5.15-stable review patch. If anyone has any objections, please let me know.
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From: James Morse james.morse@arm.com
[ Upstream commit a1152be30a043d2d4dcb1683415f328bf3c51978 ]
Add a helper to expose the k value of the branchy loop. This is needed by the BPF JIT to generate the mitigation sequence in BPF programs.
Signed-off-by: James Morse james.morse@arm.com Reviewed-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Pu Lehui pulehui@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/include/asm/spectre.h | 1 + arch/arm64/kernel/proton-pack.c | 5 +++++ 2 files changed, 6 insertions(+)
--- a/arch/arm64/include/asm/spectre.h +++ b/arch/arm64/include/asm/spectre.h @@ -97,6 +97,7 @@ enum mitigation_state arm64_get_meltdown
enum mitigation_state arm64_get_spectre_bhb_state(void); bool is_spectre_bhb_affected(const struct arm64_cpu_capabilities *entry, int scope); +u8 get_spectre_bhb_loop_value(void); bool is_spectre_bhb_fw_mitigated(void); void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *__unused); bool try_emulate_el1_ssbs(struct pt_regs *regs, u32 instr); --- a/arch/arm64/kernel/proton-pack.c +++ b/arch/arm64/kernel/proton-pack.c @@ -998,6 +998,11 @@ bool is_spectre_bhb_affected(const struc return true; }
+u8 get_spectre_bhb_loop_value(void) +{ + return max_bhb_k; +} + static void this_cpu_set_vectors(enum arm64_bp_harden_el1_vectors slot) { const char *v = arm64_get_bp_hardening_vector(slot);