From 5443a1b463f452e439e0d33d5325d50aae60e9dc Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Wed, 10 Jan 2018 23:36:31 +0530 Subject: [PATCH 09/26] UBUNTU: SAUCE: rfi-flush: Factor out init_fallback_flush() CVE-2017-5754 [mauricfo: s/ppc64_caches.l1d.size/ppc64_caches.dsize/] Signed-off-by: Mauricio Faria de Oliveira Signed-off-by: Stefan Bader --- arch/powerpc/kernel/setup_64.c | 62 ++++++++++++++++++++++-------------------- 1 file changed, 33 insertions(+), 29 deletions(-) diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index c909cc7..e46f7655 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -775,40 +775,44 @@ void rfi_flush_enable(bool enable) rfi_flush = enable; } -void __init setup_rfi_flush(enum l1d_flush_type types, bool enable) +static void init_fallback_flush(void) { - if (types & L1D_FLUSH_FALLBACK) { - int cpu; - u64 l1d_size = ppc64_caches.dsize; - u64 limit = min(safe_stack_limit(), ppc64_rma_size); + u64 l1d_size, limit; + int cpu; - pr_info("rfi-flush: Using fallback displacement flush\n"); + l1d_size = ppc64_caches.dsize; + limit = min(safe_stack_limit(), ppc64_rma_size); + /* + * Align to L1d size, and size it at 2x L1d size, to catch possible + * hardware prefetch runoff. We don't have a recipe for load patterns to + * reliably avoid the prefetcher. + */ + l1d_flush_fallback_area = __va(memblock_alloc_base(l1d_size * 2, l1d_size, limit)); + memset(l1d_flush_fallback_area, 0, l1d_size * 2); + + for_each_possible_cpu(cpu) { /* - * Align to L1d size, and size it at 2x L1d size, to - * catch possible hardware prefetch runoff. We don't - * have a recipe for load patterns to reliably avoid - * the prefetcher. + * The fallback flush is currently coded for 8-way + * associativity. Different associativity is possible, but it + * will be treated as 8-way and may not evict the lines as + * effectively. + * + * 128 byte lines are mandatory. */ - l1d_flush_fallback_area = - __va(memblock_alloc_base(l1d_size * 2, l1d_size, limit)); - memset(l1d_flush_fallback_area, 0, l1d_size * 2); - - for_each_possible_cpu(cpu) { - /* - * The fallback flush is currently coded for 8-way - * associativity. Different associativity is possible, - * but it will be treated as 8-way and may not evict - * the lines as effectively. - * - * 128 byte lines are mandatory. - */ - u64 c = l1d_size / 8; - - paca[cpu].rfi_flush_fallback_area = l1d_flush_fallback_area; - paca[cpu].l1d_flush_congruence = c; - paca[cpu].l1d_flush_sets = c / 128; - } + u64 c = l1d_size / 8; + + paca[cpu].rfi_flush_fallback_area = l1d_flush_fallback_area; + paca[cpu].l1d_flush_congruence = c; + paca[cpu].l1d_flush_sets = c / 128; + } +} + +void __init setup_rfi_flush(enum l1d_flush_type types, bool enable) +{ + if (types & L1D_FLUSH_FALLBACK) { + pr_info("rfi-flush: Using fallback displacement flush\n"); + init_fallback_flush(); } if (types & L1D_FLUSH_ORI) -- 2.7.4