bianbu-repo-mirror/bianbu-linux-6.6
1
0
Fork 0
mirror of https://gitee.com/bianbu-linux/linux-6.6 synced 2025-04-24 14:07:52 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

module: simplify version-attribute handling

Browse source 
Instead of using the array-of-pointers trick to avoid having gcc mess up
the built-in module-version array stride, specify type alignment when
declaring entries to prevent gcc from increasing alignment.

This is essentially an alternative (one-line) fix to the problem
addressed by commit b4bc842802 ("module: deal with alignment issues in
built-in module versions").

gcc can increase the alignment of larger objects with static extent as
an optimisation, but this can be suppressed by using the aligned
attribute when declaring variables.

Note that we have been relying on this behaviour for kernel parameters
for 16 years and it indeed hasn't changed since the introduction of the
aligned attribute in gcc-3.1.

Link: https://lore.kernel.org/lkml/20201103175711.10731-1-johan@kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
This commit is contained in:
Johan Hovold 2020-11-23 11:23:15 +01:00 • committed by Jessica Yu
parent 0801a0073f
commit b112082c89
2 changed files with 17 additions and 19 deletions
Download patch file Download diff file Expand all files Collapse all files

26
include/linux/module.h
View file

@ -266,20 +266,20 @@ extern typeof(name) __mod_##type##__##name##_device_table \
#else
#define MODULE_VERSION(_version) \
MODULE_INFO(version, _version); \
static struct module_version_attribute ___modver_attr = { \
.mattr = { \
.attr = { \
.name = "version", \
.mode = S_IRUGO, \
static struct module_version_attribute __modver_attr \
__used __section("__modver") \
__aligned(__alignof__(struct module_version_attribute)) \
= { \
.mattr = { \
.attr = { \
.name = "version", \
.mode = S_IRUGO, \
}, \
.show = __modver_version_show, \
}, \
.show = __modver_version_show, \
}, \
.module_name = KBUILD_MODNAME, \
.version = _version, \
}; \
static const struct module_version_attribute \
__used __section("__modver") \
* __moduleparam_const __modver_attr = &___modver_attr
.module_name = KBUILD_MODNAME, \
.version = _version, \
};
#endif
/* Optional firmware file (or files) needed by the module