| Message ID | 20160826135803.0c5ffb42@roar.ozlabs.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Aug 26, 2016 at 01:58:03PM +1000, Nicholas Piggin wrote: > On Mon, 22 Aug 2016 20:47:58 +1000 > Nicholas Piggin <npiggin@gmail.com> wrote: > > > On Fri, 19 Aug 2016 20:44:55 +1000 > > Nicholas Piggin <npiggin@gmail.com> wrote: > > > > > On Fri, 19 Aug 2016 10:37:00 +0200 > > > Michal Marek <mmarek@suse.cz> wrote: > > > > > > > On 2016-08-19 07:09, Stephen Rothwell wrote: > > > > [snip] > > > > > > > > > > > > I may be missing something, but genksyms generates the crc's off the > > > > > preprocessed C source code and we don't have any for the asm files ... > > > > > > > > Of course you are right. Which means that we are losing type information > > > > for these exports for CONFIG_MODVERSIONS purposes. I guess it's > > > > acceptable, since the asm functions are pretty basic and their > > > > signatures do not change. > > > > > > I don't completely agree. It would be nice to have the functionality > > > still there. > > > > > > What happens if you just run cmd_modversions on the as rule? It relies on > > > !defined(__ASSEMBLY__), but we're feeding the result to genksyms, not as. > > > It would require the header be included in the .S file and be protected for > > > asm builds. > > > > > > This seems like it *could* be made to work, but there's a few problems. > > > > - .h files are not made for C consumption. Matter of manually adding the > > ifdef guards, which isn't terrible. > > > > - .S files do not all include their .h where the C declaration is. Also > > will cause some churn but doable and maybe not completely unreasonable. > > > > - genksyms parser barfs when it hits the assembly of the .S file. Best > > way to fix that seems just send the #include and EXPORT_SYMBOL lines > > from the .S to the preprocessor. That's a bit of a rabbit hole too, with > > some .S files being included, etc. > > > > I'm not sure what to do here. If nobody cares and we lose CRCs for .S > > exports, then okay we can whitelist those relocs easily. If we don't want > > to lose the functionality, the above might work but it's a bit intrusive > > an is going to require another cycle of prep patches to go through arch > > code first. > > > > Or suggestions for alternative approach? > > Here is a quick patch that I think should catch missing CRCs in > architecture independent way. If we merge something like this, we > can whitelist the symbols in arch/powerpc so people get steered to > the right place. > > Powerpc seems to be the only one really catching this, and it's > only as a side effect of a test run for CONFIG_RELOCATABLE kernels, > which means version failures probably slipped through other archs. > > I'll clean it up, do some more testing, and submit it unless > anybody dislikes it or has a better way to do it. > > Thanks, > Nick > > > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > index 4b8ffd3..1efc454 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -609,6 +609,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info, > { > unsigned int crc; > enum export export; > + int is_crc = 0; should that not be a bool here ? > > if ((!is_vmlinux(mod->name) || mod->is_dot_o) && > strncmp(symname, "__ksymtab", 9) == 0) > @@ -618,6 +619,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info, > > /* CRC'd symbol */ > if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { > + is_crc = 1; is_crc = true; > crc = (unsigned int) sym->st_value; > sym_update_crc(symname + strlen(CRC_PFX), mod, crc, > export); thx! hofrat -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 4b8ffd3..1efc454 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -609,6 +609,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info, { unsigned int crc; enum export export; + int is_crc = 0; if ((!is_vmlinux(mod->name) || mod->is_dot_o) && strncmp(symname, "__ksymtab", 9) == 0) @@ -618,6 +619,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info, /* CRC'd symbol */ if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { + is_crc = 1; crc = (unsigned int) sym->st_value; sym_update_crc(symname + strlen(CRC_PFX), mod, crc, export); @@ -663,6 +665,10 @@ static void handle_modversions(struct module *mod, struct elf_info *info, else symname++; #endif + if (is_crc && !mod->is_dot_o) { + const char *e = is_vmlinux(mod->name) ?"":".ko"; + warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n", symname + strlen(CRC_PFX), mod->name, e); + } mod->unres = alloc_symbol(symname, ELF_ST_BIND(sym->st_info) == STB_WEAK, mod->unres);