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authorLinus Torvalds <torvalds@linux-foundation.org>2014-03-31 14:13:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-03-31 14:13:25 -0700
commit176ab02d4916f09d5d8cb63372d142df4378cdea (patch)
tree7039b1282e7b34341789a5416fbd7ca5da0e557a /scripts
parente06df6a7eae1ab1ef4deb076aeeaed90e948e5c0 (diff)
parentef178f9238b142cc1020265e176b20d27fd02ba9 (diff)
downloadlinux-176ab02d4916f09d5d8cb63372d142df4378cdea.tar.gz
Merge branch 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 LTO changes from Peter Anvin: "More infrastructure work in preparation for link-time optimization (LTO). Most of these changes is to make sure symbols accessed from assembly code are properly marked as visible so the linker doesn't remove them. My understanding is that the changes to support LTO are still not upstream in binutils, but are on the way there. This patchset should conclude the x86-specific changes, and remaining patches to actually enable LTO will be fed through the Kbuild tree (other than keeping up with changes to the x86 code base, of course), although not necessarily in this merge window" * 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits) Kbuild, lto: Handle basic LTO in modpost Kbuild, lto: Disable LTO for asm-offsets.c Kbuild, lto: Add a gcc-ld script to let run gcc as ld Kbuild, lto: add ld-version and ld-ifversion macros Kbuild, lto: Drop .number postfixes in modpost Kbuild, lto, workaround: Don't warn for initcall_reference in modpost lto: Disable LTO for sys_ni lto: Handle LTO common symbols in module loader lto, workaround: Add workaround for initcall reordering lto: Make asmlinkage __visible x86, lto: Disable LTO for the x86 VDSO initconst, x86: Fix initconst mistake in ts5500 code initconst: Fix initconst mistake in dcdbas asmlinkage: Make trace_hardirqs_on/off_caller visible asmlinkage, x86: Fix 32bit memcpy for LTO asmlinkage Make __stack_chk_failed and memcmp visible asmlinkage: Mark rwsem functions that can be called from assembler asmlinkage asmlinkage: Make main_extable_sort_needed visible asmlinkage, mutex: Mark __visible asmlinkage: Make trace_hardirq visible ...
Diffstat (limited to 'scripts')
-rw-r--r--scripts/Kbuild.include9
-rw-r--r--scripts/Makefile.build2
-rw-r--r--scripts/gcc-ld29
-rwxr-xr-xscripts/ld-version.sh8
-rw-r--r--scripts/mod/modpost.c25
-rw-r--r--scripts/mod/modpost.h2
6 files changed, 71 insertions, 4 deletions
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 547e15daf03d..93a0da26582b 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -155,6 +155,15 @@ ld-option = $(call try-run,\
# Important: no spaces around options
ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))
+# ld-version
+# Usage: $(call ld-version)
+# Note this is mainly for HJ Lu's 3 number binutil versions
+ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
+
+# ld-ifversion
+# Usage: $(call ld-ifversion, -ge, 22252, y)
+ld-ifversion = $(shell [ $(call ld-version) $(1) $(2) ] && echo $(3))
+
######
###
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index d5d859c80729..9f0ee22b914f 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -198,7 +198,7 @@ $(multi-objs-y:.o=.s) : modname = $(modname-multi)
$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
-cmd_cc_s_c = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
+cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
$(obj)/%.s: $(src)/%.c FORCE
$(call if_changed_dep,cc_s_c)
diff --git a/scripts/gcc-ld b/scripts/gcc-ld
new file mode 100644
index 000000000000..cadab9a13ed7
--- /dev/null
+++ b/scripts/gcc-ld
@@ -0,0 +1,29 @@
+#!/bin/sh
+# run gcc with ld options
+# used as a wrapper to execute link time optimizations
+# yes virginia, this is not pretty
+
+ARGS="-nostdlib"
+
+while [ "$1" != "" ] ; do
+ case "$1" in
+ -save-temps|-m32|-m64) N="$1" ;;
+ -r) N="$1" ;;
+ -[Wg]*) N="$1" ;;
+ -[olv]|-[Ofd]*|-nostdlib) N="$1" ;;
+ --end-group|--start-group)
+ N="-Wl,$1" ;;
+ -[RTFGhIezcbyYu]*|\
+--script|--defsym|-init|-Map|--oformat|-rpath|\
+-rpath-link|--sort-section|--section-start|-Tbss|-Tdata|-Ttext|\
+--version-script|--dynamic-list|--version-exports-symbol|--wrap|-m)
+ A="$1" ; shift ; N="-Wl,$A,$1" ;;
+ -[m]*) N="$1" ;;
+ -*) N="-Wl,$1" ;;
+ *) N="$1" ;;
+ esac
+ ARGS="$ARGS $N"
+ shift
+done
+
+exec $CC $ARGS
diff --git a/scripts/ld-version.sh b/scripts/ld-version.sh
new file mode 100755
index 000000000000..198580d245e0
--- /dev/null
+++ b/scripts/ld-version.sh
@@ -0,0 +1,8 @@
+#!/usr/bin/awk -f
+# extract linker version number from stdin and turn into single number
+ {
+ gsub(".*)", "");
+ split($1,a, ".");
+ print a[1]*10000000 + a[2]*100000 + a[3]*10000 + a[4]*100 + a[5];
+ exit
+ }
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 99a45fdc1bbf..066355673930 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -623,7 +623,10 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
switch (sym->st_shndx) {
case SHN_COMMON:
- warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
+ if (!strncmp(symname, "__gnu_lto_", sizeof("__gnu_lto_")-1)) {
+ /* Should warn here, but modpost runs before the linker */
+ } else
+ warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
break;
case SHN_UNDEF:
/* undefined symbol */
@@ -849,6 +852,7 @@ static const char *section_white_list[] =
".xt.lit", /* xtensa */
".arcextmap*", /* arc */
".gnu.linkonce.arcext*", /* arc : modules */
+ ".gnu.lto*",
NULL
};
@@ -1455,6 +1459,10 @@ static void check_section_mismatch(const char *modname, struct elf_info *elf,
to = find_elf_symbol(elf, r->r_addend, sym);
tosym = sym_name(elf, to);
+ if (!strncmp(fromsym, "reference___initcall",
+ sizeof("reference___initcall")-1))
+ return;
+
/* check whitelist - we may ignore it */
if (secref_whitelist(mismatch,
fromsec, fromsym, tosec, tosym)) {
@@ -1693,6 +1701,19 @@ static void check_sec_ref(struct module *mod, const char *modname,
}
}
+static char *remove_dot(char *s)
+{
+ char *end;
+ int n = strcspn(s, ".");
+
+ if (n > 0 && s[n] != 0) {
+ strtoul(s + n + 1, &end, 10);
+ if (end > s + n + 1 && (*end == '.' || *end == 0))
+ s[n] = 0;
+ }
+ return s;
+}
+
static void read_symbols(char *modname)
{
const char *symname;
@@ -1731,7 +1752,7 @@ static void read_symbols(char *modname)
}
for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
- symname = info.strtab + sym->st_name;
+ symname = remove_dot(info.strtab + sym->st_name);
handle_modversions(mod, &info, sym, symname);
handle_moddevtable(mod, &info, sym, symname);
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 51207e4d5f8b..168b43dc0a59 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -127,7 +127,7 @@ struct elf_info {
Elf_Section export_gpl_sec;
Elf_Section export_unused_gpl_sec;
Elf_Section export_gpl_future_sec;
- const char *strtab;
+ char *strtab;
char *modinfo;
unsigned int modinfo_len;