Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [PATCH] modpost: abort if a module symbol is too long | Date | Fri, 07 Aug 2015 06:39:12 +0930 |
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Takashi Iwai <tiwai@suse.de> writes: > Module symbols have a limited length, but currently the build system > allows the build finishing even if the driver code contains a too long > symbol name, which eventually overflows the modversion_info[] item. > The compiler may catch at compiling *.mod.c like > CC xxx.mod.o > xxx.mod.c:18:16: warning: initializer-string for array of chars is too long > but it's merely a warning. > > This patch adds the check of the symbol length in modpost and stops > the build properly. > > As of now, MODULE_NAME_LEN is copied in modpost.c. At best, this > should be read directly from kernel headers. But including > linux/module.h is too troublesome for now, so just paper over it. > > Signed-off-by: Takashi Iwai <tiwai@suse.de> > --- > scripts/mod/modpost.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > index 12d3db3bd46b..25bda9d2868c 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -2133,6 +2133,9 @@ static void add_staging_flag(struct buffer *b, const char *name) > buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n"); > } > > +/* FIXME: better to be included from kernel header */ > +#define MODULE_NAME_LEN (64 - sizeof(unsigned long))
This isn't quite right, since modpost handles cross-compilation.
#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
Should work...
Thanks! Rusty.
> + > /** > * Record CRCs for unresolved symbols > **/ > @@ -2177,6 +2180,12 @@ static int add_versions(struct buffer *b, struct module *mod) > s->name, mod->name); > continue; > } > + if (strlen(s->name) >= MODULE_NAME_LEN) { > + merror("too long symbol \"%s\" [%s.ko]\n", > + s->name, mod->name); > + err = 1; > + break; > + } > buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n", > s->crc, s->name); > } > -- > 2.5.0
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