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@xxxxxxxxx> > > --- > > 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@xxxxxxxxx> > > + * > > + * 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 > > > -- Rgrds, legion