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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-19 15:28:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-19 15:28:22 -0700
commit5d1204582e7bc0682fb019e5666bd62cc27260b4 (patch)
treeffb59f5683f2dfc70ff2e7cf2fa8c7c81557b14d
parent14e931a264498fbd4baef07ee0644e347252393b (diff)
parent24ab82bd9bf18f3efc69a131d73577940941e1b7 (diff)
downloadlinux-stericsson-5d1204582e7bc0682fb019e5666bd62cc27260b4.tar.gz
Merge branch 'x86/ld-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 linker bug workarounds from Peter Anvin. GNU ld-2.22.52.0.[12] (*) has an unfortunate bug where it incorrectly turns certain relocation entries absolute. Section-relative symbols that are part of otherwise empty sections are silently changed them to absolute. We rely on section-relative symbols staying section-relative, and actually have several sections in the linker script solely for this purpose. See for example http://sourceware.org/bugzilla/show_bug.cgi?id=14052 We could just black-list the buggy linker, but it appears that it got shipped in at least F17, and possibly other distros too, so it's sadly not some rare unusual case. This backports the workaround from the x86/trampoline branch, and as Peter says: "This is not a minimal fix, not at all, but it is a tested code base." * 'x86/ld-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, relocs: When printing an error, say relative or absolute x86, relocs: Workaround for binutils 2.22.52.0.1 section bug x86, realmode: 16-bit real-mode code support for relocs tool (*) That's a manly release numbering system. Stupid, sure. But manly.
-rw-r--r--Makefile9
-rw-r--r--arch/x86/Makefile3
-rw-r--r--arch/x86/boot/compressed/Makefile9
-rw-r--r--arch/x86/tools/.gitignore1
-rw-r--r--arch/x86/tools/Makefile4
-rw-r--r--arch/x86/tools/relocs.c (renamed from arch/x86/boot/compressed/relocs.c)242
-rw-r--r--scripts/Makefile2
7 files changed, 205 insertions, 65 deletions
diff --git a/Makefile b/Makefile
index 48bd1f50dcc3..db2bcf3d66b8 100644
--- a/Makefile
+++ b/Makefile
@@ -442,7 +442,7 @@ asm-generic:
no-dot-config-targets := clean mrproper distclean \
cscope gtags TAGS tags help %docs check% coccicheck \
- include/linux/version.h headers_% archheaders \
+ include/linux/version.h headers_% archheaders archscripts \
kernelversion %src-pkg
config-targets := 0
@@ -979,7 +979,7 @@ prepare1: prepare2 include/linux/version.h include/generated/utsrelease.h \
include/config/auto.conf
$(cmd_crmodverdir)
-archprepare: archheaders prepare1 scripts_basic
+archprepare: archheaders archscripts prepare1 scripts_basic
prepare0: archprepare FORCE
$(Q)$(MAKE) $(build)=.
@@ -1049,8 +1049,11 @@ hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm)
PHONY += archheaders
archheaders:
+PHONY += archscripts
+archscripts:
+
PHONY += __headers
-__headers: include/linux/version.h scripts_basic asm-generic archheaders FORCE
+__headers: include/linux/version.h scripts_basic asm-generic archheaders archscripts FORCE
$(Q)$(MAKE) $(build)=scripts build_unifdef
PHONY += headers_install_all
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 41a7237606a3..94e91e401da9 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -134,6 +134,9 @@ KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
KBUILD_CFLAGS += $(mflags-y)
KBUILD_AFLAGS += $(mflags-y)
+archscripts:
+ $(Q)$(MAKE) $(build)=arch/x86/tools relocs
+
###
# Syscall table generation
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index fd55a2ff3ad8..e398bb5d63bb 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -40,13 +40,12 @@ OBJCOPYFLAGS_vmlinux.bin := -R .comment -S
$(obj)/vmlinux.bin: vmlinux FORCE
$(call if_changed,objcopy)
+targets += vmlinux.bin.all vmlinux.relocs
-targets += vmlinux.bin.all vmlinux.relocs relocs
-hostprogs-$(CONFIG_X86_NEED_RELOCS) += relocs
-
+CMD_RELOCS = arch/x86/tools/relocs
quiet_cmd_relocs = RELOCS $@
- cmd_relocs = $(obj)/relocs $< > $@;$(obj)/relocs --abs-relocs $<
-$(obj)/vmlinux.relocs: vmlinux $(obj)/relocs FORCE
+ cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $<
+$(obj)/vmlinux.relocs: vmlinux FORCE
$(call if_changed,relocs)
vmlinux.bin.all-y := $(obj)/vmlinux.bin
diff --git a/arch/x86/tools/.gitignore b/arch/x86/tools/.gitignore
new file mode 100644
index 000000000000..be0ed065249b
--- /dev/null
