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powerpc/pseries: add new branch prediction security bits for link stack

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The hypervisor interface has defined branch prediction security bits for
handling the link stack. Wire them up.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200825075612.224656-1-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2020-08-25 17:56:12 +10:00 committed by Michael Ellerman
parent 05504b4256
commit cdb1ea0276
2 changed files with 8 additions and 0 deletions
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2
arch/powerpc/include/asm/hvcall.h
View File

@ -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

6
arch/powerpc/platforms/pseries/setup.c
View File

@ -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.