]> git.karo-electronics.de Git - mv-sheeva.git/commitdiff
Merge branch 'x86/ld-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
authorLinus Torvalds <torvalds@linux-foundation.org>
Sat, 19 May 2012 22:28:22 +0000 (15:28 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 19 May 2012 22:28:22 +0000 (15:28 -0700)
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.

Makefile
arch/x86/Makefile
arch/x86/boot/compressed/Makefile
arch/x86/tools/.gitignore [new file with mode: 0644]
arch/x86/tools/Makefile
arch/x86/tools/relocs.c [moved from arch/x86/boot/compressed/relocs.c with 76% similarity]
scripts/Makefile

index 48bd1f50dcc39eada16b28883cee05d34b5f3f15..db2bcf3d66b8de00ddf849a49233c376831a4e60 100644 (file)
--- 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
index 41a7237606a3b3a26393b0c7844166d728a9ed0a..94e91e401da996fec91885b7efb8f21bb0fe589e 100644 (file)
@@ -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
 
index fd55a2ff3ad8e58c388871b1e64325c1f14c6c5b..e398bb5d63bb2656570999fffe4d1729928430b3 100644 (file)
@@ -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 := $(obj)/vmlinux.bin
diff --git a/arch/x86/tools/.gitignore b/arch/x86/tools/.gitignore
new file mode 100644 (file)
index 0000000..be0ed06
--- /dev/null
@@ -0,0 +1 @@
+relocs
index d511aa97533abd5d2d3f2144a44d5026d638bcd5..733057b435b0830e497c5d6ff6dbdda9fa49b38d 100644 (file)
@@ -36,3 +36,7 @@ HOSTCFLAGS_insn_sanity.o := -Wall -I$(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
similarity index 76%
rename from arch/x86/boot/compressed/relocs.c
rename to arch/x86/tools/relocs.c
index fb7117a4ade1e259c69d45b47d4ffc3b62196540..b43cfcd9bf40f60b7c3b71a1460c9883c322d7ce 100644 (file)
@@ -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;
 }
index df7678febf277b119cbffc4d3b6f230974fb18f0..36266665dbcbb37ca9d3c3dd466268fa0dbf1265 100644 (file)
@@ -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