talos-obmc-linux/arch/x86/kernel/cpu/microcode, branch dev-5.0

x86/microcode/amd: Don't falsely trick the late loading mechanism

2019-01-31T15:54:32+00:00

The load_microcode_amd() function searches for microcode patches and attempts to apply a microcode patch if it is of different level than the currently installed level. While the processor won't actually load a level that is less than what is already installed, the logic wrongly returns UCODE_NEW thus signaling to its caller reload_store() that a late loading should be attempted. If the file-system contains an older microcode revision than what is currently running, such a late microcode reload can result in these misleading messages: x86/CPU: CPU features have changed after loading microcode, but might not take effect. x86/CPU: Please consider either early loading through initrd/built-in or a potential BIOS update. These messages were issued on a system where SME/SEV are not enabled by the BIOS (MSR C001_0010[23] = 0b) because during boot, early_detect_mem_encrypt() is called and cleared the SME and SEV features in this case. However, after the wrong late load attempt, get_cpu_cap() is called and reloads the SME and SEV feature bits, resulting in the messages. Update the microcode level check to not attempt microcode loading if the current level is greater than(!) and not only equal to the current patch level. [ bp: massage commit message. ] Fixes: 2613f36ed965 ("x86/microcode: Attempt late loading only when new microcode is present") Signed-off-by: Tom Lendacky Signed-off-by: Borislav Petkov Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/154894518427.9406.8246222496874202773.stgit@tlendack-t1.amdoffice.net

mm: convert totalram_pages and totalhigh_pages variables to atomic

2018-12-28T20:11:47+00:00

totalram_pages and totalhigh_pages are made static inline function. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes better to remove the lock and convert variables to atomic, with preventing poteintial store-to-read tearing as a bonus. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS Suggested-by: Michal Hocko Suggested-by: Vlastimil Babka Reviewed-by: Konstantin Khlebnikov Reviewed-by: Pavel Tatashin Acked-by: Michal Hocko Acked-by: Vlastimil Babka Cc: David Hildenbrand Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: reference totalram_pages and managed_pages once per function

2018-12-28T20:11:47+00:00

Patch series "mm: convert totalram_pages, totalhigh_pages and managed pages to atomic", v5. This series converts totalram_pages, totalhigh_pages and zone->managed_pages to atomic variables. totalram_pages, zone->managed_pages and totalhigh_pages updates are protected by managed_page_count_lock, but readers never care about it. Convert these variables to atomic to avoid readers potentially seeing a store tear. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 It seemes better to remove the lock and convert variables to atomic. With the change, preventing poteintial store-to-read tearing comes as a bonus. This patch (of 4): This is in preparation to a later patch which converts totalram_pages and zone->managed_pages to atomic variables. Please note that re-reading the value might lead to a different value and as such it could lead to unexpected behavior. There are no known bugs as a result of the current code but it is better to prevent from them in principle. Link: http://lkml.kernel.org/r/1542090790-21750-2-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS Reviewed-by: Konstantin Khlebnikov Reviewed-by: David Hildenbrand Acked-by: Michal Hocko Acked-by: Vlastimil Babka Reviewed-by: Pavel Tatashin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

x86/microcode/AMD: Update copyright

2018-11-19T09:55:12+00:00

Adjust copyright. Signed-off-by: Borislav Petkov Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20181107170218.7596-17-bp@alien8.de

x86/microcode/AMD: Check the equivalence table size when scanning it

2018-11-19T09:55:12+00:00

Currently, the code scanning the CPU equivalence table read from a microcode container file assumes that it actually contains a terminating zero entry. Check also the size of this table to make sure that no reads past its end happen, in case there's no terminating zero entry at the end of the table. [ bp: Adjust to new changes. ] Signed-off-by: Maciej S. Szmigiero Signed-off-by: Borislav Petkov Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20181107170218.7596-16-bp@alien8.de

x86/microcode/AMD: Convert CPU equivalence table variable into a struct

2018-11-19T09:55:12+00:00

Convert the CPU equivalence table into a proper struct in preparation for tracking also the size of this table. [ bp: Have functions deal with struct equiv_cpu_table pointers only. Rediff. ] Signed-off-by: Maciej S. Szmigiero Signed-off-by: Borislav Petkov Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20181107170218.7596-15-bp@alien8.de

x86/microcode/AMD: Check microcode container data in the late loader

2018-11-19T09:55:11+00:00

Convert the late loading path to use the newly introduced microcode container data checking functions as it was previously done for the early loader. [ bp: Keep header length addition in install_equiv_cpu_table() and rediff. ] Signed-off-by: Maciej S. Szmigiero Signed-off-by: Borislav Petkov Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20181107170218.7596-14-bp@alien8.de

x86/microcode/AMD: Fix container size's type

2018-11-19T09:55:06+00:00

Make it size_t everywhere as this is what we get from cpio. [ bp: Fix a smatch warning. ] Originally-by: Maciej S. Szmigiero Reported-by: kbuild test robot Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20181107170218.7596-13-bp@alien8.de

x86/microcode/AMD: Convert early parser to the new verification routines

2018-11-19T09:51:06+00:00

Now that they have the required functionality, use them to verify the equivalence table and each patch, thus making parse_container() more readable. Originally-by: "Maciej S. Szmigiero" Signed-off-by: Borislav Petkov Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20181107170218.7596-12-bp@alien8.de

x86/microcode/AMD: Change verify_patch()'s return value

2018-11-19T09:51:06+00:00

Have it return 0 on success, positive value when the current patch should be skipped and negative on error. Signed-off-by: Borislav Petkov Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20181107170218.7596-11-bp@alien8.de