On Thu, 2009-05-21 at 17:50 +0100, Alan Jenkins wrote: 
> I don't mind what modinfo does; more lenient behaviour may be useful
> for debugging.
> 
> depmod I disagree with though.  As a minimum, if the old depmod could
> crash on a module then I want the new one to exit with an error code.
> That should let e.g. RPM scripts pick it up in a similar way as
> before.  I don't think you're doing that at the moment.

No you're right. The way I did it could for example have silently lost
some module aliases ...

> 
> I guess the scenario where it matters is a non-expert user installing
> extra modules.  If you're simply following instructions, you may not
> know how to uninstall invalid modules.  If the error is FATAL, you'll
> still have a working system, but you won't be able add new modules in
> future.
> 
> Maybe I've lurked on too many forums, but I admit this sounds like a
> realistic scenario :-).  If depmod can return an error code as well,
> then I'll be happy with a non-fatal ERROR.

Hmm, it seems depmod is designed to just die. We'll have to save error
codes for another day.

I've reworked the patch (now it's two patches). load_strings() in depmod
and modprobe call fatal() and modinfo calls error().

http://github.com/andr345/module-init-tools/commits/elf_cleanup3
is rebased too.

>From 32971d375158804b34113d1359c9b726e1807f03 Mon Sep 17 00:00:00 2001
From: Andreas Robinson <[email protected]>
Date: Thu, 21 May 2009 21:04:25 +0200
Subject: [PATCH] logging, modprobe: move errfn_t to logging.h

Signed-off-by: Andreas Robinson <[email protected]>
---
 logging.h  |    2 ++
 modprobe.c |    2 --
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/logging.h b/logging.h
index b7227bc..efa682f 100644
--- a/logging.h
+++ b/logging.h
@@ -18,6 +18,8 @@ extern void error(const char *fmt, ...);
 extern void warn(const char *fmt, ...);
 extern void info(const char *fmt, ...);
 
+typedef void (*errfn_t)(const char *fmt, ...);
+
 static inline void grammar(const char *cmd,
                           const char *filename, unsigned int line)
 {
diff --git a/modprobe.c b/modprobe.c
index f5a8437..9f60e71 100644
--- a/modprobe.c
+++ b/modprobe.c
@@ -64,8 +64,6 @@ struct module {
 #define MODULE_DIR "/lib/modules"
 #endif
 
-typedef void (*errfn_t)(const char *fmt, ...);
-
 static void print_usage(const char *progname)
 {
        fprintf(stderr,
-- 
1.6.0.4


>From 528db92ab1dd0d75dba415b9f3dc81f5a34773ce Mon Sep 17 00:00:00 2001
From: Andreas Robinson <[email protected]>
Date: Thu, 21 May 2009 22:10:38 +0200
Subject: [PATCH] read string sections such as .modinfo with load_strings()

Changes to load_strings():
* export in struct module_ops
* avoid buffer overruns by looking for a string terminator
  at the end of a section.
* new errfn_t parameter selects error message type.
  If load_strings fails on a missing string terminator, the module
  is probably broken.
  Therefore, modprobe and depmod sets errfn_t error = fatal.
  Modinfo on the other hand sets errfn_t error = error.

Signed-off-by: Andreas Robinson <[email protected]>
---
 depmod.c      |   42 ++++++++++++++++++++++--------------------
 elfops.h      |    3 +++
 elfops_core.c |    8 +++++---
 modinfo.c     |   25 +++++++++++++++----------
 modprobe.c    |    9 +++++----
 5 files changed, 50 insertions(+), 37 deletions(-)

diff --git a/depmod.c b/depmod.c
index a8c3a47..68fcaee 100644
--- a/depmod.c
+++ b/depmod.c
@@ -770,8 +770,8 @@ static void output_aliases(struct module *modules, FILE 
*out, char *dirname)
 {
        struct module *i;
        struct elf_file *file;
-       const char *p;
-       unsigned long size;
+       struct string_table *tbl;
+       int j;
 
        fprintf(out, "# Aliases extracted from modules themselves.\n");
        for (i = modules; i; i = i->next) {
@@ -781,19 +781,20 @@ static void output_aliases(struct module *modules, FILE 
*out, char *dirname)
                filename2modname(modname, i->pathname);
 
