| Message ID | 20191011081956.4127892-2-gladkov.alexey@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add modules.builtin.modinfo support | expand |
On Fri, Oct 11, 2019 at 10:19:53AM +0200, Alexey Gladkov wrote: >The kernel since version v5.2-rc1 exports information about built-in >modules in the modules.builtin.modinfo. Information is stored in >the same format as in the separate modules (null-terminated string >array). The module name is a prefix for each line. > >$ tr '\0' '\n' < modules.builtin.modinfo >ext4.softdep=pre: crc32c >ext4.license=GPL >ext4.description=Fourth Extended Filesystem >ext4.author=Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others >ext4.alias=fs-ext4 >ext4.alias=ext3 >ext4.alias=fs-ext3 >ext4.alias=ext2 >ext4.alias=fs-ext2 >md_mod.alias=block-major-9-* >md_mod.alias=md >md_mod.description=MD RAID framework >md_mod.license=GPL >md_mod.parmtype=create_on_open:bool >md_mod.parmtype=start_dirty_degraded:int Apologies, I thought I had replied to this already. Having this functionality is very welcome, thanks. I have some comments about the implementation. See below. >... > >Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com> >--- > Makefile.am | 1 + > libkmod/libkmod-builtin.c | 231 +++++++++++++++++++++++++++++++++++++ > libkmod/libkmod-internal.h | 8 ++ > 3 files changed, 240 insertions(+) > create mode 100644 libkmod/libkmod-builtin.c > >diff --git a/Makefile.am b/Makefile.am >index c5c2f06..176dcfc 100644 >--- a/Makefile.am >+++ b/Makefile.am >@@ -68,6 +68,7 @@ libkmod_libkmod_la_SOURCES = \ > libkmod/libkmod.h \ > libkmod/libkmod-internal.h \ > libkmod/libkmod.c \ >+ libkmod/libkmod-builtin.c \ > libkmod/libkmod-list.c \ > libkmod/libkmod-config.c \ > libkmod/libkmod-index.c \ >diff --git a/libkmod/libkmod-builtin.c b/libkmod/libkmod-builtin.c >new file mode 100644 >index 0000000..9da0010 >--- /dev/null >+++ b/libkmod/libkmod-builtin.c >@@ -0,0 +1,231 @@ >+/* >+ * libkmod - interface to kernel built-in modules >+ * >+ * Copyright (C) 2019 Alexey Gladkov <gladkov.alexey@gmail.com> >+ * >+ * This library is free software; you can redistribute it and/or >+ * modify it under the terms of the GNU Lesser General Public >+ * License as published by the Free Software Foundation; either >+ * version 2.1 of the License, or (at your option) any later version. >+ * >+ * This library is distributed in the hope that it will be useful, >+ * but WITHOUT ANY WARRANTY; without even the implied warranty of >+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >+ * Lesser General Public License for more details. >+ * >+ * You should have received a copy of the GNU Lesser General Public >+ * License along with this library; if not, see <http://www.gnu.org/licenses/>. >+ */ this remembers me we should convert these headers to spdx >+ >+#include <stdio.h> >+#include <stdlib.h> >+#include <string.h> >+#include <errno.h> >+ >+#include "libkmod.h" >+#include "libkmod-internal.h" >+ >+#define MODULES_BUILTIN_MODINFO "modules.builtin.modinfo" >+ >+struct kmod_builtin_iter { >+ struct kmod_ctx *ctx; >+ struct kmod_file *file; >+ off_t pos; >+ off_t next; >+}; >+ >+struct kmod_builtin_iter *kmod_builtin_iter_new(struct kmod_ctx *ctx) >+{ >+ char path[PATH_MAX]; >+ struct kmod_file *file; >+ struct kmod_builtin_iter *iter; >+ const char *dirname = kmod_get_dirname(ctx); >+ size_t len = strlen(dirname); >+ >+ if ((len + 1 + strlen(MODULES_BUILTIN_MODINFO) + 