+++ b/arch/x86/tools/.gitignore
@@ -0,0 +1 @@
+relocs
diff --git a/arch/x86/tools/Makefile b/arch/x86/tools/Makefile
index d511aa97533a..733057b435b0 100644
--- a/arch/x86/tools/Makefile
+++ b/arch/x86/tools/Makefile
@@ -36,3 +36,7 @@ HOSTCFLAGS_insn_sanity.o := -Wall -I$(objtree)/arch/x86/lib/ -I$(srctree)/arch/x
$(obj)/test_get_len.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
$(obj)/insn_sanity.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
+
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include
+hostprogs-y += relocs
+relocs: $(obj)/relocs
diff --git a/arch/x86/boot/compressed/relocs.c b/arch/x86/tools/relocs.c
index fb7117a4ade1..b43cfcd9bf40 100644
--- a/arch/x86/boot/compressed/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -18,6 +18,8 @@ static void die(char *fmt, ...);
static Elf32_Ehdr ehdr;
static unsigned long reloc_count, reloc_idx;
static unsigned long *relocs;
+static unsigned long reloc16_count, reloc16_idx;
+static unsigned long *relocs16;
struct section {
Elf32_Shdr shdr;
@@ -28,52 +30,86 @@ struct section {
};
static struct section *secs;
+enum symtype {
+ S_ABS,
+ S_REL,
+ S_SEG,
+ S_LIN,
+ S_NSYMTYPES
+};
+
+static const char * const sym_regex_kernel[S_NSYMTYPES] = {
/*
* Following symbols have been audited. There values are constant and do
* not change if bzImage is loaded at a different physical address than
* the address for which it has been compiled. Don't warn user about
* absolute relocations present w.r.t these symbols.
*/
-static const char abs_sym_regex[] =
+ [S_ABS] =
"^(xen_irq_disable_direct_reloc$|"
"xen_save_fl_direct_reloc$|"
"VDSO|"
- "__crc_)";
-static regex_t abs_sym_regex_c;
-static int is_abs_reloc(const char *sym_name)
-{
- return !regexec(&abs_sym_regex_c, sym_name, 0, NULL, 0);
-}
+ "__crc_)",
/*
* These symbols are known to be relative, even if the linker marks them
* as absolute (typically defined outside any section in the linker script.)
*/
-static const char rel_sym_regex[] =
- "^_end$";
-static regex_t rel_sym_regex_c;
-static int is_rel_reloc(const char *sym_name)
+ [S_REL] =
+ "^(__init_(begin|end)|"
+ "__x86_cpu_dev_(start|end)|"
+ "(__parainstructions|__alt_instructions)(|_end)|"
+ "(__iommu_table|__apicdrivers|__smp_locks)(|_end)|"
+ "_end)$"
+};
+
+
+static const char * const sym_regex_realmode[S_NSYMTYPES] = {
+/*
+ * These are 16-bit segment symbols when compiling 16-bit code.
+ */
+ [S_SEG] =
+ "^real_mode_seg$",
+
+/*
+ * These are offsets belonging to segments, as opposed to linear addresses,
+ * when compiling 16-bit code.
+ */
+ [S_LIN] =
+ "^pa_",
+};
+
+static const char * const *sym_regex;
+
+static regex_t sym_regex_c[S_NSYMTYPES];
+static int is_reloc(enum symtype type, const char *sym_name)
{
- return !regexec(&rel_sym_regex_c, sym_name, 0, NULL, 0);
+ return sym_regex[type] &&
+ !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0);
}
-static void regex_init(void)
+static void regex_init(int use_real_mode)
{
char errbuf[128];
int err;
-
- err = regcomp(&abs_sym_regex_c, abs_sym_regex,
- REG_EXTENDED|REG_NOSUB);
- if (err) {
- regerror(err, &abs_sym_regex_c, errbuf, sizeof errbuf);
- die("%s", errbuf);
- }
+ int i;
+
+ if (use_real_mode)
+ sym_regex = sym_regex_realmode;
+ else
+ sym_regex = sym_regex_kernel;
- err = regcomp(&rel_sym_regex_c, rel_sym_regex,
- REG_EXTENDED|REG_NOSUB);
- if (err) {
- regerror(err, &rel_sym_regex_c, errbuf, sizeof errbuf);
- die("%s", errbuf);
+ for (i = 0; i < S_NSYMTYPES; i++) {
+ if (!sym_regex[i])
+ continue;
+
+ err = regcomp(&sym_regex_c[i], sym_regex[i],
+ REG_EXTENDED|REG_NOSUB);
+
+ if (err) {
+ regerror(err, &sym_regex_c[i], errbuf, sizeof errbuf);
+ die("%s", errbuf);
+ }
}
}
@@ -154,6 +190,10 @@ static const char *rel_type(unsigned type)
REL_TYPE(R_386_RELATIVE),
REL_TYPE(R_386_GOTOFF),
REL_TYPE(R_386_GOTPC),
+ REL_TYPE(R_386_8),
+ REL_TYPE(R_386_PC8),
+ REL_TYPE(R_386_16),
+ REL_TYPE(R_386_PC16),
#undef REL_TYPE
};
const char *name = "unknown type rel type name";
@@ -189,7 +229,7 @@ static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
name = sym_strtab + sym->st_name;
}
else {
- name = sec_name(secs[sym->st_shndx].shdr.sh_name);
+ name = sec_name(sym->st_shndx);
}
return name;
}
@@ -472,7 +512,7 @@ static void print_absolute_relocs(void)
* Before warning check if this absolute symbol
* relocation is harmless.
