Messages in this thread Patch in this message | | | Subject | Re: always store MODULE_VERSION("") data? | From | Rusty Russell <> | Date | Mon, 03 May 2004 12:20:19 +1000 |
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On Mon, 2004-05-03 at 04:31, Sam Ravnborg wrote: > On Thu, Apr 29, 2004 at 10:55:22AM +1000, Rusty Russell wrote: > > > > +config MODULE_SRCVERSION_ALL > > + bool "Source checksum for all modules" > > + depends on MODULES > > + help > > + Modules which contain a MODULE_VERSION get an extra "srcversion" > > + field inserting into their modinfo section, which contains a > > + sum of the source files which made it. This helps maintainers > > + see exactly which source was used to build a module (since > > + others sometimes change the module source without updating > > + the version). With this option, such a "srcversion" field > > + will be created for all modules. If unsure, say N. > > I had to read the above twice to get the fact that it was added to all modules regardless. > Move the second last sentence first, so the explanation comes after? > Any reason not to enable it pr. default, at least to give it some exposure?
Good question. I didn't want to slow the build process, but measuring here gives no real difference. My original feeling was that if the author doesn't care enough to put a version string in, then usually they're relying on the "oh, you're using 2.6.5" method and won't use srcversion either.
Patch below makes it unconditional.
Name: Put Module Source Checksum In "srcversion" Status: Booted on 2.6.6-rc3-bk4
Matt Domsch <Matt_Domsch@dell.com> writes: > How hard would it be to always include the space for the > MODULE_VERSION("") data rather than specifying it in each file that > doesn't care, and only modules with their own versioning could put > MODULE_VERSION("myversion") to override the default?
Actually, it's probably best to separate the source checksum from the rest of the version, and do it for all modules: it's so fast it has no measurable effect on build times here.
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .27380-linux-2.6.6-rc2-bk5/include/linux/module.h .27380-linux-2.6.6-rc2-bk5.updated/include/linux/module.h --- .27380-linux-2.6.6-rc2-bk5/include/linux/module.h 2004-04-22 08:03:55.000000000 +1000 +++ .27380-linux-2.6.6-rc2-bk5.updated/include/linux/module.h 2004-04-28 15:16:34.000000000 +1000 @@ -140,11 +140,9 @@ extern struct module __this_module; customizations, eg "rh3" or "rusty1". - Using this automatically adds a checksum of the .c files and the - local headers to the end. Use MODULE_VERSION("") if you want just - this. Macro includes room for this. + Note that the checksum of the .c file and local headers is always + included in a modules "srcversion" modinfo field. */ -#define MODULE_VERSION(_version) \ - MODULE_INFO(version, _version "\0xxxxxxxxxxxxxxxxxxxxxxxx") +#define MODULE_VERSION(_version) MODULE_INFO(version, _version) /* Given an address, look for it in the exception tables */ const struct exception_table_entry *search_exception_tables(unsigned long add); diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .27380-linux-2.6.6-rc2-bk5/scripts/modpost.c .27380-linux-2.6.6-rc2-bk5.updated/scripts/modpost.c --- .27380-linux-2.6.6-rc2-bk5/scripts/modpost.c 2004-04-28 08:53:14.000000000 +1000 +++ .27380-linux-2.6.6-rc2-bk5.updated/scripts/modpost.c 2004-04-28 16:18:08.000000000 +1000 @@ -1,7 +1,7 @@ /* Postprocess module symbol versions * * Copyright 2003 Kai Germaschewski - * 2002-2003 Rusty Russell, IBM Corporation + * Copyright 2002-2004 Rusty Russell, IBM Corporation * * Based in part on module-init-tools/depmod.c,file2alias * @@ -393,10 +395,44 @@ is_vmlinux(const char *modname) return strcmp(myname, "vmlinux") == 0; } +/* Parse tag=value strings from .modinfo section */ +static char *next_string(char *string, unsigned long *secsize) +{ + /* Skip non-zero chars */ + while (string[0]) { + string++; + if ((*secsize)-- <= 1) + return NULL; + } + + /* Skip any zero padding. */ + while (!string[0]) { + string++; + if ((*secsize)-- <= 1) + return NULL; + } + return string; +} + +static char *get_modinfo(void *modinfo, unsigned long modinfo_len, + const char *tag) +{ + char *p; + unsigned int taglen = strlen(tag); + unsigned long size = modinfo_len; + + for (p = modinfo; p; p = next_string(p, &size)) { + if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') + return p + taglen + 1; + } + return NULL; +} + void read_symbols(char *modname) { const char *symname; + char *version; struct module *mod; struct elf_info info = { }; Elf_Sym *sym; @@ -423,8 +459,15 @@ read_symbols(char *modname) handle_modversions(mod, &info, sym, symname); handle_moddevtable(mod, &info, sym, symname); } - maybe_frob_version(modname, info.modinfo, info.modinfo_len, - (void *)info.modinfo - (void *)info.hdr); + + version = get_modinfo(info.modinfo, info.modinfo_len, "version"); + if (version) + maybe_frob_rcs_version(modname, version, info.modinfo, + version - (char *)info.hdr); + if (!is_vmlinux(modname)) + get_src_version(modname, mod->srcversion, + sizeof(mod->srcversion)-1); + parse_elf_finish(&info); /* Our trick to get versioning