1) >= PATH_MAX) { >+ errno = ENAMETOOLONG; >+ return NULL; >+ } >+ >+ snprintf(path, PATH_MAX, "%s/%s", dirname, MODULES_BUILTIN_MODINFO); >+ >+ file = kmod_file_open(ctx, path); >+ if (!file) >+ return NULL; >+ >+ iter = malloc(sizeof(*iter)); >+ if (!iter) { >+ kmod_file_unref(file); >+ errno = ENOMEM; >+ return NULL; >+ } >+ >+ iter->ctx = ctx; >+ iter->file = file; >+ iter->pos = 0; >+ iter->next = 0; >+ >+ return iter; >+} >+ >+bool kmod_builtin_iter_next(struct kmod_builtin_iter *iter) >+{ >+ char *mm, *s, *dot; >+ off_t offset, mmsize; >+ size_t len, modlen; >+ char *modname = NULL; >+ >+ mm = kmod_file_get_contents(iter->file); >+ mmsize = kmod_file_get_size(iter->file); humn... kmod_file is more target for handling modules. This is only < 100k and we would access it sequentially. I think we are fine just using stdio. >+ >+ offset = iter->next; >+ >+ while (offset < mmsize) { >+ s = mm + offset; >+ >+ dot = strchr(s, '.'); >+ if (!dot) >+ return false; wouldn't this fail if in the description of a module/param we have a dot? I think a more correct approach is to search for \0 and then try to match the prefix. Actually, maybe even better to memmem() "\0<module-name>.", first being an exception. >+ >+ len = dot - s; >+ >+ if (!modname) { >+ modname = s; >+ modlen = len; >+ } else if (modlen != len || strncmp(modname, s, len)) { >+ break; >+ } >+ >+ offset += strlen(s) + 1; >+ } >+ >+ if (!modname) >+ return false; >+ >+ iter->next = offset; >+ >+ return true; >+} >+ >+void kmod_builtin_iter_free(struct kmod_builtin_iter *iter) >+{ >+ kmod_file_unref(iter->file); >+ free(iter); >+} >+ >+int kmod_builtin_iter_get_strings(struct kmod_builtin_iter *iter, >+ const char **strings) >+{ >+ char *mm = kmod_file_get_contents(iter->file); >+ off_t pos = iter->pos; >+ >+ char *start = NULL; >+ size_t count = 0; >+ size_t modlen = 0; >+ >+ while (pos < iter->next) { >+ char *dot = strchr(mm + pos, '.'); >+ size_t len; >+ >+ if (!dot) >+ return -1; >+ >+ len = dot - (mm + pos); >+ >+ if (!start) { >+ start = mm + pos; >+ modlen = len; >+ } else if (modlen != len || strncmp(start, mm + pos, len)) { >+ break; >+ } >+ >+ pos += strlen(mm + pos) + 1; >+ count++; >+ } >+ >+ *strings = start; >+ iter->pos = iter->next; >+ >+ return count; >+} >+ >+/* array will be allocated with strings in a single malloc, just free *array */ >+int kmod_builtin_get_modinfo(struct kmod_ctx *ctx, const char *modname, >+ char ***modinfo) >+{ >+ char *mm, *s, *section, *dot; >+ off_t n, size, offset, mmoffset, mmsize; >+ size_t modlen, len; >+ struct kmod_builtin_iter *iter; >+ int count = 0; >+ >+ iter = kmod_builtin_iter_new(ctx); >+ >+ if (!iter) >+ return -1; >+ >+ modlen = strlen(modname); >+ >+ mmsize = kmod_file_get_size(iter->file); >+ mm = kmod_file_get_contents(iter->file); >+ >+ section = NULL; >+ size = 0; >+ >+ for (mmoffset = 0; mmoffset < mmsize;) { >+ s = mm + mmoffset; >+ dot = strchr(s, '.'); >+ >+ if (!dot) { >+ count = -ENODATA; >+ goto fail; >+ } >+ >+ len = dot - s; >+ >+ if (modlen != len || strncmp(modname, s, len)) { >+ if (count) >+ break; >+ mmoffset += strlen(s) + 1; >+ continue; >+ } else if (!count) { >+ section = s; >+ } >+ >+ len = strlen(dot + 1) + 1; >+ mmoffset += modlen + 1 + len; >+ size += len; >+ >+ count++; >+ } >+ >+ if (!count) { >+ count = -ENOSYS; >+ goto fail; >+ } >+ >+ *modinfo = malloc(size + sizeof(char *) * (count + 1)); >+ if (!