diff mbox series

[28/46] scripts, lto: re-add gcc-ld

Message ID	20221114114344.18650-29-jirislaby@kernel.org
State	New
Headers	Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; From: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> To: linux-kernel@vger.kernel.org Cc: Andi Kleen <ak@linux.intel.com>, Masahiro Yamada <masahiroy@kernel.org>, Michal Marek <michal.lkml@markovi.net>, Nick Desaulniers <ndesaulniers@google.com>, linux-kbuild@vger.kernel.org, Martin Liska <mliska@suse.cz>, Jiri Slaby <jslaby@suse.cz> Subject: [PATCH 28/46] scripts, lto: re-add gcc-ld Date: Mon, 14 Nov 2022 12:43:26 +0100 Message-Id: <20221114114344.18650-29-jirislaby@kernel.org> In-Reply-To: <20221114114344.18650-1-jirislaby@kernel.org> References: <20221114114344.18650-1-jirislaby@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	gcc-LTO support for the kernel \| [00/46] gcc-LTO support for the kernel [01/46] x86/boot: robustify calling startup_{32,64}() from the decompressor code [02/46] kbuild: pass jobserver to cmd_ld_vmlinux.o [03/46] kbuild: lto: preserve MAKEFLAGS for module linking [04/46] compiler.h: introduce __visible_on_lto [05/46] compiler.h: introduce __global_on_lto [06/46] Compiler Attributes, lto: introduce __noreorder [07/46] tracepoint, lto: Mark static call functions as __visible [08/46] static_call, lto: Mark static keys as __visible [09/46] static_call, lto: Mark static_call_return0() as __visible [10/46] static_call, lto: Mark func_a() as __visible_on_lto [11/46] x86/alternative, lto: Mark int3_() as global and __visible [12/46] x86/paravirt, lto: Mark native_steal_clock() as __visible_on_lto [13/46] x86/preempt, lto: Mark preempt_schedule_thunk() as __visible [14/46] x86/sev, lto: Mark cpuid_table_copy as __visible_on_lto [15/46] x86/xen, lto: Mark xen_vcpu_stolen() as __visible [16/46] x86, lto: Mark gdt_page and native_sched_clock() as __visible [17/46] amd, lto: Mark amd pmu and pstate functions as __visible_on_lto [18/46] entry, lto: Mark raw_irqentry_exit_cond_resched() as __visible [19/46] export, lto: Mark __kstrtab* in EXPORT_SYMBOL() as global and __visible [20/46] softirq, lto: Mark irq_enter/exit_rcu() as __visible [21/46] btf, lto: pass scope as strings [22/46] btf, lto: Make all BTF IDs global on LTO [23/46] init.h, lto: mark initcalls as __noreorder [24/46] bpf, lto: mark interpreter jump table as __noreorder [25/46] sched, lto: mark sched classes as __noreorder [26/46] x86/apic, lto: Mark apic_driver*() as __noreorder [27/46] linkage, lto: use C version for SYSCALL_ALIAS() / cond_syscall() [28/46] scripts, lto: re-add gcc-ld [29/46] scripts, lto: use CONFIG_LTO for many LTO specific actions [30/46] Kbuild, lto: Add Link Time Optimization support [31/46] x86/purgatory, lto: Disable gcc LTO for purgatory [32/46] x86/realmode, lto: Disable gcc LTO for real mode code [33/46] x86/vdso, lto: Disable gcc LTO for the vdso [34/46] scripts, lto: disable gcc LTO for some mod sources [35/46] Kbuild, lto: disable gcc LTO for bounds+asm-offsets [36/46] lib/string, lto: disable gcc LTO for string.o [37/46] Compiler attributes, lto: disable __flatten with LTO [38/46] Kbuild, lto: don't include weak source file symbols in System.map [39/46] x86, lto: Disable relative init pointers with gcc LTO [40/46] x86/livepatch, lto: Disable live patching with gcc LTO [41/46] x86/lib, lto: Mark 32bit mem{cpy,move,set} as __used [42/46] mm/kasan, lto: Mark kasan mem{cpy,move,set} as __used [43/46] scripts, lto: check C symbols for modversions [44/46] scripts/bloat-o-meter, lto: handle gcc LTO [45/46] kasan, lto: remove extra BUILD_BUG() in memory_is_poisoned [46/46] x86, lto: Finally enable gcc LTO for x86

Commit Message

Jiri Slaby Nov. 14, 2022, 11:43 a.m. UTC

  From: Andi Kleen <ak@linux.intel.com>

The primary goal of the script is to mangle linker command line arguments
into something which gcc understands. Such as converting "-z now" into
"-Wl,-z,now".

The script was removed by commit 86879fd277e8 (scripts: remove obsolete
gcc-ld script) as there was no use in the kernel. It had been added long
time ago to support exactly these lto patches, so we need to add it back
now.

Since the removed version, it is improved a bit:
* some missing linker and gcc command line arguments were added, and
* when V=1 is specified, it prints the final gcc command line

[js] rebase + commit message massage

Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Martin Liska <mliska@suse.cz>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 scripts/gcc-ld | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100755 scripts/gcc-ld

diff mbox series

Patch

diff --git a/scripts/gcc-ld b/scripts/gcc-ld
new file mode 100755
index 000000000000..13e85ece8d04
--- /dev/null
+++ b/scripts/gcc-ld
@@ -0,0 +1,40 @@ 
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# run gcc with ld options
+# used as a wrapper to execute link time optimizations
+# yes virginia, this is not pretty
+
+ARGS="-nostdlib"
+
+for j in "$@" ; do
+	if [ "$j" = -v ] ; then
+		exec `$CC -print-prog-name=ld` -v
+	fi
+done
+
+while [ "$1" != "" ] ; do
+	case "$1" in
+	-save-temps*|-m32|-m64) N="$1" ;;
+	-r) N="$1" ;;
+	-flinker-output*) N="$1" ;;
+	-[Wg]*) N="$1" ;;
+	-[olv]|-[Ofd]*|-nostdlib) N="$1" ;;
+	--end-group|--start-group|--whole-archive|--no-whole-archive|\
+--no-undefined|--hash-style*|--build-id*|--eh-frame-hdr|-Bsymbolic)
+		 N="-Wl,$1" ;;
+	-[RTFGhIezcbyYu]*|\
+--script|--defsym|-init|-Map|--oformat|-rpath|\
+-rpath-link|--sort-section|--section-start|-Tbss|-Tdata|-Ttext|-soname|\
+--version-script|--dynamic-list|--version-exports-symbol|--wrap|-m|-z)
+		A="$1" ; shift ; N="-Wl,$A,$1" ;;
+	-[m]*) N="$1" ;;
+	-*) N="-Wl,$1" ;;
+	*)  N="$1" ;;
+	esac
+	ARGS="$ARGS $N"
+	shift
+done
+
+[ -n "$V" ] && echo >&2 $CC $ARGS
+
+exec $CC $ARGS