                /* Grab from old-style .modalias section. */
-               for (p = file->ops->get_aliases(file, &size);
-                    p;
-                    p = next_string(p, &size))
-                       fprintf(out, "alias %s %s\n", p, modname);
-
-               /* Grab form new-style .modinfo section. */
-               for (p = file->ops->get_modinfo(file, &size);
-                    p;
-                    p = next_string(p, &size)) {
+               tbl = file->ops->load_strings(file, ".modalias", NULL, fatal);
+               for (j = 0; tbl && j < tbl->cnt; j++)
+                       fprintf(out, "alias %s %s\n", tbl->str[j], modname);
+               strtbl_free(tbl);
+
+               /* Grab from new-style .modinfo section. */
+               tbl = file->ops->load_strings(file, ".modinfo", NULL, fatal);
+               for (j = 0; tbl && j < tbl->cnt; j++) {
+                       const char *p = tbl->str[j];
                        if (strstarts(p, "alias="))
                                fprintf(out, "alias %s %s\n",
                                        p + strlen("alias="), modname);
                }
+               strtbl_free(tbl);
        }
 }
 
@@ -801,9 +802,9 @@ static void output_aliases_bin(struct module *modules, FILE 
*out, char *dirname)
 {
        struct module *i;
        struct elf_file *file;
-       const char *p;
+       struct string_table *tbl;
+       int j;
        char *alias;
-       unsigned long size;
        struct index_node *index;
        int duplicate;
 
@@ -816,10 +817,9 @@ static void output_aliases_bin(struct module *modules, 
FILE *out, char *dirname)
                filename2modname(modname, i->pathname);
 
                /* Grab from old-style .modalias section. */
-               for (p = file->ops->get_aliases(file, &size);
-                    p;
-                    p = next_string(p, &size)) {
-                       alias = NOFAIL(strdup(p));
+               tbl = file->ops->load_strings(file, ".modalias", NULL, fatal);
+               for (j = 0; tbl && j < tbl->cnt; j++) {
+                       alias = NOFAIL(strdup(tbl->str[j]));
                        underscores(alias);
                        duplicate = index_insert(index, alias, modname, 
i->order);
                        if (duplicate && warn_dups)
@@ -827,11 +827,12 @@ static void output_aliases_bin(struct module *modules, 
FILE *out, char *dirname)
                                        alias, modname);
                        free(alias);
                }
+               strtbl_free(tbl);
 
                /* Grab from new-style .modinfo section. */
-               for (p = file->ops->get_modinfo(file, &size);
-                    p;
-                    p = next_string(p, &size)) {
+               tbl = file->ops->load_strings(file, ".modinfo", NULL, fatal);
+               for (j = 0; tbl && j < tbl->cnt; j++) {
+                       const char *p = tbl->str[j];
                        if (strstarts(p, "alias=")) {
                                alias = NOFAIL(strdup(p + strlen("alias=")));
                                underscores(alias);
@@ -842,6 +843,7 @@ static void output_aliases_bin(struct module *modules, FILE 
*out, char *dirname)
                                free(alias);
                        }
                }
+               strtbl_free(tbl);
        }
        
        index_write(index, out);
diff --git a/elfops.h b/elfops.h
index 7069d92..c3d2e33 100644
--- a/elfops.h
+++ b/elfops.h
@@ -2,6 +2,7 @@
 #define MODINITTOOLS_MODULEOPS_H
 #include <stdio.h>
 #include <stdint.h>
+#include "logging.h"
 
 /* All the icky stuff to do with manipulating 64 and 32-bit modules
    belongs here. */
@@ -71,6 +72,8 @@ struct module_ops
 {
        void *(*load_section)(struct elf_file *module,
                const char *secname, unsigned long *secsize);
+       struct string_table *(*load_strings)(struct elf_file *module,
+               const char *secname, struct string_table *tbl, errfn_t error);
        struct string_table *(*load_symbols)(struct elf_file *module);
        struct string_table *(*load_dep_syms)(const char *pathname,
                struct elf_file *module, struct string_table **types);
diff --git a/elfops_core.c b/elfops_core.c
index 4283d65..c5e84ba 100644
--- a/elfops_core.c
+++ b/elfops_core.c
@@ -80,7 +80,8 @@ static void *PERBIT(load_section)(struct elf_file *module,
 
 static struct string_table *PERBIT(load_strings)(struct elf_file *module,
                                                 const char *secname,
-                                                struct string_table *tbl)
+                                                struct string_table *tbl,
+                                                errfn_t error)
 {
        unsigned long size;
        const char *strings;
@@ -108,11 +109,11 @@ static struct string_table *PERBIT(load_symbols)(struct 
elf_file *module)
        symtbl = NULL;
 