*modinfo) { >+ count = -errno; >+ goto fail; >+ } >+ >+ s = (char *)(*modinfo + count + 1); >+ >+ n = 0; >+ mmoffset = 0; >+ >+ for (offset = 0; offset < size;) { >+ len = strlen(section + mmoffset + modlen + 1) + 1; >+ >+ strncpy(s + offset, section + mmoffset + modlen + 1, len); >+ (*modinfo)[n++] = s + offset; >+ >+ mmoffset += modlen + 1 + len; >+ offset += len; >+ } >+ >+fail: >+ kmod_builtin_iter_free(iter); >+ return count; >+} >diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h >index a65ddd1..17ae541 100644 >--- a/libkmod/libkmod-internal.h >+++ b/libkmod/libkmod-internal.h >@@ -193,3 +193,11 @@ struct kmod_signature_info { > }; > bool kmod_module_signature_info(const struct kmod_file *file, struct kmod_signature_info *sig_info) _must_check_ __attribute__((nonnull(1, 2))); > void kmod_module_signature_info_free(struct kmod_signature_info *sig_info) __attribute__((nonnull)); >+ >+/* libkmod-builtin.c */ >+struct kmod_builtin_iter; >+struct kmod_builtin_iter *kmod_builtin_iter_new(struct kmod_ctx *ctx) __attribute__((nonnull(1))); >+void kmod_builtin_iter_free(struct kmod_builtin_iter *iter) __attribute__((nonnull(1))); >+bool kmod_builtin_iter_next(struct kmod_builtin_iter *iter) __attribute__((nonnull(1))); >+int kmod_builtin_iter_get_strings(struct kmod_builtin_iter *iter, const char **modinfo) __attribute__((nonnull(1, 2))); >+int kmod_builtin_get_modinfo(struct kmod_ctx *ctx, const char *modname, char ***modinfo) __attribute__((nonnull(1, 2, 3))); >-- >2.21.0 >
On Thu, Nov 07, 2019 at 12:23:10AM -0800, Lucas De Marchi wrote: > On Fri, Oct 11, 2019 at 10:19:53AM +0200, Alexey Gladkov wrote: > > The kernel since version v5.2-rc1 exports information about built-in > > modules in the modules.builtin.modinfo. Information is stored in > > the same format as in the separate modules (null-terminated string > > array). The module name is a prefix for each line. > > > > $ tr '\0' '\n' < modules.builtin.modinfo > > ext4.softdep=pre: crc32c > > ext4.license=GPL > > ext4.description=Fourth Extended Filesystem > > ext4.author=Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others > > ext4.alias=fs-ext4 > > ext4.alias=ext3 > > ext4.alias=fs-ext3 > > ext4.alias=ext2 > > ext4.alias=fs-ext2 > > md_mod.alias=block-major-9-* > > md_mod.alias=md > > md_mod.description=MD RAID framework > > md_mod.license=GPL > > md_mod.parmtype=create_on_open:bool > > md_mod.parmtype=start_dirty_degraded:int > > > Apologies, I thought I had replied to this already. Having this > functionality is very welcome, thanks. I have some comments about the > implementation. See below. > > > > ... > > > > Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com> > > --- > > Makefile.am | 1 + > > libkmod/libkmod-builtin.c | 231 +++++++++++++++++++++++++++++++++++++ > > libkmod/libkmod-internal.h | 8 ++ > > 3 files changed, 240 insertions(+) > > create mode 100644 libkmod/libkmod-builtin.c > > > > diff --git a/Makefile.am b/Makefile.am > > index c5c2f06..176dcfc 100644 > > --- a/Makefile.am > > +++ b/Makefile.am > > @@ -68,6 +68,7 @@ libkmod_libkmod_la_SOURCES = \ > > libkmod/libkmod.h \ > > libkmod/libkmod-internal.h \ > > libkmod/libkmod.c \ > > + libkmod/libkmod-builtin.c \ > > libkmod/libkmod-list.c \ > > libkmod/libkmod-config.c \ > > libkmod/libkmod-index.c \ > > diff --git a/libkmod/libkmod-builtin.c b/libkmod/libkmod-builtin.c > > new file mode 100644 > > index 0000000..9da0010 > > --- /dev/null > > +++ b/libkmod/libkmod-builtin.c > > @@ -0,0 +1,231 @@ > > +/* > > + * libkmod - interface to kernel built-in modules > > + * > > + * Copyright (C) 2019 Alexey Gladkov <gladkov.alexey@gmail.com> > > + * > > + * This library is free software; you can redistribute it and/or > > + * modify it under the terms of the GNU Lesser General Public > > + * License as published by the Free Software Foundation; either > > + * version 2.1 of the License, or (at your option) any later version. > > + * > > + * This library is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > > + * Lesser General Public License for more details. > > + * > > + * You should have received a copy of the GNU Lesser General Public > > + * License along with this library; if not, see <http://www.gnu.org/licenses/>. > > + */ > > this remembers me we should convert these headers to spdx > > > + > > +#include <stdio.h> > > +#include <stdlib.h> > > +#include <string.h> > > +#include <errno.h> > > + > > +#include "libkmod.h" > > +#include "libkmod-internal.h" > > + > > +#define MODULES_BUILTIN_MODINFO "modules.builtin.modinfo" > > + > > +struct kmod_builtin_iter { > > + struct kmod_ctx *ctx; > > + struct kmod_file *file; > > + off_t pos; > > + off_t next; > > +}; > > + > > +struct kmod_builtin_iter *kmod_builtin_iter_new(struct kmod_ctx *ctx) > > +{ > > + char path[PATH_MAX]; > > + struct kmod_file *file; > > + struct kmod_builtin_iter *iter; > > + const char *dirname = kmod_get_dirname(ctx); > > + size_t len = strlen(dirname); > > + > > + if ((len + 1 + strlen(MODULES_BUILTIN_MODINFO) + 1) >= PATH_MAX) { > > + errno = ENAMETOOLONG; > > + return NULL; > > + } > > + > > + snprintf(path, PATH_MAX, "%s/%s", dirname, MODULES_BUILTIN_MODINFO); > > + > > + file = kmod_file_open(ctx, path); > > + if (!file) > > + return NULL; > > + > > + iter = malloc(sizeof(*iter)); > > + if (!iter) { > > + kmod_file_unref(file); > > + errno = ENOMEM; > > + return NULL; > > + } > > + > > + iter->ctx = ctx; > > + iter->file = file; > > + iter->pos = 0; > > + iter->next = 0; > > + > > + return iter; > > +} > > + > > +bool kmod_builtin_iter_next(struct kmod_builtin_iter *iter) > > +{ > > + char *mm, *s, *dot; > > + off_t offset, mmsize; > > + size_t len, modlen; > > + char *modname = NULL; > > + > > + mm = kmod_file_get_contents(iter->file); > > + mmsize = kmod_file_get_size(iter->file); > > humn... kmod_file is more target for handling modules. This is only > < 100k and we would access it sequentially. I think we are fine just > using stdio. Make sense. > > + > > + offset = iter->next; > > + > > + while (offset < mmsize) { > > + s = mm + offset; > > + > > + dot = strchr(s, '.'); > > + if (!dot) > > + return false; > > wouldn't this fail if in the description of a module/param we have a dot? No. All fields have a module name as a prefix. > I think a more correct approach is to search for \0 and then try to > match the prefix. > > Actually, maybe even better to memmem() "\0<module-name>.", first being > an exception. > > > > + > > + len = dot - s; > > + > > + if (!modname) { > > + modname = s; > > + modlen = len; > > + } else if (modlen != len || strncmp(modname, s, len)) { > > + break; > > + } > > + > > + offset += strlen(s) + 1; > > + } > > + > > + if (!modname) > > + return false; > > + > > + iter->next = offset; > > + > > + return true; > > +} > > + > > +void kmod_builtin_iter_free(struct kmod_builtin_iter *iter) > > +{ > > + kmod_file_unref(iter->file); > > + free(iter); > > +} > > + > > +int kmod_builtin_iter_get_strings(struct kmod_builtin_iter *iter, > > + const char **strings) > > +{ > > + char *mm = kmod_file_get_contents(iter->file); > > + off_t pos = iter->pos; > > + > > + char *start = NULL; > > + size_t count = 0; > > + size_t modlen = 0; > > + > > + while (pos < iter->next) { > > + char *dot = strchr(mm + pos, '.'); > > + size_t len; > > + > > + if (!dot) > > + return -1; > > + > > + len = dot - (mm + pos); > > + > > + if (!start) { > > + start = mm + pos; > > + modlen = len; > > + } else if (modlen != len || strncmp(start, mm + pos, len)) { > > + break; > > + } > > + > > + pos += strlen(mm + pos) + 1; > > + count++; > > + } > > + > > + *strings = start; > > + iter->pos = iter->next; > > + > > + return count; > > +} > > + > > +/* array will be allocated with strings in a single malloc, just free *array */ > > +int kmod_builtin_get_modinfo(struct kmod_ctx *ctx, const char *modname, > > + char ***modinfo) > > +{ > > + char *mm, *s, *section, *dot; > > + off_t n, size, offset, mmoffset, mmsize; > > + size_t modlen, len; > > + struct kmod_builtin_iter *iter; > > + int count = 0; > > + > > + iter = kmod_builtin_iter_new(ctx); > > + > > + if (!iter) > > + return -1; > > + > > + modlen = strlen(modname); > > + > > + mmsize = kmod_file_get_size(iter->file); > > + mm = kmod_file_get_contents(iter->file); > > + > > + section = NULL; > > + size = 0; > > + > > + for (mmoffset = 0; mmoffset < mmsize;) { > > + s = mm + mmoffset; > > + dot = strchr(s, '.'); > > + > > + if (!dot) { > > + count = -ENODATA; > > + goto fail; > > + } > > + > > + len = dot - s; > > + > > + if (modlen != len || strncmp(modname, s, len)) { > > + if (count) > > + break; > > + mmoffset += strlen(s) + 1; > > + continue; > > + } else if (!count) { > > + section = s; > > + } > > + > > + len = strlen(dot + 1) + 1; > > + mmoffset += modlen + 1 + len; > > + size += len; > > + > > + count++; > > + } > > + > > + if (!count) { > > + count = -ENOSYS; > > + goto fail; > > + } > > + > > + *modinfo = malloc(size + sizeof(char *) * (count + 1)); > > + if (!*modinfo) { > > + count = -errno; > > + goto fail; > > + } > > + > > + s = (char *)(*modinfo + count + 1); > > + > > + n = 0; > > + mmoffset = 0; > > + > > + for (offset = 0; offset < size;) { > > + len = strlen(section + mmoffset + modlen + 1) + 1; > > + > > + strncpy(s + offset, section + mmoffset + modlen + 1, len); > > + (*modinfo)[n++] = s + offset; > > + > > + mmoffset += modlen + 1 + len; > > + offset += len; > > + } > > + > > +fail: > > + kmod_builtin_iter_free(iter); > > + return count; > > +} > > diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h > > index a65ddd1..17ae541 100644 > > --- a/libkmod/libkmod-internal.h > > +++ b/libkmod/libkmod-internal.h > > @@ -193,3 +193,11 @@ struct kmod_signature_info { > > }; > > bool kmod_module_signature_info(const struct kmod_file *file, struct kmod_signature_info *sig_info) _must_check_ __attribute__((nonnull(1, 2))); > > void kmod_module_signature_info_free(struct kmod_signature_info *sig_info) __attribute__((nonnull)); > > + > > +/* libkmod-builtin.c */ > > +struct kmod_builtin_iter; > > +struct kmod_builtin_iter *kmod_builtin_iter_new(struct kmod_ctx *ctx) __attribute__((nonnull(1))); > > +void kmod_builtin_iter_free(struct kmod_builtin_iter *iter) __attribute__((nonnull(1))); > > +bool kmod_builtin_iter_next(struct kmod_builtin_iter *iter) __attribute__((nonnull(1))); > > +int kmod_builtin_iter_get_strings(struct kmod_builtin_iter *iter, const char **modinfo) __attribute__((nonnull(1, 2))); > > +int kmod_builtin_get_modinfo(struct kmod_ctx *ctx, const char *modname, char ***modinfo) __attribute__((nonnull(1, 2, 3))); > > -- > > 2.21.0 > > >
