On Thu, 31 Dec 2009 22:15:08 +0100 Helge Deller <deller@xxxxxx> wrote: > On 12/30/2009 04:49 PM, James Bottomley wrote: > > A better, and more comprehensive patch would be to try not to count the > > empty text sections when we're building the notes section (and actually > > anywhere else in the file). This patch actually relies on the fact that > > if sh_size is zero for the text section it should be for the > > corresponding notes section. If that doesn't work, we'd actually have > > to do the matching in the construction piece. > > > > Can you try it to see if it works for you? If it doesn't, I'll try > > matching notes to text. It works fine on parisc, but as we don't have a > > notes section, that's not saying much ... > > > > Thanks, > > > > James > > > Ben Hutchings already sent a similar patch. > See: http://patchwork.kernel.org/patch/68925/ > > IMHO James patch below seems better since it > checks if a section will be allocated at a few more > places... > Ben's patch (which is below) is currently in linux-next, via a Rusty tree. It is marked for -stable backporting. If James's patch is preferable then there's an opportunity to do the swap if we move promptly. commit 9e9b48a89ed43c73d7355ff999b8e87b0628e1cd Author: Ben Hutchings <ben@xxxxxxxxxxxxxxx> AuthorDate: Sat Dec 19 14:43:01 2009 +0000 Commit: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> CommitDate: Tue Jan 5 08:44:50 2010 +1100 modules: Skip empty sections when exporting section notes Commit 35dead4 "modules: don't export section names of empty sections via sysfs" changed the set of sections that have attributes, but did not change the iteration over these attributes in add_notes_attrs(). This can lead to add_notes_attrs() creating attributes with the wrong names or with null name pointers. Introduce a sect_empty() function and use it in both add_sect_attrs() and add_notes_attrs(). Reported-by: Martin Michlmayr <tbm@xxxxxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> Tested-by: Martin Michlmayr <tbm@xxxxxxxxxx> Cc: stable@xxxxxxxxxx Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> diff --git a/kernel/module.c b/kernel/module.c index e96b8ed..f82386b 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1010,6 +1010,12 @@ static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs, * J. Corbet <corbet@xxxxxxx> */ #if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS) + +static inline bool sect_empty(const Elf_Shdr *sect) +{ + return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; +} + struct module_sect_attr { struct module_attribute mattr; @@ -1051,8 +1057,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect, /* Count loaded sections and allocate structures */ for (i = 0; i < nsect; i++) - if (sechdrs[i].sh_flags & SHF_ALLOC - && sechdrs[i].sh_size) + if (!sect_empty(&sechdrs[i])) nloaded++; size[0] = ALIGN(sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0]), @@ -1070,9 +1075,7 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect, sattr = §_attrs->attrs[0]; gattr = §_attrs->grp.attrs[0]; for (i = 0; i < nsect; i++) { - if (! (sechdrs[i].sh_flags & SHF_ALLOC)) - continue; - if (!sechdrs[i].sh_size) + if (sect_empty(&sechdrs[i])) continue; sattr->address = sechdrs[i].sh_addr; sattr->name = kstrdup(secstrings + sechdrs[i].sh_name, @@ -1156,7 +1159,7 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect, /* Count notes sections and allocate structures. */ notes = 0; for (i = 0; i < nsect; i++) - if ((sechdrs[i].sh_flags & SHF_ALLOC) && + if (!sect_empty(&sechdrs[i]) && (sechdrs[i].sh_type == SHT_NOTE)) ++notes; @@ -1172,7 +1175,7 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect, notes_attrs->notes = notes; nattr = ¬es_attrs->attrs[0]; for (loaded = i = 0; i < nsect; ++i) { - if (!(sechdrs[i].sh_flags & SHF_ALLOC)) + if (sect_empty(&sechdrs[i])) continue; if (sechdrs[i].sh_type == SHT_NOTE) { nattr->attr.name = mod->sect_attrs->attrs[loaded].name; -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
