On Mon, Oct 06, 2025 at 09:16:37PM -0400, Charles Mirabile wrote: > On Thu, Sep 18, 2025 at 10:05:51AM +0200, Alexey Gladkov wrote: > > 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. > > Hi - > > This patch broke RISC-V builds for me. During the final objcopy where the new > symbols are supposed to be stripped, an error occurs producing lots of error > messages similar to this one: > > riscv64-linux-gnu-objcopy: not stripping symbol `__mod_device_table__...' > because it is named in a relocation > > It does not occur using defconfig, but I was able to bisect my way to this > commit and then reduce my config delta w.r.t defconfig until I landed on: > > cat > .config <<'EOF' > CONFIG_RELOCATABLE=y > CONFIG_KASAN=y > EOF > ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- make olddefconfig > ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- make -j $(nproc) > ... > LD vmlinux.unstripped > NM System.map > SORTTAB vmlinux.unstripped > CHKREL vmlinux.unstripped > OBJCOPY vmlinux > OBJCOPY modules.builtin.modinfo > GEN modules.builtin > riscv64-linux-gnu-objcopy: not stripping symbol `<long symbol name>' > because it is named in a relocation > <repeats with different symbol names about a dozen times> > make[3]: *** [scripts/Makefile.vmlinux:97: vmlinux] Error 1 > make[3]: *** Deleting file 'vmlinux' > make[2]: *** [Makefile:1242: vmlinux] Error 2 > make[1]: *** [/tmp/linux/Makefile:369: __build_one_by_one] Error 2 > make: *** [Makefile:248: __sub-make] Error 2 > > I confirmed that reverting this commit fixes the issue.
Hm. Indeed. I haven't found a good solution yet, but you can use the following patch to unlock compilation. It won't solve the problem, it will only hide it. --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -84,7 +84,7 @@ endif remove-section-y := .modinfo remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' -remove-symbols := -w --strip-symbol='__mod_device_table__*' +remove-symbols := -w --strip-unneeded-symbol='__mod_device_table__*' # To avoid warnings: "empty loadable segment detected at ..." from GNU objcopy, # it is necessary to remove the PT_LOAD flag from the segment. > > > > Signed-off-by: Masahiro Yamada <[email protected]> > > Signed-off-by: Alexey Gladkov <[email protected]> > > Tested-by: Stephen Rothwell <[email protected]> > > --- > > include/linux/module.h | 4 ---- > > scripts/Makefile.vmlinux | 4 +++- > > scripts/mksysmap | 3 +++ > > scripts/mod/file2alias.c | 19 ++++++++++++++++++- > > scripts/mod/modpost.c | 15 +++++++++++++++ > > scripts/mod/modpost.h | 2 ++ > > 6 files changed, 41 insertions(+), 6 deletions(-) > > > > diff --git a/include/linux/module.h b/include/linux/module.h > > index e31ee29fac6b7..e135cc79aceea 100644 > > --- a/include/linux/module.h > > +++ b/include/linux/module.h > > @@ -256,14 +256,10 @@ struct module_kobject > > *lookup_or_create_module_kobject(const char *name); > > __PASTE(type, \ > > __PASTE(__, name))))) > > > > -#ifdef MODULE > > /* Creates an alias so file2alias.c can find device table. */ > > #define MODULE_DEVICE_TABLE(type, name) > > \ > > static typeof(name) __mod_device_table(type, name) \ > > __attribute__ ((used, alias(__stringify(name)))) > > -#else /* !MODULE */ > > -#define MODULE_DEVICE_TABLE(type, name) > > -#endif > > > > /* Version of form [<epoch>:]<version>[-<extra-version>]. > > * Or for CVS/RCS ID version, everything but the number is stripped. > > diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux > > index ce79461714979..1e5e37aadcd05 100644 > > --- a/scripts/Makefile.vmlinux > > +++ b/scripts/Makefile.vmlinux > > @@ -89,11 +89,13 @@ endif > > remove-section-y := .modinfo > > remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' > > > > +remove-symbols := -w --strip-symbol='__mod_device_table__*' > > + > > # To avoid warnings: "empty loadable segment detected at ..." from GNU > > objcopy, > > # it is necessary to remove the PT_LOAD flag from the segment. > > quiet_cmd_strip_relocs = OBJCOPY $@ > > cmd_strip_relocs = $(OBJCOPY) $(patsubst %,--set-section-flags > > %=noload,$(remove-section-y)) $< $@; \ > > - $(OBJCOPY) $(addprefix > > --remove-section=,$(remove-section-y)) $@ > > + $(OBJCOPY) $(addprefix > > --remove-section=,$(remove-section-y)) $(remove-symbols) $@ > > > > targets += vmlinux > > vmlinux: vmlinux.unstripped FORCE > > diff --git a/scripts/mksysmap b/scripts/mksysmap > > index a607a0059d119..c4531eacde202 100755 > > --- a/scripts/mksysmap > > +++ b/scripts/mksysmap > > @@ -59,6 +59,9 @@ > > # EXPORT_SYMBOL (namespace) > > / __kstrtabns_/d > > > > +# MODULE_DEVICE_TABLE (symbol name) > > +/ __mod_device_table__/d > > + > > # > > --------------------------------------------------------------------------- > > # Ignored suffixes > > # (do not forget '$' after each pattern) > > diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c > > index 1260bc2287fba..7da9735e7ab3e 100644 > > --- a/scripts/mod/file2alias.c > > +++ b/scripts/mod/file2alias.c > > @@ -1477,7 +1477,7 @@ void handle_moddevtable(struct module *mod, struct > > elf_info *info, > > void *symval; > > char *zeros = NULL; > > const char *type, *name, *modname; > > - size_t typelen; > > + size_t typelen, modnamelen; > > static const char *prefix = "__mod_device_table__"; > > > > /* We're looking for a section relative symbol */ > > @@ -1500,6 +1500,7 @@ void handle_moddevtable(struct module *mod, struct > > elf_info *info, > > type = strstr(modname, "__"); > > if (!type) > > return; > > + modnamelen = type - modname; > > type += strlen("__"); > > > > name = strstr(type, "__"); > > @@ -1526,5 +1527,21 @@ void handle_moddevtable(struct module *mod, struct > > elf_info *info, > > } > > } > > > > + if (mod->is_vmlinux) { > > + struct module_alias *alias; > > + > > + /* > > + * If this is vmlinux, record the name of the builtin module. > > + * Traverse the linked list in the reverse order, and set the > > + * builtin_modname unless it has already been set in the > > + * previous call. > > + */ > > + list_for_each_entry_reverse(alias, &mod->aliases, node) { > > + if (alias->builtin_modname) > > + break; > > + alias->builtin_modname = xstrndup(modname, modnamelen); > > + } > > + } > > + > > free(zeros); > > } > > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > > index 5ca7c268294eb..47c8aa2a69392 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 <linux/export-internal.h>\n"); > > > > add_exported_symbols(&buf, mod); > > + > > + buf_printf(&buf, > > + "#include <linux/module.h>\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); > > } > > diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h > > index 9133e4c3803f0..2aecb8f25c87e 100644 > > --- a/scripts/mod/modpost.h > > +++ b/scripts/mod/modpost.h > > @@ -99,10 +99,12 @@ buf_write(struct buffer *buf, const char *s, int len); > > * struct module_alias - auto-generated MODULE_ALIAS() > > * > > * @node: linked to module::aliases > > + * @modname: name of the builtin module (only for vmlinux) > > * @str: a string for MODULE_ALIAS() > > */ > > struct module_alias { > > struct list_head node; > > + char *builtin_modname; > > char str[]; > > }; > > > > -- > > 2.51.0 > > > -- Rgrds, legion
