2 files changed, 166 insertions, 1 deletions

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index dbe1fb5e8cc0..61742771c65d 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -11,6 +11,8 @@
  * Usage: modpost vmlinux module1.o module2.o ...
  */
 
+#define _GNU_SOURCE
+#include <stdio.h>
 #include <ctype.h>
 #include "modpost.h"
 #include "../../include/linux/license.h"
@@ -435,6 +437,8 @@ static int parse_elf(struct elf_info *info, const char *filename)
                         info->export_unused_gpl_sec = i;
                 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
                         info->export_gpl_future_sec = i;
+                else if (strcmp(secname, "__markers_strings") == 0)
+                        info->markers_strings_sec = i;
 
                 if (sechdrs[i].sh_type != SHT_SYMTAB)
                         continue;
@@ -1470,6 +1474,62 @@ static void check_sec_ref(struct module *mod, const char *modname,
         }
 }
 
+static void get_markers(struct elf_info *info, struct module *mod)
+{
+        const Elf_Shdr *sh = &info->sechdrs[info->markers_strings_sec];
+        const char *strings = (const char *) info->hdr + sh->sh_offset;
+        const Elf_Sym *sym, *first_sym, *last_sym;
+        size_t n;
+
+        if (!info->markers_strings_sec)
+                return;
+
+        /*
+         * First count the strings.  We look for all the symbols defined
+         * in the __markers_strings section named __mstrtab_*.  For
+         * these local names, the compiler puts a random .NNN suffix on,
+         * so the names don't correspond exactly.
+         */
+        first_sym = last_sym = NULL;
+        n = 0;
+        for (sym = info->symtab_start; sym < info->symtab_stop; sym++)
+                if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT &&
+                    sym->st_shndx == info->markers_strings_sec &&
+                    !strncmp(info->strtab + sym->st_name,
+                             "__mstrtab_", sizeof "__mstrtab_" - 1)) {
+                        if (first_sym == NULL)
+                                first_sym = sym;
+                        last_sym = sym;
+                        ++n;
+                }
+
+        if (n == 0)
+                return;
+
+        /*
+         * Now collect each name and format into a line for the output.
+         * Lines look like:
+         *      marker_name     vmlinux marker %s format %d
+         * The format string after the second \t can use whitespace.
+         */
+        mod->markers = NOFAIL(malloc(sizeof mod->markers[0] * n));
+        mod->nmarkers = n;
+
+        n = 0;
+        for (sym = first_sym; sym <= last_sym; sym++)
+                if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT &&
+                    sym->st_shndx == info->markers_strings_sec &&
+                    !strncmp(info->strtab + sym->st_name,
+                             "__mstrtab_", sizeof "__mstrtab_" - 1)) {
+                        const char *name = strings + sym->st_value;
+                        const char *fmt = strchr(name, '\0') + 1;
+                        char *line = NULL;
+                        asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt);
+                        NOFAIL(line);
+                        mod->markers[n++] = line;
+                }
+}
+
 static void read_symbols(char *modname)
 {
         const char *symname;
@@ -1521,6 +1581,8 @@ static void read_symbols(char *modname)
                 get_src_version(modname, mod->srcversion,
                                 sizeof(mod->srcversion)-1);
 
+        get_markers(&info, mod);
+
         parse_elf_finish(&info);
 
         /* Our trick to get versioning for struct_module - it's
@@ -1867,16 +1929,104 @@ static void write_dump(const char *fname)
         write_if_changed(&buf, fname);
 }
 
