1 files changed, 366 insertions, 0 deletions

diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h
new file mode 100644
index 000000000000..7f39d0943d2d
--- /dev/null
+++ b/scripts/recordmcount.h
@@ -0,0 +1,366 @@
+/*
+ * recordmcount.h
+ *
+ * This code was taken out of recordmcount.c written by
+ * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
+ *
+ * The original code had the same algorithms for both 32bit
+ * and 64bit ELF files, but the code was duplicated to support
+ * the difference in structures that were used. This
+ * file creates a macro of everything that is different between
+ * the 64 and 32 bit code, such that by including this header
+ * twice we can create both sets of functions by including this
+ * header once with RECORD_MCOUNT_64 undefined, and again with
+ * it defined.
+ *
+ * This conversion to macros was done by:
+ * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
+ *
+ * Licensed under the GNU General Public License, version 2 (GPLv2).
+ */
+#undef append_func
+#undef sift_rel_mcount
+#undef find_secsym_ndx
+#undef __has_rel_mcount
+#undef has_rel_mcount
+#undef tot_relsize
+#undef do_func
+#undef Elf_Ehdr
+#undef Elf_Shdr
+#undef Elf_Rel
+#undef Elf_Rela
+#undef Elf_Sym
+#undef ELF_R_SYM
+#undef ELF_R_INFO
+#undef ELF_ST_BIND
+#undef uint_t
+#undef _w
+#undef _align
+#undef _size
+
+#ifdef RECORD_MCOUNT_64
+# define append_func            append64
+# define sift_rel_mcount        sift64_rel_mcount
+# define find_secsym_ndx        find64_secsym_ndx
+# define __has_rel_mcount       __has64_rel_mcount
+# define has_rel_mcount         has64_rel_mcount
+# define tot_relsize            tot64_relsize
+# define do_func                do64
+# define Elf_Ehdr               Elf64_Ehdr
+# define Elf_Shdr               Elf64_Shdr
+# define Elf_Rel                Elf64_Rel
+# define Elf_Rela               Elf64_Rela
+# define Elf_Sym                Elf64_Sym
+# define ELF_R_SYM              ELF64_R_SYM
+# define ELF_R_INFO             ELF64_R_INFO
+# define ELF_ST_BIND            ELF64_ST_BIND
+# define uint_t                 uint64_t
+# define _w                     w8
+# define _align                 7u
+# define _size                  8
+#else
+# define append_func            append32
+# define sift_rel_mcount        sift32_rel_mcount
+# define find_secsym_ndx        find32_secsym_ndx
+# define __has_rel_mcount       __has32_rel_mcount
+# define has_rel_mcount         has32_rel_mcount
+# define tot_relsize            tot32_relsize
+# define do_func                do32
+# define Elf_Ehdr               Elf32_Ehdr
+# define Elf_Shdr               Elf32_Shdr
+# define Elf_Rel                Elf32_Rel
+# define Elf_Rela               Elf32_Rela
+# define Elf_Sym                Elf32_Sym
+# define ELF_R_SYM              ELF32_R_SYM
+# define ELF_R_INFO             ELF32_R_INFO
+# define ELF_ST_BIND            ELF32_ST_BIND
+# define uint_t                 uint32_t
+# define _w                     w
+# define _align                 3u
+# define _size                  4
+#endif
+
+/* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */
+static void append_func(Elf_Ehdr *const ehdr,
+                        Elf_Shdr *const shstr,
+                        uint_t const *const mloc0,
+                        uint_t const *const mlocp,
+                        Elf_Rel const *const mrel0,
+                        Elf_Rel const *const mrelp,
+                        unsigned int const rel_entsize,
+                        unsigned int const symsec_sh_link)
+{
+        /* Begin constructing output file */
+        Elf_Shdr mcsec;
+        char const *mc_name = (sizeof(Elf_Rela) == rel_entsize)
+                ? ".rela__mcount_loc"
+                :  ".rel__mcount_loc";
+        unsigned const old_shnum = w2(ehdr->e_shnum);
+        uint_t const old_shoff = _w(ehdr->e_shoff);
+        uint_t const old_shstr_sh_size   = _w(shstr->sh_size);
+        uint_t const old_shstr_sh_offset = _w(shstr->sh_offset);
+        uint_t t = 1 + strlen(mc_name) + _w(shstr->sh_size);
+        uint_t new_e_shoff;
+
+        shstr->sh_size = _w(t);
+        shstr->sh_offset = _w(sb.st_size);
+        t += sb.st_size;
+        t += (_align & -t);  /* word-byte align */
+        new_e_shoff = t;
+
+        /* body for new shstrtab */
+        ulseek(fd_map, sb.st_size, SEEK_SET);
+        uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size);
+        uwrite(fd_map, mc_name, 1 + strlen(mc_name));
+
+        /* old(modified) Elf_Shdr table, word-byte aligned */
+        ulseek(fd_map, t, SEEK_SET);
+        t += sizeof(Elf_Shdr) * old_shnum;
+        uwrite(fd_map, old_shoff + (void *)ehdr,
+               sizeof(Elf_Shdr) * old_shnum);
+
+        /* new sections __mcount_loc and .rel__mcount_loc */
