJu0YxQLQRhNLr/EUQSiKtBp3FYBWd15XbD2tnh9Bd7ZppU+x1lgYaF rTkRXsV2JM0v+Jwm5Ty3CvsTOVnhJsVVhMn8QiMwOCJz2Up/RBvuTqv6BT6MI2G97swz0F0M6ku DWJAVXHEx9A== X-Received: from dybpl3.prod.google.com ([2002:a05:7301:4303:b0:304:d272:2198]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7301:1e4a:b0:304:de2b:446f with SMTP id 5a478bee46e88-3077b7ebe91mr5032872eec.28.1780758900649; Sat, 06 Jun 2026 08:15:00 -0700 (PDT) Date: Sat, 6 Jun 2026 08:14:46 -0700 In-Reply-To: <20260606072125.2786845-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260606072125.2786845-1-irogers@google.com> X-Mailer: git-send-email 2.54.0.1032.g2f8565e1d1-goog Message-ID: <20260606151451.2913860-1-irogers@google.com> Subject: [PATCH v16 0/5] perf tools: Add inject --aslr feature, early maps loading, and decoupling fixes From: Ian Rogers To: irogers@google.com, acme@kernel.org, namhyung@kernel.org Cc: adrian.hunter@intel.com, gmx@google.com, james.clark@linaro.org, jolsa@kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, mingo@redhat.com, peterz@infradead.org Content-Type: text/plain; charset="UTF-8" This patch series introduces the new 'perf inject --aslr' feature to remap virtual memory addresses or drop physical memory event leaks when profile record data is shared between machines. Bundled with this feature is a bug fix inside the core map tracking tool that hardens perf session analysis against concurrent lookup data races. Detailed Mechanism of MMAP Mapping and ASLR virtual Address Allocation: The ASLR tool virtualizes the address space of the recorded processes by intercepting MMAP and MMAP2 events to build a consistent translation database, which is subsequently used to rewrite sample addresses. It maintains two primary lookup databases using hash maps: 1. 'remap_addresses': Maps an original mapping key to its new remapped base address. The key uses topological invariant coordinates: (machine, dso, invariant). The invariant is computed as (start - pgoff) for DSO-backed mappings. This invariant remains constant even when perf's internal overlap-resolution splits a VMA into fragmented pieces, ensuring split maps resolve consistently back to the same remapped base. 2. 'top_addresses': Tracks the allocation state per process (machine, pid). It maintains 'remapped_max' (the highest allocated address in the virtualized space). For each MMAP/MMAP2 event: - We look up the DSO and invariant key in 'remap_addresses'. If found, we reuse the translation, preserving the offset within the mapping. - If not found, we allocate a new remapped address space: - We use thread__find_map to look up the mapping immediately preceding the new one in the original address space (at start - 1). If the preceding mapping was also remapped, we place the new mapping contiguously after it in the remapped space. This preserves contiguity of split mappings (e.g., symbols split by HugeTLB, or anonymous .bss segments adjacent to initialized data). - If no contiguous mapping is found, we insert a 1-page gap from the highest allocated address (remapped_max) to prevent accidental merging of unrelated VMAs. - The event's start address (and pgoff for kernel maps) is rewritten, and the event is delegated to the output writer. To remain strictly conservative and guarantee security, the tool scrubs breakpoint addresses (bp_addr) from all synthesized stream headers, completely drops PERF_RECORD_TEXT_POKE events to prevent absolute immediate pointer operands leaks, and drops unsupported complex payloads (such as user register stacks, raw tracepoints, and hardware AUX tracing frames). Verification is reinforced with shell test ('inject_aslr.sh'). Prerequisite Bug Fix (Patch 1). During development, a core map indexing issue was identified and resolved to prevent concurrent lookup data races during session analysis. Changes since v15: - Patch 2: Added bounds checking for event->header.size before writing to breakpoint fields to avoid heap buffer overflow on older ABI events. - Patch 2: Fixed asymmetric calculation bug in aslr_tool__findnew_mapping() where pgoff for anonymous kernel memory was not properly subtracted upon insertion, causing the lookup addition to overflow. - Patch 2: Added detailed comments documenting the symmetric lookup and insertion math for unmapped and mapped memory blocks. - Patch 5: Add missing kprobe and uprobe scrubbing of config1 and config2 during aslr_tool__strip_evlist() to strictly conform with repipe constraints. Changes since v14: - Patch 2: Removed unnecessary vertical whitespace in builtin-inject.c. - Patch 2: Added comments explaining why pgoff is