*/
- if (is_abs_reloc(name) || is_rel_reloc(name))
+ if (is_reloc(S_ABS, name) || is_reloc(S_REL, name))
continue;
if (!printed) {
@@ -496,7 +536,8 @@ static void print_absolute_relocs(void)
printf("\n");
}
-static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
+static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym),
+ int use_real_mode)
{
int i;
/* Walk through the relocations */
@@ -521,30 +562,67 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
Elf32_Rel *rel;
Elf32_Sym *sym;
unsigned r_type;
+ const char *symname;
+ int shn_abs;
+
rel = &sec->reltab[j];
sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
r_type = ELF32_R_TYPE(rel->r_info);
- /* Don't visit relocations to absolute symbols */
- if (sym->st_shndx == SHN_ABS &&
- !is_rel_reloc(sym_name(sym_strtab, sym))) {
- continue;
- }
+
+ shn_abs = sym->st_shndx == SHN_ABS;
+
switch (r_type) {
case R_386_NONE:
case R_386_PC32:
+ case R_386_PC16:
+ case R_386_PC8:
/*
* NONE can be ignored and and PC relative
* relocations don't need to be adjusted.
*/
break;
+
+ case R_386_16:
+ symname = sym_name(sym_strtab, sym);
+ if (!use_real_mode)
+ goto bad;
+ if (shn_abs) {
+ if (is_reloc(S_ABS, symname))
+ break;
+ else if (!is_reloc(S_SEG, symname))
+ goto bad;
+ } else {
+ if (is_reloc(S_LIN, symname))
+ goto bad;
+ else
+ break;
+ }
+ visit(rel, sym);
+ break;
+
case R_386_32:
- /* Visit relocations that need to be adjusted */
+ symname = sym_name(sym_strtab, sym);
+ if (shn_abs) {
+ if (is_reloc(S_ABS, symname))
+ break;
+ else if (!is_reloc(S_REL, symname))
+ goto bad;
+ } else {
+ if (use_real_mode &&
+ !is_reloc(S_LIN, symname))
+ break;
+ }
visit(rel, sym);
break;
default:
die("Unsupported relocation type: %s (%d)\n",
rel_type(r_type), r_type);
break;
+ bad:
+ symname = sym_name(sym_strtab, sym);
+ die("Invalid %s %s relocation: %s\n",
+ shn_abs ? "absolute" : "relative",
+ rel_type(r_type), symname);
}
}
}
@@ -552,13 +630,19 @@ static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
{
- reloc_count += 1;
+ if (ELF32_R_TYPE(rel->r_info) == R_386_16)
+ reloc16_count++;
+ else
+ reloc_count++;
}
static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
{
/* Remember the address that needs to be adjusted. */
- relocs[reloc_idx++] = rel->r_offset;
+ if (ELF32_R_TYPE(rel->r_info) == R_386_16)
+ relocs16[reloc16_idx++] = rel->r_offset;
+ else
+ relocs[reloc_idx++] = rel->r_offset;
}
static int cmp_relocs(const void *va, const void *vb)
@@ -568,23 +652,41 @@ static int cmp_relocs(const void *va, const void *vb)
return (*a == *b)? 0 : (*a > *b)? 1 : -1;
}
-static void emit_relocs(int as_text)
+static int write32(unsigned int v, FILE *f)
+{
+ unsigned char buf[4];
+
+ put_unaligned_le32(v, buf);
+ return fwrite(buf, 1, 4, f) == 4 ? 0 : -1;
+}
+
+static void emit_relocs(int as_text, int use_real_mode)
{
int i;
/* Count how many relocations I have and allocate space for them. */
reloc_count = 0;
- walk_relocs(count_reloc);
+ walk_relocs(count_reloc, use_real_mode);
relocs = malloc(reloc_count * sizeof(relocs[0]));
if (!relocs) {
die("malloc of %d entries for relocs failed\n",
reloc_count);
}
+
+ relocs16 = malloc(reloc16_count * sizeof(relocs[0]));
+ if (!relocs16) {
+ die("malloc of %d entries for relocs16 failed\n",
+ reloc16_count);
+ }
/* Collect up the relocations */
reloc_idx = 0;
- walk_relocs(collect_reloc);
+ walk_relocs(collect_reloc, use_real_mode);
+
