On Wed, 11 Jul 2018 16:19:17 +0100 Hazel Russman <[email protected]> wrote:
> Does the "patchwork" site in your link contain the actual patch files > that correspond to those weird alphanumeric codes? Hazel, Yes! At the page: https://patchwork.kernel.org/patch/9847857/ Look at the headers near the top. The link to the patch is labeled "patch" under the Download section. e.g., https://patchwork.kernel.org/patch/9847857/raw/ That will give you the patch that caused those changes which are identified as "commit 7744ccdbc16f0ac4adae21b3678af93775b3a386": tip-x86-mm-x86-mm-Add-Secure-Memory-Encryption-SME-support.patch Now, I have learned that reversing a patch is often not as simple as just calling patch with the -R option. Here are the 5 steps to reverse that patch and remove the memory encrypt changes from your kernel. Make a copy of your "bad/recent/4.15" kernel tree (cp -a , etc.) and then do the following five changes to the copy: To revert the tip-x86-mm-x86-mm-Add-Secure-Memory-Encryption-SME-support.patch *** 1. in file arch/x86/Kconfig delete these lines around 1415: config ARCH_HAS_MEM_ENCRYPT def_bool y config AMD_MEM_ENCRYPT bool "AMD Secure Memory Encryption (SME) support" depends on X86_64 && CPU_SUP_AMD ---help--- Say yes to enable support for the encryption of system memory. This requires an AMD processor that supports Secure Memory Encryption (SME). config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT bool "Activate AMD Secure Memory Encryption (SME) by default" default y depends on AMD_MEM_ENCRYPT ---help--- Say yes to have system memory encrypted by default if running on an AMD processor that supports Secure Memory Encryption (SME). If set to Y, then the encryption of system memory can be deactivated with the mem_encrypt=off command line option. If set to N, then the encryption of system memory can be activated with the mem_encrypt=on command line option. *** 2. delete the file arch/x86/include/asm/mem_encrypt.h *** 3. in file arch/x86/mm/Makefile delete the line around 39: obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt.o *** 4. delete the file arch/x86/mm/mem_encrypt.c *** 5. delete the file include/linux/mem_encrypt.h You may also want to comment out or delete the lines in your kernel .config related to: # CONFIG_ARCH_HAS_MEM_ENCRYPT is not set # CONFIG_AMD_MEM_ENCRYPT is not set # CONFIG_NUMA is not set rerun makeconfig, save your configuration, and then try to build and install the kernel. Does the modified 4.15 kernel boot OK now? If so, we are now certain where the problem is. If not, then the problem is not related to the memory encryption patch/change after all - tell me as best you can how you came to determine that the memory encryption change was the one where the problem first appears. Here is the info I found on how to biset a kernel problem: https://www.kernel.org/doc/html/v4.14/admin-guide/bug-bisect.html http://webchick.net/node/99 If the reversion of the memory encrypt changes don't fix the problem, then maybe you were off by one with the bisect and this is the next likely troublemaker: https://patchwork.kernel.org/patch/9847859/ to revert that one, edit the arch/x86/mm/ioremap.c file and *delete* the lines that are labeled with + and *add* those that labeled with a - (remembering to remove those leading - labels when you actually add them back in). Watch out to include the "odd man out" line in between the + and -'s: (void __force *)addr < phys_to_virt(ISA_END_ADDRESS)) > and it would be better done off-list because after all it's not an > LFS problem (and certainly nothing to do with systemd!) When you reply to this message, just reply to the message from my email address and not the one from/to the LFS list. If we ever find what the problem is, then we can later post that back to the list so that others will also know. Cheers, Mike -- http://lists.linuxfromscratch.org/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page Do not top post on this list. A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? http://en.wikipedia.org/wiki/Posting_style