+        t += 2*sizeof(mcsec);
+        mcsec.sh_name = w((sizeof(Elf_Rela) == rel_entsize) + strlen(".rel")
+                + old_shstr_sh_size);
+        mcsec.sh_type = w(SHT_PROGBITS);
+        mcsec.sh_flags = _w(SHF_ALLOC);
+        mcsec.sh_addr = 0;
+        mcsec.sh_offset = _w(t);
+        mcsec.sh_size = _w((void *)mlocp - (void *)mloc0);
+        mcsec.sh_link = 0;
+        mcsec.sh_info = 0;
+        mcsec.sh_addralign = _w(_size);
+        mcsec.sh_entsize = _w(_size);
+        uwrite(fd_map, &mcsec, sizeof(mcsec));
+
+        mcsec.sh_name = w(old_shstr_sh_size);
+        mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize)
+                ? w(SHT_RELA)
+                : w(SHT_REL);
+        mcsec.sh_flags = 0;
+        mcsec.sh_addr = 0;
+        mcsec.sh_offset = _w((void *)mlocp - (void *)mloc0 + t);
+        mcsec.sh_size   = _w((void *)mrelp - (void *)mrel0);
+        mcsec.sh_link = w(symsec_sh_link);
+        mcsec.sh_info = w(old_shnum);
+        mcsec.sh_addralign = _w(_size);
+        mcsec.sh_entsize = _w(rel_entsize);
+        uwrite(fd_map, &mcsec, sizeof(mcsec));
+
+        uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0);
+        uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0);
+
+        ehdr->e_shoff = _w(new_e_shoff);
+        ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum));  /* {.rel,}__mcount_loc */
+        ulseek(fd_map, 0, SEEK_SET);
+        uwrite(fd_map, ehdr, sizeof(*ehdr));
+}
+
+
+/*
+ * Look at the relocations in order to find the calls to mcount.
+ * Accumulate the section offsets that are found, and their relocation info,
+ * onto the end of the existing arrays.
+ */
+static uint_t *sift_rel_mcount(uint_t *mlocp,
+                               unsigned const offbase,
+                               Elf_Rel **const mrelpp,
+                               Elf_Shdr const *const relhdr,
+                               Elf_Ehdr const *const ehdr,
+                               unsigned const recsym,
+                               uint_t const recval,
+                               unsigned const reltype)
+{
+        uint_t *const mloc0 = mlocp;
+        Elf_Rel *mrelp = *mrelpp;
+        Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
+                + (void *)ehdr);
+        unsigned const symsec_sh_link = w(relhdr->sh_link);
+        Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
+        Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
+                + (void *)ehdr);
+
+        Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
+        char const *const str0 = (char const *)(_w(strsec->sh_offset)
+                + (void *)ehdr);
+
+        Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
+                + (void *)ehdr);
+        unsigned rel_entsize = _w(relhdr->sh_entsize);
+        unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
+        Elf_Rel const *relp = rel0;
+
+        unsigned mcountsym = 0;
+        unsigned t;
+
+        for (t = nrel; t; --t) {
+                if (!mcountsym) {
+                        Elf_Sym const *const symp =
+                                &sym0[ELF_R_SYM(_w(relp->r_info))];
+                        char const *symname = &str0[w(symp->st_name)];
+
+                        if ('.' == symname[0])
+                                ++symname;  /* ppc64 hack */
+                        if (0 == strcmp((('_' == gpfx) ? "_mcount" : "mcount"),
+                                        symname))
+                                mcountsym = ELF_R_SYM(_w(relp->r_info));
+                }
+
+                if (mcountsym == ELF_R_SYM(_w(relp->r_info))) {
+                        uint_t const addend = _w(_w(relp->r_offset) - recval);
+
+                        mrelp->r_offset = _w(offbase
+                                + ((void *)mlocp - (void *)mloc0));
+                        mrelp->r_info = _w(ELF_R_INFO(recsym, reltype));
+                        if (sizeof(Elf_Rela) == rel_entsize) {
+                                ((Elf_Rela *)mrelp)->r_addend = addend;
+                                *mlocp++ = 0;
+                        } else
+                                *mlocp++ = addend;
+
+                        mrelp = (Elf_Rel *)(rel_entsize + (void *)mrelp);
+                }
+                relp = (Elf_Rel const *)(rel_entsize + (void *)relp);
+        }
+        *mrelpp = mrelp;
+        return mlocp;
+}
+
+
+/*
+ * Find a symbol in the given section, to be used as the base for relocating
+ * the table of offsets of calls to mcount.  A local or global symbol suffices,
+ * but avoid a Weak symbol because it may be overridden; the change in value
+ * would invalidate the relocations of the offsets of the calls to mcount.
