From 5ab23c7923a1d2ae1890026866a2d8506b010a4a Mon Sep 17 00:00:00 2001 From: Alexey Gladkov Date: Thu, 18 Sep 2025 10:05:51 +0200 Subject: modpost: Create modalias for builtin modules For some modules, modalias is generated using the modpost utility and the section is added to the module file. When a module is added inside vmlinux, modpost does not generate modalias for such modules and the information is lost. As a result kmod (which uses modules.builtin.modinfo in userspace) cannot determine that modalias is handled by a builtin kernel module. $ cat /sys/devices/pci0000:00/0000:00:14.0/modalias pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30 $ modinfo xhci_pci name: xhci_pci filename: (builtin) license: GPL file: drivers/usb/host/xhci-pci description: xHCI PCI Host Controller Driver Missing modalias "pci:v*d*sv*sd*bc0Csc03i30*" which will be generated by modpost if the module is built separately. To fix this it is necessary to generate the same modalias for vmlinux as for the individual modules. Fortunately '.vmlinux.export.o' is already generated from which '.modinfo' can be extracted in the same way as for vmlinux.o. Signed-off-by: Masahiro Yamada Signed-off-by: Alexey Gladkov Tested-by: Stephen Rothwell Reviewed-by: Nicolas Schier Link: https://patch.msgid.link/28d4da3b0e3fc8474142746bcf469e03752c3208.1758182101.git.legion@kernel.org Signed-off-by: Nathan Chancellor --- scripts/mod/modpost.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'scripts/mod/modpost.c') diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 5ca7c268294e..47c8aa2a6939 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -2067,11 +2067,26 @@ static void write_if_changed(struct buffer *b, const char *fname) static void write_vmlinux_export_c_file(struct module *mod) { struct buffer buf = { }; + struct module_alias *alias, *next; buf_printf(&buf, "#include \n"); add_exported_symbols(&buf, mod); + + buf_printf(&buf, + "#include \n" + "#undef __MODULE_INFO_PREFIX\n" + "#define __MODULE_INFO_PREFIX\n"); + + list_for_each_entry_safe(alias, next, &mod->aliases, node) { + buf_printf(&buf, "MODULE_INFO(%s.alias, \"%s\");\n", + alias->builtin_modname, alias->str); + list_del(&alias->node); + free(alias->builtin_modname); + free(alias); + } + write_if_changed(&buf, ".vmlinux.export.c"); free(buf.p); } -- cgit