        /* New-style: strings are in this section. */
-       symtbl = PERBIT(load_strings)(module, "__ksymtab_strings", symtbl);
+       symtbl = PERBIT(load_strings)(module, "__ksymtab_strings", symtbl, 
fatal);
        if (symtbl) {
                /* GPL symbols too */
                return PERBIT(load_strings)(module, "__ksymtab_strings_gpl",
-                       symtbl);
+                       symtbl, fatal);
        }
 
        /* Old-style. */
@@ -338,6 +339,7 @@ static int PERBIT(dump_modversions)(struct elf_file *module)
 
 struct module_ops PERBIT(mod_ops) = {
        .load_section   = PERBIT(load_section),
+       .load_strings   = PERBIT(load_strings),
        .load_symbols   = PERBIT(load_symbols),
        .load_dep_syms  = PERBIT(load_dep_syms),
        .fetch_tables   = PERBIT(fetch_tables),
diff --git a/modinfo.c b/modinfo.c
index d8412db..1c1b57e 100644
--- a/modinfo.c
+++ b/modinfo.c
@@ -50,9 +50,10 @@ static struct param *add_param(const char *name, struct 
param **list)
        return i;
 }
 
-static void print_tag(const char *tag, const char *info, unsigned long size,
+static void print_tag(const char *tag, struct string_table *tags,
                      const char *filename, char sep)
 {
+       int j;
        unsigned int taglen = strlen(tag);
 
        if (streq(tag, "filename")) {
@@ -60,18 +61,22 @@ static void print_tag(const char *tag, const char *info, 
unsigned long size,
                return;
        }
 
-       for (; info; info = next_string(info, &size))
+       for (j = 0; j < tags->cnt; j++) {
+               const char *info = tags->str[j];
                if (strncmp(info, tag, taglen) == 0 && info[taglen] == '=')
                        printf("%s%c", info + taglen + 1, sep);
+       }
 }
 
-static void print_all(const char *info, unsigned long size,
+static void print_all(struct string_table *tags,
                      const char *filename, char sep)
 {
+       int j;
        struct param *i, *params = NULL;
 
        printf("%-16s%s%c", "filename:", filename, sep);
-       for (; info; info = next_string(info, &size)) {
+       for (j = 0; j < tags->cnt; j++) {
+               const char *info = tags->str[j];
                char *eq, *colon;
 
                /* We expect this in parm and parmtype. */
@@ -294,8 +299,7 @@ int main(int argc, char *argv[])
        }
 
        for (opt = optind; opt < argc; opt++) {
-               void *info;
-               unsigned long infosize = 0;
+               struct string_table *tags;
                struct elf_file *mod;
 
                mod = grab_module(argv[opt], kernel, basedir);
@@ -303,15 +307,16 @@ int main(int argc, char *argv[])
                        ret = 1;
                        continue;
                }
-               info = mod->ops->get_modinfo(mod, &infosize);
-               if (!info) {
+               tags = mod->ops->load_strings(mod, ".modinfo", NULL, error);
+               if (!tags) {
                        release_elf_file(mod);
                        continue;
                }
                if (field)
-                       print_tag(field, info, infosize, mod->pathname, sep);
+                       print_tag(field, tags, mod->pathname, sep);
                else
-                       print_all(info, infosize, mod->pathname, sep);
+                       print_all(tags, mod->pathname, sep);
+               strtbl_free(tags);
                release_elf_file(mod);
        }
        return ret;
diff --git a/modprobe.c b/modprobe.c
index 9f60e71..a3cdbf6 100644
--- a/modprobe.c
+++ b/modprobe.c
@@ -324,15 +324,16 @@ static void rename_module(struct elf_file *module,
 
 static void clear_magic(struct elf_file *module)
 {
-       const char *p;
-       unsigned long len;
+       struct string_table *tbl;
+       int j;
 
        /* Old-style: __vermagic section */
        module->ops->strip_section(module, "__vermagic");
 
        /* New-style: in .modinfo section */
-       p = module->ops->get_modinfo(module, &len);
-       for (; p; p = next_string(p, &len)) {
+       tbl = module->ops->load_strings(module, ".modinfo", NULL, fatal);
+       for (j = 0; tbl && j < tbl->cnt; j++) {
+               const char *p = tbl->str[j];
                if (strstarts(p, "vermagic=")) {
                        memset((char *)p, 0, strlen(p));
                        return;
-- 
1.6.0.4


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