diff --git a/Makefile.am b/Makefile.am index c5c2f06..176dcfc 100644 --- a/Makefile.am +++ b/Makefile.am @@ -68,6 +68,7 @@ libkmod_libkmod_la_SOURCES = \ libkmod/libkmod.h \ libkmod/libkmod-internal.h \ libkmod/libkmod.c \ + libkmod/libkmod-builtin.c \ libkmod/libkmod-list.c \ libkmod/libkmod-config.c \ libkmod/libkmod-index.c \ diff --git a/libkmod/libkmod-builtin.c b/libkmod/libkmod-builtin.c new file mode 100644 index 0000000..9da0010 --- /dev/null +++ b/libkmod/libkmod-builtin.c @@ -0,0 +1,231 @@ +/* + * libkmod - interface to kernel built-in modules + * + * Copyright (C) 2019 Alexey Gladkov <gladkov.alexey@gmail.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/>. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> + +#include "libkmod.h" +#include "libkmod-internal.h" + +#define MODULES_BUILTIN_MODINFO "modules.builtin.modinfo" + +struct kmod_builtin_iter { + struct kmod_ctx *ctx; + struct kmod_file *file; + off_t pos; + off_t next; +}; + +struct kmod_builtin_iter *kmod_builtin_iter_new(struct kmod_ctx *ctx) +{ + char path[PATH_MAX]; + struct kmod_file *file; + struct kmod_builtin_iter *iter; + const char *dirname = kmod_get_dirname(ctx); + size_t len = strlen(dirname); + + if ((len + 1 + strlen(MODULES_BUILTIN_MODINFO) + 1) >= PATH_MAX) { + errno = ENAMETOOLONG; + return NULL; + } + + snprintf(path, PATH_MAX, "%s/%s", dirname, MODULES_BUILTIN_MODINFO); + + file = kmod_file_open(ctx, path); + if (!file) + return NULL; + + iter = malloc(sizeof(*iter)); + if (!iter) { + kmod_file_unref(file); + errno = ENOMEM; + return NULL; + } + + iter->ctx = ctx; + iter->file = file; + iter->pos = 0; + iter->next = 0; + + return iter; +} + +bool kmod_builtin_iter_next(struct kmod_builtin_iter *iter) +{ + char *mm, *s, *dot; + off_t offset, mmsize; + size_t len, modlen; + char *modname = NULL; + + mm = kmod_file_get_contents(iter->file); + mmsize = kmod_file_get_size(iter->file); + + offset = iter->next; + + while (offset < mmsize) { + s = mm + offset; + + dot = strchr(s, '.'); + if (!dot) + return false; + + len = dot - s; + + if (!modname) { + modname = s; + modlen = len; + } else if (modlen != len || strncmp(modname, s, len)) { + break; + } + + offset += strlen(s) + 1; + } + + if (!modname) + return false; + + iter->next = offset; + + return true; +} + +void kmod_builtin_iter_free(struct kmod_builtin_iter *iter) +{ + kmod_file_unref(iter->file); + free(iter); +} + +int kmod_builtin_iter_get_strings(struct kmod_builtin_iter *iter, + const char **strings) +{ + char *mm = kmod_file_get_contents(iter->file); + off_t pos = iter->pos; + + char *start = NULL; + size_t count = 0; + size_t modlen = 0; + + while (pos < iter->next) { + char *dot = strchr(mm + pos, '.'); + size_t len; + + if (!dot) + return -1; + + len = dot - (mm + pos); + + if (!start) { + start = mm + pos; + modlen = len; + } else if (modlen != len || strncmp(start, mm + pos, len)) { + break; + } + + pos += strlen(mm + pos) + 1; + count++; + } + + *strings = start; + iter->pos = iter->next; + + return count; +} + +/* array will be allocated with strings in a single malloc, just free *array */ +int kmod_builtin_get_modinfo(struct kmod_ctx *ctx, const char *modname, + char ***modinfo) +{ + char *mm, *s, *section, *dot; + off_t n, size, offset, mmoffset, mmsize; + size_t modlen, len; + struct kmod_builtin_iter *iter; + int count = 0; + + iter = kmod_builtin_iter_new(ctx); + + if (!iter) + return -1; + + modlen = strlen(modname); + + mmsize = kmod_file_get_size(iter->file); + mm = kmod_file_get_contents(iter->file); + + section = NULL; + size = 0; + + for (mmoffset = 0; mmoffset < mmsize;) { + s = mm + mmoffset; + dot = strchr(s, '.'); + + if (!dot) { + count = -ENODATA; + goto fail; + } + + len = dot - s; + + if (modlen != len || strncmp(modname, s, len)) { + if (count) + break; + mmoffset += strlen(s) + 1; + continue; + } else if (!count) { + section = s; + } + + len = strlen(dot + 1) + 1; + mmoffset += modlen + 1 + len; + size += len; + + count++; + } + + if (!count) { + count = -ENOSYS; + goto fail; + } + + *modinfo = malloc(size + sizeof(char *) * (count + 1)); + if (!*modinfo) { + count = -errno; + goto fail; + } + + s = (char *)(*modinfo + count + 1); + + n = 0; + mmoffset = 0; + + for (offset = 0; offset < size;) { + len = strlen(section + mmoffset + modlen + 1) + 1; + + strncpy(s + offset, section + mmoffset + modlen + 1, len); + (*modinfo)[n++] = s + offset; + + mmoffset += modlen + 1 + len; + offset += len; + } + +fail: + kmod_builtin_iter_free(iter); + return count; +} diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h index a65ddd1..17ae541 100644 --- a/libkmod/libkmod-internal.h +++ b/libkmod/libkmod-internal.h @@ -193,3 +193,11 @@ struct kmod_signature_info { }; bool kmod_module_signature_info(const struct kmod_file *file, struct kmod_signature_info *sig_info) _must_check_ __attribute__((nonnull(1, 2))); void kmod_module_signature_info_free(struct kmod_signature_info *sig_info) __attribute__((nonnull)); + +/* libkmod-builtin.c */ +struct kmod_builtin_iter; +struct kmod_builtin_iter *kmod_builtin_iter_new(struct kmod_ctx *ctx) __attribute__((nonnull(1))); +void kmod_builtin_iter_free(struct kmod_builtin_iter *iter) __attribute__((nonnull(1))); +bool kmod_builtin_iter_next(struct kmod_builtin_iter *iter) __attribute__((nonnull(1))); +int kmod_builtin_iter_get_strings(struct kmod_builtin_iter *iter, const char **modinfo) __attribute__((nonnull(1, 2))); +int kmod_builtin_get_modinfo(struct kmod_ctx *ctx, const char *modname, char ***modinfo) __attribute__((nonnull(1, 2, 3)));
The kernel since version v5.2-rc1 exports information about built-in modules in the modules.builtin.modinfo. Information is stored in the same format as in the separate modules (null-terminated string array). The module name is a prefix for each line. $ tr '\0' '\n' < modules.builtin.modinfo ext4.softdep=pre: crc32c ext4.license=GPL ext4.description=Fourth Extended Filesystem ext4.author=Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others ext4.alias=fs-ext4 ext4.alias=ext3 ext4.alias=fs-ext3 ext4.alias=ext2 ext4.alias=fs-ext2 md_mod.alias=block-major-9-* md_mod.alias=md md_mod.description=MD RAID framework md_mod.license=GPL md_mod.parmtype=create_on_open:bool md_mod.parmtype=start_dirty_degraded:int ... Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com> --- Makefile.am | 1 + libkmod/libkmod-builtin.c | 231 +++++++++++++++++++++++++++++++++++++ libkmod/libkmod-internal.h | 8 ++ 3 files changed, 240 insertions(+) create mode 100644 libkmod/libkmod-builtin.c