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93e051860a
Align ro_after_init using MAXPAGESIZE instead of COMMONPAGESIZE. COMMONPAGESIZE may be smaller than the actual page size supported by the target ABI. This can leave ro_after_init sharing an OS page with adjacent sections, causing mprotect() to change permissions on data outside ro_after_init. Use MAXPAGESIZE so the section boundaries are aligned to the maximum page size required by the target linker/ABI. This is particularly important on architectures such as ppc64le and aarch64, where the runtime page size can differ from COMMONPAGESIZE. Before: .data 0x...1b80000 ro_after_init 0x...1c70000 .bss 0x...1c72000 After: ro_after_init starts and ends on MAXPAGESIZE boundaries, ensuring mprotect() only affects pages belonging to ro_after_init. Co-authored-by: ChatGPT GPT-5.6 Luna <noreply@openai.com>
32 lines
1.1 KiB
Plaintext
32 lines
1.1 KiB
Plaintext
/*
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Copyright (c) 2026, MariaDB plc, MariaDB Foundation
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
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/*
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Give the "ro_after_init" section a page-aligned span of its own, so that the
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variables placed there (with READ_ONLY_SYSVAR tag) can be mprotect()-ed
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once server initialization is complete, without affecting neighbouring data.
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*/
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SECTIONS
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{
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ro_after_init ALIGN(CONSTANT(MAXPAGESIZE)) :
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{
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ro_after_init_start = .;
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*(ro_after_init)
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. = ALIGN(CONSTANT(MAXPAGESIZE));
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ro_after_init_end = .;
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}
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} INSERT AFTER .data;
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