From 457bd9cf2e27550dd66b2d8f3c5a8dbd0dfb398f Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Fri, 12 Jan 2024 10:19:41 -0800 Subject: x86-64: Check if mprotect works before rewriting PLT Systemd execution environment configuration may prohibit changing a memory mapping to become executable: MemoryDenyWriteExecute= Takes a boolean argument. If set, attempts to create memory mappings that are writable and executable at the same time, or to change existing memory mappings to become executable, or mapping shared memory segments as executable, are prohibited. When it is set, systemd service stops working if PLT rewrite is enabled. Check if mprotect works before rewriting PLT. This fixes BZ #31230. This also works with SELinux when deny_execmem is on. Reviewed-by: Carlos O'Donell --- sysdeps/x86_64/dl-plt-rewrite.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 sysdeps/x86_64/dl-plt-rewrite.h (limited to 'sysdeps/x86_64/dl-plt-rewrite.h') diff --git a/sysdeps/x86_64/dl-plt-rewrite.h b/sysdeps/x86_64/dl-plt-rewrite.h new file mode 100644 index 0000000000..cab6fe75ea --- /dev/null +++ b/sysdeps/x86_64/dl-plt-rewrite.h @@ -0,0 +1,25 @@ +/* PLT rewrite helper function. x86-64 version. + Copyright (C) 2024 Free Software Foundation, Inc. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include + +static __always_inline bool +dl_plt_rewrite_supported (void) +{ + return true; +} -- cgit 1.4.1