From cdb1ea0276bd6a225aa1203b4829b8c3c0d4d069 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 25 Aug 2020 17:56:12 +1000 Subject: [PATCH] powerpc/pseries: add new branch prediction security bits for link stack The hypervisor interface has defined branch prediction security bits for handling the link stack. Wire them up. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200825075612.224656-1-npiggin@gmail.com --- arch/powerpc/include/asm/hvcall.h | 2 ++ arch/powerpc/platforms/pseries/setup.c | 6 ++++++ 2 files changed, 8 insertions(+) diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h index e8f116a425f9..c1fbccb04390 100644 --- a/arch/powerpc/include/asm/hvcall.h +++ b/arch/powerpc/include/asm/hvcall.h @@ -375,11 +375,13 @@ #define H_CPU_CHAR_THREAD_RECONFIG_CTRL (1ull << 57) // IBM bit 6 #define H_CPU_CHAR_COUNT_CACHE_DISABLED (1ull << 56) // IBM bit 7 #define H_CPU_CHAR_BCCTR_FLUSH_ASSIST (1ull << 54) // IBM bit 9 +#define H_CPU_CHAR_BCCTR_LINK_FLUSH_ASSIST (1ull << 52) // IBM bit 11 #define H_CPU_BEHAV_FAVOUR_SECURITY (1ull << 63) // IBM bit 0 #define H_CPU_BEHAV_L1D_FLUSH_PR (1ull << 62) // IBM bit 1 #define H_CPU_BEHAV_BNDS_CHK_SPEC_BAR (1ull << 61) // IBM bit 2 #define H_CPU_BEHAV_FLUSH_COUNT_CACHE (1ull << 58) // IBM bit 5 +#define H_CPU_BEHAV_FLUSH_LINK_STACK (1ull << 57) // IBM bit 6 /* Flag values used in H_REGISTER_PROC_TBL hcall */ #define PROC_TABLE_OP_MASK 0x18 diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index 2f4ee0a90284..633c45ec406d 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -519,9 +519,15 @@ static void init_cpu_char_feature_flags(struct h_cpu_char_result *result) if (result->character & H_CPU_CHAR_BCCTR_FLUSH_ASSIST) security_ftr_set(SEC_FTR_BCCTR_FLUSH_ASSIST); + if (result->character & H_CPU_CHAR_BCCTR_LINK_FLUSH_ASSIST) + security_ftr_set(SEC_FTR_BCCTR_LINK_FLUSH_ASSIST); + if (result->behaviour & H_CPU_BEHAV_FLUSH_COUNT_CACHE) security_ftr_set(SEC_FTR_FLUSH_COUNT_CACHE); + if (result->behaviour & H_CPU_BEHAV_FLUSH_LINK_STACK) + security_ftr_set(SEC_FTR_FLUSH_LINK_STACK); + /* * The features below are enabled by default, so we instead look to see * if firmware has *disabled* them, and clear them if so. -- 2.20.1