fe00ab1eb3
[ Upstream commit 8f9e0a52810dd83406c768972d022c37e7a18f1f ] The ACPICA code has been built with '-Os' since the beginning of git history, though there's no explanatory comment as to why. This is unfortunate as GCC drops the alignment specificed by '-falign-functions=N' when '-Os' is used, as reported in GCC bug 88345: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88345 This prevents CONFIG_FUNCTION_ALIGNMENT and CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B from having their expected effect on the ACPICA code. This is doubly unfortunate as in subsequent patches arm64 will depend upon CONFIG_FUNCTION_ALIGNMENT for its ftrace implementation. Drop the '-Os' flag when building the ACPICA code. With this removed, the code builds cleanly and works correctly in testing so far. I've tested this by selecting CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B=y, building and booting a kernel using ACPI, and looking for misaligned text symbols: * arm64: Before, v6.2-rc3: # uname -rm 6.2.0-rc3 aarch64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 5009 Before, v6.2-rc3 + fixed __cold: # uname -rm 6.2.0-rc3-00001-g2a2bedf8bfa9 aarch64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 919 After: # uname -rm 6.2.0-rc3-00002-g267bddc38572 aarch64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 323 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | grep acpi | wc -l 0 * x86_64: Before, v6.2-rc3: # uname -rm 6.2.0-rc3 x86_64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 11537 Before, v6.2-rc3 + fixed __cold: # uname -rm 6.2.0-rc3-00001-g2a2bedf8bfa9 x86_64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 2805 After: # uname -rm 6.2.0-rc3-00002-g267bddc38572 x86_64 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | wc -l 1357 # grep ' [Tt] ' /proc/kallsyms | grep -iv '[048c]0 [Tt] ' | grep acpi | wc -l 0 With the patch applied, the remaining unaligned text labels are a combination of static call trampolines and labels in assembly, which can be dealt with in subsequent patches. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Florent Revest <revest@chromium.org> Cc: Len Brown <lenb@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert Moore <robert.moore@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Deacon <will@kernel.org> Cc: linux-acpi@vger.kernel.org Link: https://lore.kernel.org/r/20230123134603.1064407-4-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.