+ if (reloc16_count && !use_real_mode)
+ die("Segment relocations found but --realmode not specified\n");
/* Order the relocations for more efficient processing */
qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs);
+ qsort(relocs16, reloc16_count, sizeof(relocs16[0]), cmp_relocs);
/* Print the relocations */
if (as_text) {
@@ -593,58 +695,83 @@ static void emit_relocs(int as_text)
*/
printf(".section \".data.reloc\",\"a\"\n");
printf(".balign 4\n");
- for (i = 0; i < reloc_count; i++) {
- printf("\t .long 0x%08lx\n", relocs[i]);
+ if (use_real_mode) {
+ printf("\t.long %lu\n", reloc16_count);
+ for (i = 0; i < reloc16_count; i++)
+ printf("\t.long 0x%08lx\n", relocs16[i]);
+ printf("\t.long %lu\n", reloc_count);
+ for (i = 0; i < reloc_count; i++) {
+ printf("\t.long 0x%08lx\n", relocs[i]);
+ }
+ } else {
+ /* Print a stop */
+ printf("\t.long 0x%08lx\n", (unsigned long)0);
+ for (i = 0; i < reloc_count; i++) {
+ printf("\t.long 0x%08lx\n", relocs[i]);
+ }
}
+
printf("\n");
}
else {
- unsigned char buf[4];
- /* Print a stop */
- fwrite("\0\0\0\0", 4, 1, stdout);
- /* Now print each relocation */
- for (i = 0; i < reloc_count; i++) {
- put_unaligned_le32(relocs[i], buf);
- fwrite(buf, 4, 1, stdout);
+ if (use_real_mode) {
+ write32(reloc16_count, stdout);
+ for (i = 0; i < reloc16_count; i++)
+ write32(relocs16[i], stdout);
+ write32(reloc_count, stdout);
+
+ /* Now print each relocation */
+ for (i = 0; i < reloc_count; i++)
+ write32(relocs[i], stdout);
+ } else {
+ /* Print a stop */
+ write32(0, stdout);
+
+ /* Now print each relocation */
+ for (i = 0; i < reloc_count; i++) {
+ write32(relocs[i], stdout);
+ }
}
}
}
static void usage(void)
{
- die("relocs [--abs-syms |--abs-relocs | --text] vmlinux\n");
+ die("relocs [--abs-syms|--abs-relocs|--text|--realmode] vmlinux\n");
}
int main(int argc, char **argv)
{
int show_absolute_syms, show_absolute_relocs;
- int as_text;
+ int as_text, use_real_mode;
const char *fname;
FILE *fp;
int i;
- regex_init();
-
show_absolute_syms = 0;
show_absolute_relocs = 0;
as_text = 0;
+ use_real_mode = 0;
fname = NULL;
for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (*arg == '-') {
- if (strcmp(argv[1], "--abs-syms") == 0) {
+ if (strcmp(arg, "--abs-syms") == 0) {
show_absolute_syms = 1;
continue;
}
-
- if (strcmp(argv[1], "--abs-relocs") == 0) {
+ if (strcmp(arg, "--abs-relocs") == 0) {
show_absolute_relocs = 1;
continue;
}
- else if (strcmp(argv[1], "--text") == 0) {
+ if (strcmp(arg, "--text") == 0) {
as_text = 1;
continue;
}
+ if (strcmp(arg, "--realmode") == 0) {
+ use_real_mode = 1;
+ continue;
+ }
}
else if (!fname) {
fname = arg;
@@ -655,6 +782,7 @@ int main(int argc, char **argv)
if (!fname) {
usage();
}
+ regex_init(use_real_mode);
fp = fopen(fname, "r");
if (!fp) {
die("Cannot open %s: %s\n",
@@ -673,6 +801,6 @@ int main(int argc, char **argv)
print_absolute_relocs();
return 0;
}
- emit_relocs(as_text);
+ emit_relocs(as_text, use_real_mode);
return 0;
}
diff --git a/scripts/Makefile b/scripts/Makefile
index df7678febf27..36266665dbcb 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -8,6 +8,8 @@
# conmakehash: Create arrays for initializing the kernel console tables
# docproc: Used in Documentation/DocBook
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include
+
hostprogs-$(CONFIG_KALLSYMS) += kallsyms
hostprogs-$(CONFIG_LOGO) += pnmtologo
hostprogs-$(CONFIG_VT) += conmakehash