Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S968295Ab2ESC4N (ORCPT ); Fri, 18 May 2012 22:56:13 -0400 Received: from terminus.zytor.com ([198.137.202.10]:49993 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753626Ab2ESC4I (ORCPT ); Fri, 18 May 2012 22:56:08 -0400 Date: Fri, 18 May 2012 19:55:44 -0700 Message-Id: <201205190255.q4J2tiGR019358@terminus.zytor.com> From: "H. Peter Anvin" To: Linus Torvalds Subject: [GIT PULL/RFC] x86/relocs fixes for ld 2.22.52.0.x bug Cc: , "H. Peter Anvin" , "H. Peter Anvin" , "H.J. Lu" , Ingo Molnar , Ingo Molnar , Jarkko Sakkinen , Linux Kernel Mailing List , Thomas Gleixner X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Fri, 18 May 2012 19:55:50 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 16573 Lines: 565 Hi Linus, This is in case you want to take the patches for the GNU ld 2.22.52.0.x bug at this time -- the code is a direct cherry-pick from the tip:x86/trampoline branch, except I have folded five patches on that branch into three. This is not a minimal fix, not at all, but it is a tested code base. The following changes since commit 36be50515fe2aef61533b516fa2576a2c7fe7664: Linux 3.4-rc7 (2012-05-12 18:37:47 -0700) are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/ld-fix The head of this tree is 24ab82bd9bf18f3efc69a131d73577940941e1b7. H. Peter Anvin (3): x86, realmode: 16-bit real-mode code support for relocs tool x86, relocs: Workaround for binutils 2.22.52.0.1 section bug x86, relocs: When printing an error, say relative or absolute Makefile | 9 +- arch/x86/Makefile | 3 + arch/x86/boot/compressed/Makefile | 9 +- arch/x86/tools/.gitignore | 1 + arch/x86/tools/Makefile | 4 + arch/x86/{boot/compressed => tools}/relocs.c | 242 ++++++++++++++++++++------ scripts/Makefile | 2 + 7 files changed, 205 insertions(+), 65 deletions(-) diff --git a/Makefile b/Makefile index 48bd1f5..db2bcf3 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 41a7237..94e91e4 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 fd55a2f..e398bb5 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 := $(obj)/vmlinux.bin diff --git a/arch/x86/tools/.gitignore b/arch/x86/tools/.gitignore new file mode 100644 index 0000000..be0ed06 --- /dev/null +++ b/arch/x86/tools/.gitignore @@ -0,0 +1 @@ +relocs diff --git a/arch/x86/tools/Makefile b/arch/x86/tools/Makefile index d511aa9..733057b 100644 --- a/arch/x86/tools/Makefile +++ b/arch/x86/tools/Makefile @@ -36,3 +36,7 @@ HOSTCFLAGS_insn_sanity.o := -Wall -I$(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: $(obj)/relocs diff --git a/arch/x86/boot/compressed/relocs.c b/arch/x86/tools/relocs.c similarity index 76% rename from arch/x86/boot/compressed/relocs.c rename to arch/x86/tools/relocs.c index fb7117a..b43cfcd 100644 --- a/arch/x86/boot/compressed/relocs.c +++ b/arch/x86/tools/relocs.c @@ -18,6 +18,8 @@ static void die(char *fmt, ...); static Elf32_Ehdr ehdr; static unsigned long reloc_count, reloc_idx; static unsigned long *relocs; +static unsigned long reloc16_count, reloc16_idx; +static unsigned long *relocs16; struct section { Elf32_Shdr shdr; @@ -28,52 +30,86 @@ struct section { }; static struct section *secs; +enum symtype { + S_ABS, + S_REL, + S_SEG, + S_LIN, + S_NSYMTYPES +}; + +static const char * const sym_regex_kernel[S_NSYMTYPES] = { /* * Following symbols have been audited. There values are constant and do * not change if bzImage is loaded at a different physical address than * the address for which it has been compiled. Don't warn user about * absolute relocations present w.r.t these symbols. */ -static const char abs_sym_regex[] = + [S_ABS] = "^(xen_irq_disable_direct_reloc$|" "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 df7678f..3626666 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/