From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from va-1-111.ptr.blmpb.com (va-1-111.ptr.blmpb.com [209.127.230.111]) (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 0A73E46C4CD for ; Fri, 7 Aug 2026 08:16:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.127.230.111 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786090575; cv=none; b=K+dI2BmpSceBUAS/rYMQaUGyF+SmBNC11wTfavJM7oIFBC26kBYYFv8jgLPnjlU8C03aHLEQKLi4JOuSv+JQdEECtLrdbOPDKljJXSs55kSFmXfP68MP3+ZzYOdJjhYMeK1M/GLxeQd2CRkwHB2w0wa4mZif2N1/3LeqcHrF/t4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786090575; c=relaxed/simple; bh=qozgKeqjQY8jqxFJp3ds9EO0gAHwRe1fjjWm2OUEFWo=; h=To:Subject:References:Content-Type:From:Date:In-Reply-To:Cc: Message-Id:Mime-Version; b=FB1pp4AI7Rwu7eM8L/nz3SIHfh3xrm+uo+lgzLZvZKh4+krSb5T5wXv2jS4Fs2qeuTeEaQUk03x8u3Iy1FaiPDnidcrOj7WCR385RqJ6BY4aPORNGyoay5YZ0FDA4DZhNPmnxt3s/592uv1SIKtIQwqvMmFsXyqJ2nzH8I/2OMs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com; spf=pass smtp.mailfrom=bytedance.com; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b=dI2LgVzg; arc=none smtp.client-ip=209.127.230.111 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bytedance.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b="dI2LgVzg" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=2212171451; d=bytedance.com; t=1786090559; h=from:subject: mime-version:from:date:message-id:subject:to:cc:reply-to:content-type: mime-version:in-reply-to:message-id; bh=m5Q6pj+2aZgVsaFgFCzX1cAV4lDF7uuJhuFlfFc6gII=; b=dI2LgVzgvZXAKE5kY2lgFx0jK2dQgdcnI31YfYbo2bRuU7itBKM+b2B1azWpyR/w4eIQ8l 7igJcWysMrdgHm+xG5VyHd9GA3F83z0GslJOoFURj6OxQ9Sfk/biql5bwluoZxowWEb40E 7ciyQ/vysfkpEPFTOxu4kfQI1FMIYhFJPke/XwEgu3U8TudctaXoBDo9jFaMLX+lln5f7h 7RaPZoIKPBwFY7e96zKDu7fekOPFUA7Mtn43N+FQkvI2x5VhI5fpeBr5oIhspyCP2058D8 wQCl5Gm/SKrdkLmyIxVwMHg7SnOq+7W8ZZlQ7U3lf0BIsWEOd11nfpSgOqxGrQ== To: "Steven Rostedt" , "Masami Hiramatsu" Subject: [PATCH v2 2/2] selftests/ftrace: Convert ELF entry point to file offset in uprobe test X-Lms-Return-Path: References: <20260806083101.2651025-1-qirui.001@bytedance.com> <20260807081512.2974757-1-qirui.001@bytedance.com> Content-Type: text/plain; charset=UTF-8 From: "Rui Qi" Date: Fri, 7 Aug 2026 16:15:12 +0800 In-Reply-To: <20260807081512.2974757-1-qirui.001@bytedance.com> Cc: "Mathieu Desnoyers" , "Shuah Khan" , "Heiko Carstens" , , , , "Rui Qi" Message-Id: <20260807081512.2974757-3-qirui.001@bytedance.com> Content-Transfer-Encoding: 7bit X-Mailer: git-send-email 2.20.1 X-Original-From: Rui Qi Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 The add_remove_uprobe test uses readelf -h to obtain the ELF entry point (e_entry) and passes it directly as the offset to uprobe_events. However, uprobe_events expects a file offset, not a virtual address. For PIE binaries, the virtual address happens to equal the file offset because the first LOAD segment has p_vaddr == p_offset, so the test works by coincidence. But for non-PIE executables, e_entry is an absolute virtual address that can far exceed the file size. When the probe is enabled, uprobe_register() checks offset > i_size_read(inode) and rejects it with -EINVAL. Fix this by converting the virtual address to a file offset using the ELF program headers: scan readelf -lW output for the LOAD segment containing the entry point, then compute file_offset = e_entry - p_vaddr + p_offset. For PIE binaries the result is unchanged; for non-PIE binaries the offset is correctly translated. The conversion uses only POSIX shell primitives, with no dependency on gawk or perl. Fixes: dc4b165855f2 ("selftests/ftrace: Use readelf to find entry point in uprobe test") Signed-off-by: Rui Qi --- .../test.d/dynevent/add_remove_uprobe.tc | 27 +++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc index f2048c244526..19430bd5864c 100644 --- a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc +++ b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_uprobe.tc @@ -12,9 +12,32 @@ echo 0 > events/enable echo > dynamic_events REALBIN=`readlink -f /bin/sh` -ENTRYPOINT=`readelf -h ${REALBIN} | grep Entry | sed -e 's/[^0]*//'` -echo "p:myevent ${REALBIN}:${ENTRYPOINT}" >> uprobe_events +# Get the entry point virtual address from ELF header +ENTRY=`readelf -hW ${REALBIN} | grep "Entry point" | awk '{print $NF}'` + +# Convert virtual address to file offset: find the LOAD segment containing +# the entry point, then compute file_offset = e_entry - p_vaddr + p_offset. +# For PIE binaries this is a no-op (vaddr == file offset), but for non-PIE +# executables the virtual address is much larger than the file size and +# must be converted, otherwise uprobe_register() rejects it with -EINVAL. +ENTRY_DEC=$(printf '%d' "$ENTRY") +OFFSET=$ENTRY +while IFS= read -r line; do + set -- $line + [ "$1" = "LOAD" ] || continue + VA_DEC=$(printf '%d' "$3") + OFF_DEC=$(printf '%d' "$2") + FSZ_DEC=$(printf '%d' "$5") + if [ "$ENTRY_DEC" -ge "$VA_DEC" ] && [ "$ENTRY_DEC" -lt "$((VA_DEC + FSZ_DEC))" ]; then + OFFSET=$(printf '0x%x' "$((ENTRY_DEC - VA_DEC + OFF_DEC))") + break + fi +done << EOF +$(readelf -lW ${REALBIN} | grep LOAD) +EOF + +echo "p:myevent ${REALBIN}:${OFFSET}" >> uprobe_events grep -q myevent uprobe_events test -d events/uprobes/myevent -- 2.20.1