assigned for anonymous memory maps to prevent ASLR leaks. - Patch 2: Removed orig_last_end tracking and refactored contiguous mapping detection to use thread__find_map(..., start - 1, ...) based on Gabriel's feedback. - Patch 2: Scrub kprobe/uprobe event config1 and config2 fields to prevent address leaks. - Patch 2: Overwrite pgoff with the remapped start address for anonymous mappings (detected via is_anon_memory and is_no_dso_memory). - Patch 3: Fix C90 mixed declaration error for orig_needs_swap. - Patch 3: Temporarily disable evsel->needs_swap during the secondary evsel__parse_sample() call to prevent branch stack double-swapping bugs. Changes since v13: - Patch 2: Added a NULL check for env before calling perf_env__kernel_is_64_bit(env) to prevent potential segfaults if the recorded environment has no headers. - Patch 5: Fixed sample_size and id_pos going out of sync during aslr_tool__strip_evlist() and aslr_tool__restore_evlist(). Instead of using evsel__reset_sample_bit(), which was acting as a no-op due to early bit clearing and corrupted sample_size, the tool now directly updates sample_type and recomputes sample_size/id_pos dynamically. Added orig_sample_size to aslr_evsel_priv to correctly restore the state. Changes since v12: - Patch 2: Fixed potential NULL pointer dereference in remap_addresses__hash() when handling unmapped memory events (key->dso is NULL) under REFCNT_CHECKING. - Patch 2: Dynamically detect machine architecture bitness via perf_env__kernel_is_64_bit() to select appropriate kernel_space_start boundaries, avoiding 64-bit address injection on 32-bit platforms. Changes since v11: - Patch 1: Fixed struct dso name accessor in maps.c by using dso__name() instead of ->name. - Patch 2: Fixed hash function in aslr.c to hash the underlying dso pointer using RC_CHK_ACCESS to support reference count checking. Changes since v10: - Patch 1: Added explicit tracking array logic in maps__load_maps() to correctly accumulate valid maps (skipping NULL entries after failures) and safely return the exact populated count, resolving out-of-bounds pointer iteration panics. - Patch 3: Fixed endianness bug during cross-endian sample parsing by passing evsel->needs_swap instead of false to __evsel__parse_sample in aslr.c, ensuring correct 32-bit field byte unswapping for packed fields. Refactored evsel__parse_sample to take a needs_swap argument via __evsel__parse_sample. - Patch 4: Fixed inject_aslr.sh exit code handling in trap functions to capture and propagate the correct pipeline failure status code instead of unconditionally returning success or failing the test. Changes since v9: - Patch 1: Added `-ENOMEM` error check inside `maps__find_symbol_by_name()` and return `NULL` early. Added map sorting state invalidation on early return in `maps__load_maps()`. - Patch 2: Fixed encapsulation by using `thread__maps()` and `thread__pid()` accessors in `aslr_tool__findnew_mapping()`. Added `pr_warning_once` warning when raw auxtrace data is dropped. - Patch 3: Fixed encapsulation by using `thread__maps()` and `thread__pid()` accessors in `aslr_tool__remap_address()`. Wrapped `evsel__parse_sample()` to temporarily disable `needs_swap` to avoid branch stack endianness corruption on cross-endian files. Fixed ISO C90 warning for declaration-after-statement for `orig_needs_swap`. - Patch 4: Fixed duplicate cleanup by explicitly removing trap handlers (`trap - EXIT TERM INT`) inside the `cleanup()` function. - Patch 5: Fixed heap corruption by adding size bounds checking before writing to `sample_regs_user` and `sample_regs_intr` fields. Added missing register mask clearing logic for the `itrace` synthesis path of `perf_event__repipe_attr()`. Ian Rogers (5): perf maps: Add maps__mutate_mapping perf inject/aslr: Add ASLR tool infrastructure and MMAP tracking perf inject/aslr: Implement sample address remapping perf test: Add inject ASLR test perf aslr: Strip sample registers tools/perf/builtin-inject.c | 104 +- tools/perf/tests/shell/inject_aslr.sh | 519 ++++++++++ tools/perf/util/Build | 1 + tools/perf/util/aslr.c | 1322 +++++++++++++++++++++++++ tools/perf/util/aslr.h | 41 + tools/perf/util/evsel.c | 6 +- tools/perf/util/evsel.h | 10 +- tools/perf/util/machine.c | 32 +- tools/perf/util/maps.c | 149 ++- tools/perf/util/maps.h | 3 + tools/perf/util/symbol-elf.c | 41 +- tools/perf/util/symbol.c | 17 +- 12 files changed, 2180 insertions(+), 65 deletions(-) create mode 100755 tools/perf/tests/shell/inject_aslr.sh create mode 100644 tools/perf/util/aslr.c create mode 100644 tools/perf/util/aslr.h -- 2.54.0.1032.g2f8565e1d1-goog