Messages in this thread |  | | | From | Rusty Russell <> | | Subject | Re: [PATCH] Show version information for built-in modules in sysfs | | Date | Wed, 22 Dec 2010 11:32:40 +1030 |
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On Thu, 16 Dec 2010 08:30:19 am Dmitry Torokhov wrote: > Currently only drivers that are built as modules have their versions > shown in /sys/module/<module_name>/version, but this information might > also be useful for built-in drivers as well. This especially important > for drivers that do not define any parameters - such drivers, if > built-in, are completely invisible from userspace. > > This patch changes MODULE_VERSION() macro so that in case when we are > compiling built-in module, version information is stored in a separate > section. Kernel then uses this data to create 'version' sysfs attribute > in the same fashion it creates attributes for module parameters. > > Signed-off-by: Dmitry Torokhov <dtor@vmware.com> > --- > > This change is driven by our desire to detect whether vmw_balloon driver > is built-in into the kernel when we installing our tool package in the > guest and avoid installing our own version of the driver. > > Since vmw_balloon does not have any module parameter nor registers any > driver core devices, without this patch it is completely invisible from > userspace when built into the kernel. > > Thanks, > Dmitry > > include/asm-generic/vmlinux.lds.h | 7 ++++ > include/linux/module.h | 27 +++++++++++++++ > kernel/params.c | 65 ++++++++++++++++++++++++++++++------ > 3 files changed, 88 insertions(+), 11 deletions(-) > > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h > index bd69d79..0d83dd1 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -355,6 +355,13 @@ > VMLINUX_SYMBOL(__start___param) = .; \ > *(__param) \ > VMLINUX_SYMBOL(__stop___param) = .; \ > + } \ > + \ > + /* Built-in module versions. */ \ > + __modver : AT(ADDR(__modver) - LOAD_OFFSET) { \ > + VMLINUX_SYMBOL(__start___modver) = .; \ > + *(__modver) \ > + VMLINUX_SYMBOL(__stop___modver) = .; \ > . = ALIGN((align)); \ > VMLINUX_SYMBOL(__end_rodata) = .; \ > } \ > diff --git a/include/linux/module.h b/include/linux/module.h > index 7575bbb..f74ddda 100644 > --- a/include/linux/module.h > +++ b/include/linux/module.h > @@ -58,6 +58,12 @@ struct module_attribute { > void (*free)(struct module *); > }; > > +struct module_version_attribute { > + struct module_attribute mattr; > + const char *module_name; > + const char *version; > +}; > + > struct module_kobject > { > struct kobject kobj; > @@ -161,7 +167,28 @@ extern struct module __this_module; > Using this automatically adds a checksum of the .c files and the > local headers in "srcversion". > */ > + > +#ifdef MODULE > #define MODULE_VERSION(_version) MODULE_INFO(version, _version) > +#else > +#define MODULE_VERSION(_version) \ > + extern ssize_t __modver_version_show(struct module_attribute *, \ > + struct module *, char *); \ > + static struct module_version_attribute __modver_version_attr \ > + __used \ > + __attribute__ ((unused,__section__ ("__modver"),aligned(sizeof(void *)))) \
__used and unused seems overkill, and confused.
Removed unused.
Cheers, Rusty.
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