+ * Often the found symbol will be the unnamed local symbol generated by
+ * GNU 'as' for the start of each section.  For example:
+ *    Num:    Value  Size Type    Bind   Vis      Ndx Name
+ *      2: 00000000     0 SECTION LOCAL  DEFAULT    1
+ */
+static unsigned find_secsym_ndx(unsigned const txtndx,
+                                char const *const txtname,
+                                uint_t *const recvalp,
+                                Elf_Shdr const *const symhdr,
+                                Elf_Ehdr const *const ehdr)
+{
+        Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symhdr->sh_offset)
+                + (void *)ehdr);
+        unsigned const nsym = _w(symhdr->sh_size) / _w(symhdr->sh_entsize);
+        Elf_Sym const *symp;
+        unsigned t;
+
+        for (symp = sym0, t = nsym; t; --t, ++symp) {
+                unsigned int const st_bind = ELF_ST_BIND(symp->st_info);
+
+                if (txtndx == w2(symp->st_shndx)
+                        /* avoid STB_WEAK */
+                    && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
+                        *recvalp = _w(symp->st_value);
+                        return symp - sym0;
+                }
+        }
+        fprintf(stderr, "Cannot find symbol for section %d: %s.\n",
+                txtndx, txtname);
+        fail_file();
+}
+
+
+/* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */
+static char const *
+__has_rel_mcount(Elf_Shdr const *const relhdr,  /* is SHT_REL or SHT_RELA */
+                 Elf_Shdr const *const shdr0,
+                 char const *const shstrtab,
+                 char const *const fname)
+{
+        /* .sh_info depends on .sh_type == SHT_REL[,A] */
+        Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)];
+        char const *const txtname = &shstrtab[w(txthdr->sh_name)];
+
+        if (0 == strcmp("__mcount_loc", txtname)) {
+                fprintf(stderr, "warning: __mcount_loc already exists: %s\n",
+                        fname);
+                succeed_file();
+        }
+        if (SHT_PROGBITS != w(txthdr->sh_type) ||
+            !is_mcounted_section_name(txtname))
+                return NULL;
+        return txtname;
+}
+
+static char const *has_rel_mcount(Elf_Shdr const *const relhdr,
+                                  Elf_Shdr const *const shdr0,
+                                  char const *const shstrtab,
+                                  char const *const fname)
+{
+        if (SHT_REL  != w(relhdr->sh_type) && SHT_RELA != w(relhdr->sh_type))
+                return NULL;
+        return __has_rel_mcount(relhdr, shdr0, shstrtab, fname);
+}
+
+
+static unsigned tot_relsize(Elf_Shdr const *const shdr0,
+                            unsigned nhdr,
+                            const char *const shstrtab,
+                            const char *const fname)
+{
+        unsigned totrelsz = 0;
+        Elf_Shdr const *shdrp = shdr0;
+
+        for (; nhdr; --nhdr, ++shdrp) {
+                if (has_rel_mcount(shdrp, shdr0, shstrtab, fname))
+                        totrelsz += _w(shdrp->sh_size);
+        }
+        return totrelsz;
+}
+
+
+/* Overall supervision for Elf32 ET_REL file. */
+static void
+do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype)
+{
+        Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
+                + (void *)ehdr);
+        unsigned const nhdr = w2(ehdr->e_shnum);
+        Elf_Shdr *const shstr = &shdr0[w2(ehdr->e_shstrndx)];
+        char const *const shstrtab = (char const *)(_w(shstr->sh_offset)
+                + (void *)ehdr);
+
+        Elf_Shdr const *relhdr;
+        unsigned k;
+
+        /* Upper bound on space: assume all relevant relocs are for mcount. */
+        unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname);
+        Elf_Rel *const mrel0 = umalloc(totrelsz);
+        Elf_Rel *      mrelp = mrel0;
+
+        /* 2*sizeof(address) <= sizeof(Elf_Rel) */
+        uint_t *const mloc0 = umalloc(totrelsz>>1);
+        uint_t *      mlocp = mloc0;
+
+        unsigned rel_entsize = 0;
+        unsigned symsec_sh_link = 0;
+
+        for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) {
+                char const *const txtname = has_rel_mcount(relhdr, shdr0,
+                        shstrtab, fname);
+                if (txtname) {
+                        uint_t recval = 0;
+                        unsigned const recsym = find_secsym_ndx(
+                                w(relhdr->sh_info), txtname, &recval,
+                                &shdr0[symsec_sh_link = w(relhdr->sh_link)],
+                                ehdr);
+
+                        rel_entsize = _w(relhdr->sh_entsize);
+                        mlocp = sift_rel_mcount(mlocp,
+                                (void *)mlocp - (void *)mloc0, &mrelp,
+                                relhdr, ehdr, recsym, recval, reltype);
+                }
+        }
+        if (mloc0 != mlocp) {
+                append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp,
+                            rel_entsize, symsec_sh_link);
+        }
+        free(mrel0);
+        free(mloc0);
+}