On Fri, Feb 2, 2018 at 8:49 PM, Nicolas Pitre <nicolas.pitre@xxxxxxxxxx> wrote: > On Fri, 2 Feb 2018, Arnd Bergmann wrote: > >> crypto_it_tab and the other symbols like it are defined in >> crypto/aes_generic.c and exported for loadable modules. When >> building with LTO and CONFIG_TRIM_UNUSED_KSYMS, the exports >> are eliminated, since kbuild fails to take the users in >> the arch/x86/crypto/aes-i586-asm_32.S assembler file into >> account. >> >> This adds an ugly workaround by adding a reference to each symbol >> into aes_glue.c, which gets linked together with the assembler >> file. >> >> We obviously want to fix the CONFIG_TRIM_UNUSED_KSYMS logic >> to do the right thing here instead, but I couldn't come up >> with a good fix, so I use this instead to get a clean build >> for testing. > > Could you give me the .config you used for this? So far I can't > reproduce, and guessing with LTO takes lots of time. I've uploaded my randconfig file to https://pastebin.com/raw/iLk4sSpw >> This fix only works most of the time, but I still ran into >> some cases where combining an .S with a .c file did not >> produce the correct .ko file, as the lto linker apparently >> did not expect that kind of input. 'nm' on the file after >> 'ld -r' showed only the contents of the assembler file, and >> after the lto-ld stage, only the contents of the .c file >> are there. > > 'ld -r' does not support mixed (LTO and non-LTO) objects. Ok, that would explain it. I checked that CONFIG_THIN_ARCHIVES is set here, but I see clearly that the module is linked using x86_64-linux-ld -m elf_x86_64 -r -o arch/x86/crypto/aes-x86_64.o arch/x86/crypto/aes-x86_64-asm_64.o arch/x86/crypto/aes_glue.o ; scripts/mod/modpost arch/x86/crypto/aes-x86_64.o Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