for struct_module - it's @@ -574,6 +617,14 @@ add_depends(struct buffer *b, struct mod } void +add_srcversion(struct buffer *b, struct module *mod) +{ + buf_printf(b, "\n"); + buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", + mod->srcversion); +} + +void write_if_changed(struct buffer *b, const char *fname) { char *tmp; @@ -725,6 +781,7 @@ main(int argc, char **argv) add_versions(&buf, mod); add_depends(&buf, mod, modules); add_moddevtable(&buf, mod); + add_srcversion(&buf, mod); sprintf(fname, "%s.mod.c", mod->name); write_if_changed(&buf, fname); diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .27380-linux-2.6.6-rc2-bk5/scripts/modpost.h .27380-linux-2.6.6-rc2-bk5.updated/scripts/modpost.h --- .27380-linux-2.6.6-rc2-bk5/scripts/modpost.h 2004-04-22 08:04:10.000000000 +1000 +++ .27380-linux-2.6.6-rc2-bk5.updated/scripts/modpost.h 2004-04-28 15:39:00.000000000 +1000 @@ -75,6 +75,7 @@ struct module { int seen; int skip; struct buffer dev_table_buf; + char srcversion[25]; }; struct elf_info { @@ -93,10 +94,11 @@ void handle_moddevtable(struct module *m void add_moddevtable(struct buffer *buf, struct module *mod); -void maybe_frob_version(const char *modfilename, - void *modinfo, - unsigned long modinfo_len, - unsigned long modinfo_offset); +void maybe_frob_rcs_version(const char *modfilename, + char *version, + void *modinfo, + unsigned long modinfo_offset); +void get_src_version(const char *modname, char sum[], unsigned sumlen); void *grab_file(const char *filename, unsigned long *size); char* get_next_line(unsigned long *pos, void *file, unsigned long size); diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .27380-linux-2.6.6-rc2-bk5/scripts/sumversion.c .27380-linux-2.6.6-rc2-bk5.updated/scripts/sumversion.c --- .27380-linux-2.6.6-rc2-bk5/scripts/sumversion.c 2004-04-05 09:04:50.000000000 +1000 +++ .27380-linux-2.6.6-rc2-bk5.updated/scripts/sumversion.c 2004-04-28 15:39:17.000000000 +1000 @@ -5,39 +5,6 @@ #include <string.h> #include "modpost.h" -/* Parse tag=value strings from .modinfo section */ -static char *next_string(char *string, unsigned long *secsize) -{ - /* Skip non-zero chars */ - while (string[0]) { - string++; - if ((*secsize)-- <= 1) - return NULL; - } - - /* Skip any zero padding. */ - while (!string[0]) { - string++; - if ((*secsize)-- <= 1) - return NULL; - } - return string; -} - -static char *get_modinfo(void *modinfo, unsigned long modinfo_len, - const char *tag) -{ - char *p; - unsigned int taglen = strlen(tag); - unsigned long size = modinfo_len; - - for (p = modinfo; p; p = next_string(p, &size)) { - if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') - return p + taglen + 1; - } - return NULL; -} - /* * Stolen form Cryptographic API. * @@ -404,11 +370,11 @@ out: return ret; } -static int get_version(const char *modname, char sum[]) +/* Calc and record src checksum. */ +void get_src_version(const char *modname, char sum[], unsigned sumlen) { void *file; unsigned long len; - int ret = 0; struct md4_ctx md; char *sources, *end, *fname; const char *basename; @@ -428,7 +394,7 @@ static int get_version(const char *modna if (!file) { fprintf(stderr, "Warning: could not find versions for %s\n", filelist); - return 0; + return; } sources = strchr(file, '\n'); @@ -453,12 +419,9 @@ static int get_version(const char *modna goto release; } - /* sum is of form \0<padding>. */ - md4_final_ascii(&md, sum, 1 + strlen(sum+1)); - ret = 1; + md4_final_ascii(&md, sum, sumlen); release: release_file(file, len); - return ret; } static void write_version(const char *filename, const char *sum, @@ -488,12 +451,12 @@ out: close(fd); } -void strip_rcs_crap(char *version) +static int strip_rcs_crap(char *version) { unsigned int len, full_len; if (strncmp(version, "$Revision", strlen("$Revision")) != 0) - return; + return 0; /* Space for version string follows. */ full_len = strlen(version) + strlen(version + strlen(version) + 1) + 2; @@ -514,31 +477,15 @@ void strip_rcs_crap(char *version) len++; memmove(version + len, version + strlen(version), full_len - strlen(version)); + return 1; } -/* If the modinfo contains a "version" value, then set this. */ -void maybe_frob_version(const char *modfilename, - void *modinfo, - unsigned long modinfo_len, - unsigned long modinfo_offset) +/* Clean up RCS-style version numbers. */ +void maybe_frob_rcs_version(const char *modfilename, + char *version, + void *modinfo, + unsigned long version_offset) { - char *version, *csum; - - version = get_modinfo(modinfo, modinfo_len, "version"); - if (!version) - return; - - /* RCS $Revision gets stripped out. */ - strip_rcs_crap(version); - - /* Check against double sumversion */ - if (strchr(version, ' ')) - return; - - /* Version contains embedded NUL: second half has space for checksum */ - csum = version + strlen(version); - *(csum++) = ' '; - if (get_version(modfilename, csum)) - write_version(modfilename, version, - modinfo_offset + (version - (char *)modinfo)); + if (strip_rcs_crap(version)) + write_version(modfilename, version, version_offset); } -- Anyone who quotes me in their signature is an idiot -- Rusty Russell
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