+static void add_marker(struct module *mod, const char *name, const char *fmt)
+{
+        char *line = NULL;
+        asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt);
+        NOFAIL(line);
+
+        mod->markers = NOFAIL(realloc(mod->markers, ((mod->nmarkers + 1) *
+                                                     sizeof mod->markers[0])));
+        mod->markers[mod->nmarkers++] = line;
+}
+
+static void read_markers(const char *fname)
+{
+        unsigned long size, pos = 0;
+        void *file = grab_file(fname, &size);
+        char *line;
+
+        if (!file)              /* No old markers, silently ignore */
+                return;
+
+        while ((line = get_next_line(&pos, file, size))) {
+                char *marker, *modname, *fmt;
+                struct module *mod;
+
+                marker = line;
+                modname = strchr(marker, '\t');
+                if (!modname)
+                        goto fail;
+                *modname++ = '\0';
+                fmt = strchr(modname, '\t');
+                if (!fmt)
+                        goto fail;
+                *fmt++ = '\0';
+                if (*marker == '\0' || *modname == '\0')
+                        goto fail;
+
+                mod = find_module(modname);
+                if (!mod) {
+                        if (is_vmlinux(modname))
+                                have_vmlinux = 1;
+                        mod = new_module(NOFAIL(strdup(modname)));
+                        mod->skip = 1;
+                }
+
+                add_marker(mod, marker, fmt);
+        }
+        return;
+fail:
+        fatal("parse error in markers list file\n");
+}
+
+static int compare_strings(const void *a, const void *b)
+{
+        return strcmp(*(const char **) a, *(const char **) b);
+}
+
+static void write_markers(const char *fname)
+{
+        struct buffer buf = { };
+        struct module *mod;
+        size_t i;
+
+        for (mod = modules; mod; mod = mod->next)
+                if ((!external_module || !mod->skip) && mod->markers != NULL) {
+                        /*
+                         * Sort the strings so we can skip duplicates when
+                         * we write them out.
+                         */
+                        qsort(mod->markers, mod->nmarkers,
+                              sizeof mod->markers[0], &compare_strings);
+                        for (i = 0; i < mod->nmarkers; ++i) {
+                                char *line = mod->markers[i];
+                                buf_write(&buf, line, strlen(line));
+                                while (i + 1 < mod->nmarkers &&
+                                       !strcmp(mod->markers[i],
+                                               mod->markers[i + 1]))
+                                        free(mod->markers[i++]);
+                                free(mod->markers[i]);
+                        }
+                        free(mod->markers);
+                        mod->markers = NULL;
+                }
+
+        write_if_changed(&buf, fname);
+}
+
 int main(int argc, char **argv)
 {
         struct module *mod;
         struct buffer buf = { };
         char *kernel_read = NULL, *module_read = NULL;
         char *dump_write = NULL;
+        char *markers_read = NULL;
+        char *markers_write = NULL;
         int opt;
         int err;
 
-        while ((opt = getopt(argc, argv, "i:I:msSo:aw")) != -1) {
+        while ((opt = getopt(argc, argv, "i:I:msSo:awM:K:")) != -1) {
                 switch (opt) {
                 case 'i':
                         kernel_read = optarg;
@@ -1903,6 +2053,12 @@ int main(int argc, char **argv)
                 case 'w':
                         warn_unresolved = 1;
                         break;
+                        case 'M':
+                                markers_write = optarg;
+                                break;
+                        case 'K':
+                                markers_read = optarg;
+                                break;
                 default:
                         exit(1);
                 }
@@ -1950,5 +2106,11 @@ int main(int argc, char **argv)
                      "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
                      sec_mismatch_count);
 
+        if (markers_read)
+                read_markers(markers_read);
+
+        if (markers_write)
+                write_markers(markers_write);
+
         return err;
 }
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 999f15e0e008..565c5872407e 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -112,6 +112,8 @@ struct module {
         int has_init;
         int has_cleanup;
         struct buffer dev_table_buf;
+        char **markers;
+        size_t nmarkers;
         char         srcversion[25];
 };
 
@@ -126,6 +128,7 @@ struct elf_info {
         Elf_Section  export_gpl_sec;
         Elf_Section  export_unused_gpl_sec;
         Elf_Section  export_gpl_future_sec;
+        Elf_Section  markers_strings_sec;
         const char   *strtab;
         char         *modinfo;
         unsigned int modinfo_len;